Published March 24, 2014
I have been interested in alternative color television picture tube technologies developed over the past decades in an attempt to improve on the Federal Communication Commission RCA color system adopted 1953 in the United States. I spent several years researching the Chromatron and originally the text and images appeared on several different pages of this Timeline website. Now I decided to merge this information and give the Chromatron it’s own dedicated page. It is not my intention to describe detailed technical data which would require volumes of material to post. Rather, a brief overview follows.
In 1951, Nobel Prize winner Dr. Ernest O. Lawrence, inventor of the Cyclotron from the University of California Berkley, invented the Lawrence Tube in his garage at home. The Lawrence Tube was unique in that it created the color image with one gun and one electron beam. It used no shadow mask, but instead, a grid of fine wires that’s were placed directly behind the vertically aligned tri-color phosphor stripes on the screen. The wires were charged with high voltage and when the single electron beam passed through the wires, in a type of electronic lens, they were accelerated and deflected onto the phosphor stripes. The original Lawrence Tube was conceived to work with both one and three guns. The one gun version received the most attention because of it’s simplicity and potential lower manufacturing costs. A three gun Chromatron was brighter then the one gun. Both types were developed in prototype form. Dr. Lawrence later partnered with Paramount Pictures Corporation to develop the Lawrence Tube. View the Patent.
In 1951, Chromatic Television Laboratory, a subsidiary of Paramount based in New York City, with an office in Oakland California, was created to commercially develop the Lawrence Tube and renamed it the “Chromatron”. The work was done in tight quarters in the Paramount building in the heart of New York City on Broadway.
First details about the Lawrence/Chromatron appear in this article from Electronics Magazine, December, 1951. View PDF. Courtesy Electronics Magazine.
Here is an article from Billboard Magazine, published October 6, 1951, anounceing the first Paramount sets incoroporating the Chromatron CRT. This same article also announced that the first CBS-Columbia color sets hit the market on September 28, 1951.
This was a time when CBS was working on the mechanical spinning color wheel field sequential color system while RCA was working on the electronic compatible Tri Color dot sequential shadow mask system and Color Television Incorporated proposed the line sequential system. During the FCC trials and public demonstrations of these color systems, Chromatic Television Laboratory was invited to demonstrate their Chromatron one gun color tube. The Chromatron would work with CBS’s system, thereby eliminating the mechanical spinning wheel or drum and it would work with a one or three gun RCA system.
The CBS system was approved first by the FCC on October 10, 1950. In public viewing tests, it was deemed to have the best color reproduction, particularly the flesh tones. These first television sets were sold to receive the very limited color programming available. Then the war effort in Korea caused the suspension of production of CBS television sets. But, in the meantime, RCA greatly improved their color system and their biggest advantage was that black and white telecasts could be viewed on the Compatible RCA color system sets. The CBS system required an adaptor to watch black and white telecasts which dominated television programming at that time. RCA resubmitted their application of the compatible dot sequential electronic system to the FCC and they reversed their 1950 decision, approving the RCA system on December 17, 1953.
RCA manufactured and sold their first color television in April, 1954, the CT-100 with a 15 inch color tube, (12.5 inch viewable) using the phosphor dot/shadow mask tube.
RCA licensed their 15 inch color tube to other manufactures such as Admiral and Westinghouse shown below, in an effort to promote the fledgling color television industry and a race to introduce the first compatible, electronic color television ensued.
This is the first color set, the Admiral C1617A which was introduced to the public on December 30, 1953.
A New York Times article published December 31, 1953.
On page 106 of the book, Television: The Life Story of a Technology, it is stated: “Admiral Television Corporation put the first receivers (color) on the market for $1175.00 on December 30, 1953, so that it could take a deductible tax loss on its color factory investment.”
Here is an article from the Pittsburg Post-Gazette published February 24, 1954.
The second color set to go on sale was this Westinghouse H840CK15 in March, 1954.
One of the constant complaints of the RCA system used in these first color sets, was the very dim color. One had to turn the lights down and draw the drapes in their homes to see the image clearly. Another problem, color fringing on black and white programs and blurred images with color. This is why the Chromatron (and other systems such as the Apple tube by Philco) were proposed. The RCA system used a metal sheet with many perforations or holes as a color selection method. This was called the shadow mask. The early RCA television tubes with shadow mask blocked 85% of the light from the three electron beams causing a dim image. The original Lawrence Tube only absorbed 14% of the single electron beam light energy, or 86% efficient.
Citation: THE PDF CHROMATRON-A SINGLE OR MULTI-GUN TRI-COLOR CATHODE-RAY TUBE by Robert Dressler from the PROCEEDINGS OF THE I.R.E. VOL.41, NO. 7, JULY, 1953.
In other words, the wire grid was much more transparent and this tube was as bright as a conventional black and white television of the time. Another big advantage of the Chromatron tube was in theory, it had perfect registration with no convergence requirements because it used just one gun. The Chromatron was said to be less expensive to manufacture, used fewer parts, smaller and lighter.
On June 2, 1953, the first color television telecast in England was conducted using an experimental field sequential system developed by Pye and Chromatic Television Labratory. Televisions with Chromatron tubes were set up in a children’s hospital to view the coronation of Queen Elizabeth II. The New York Times reported that a Chromatic representative concluded the test was a complete success.
Here is a 1953 specification sheet from Chromatic Television Labratory.
Update September 2, 2014: Here is a Chromatron Trade PDF by Chromatic Televisions Laboratory Inc., courtesy of the Smithsonian Museum of American History. On page 10, this author learned for the first time that Chromatic was developing beam index CRT’s as well. We annotated the text where this information appears. The PDF file is reversed starting with page 27. Just scroll down to page 1. View PDF.
One of Paramount’s interest in the Chromatron was for use with a pay TV system in hotels. In June, 1954, a test was done at the Park Sheraton hotel in New York City and 1600 guest rooms were hooked up using the Chromatron with the Telemeter coin set top box.
In a July 10, 1954 Billboard magazine article, it was reported that Chromatic Television Laboratory expected to release a 21 inch, one-gun Chromatron in early 1955 under the Chromatic label. Crosley was licensed to manufacture the set domestically and Philips of Holland had the international license.
Chromatic handeled the basic development of the Chromatron and then about August, 1957, split the project in two sections, Du Mont in New Jersey was licensed for commercial picture tube fabrication and Lytton Industries in Emmeryville, California for the military.
The original Lawrence Tube had 800 vertical phosphor stripes, 400 of which were green. The red and blue stripes were twice as wide as the green to equalize the color across the screen. Chromatic was working to increase the resolution by adding more vertical phosphor stripes. At first, 1000 stripes, later, a development CRT increased to 1600 stripes. Notice the design change in the photo below, the mass has been reduced and the tube takes on a modern appearance.
At about 1960, Chromatic was renamed Autometric Corporation (source Sy Yusem) and moved to an industrial-type building on the West side of the city where one floor was devoted to picture tube development and another floor was for the electronics. Up to this point, neither Paramount, Chromatic/Autometric, Crosley, Philips, Du Mont, Lytton, Muntz, General Electronics and others had successfully developed a Chromatron receiver for the home consumer market.
Now I digress from the story temporally to tell you about Julius Shapiro, who I discovered after reading this story “THE WONDROUS LIVES OF JULIUS SHAPIRO” by Laurie Gwen Shapiro an Emmy-nominated documentary filmmaker as well as a novelist. She is currently working on her first non-fiction book, about a Lower East Side teen stowaway on Commander Byrd’s 1928 expedition to Antarctica. (Simon & Schuster)
Utterly fascinated, I looked up Laurie’s phone number and called her. She answered on the first try. I was hoping to find more information about her fathers involvement with the Chromatron project. A stranger was calling and yet she accepted me enthusiastically and all my questions. I learned that her father was interviewed to work on the Manhattan Project, he was a chemist, electrical engineer and computer systems manager.
He worked with Nobel prize winners and loves to play chess. He’s 93 now and doesn’t like to talk much about the past. He remembers his work at Chromatic as a project engineer working with the tubes.
Laurie invited me to call her father and so I did. It was a very pleasant conversation and Mr. Shapiro asked me to call his good friend Seymour Yusem and co-project engineer at Chromatic. “Sy would know everything I wanted to know” and so I did. Thank you sir.
I called Mr. Yusem, and left a voice message on his machine. He returned my call several hours later. It was a most interesting conversation and learned that Sy is 88 years old and started work with Chromatic from 1957 to 1962. He was a project engineer working on the Chromatron color tube receiver. He co-authored a technical paper with Robert Dressler entitled “THE PDF CHROMATRON-A SINGLE OR MULTI-GUN TRI-COLOR CATHODE-RAY TUBE” it can be found in the Proceedings of the I.R.E. Vol. 41, No. 7, July, 1953. Robert Dressler “was the brains of the project” and headed up Sy’s unit and has since passed away. Mr. Yusem sent me a copy and two other technical papers, thank you very much sir. (Laurie told me that Sy went to Japan to meet Sony, but he did not mention this in a follow-up email).
Mr. Yusem told me that the problem with the Chromatron was its resolution. It had very high brightness, but low resolution (not enough phosphor stripes across the screen) He said the RCA system had high resolution, but low brightness. He said RCA could have increased the brightness by enlarging the holes in the shadow mask at the expense of lowering the resolution.
Mr. Yusem explained the Telmeter pay TV system Paramount was working on in conjunction with a coin operated set top box. By inference, I make an assumption that the Chromatron was a part of this system because of earlier research on the subject.
Laurie’s father said Sony purchased the license and development rights to the Chromatron for one million dollars at a restaurant and Mr. Yusem said “When I was told that Sony had purchased the patents and development rights it was also stated that Sony had plans to transistorize the chassis. I took that to mean there was no future for me with Sony”.
Mr. Shapiro left Autometric a year earlier then Mr. Yusem and accepted a position as a Computer Systems Manager with another company.
Mr. Yusem left Autometric formerly Chromatic in 1962 and joined the CBS Television Network as a project engineer. He said they had a color TV plant. He received his BSE from City College.
Finally, Mr. Yusem sent me a black and white glossy 8×10 photo, an original of a prototype chassis built by Autometric in 1962 to demonstrate the Chromatron to various manufactures. The arrow points to the encoding section which could be changed for different encodings required for 1 gun or 3 gun Chromatrons. Mr. Yusem said Sony transistorized the chassis, which he felt was an achievement for that time. Thank you very much for this piece of history sir.
I feel honored to have spoken to these pioneering electrical engineers from the early days of development work on the Chromatron and to share their stories. We would like to learn more and will update you further.
Thank you Laurie for making it happen.
Below, see the 1962 Chromatron prototype chassis.
Going back to the story, in March, 1961, Sony saw the Chromatron demonstrated at the Autometric booth within the IRE trade show in New York. It was used by the military to help identify friend or foe. What Sony immediately knew was this very bright tube is what they were searching for as an alternative to the RCA shadow mask color system. Akio Morita, Sony’s co-founder, attended the show with his young engineers and immediately called the President of Autometric to arrange a meeting. The next day it was done as Julius Shapiro said, “the deal was cooked up after an executive has one drink with a Sony man for a million dollars”.
For Julius and Sy, this meant the end of their careers at Autometric, but by no means the end of their contributions in their respective fields of endeavor.
For Sony, this was the start of a new beginning. They knew it would be a difficult task but accepted the challenge. According to an article appearing in the German magazine, Der Spiegel, dated September 23, 1964, Sony assigned 50 members from the Research Institute to work on the completion of the Chromatron. History books tell us that Sony failed in their efforts to develop the Chromatron, but they did not fail. Their continuing work on the Chromatron ultimately led to an improved Chromatron renamed Trinitron. They corrected the Lawrence tube problems with their own ideas and Trinitron went on to be the most successful color television system in the world with a 40 year production run. Julius Shapiro and Seymour Yusem, two dedicated project engineers can be very proud of their early contributions to the project.
The (Autometric/Sony) Chromatron (Sony started development in 1962 under Paramount license) CRT has now evolved into an inline three gun CRT offering in excess of 300 foot-lamberts highlight brightness in normal operation. (A typical shadow mask CRT develops 30 to 45 foot-lamberts highlight brightness.) A slender black stripe is laid down between each color phosphor to increase contrast. The tube does away with the beam switching grid with it’s associated r.f.power which characterized the older tube. The post-deflection focusing second-anode grid is an array of closely spaced parallel taut wires located about 1/2 inch in front of the phosphors. The grid is operated with about 6 KV difference between it and the electron guns. Source: Electronics World, January, 1964.
The story continues below in my various collections and concluding with the finding of an extremely rare working Sony Chromatron in 2013.
There was another color system developed to improve upon the RCA system. Please see the Indextron page.
Article about the upcoming Sony Chromatron color television in December, 1964 issue of Radio-TV Experimenters magazine.
1965 Sony Chromatron 19C 70 Color Television
You are looking at the world’s * (Yaou Electric Co. may have introduced a 8 inch Chromatron to the Japanese market in 1965) first mass produced Chromatron color television pictured below. What’s so special about the Chromatron you ask? Dr. Ernest O. Lawrence invented the tube in 1951. It was a single gun CRT using vertical stripes of red, green and blue on the screen much like the Sony Trinitron, now out of production due to the emergence of flat panel displays. The design patent by Dr. Lawrence, a Nobel prize winner from California, came 17 years prior to the Trinitron! Additionally it did not require a shadow mask, thereby allowing for a 75% brighter image. Behind these stripes were vertical wires which could be charged with electric current to deflect the single electron beam to each of the stripes. The tube did not require convergence circuitry, used less parts and lower power consumption. The bright color images of the prototypes looked promising, but unfortunately, Paramount Pictures, Chromatic Television Laboratories, a subsidiary of Paramount, Litton Industries, licensed under Chromatic and others failed to solve the difficult manufacturing process and a mass produced Chromatron was never brought to market until this Sony 19C 70 in Japan in 1965. A rare photo, believed to be one of a very few existing photographs of a 19 inch 1965 model 19C 70 Chromatron by Sony on display at the Sony History Museum. This model was first shown in Japan in September, 1964 as a prototype using one gun. In May, 1965 the 19C 70 Chromatron went on sale to the Japanese market only, using a delta three gun system. The chassis was not transistorized. Sony offered a unique life time warranty on it’s first color television product, if it broke, Sony fixed it for free. Only 13 to 18 thousand units were sold in 1965 and 1966 at a very expensive $550.00 American dollars, but it cost Sony more then double that amount to produce each one. The Chromatron was a unique color CRT which promised very bright images and had many technical advantages over the conventional shadow mask color CRT. It was the first Chromatron to be sold to the public, but Sony was plagued with numerous technical problems, only 2 or 3 out of 1000 on the production line were good, so Sony stopped production * in September, 1966. The Chromatron development did not die, you can read more about the Chromatron below and on the internet. Thanks to pchome.net for the photo.
* Update, July 21, 2014: Just found out from my online friend, Noriyoshi from Japan, that Sony manufactured two additional Chromatron models in 1967. They are the 19C 80 and 19C 100 both delta three gun, all tube televisions. Noriyoshi is currently repairing a 19C 100. More information to follow.
* Update August 26, 2014: My friend Jerome Halphen found this Chromatron data book which has detailed information on the Sony Chromatron 19C 70. Unfortunatley it is not written in the English language. Perhaps one of my Japanese viewers could translate the following 8 pages. Thank you for the scans Jerome. The book discloses yet another Sony Chromatron model previously unknown by this author, the model 19C 90. We now have a total of four Sony Chromatron models the 19C 70, 19C 80, 19C 90 and 19C 100. The last three were manufactured in 1967. Tap or click on images for full view.
Yaou Chromatron Color Portable
I found this photo with caption below, in the August, 1965 issue of Popular Mechanics magazine. It is also referenced in the Radiomuseum.org website and in the book, The History of Television, 1942 to 2000 by Albert Abramson. This book recites that Yaou Electric Co. of Japan produced a line sequential Chromatron with an 8 inch CRT and introduced it to the Japanese market as early as 1963. If this is true, this set could claim the title as first Chromatron to be marketed, ahead of the above Sony 19 inch Chromatron in 1965. The Popular Mechanics article states this television had a planned U.S. introduction in Fall, 1965. This photo appears to show only a VHF tuning selector, however it may have an integrated UHF tuner. If the set was marketed in 1965, the FCC required that all televisions sold after 1964, incorporate a built in UHF tuner.
Update October 11, 2013: My friend Jerome Halphen from Paris, France and his friend Noriyoshi recently visited the NHK museum in Tokyo, Japan. There, they found on display, the Yaou Chromatron Color Portable TV among other things. This model is called GENERAL TELEVISION COLORNET GTC-9.
The following is a report from Jerome:
“What we previously called the YAOU TV is in fact a GENERAL (TELEVISION COLORNET GTC-9.
Noryoshi said that he had one to repair 10 years ago and that it had a very mediocre (coarse) color picture. This proves that at least some where indeed sold on the Japanese domestic market.
Noryoshi also estimated the NHK date label as wrong, he said 1965-1966 which would be consistent with the YAOU text we have on the B&W only photo we had previously. Maybe 1963 was the prototype date issue and that’s why NHK labelled it so.
Another thing Noryoshi told me is that the entire YAOU development team was poached by SONY who was then midstream between the non-working Chromatron and the not yet developped Trinitron. This would make sense as SONY surely needed to muscle its teams in color CRT technology when they were frantically trying to come up with a viable color CRT solution.
Speculation here, but if YAOU’s R&D became a hollow shell, they probably dropped the project, sold the technology to GENERAL who ultimately marketed the TV.
The schematic is very advanced for a 1965 color set. It’s entirely transistorized except for the usual 3x miniaturized EHT rectifiers. The tubes are IDK-37 or 1DK-37, probably the same as in the SONY 5″ B&W 5-303W.
It’s a cute set! i asked Noryoshi to grab one if ever he sees another. The color CRT has no reference other than COLORNETRON. It uses 14.4KV final EHT voltage and a 4.7KV to 6.3KV swinging voltage on the color selection grids.
Y Luminance is applied to the Cathode, the Color signal to the G1 Grid.”
A few photos courtesy Jerome Halphen.
Thank you my friend Jerome and to Noriyoshi. Jerome is a long time collector of vintage television and Noriyoshi is an electrical engineer in Japan, he has his own website:
To sum up, I’m still conflicted on the introduction date, so for now, will keep this television in place. (1965) We now know it went to market in Japan therefore, all references on this site to the Sony Chromatron 19C 70 being the “first or only” Chromatron to be marketed to the public are amended. A very interesting addition to Chromatron Color CRT history.
Update October 16, 2013:
Additional research courtesy the Radio Museum revealed the following,
Yaou Radio Co ltd ; Kanagawa-ken
Yaou Electric Co., Ltd.
Yaou Electric Co.Ltd. was a manufacturer of radios and tv-sets, marked as “General” on the front.
Yaou is mentioned in “The history of television, 1942 to 2000″ by Albert Abramson : They introduced their first color-TV in spring 1963 with a line-sequential 8″ Chromatron one-gun type CRT.
It may be hard to identify “General” as “Yaou” products because the circuit diagrams inside of their radio models are issued (sometimes) in Japanese language.
Yaou Electric Co. Limited. 1116 – Suenaga Kawasaki-Shi Kanagawa-Ken Japan
I found the Patent: Application January 25, 1963 Patented February 7, 1967 Number 3,303,275. With this information, you can research the Patent on-line.
Update April 6, 2014:
I found a July, 1965 IEEE paper stating that the Yaou Colornet utilizes a variation of the Lawrence tube and was available late 1965.
Broadcast and Television Receivers, IEEE Transactions on (Volume:11 , Issue: 2 )
Date of Publication:
38 – 49
Digital Object Identifier :
Date of Current Version :
12 November 2007
Issue Date :
This confirms Noriyoshi’s belief that a 1963 release of the Yaou Colornet was incorrect.
Update, May 31, 2014. Additional details appear.
In the November, 1964 issue of Electronics World, we found the article posted below. The CRT is called “Colornetron” and is 9 inches? The new tube and circuitry is still going through the patent process and details are not available. It is revealed that this CRT uses line-sequential color generation. In this approach, the color phosphers are laid down in fine horizontal lines down the screen, unlike the Sony Chromatron.
Look at the left photo. There are small differences in the design compared to the model displayed in the NHK Museum. The handle is now a leather strap instead of a rigid folding handle. The two control knobs on the side appear to be mounted higher and the speaker grill is mounted lower. There appears to be additional “filler” material surrounding the Colornetron CRT compared to the 9 inch black and white model on the right, therefor we think this article misstated the screen size and the Colornetron CRT is 7 1/2 inches as reported above. This set still does not appear to have a UHF selector dial which was required after 1964.
Look at the next photo below. This is the 1965 Philco-Ford model N1052BK 9 inch black and white television that was sold by Ford dealerships as an accessory for the Ford Mustang. A dead ringer right down to the rocker switch and identity tag. The only difference is that this Philco model added the required UHF tuner. You can see the UHF selector on the left side of the control panel. Did Philco secure a license from Yaou Electric to market the Colornet under the Philco-Ford brand name? We do know that Philco worked for 10 years in the 1950′s to develop the beam index tube. The project was terminated without success. We recently learned that Philco was still interested in alternate color picture tube technology when in 1967, they purchased a license from Paramount Pictures Corporation to develop a Chromatron color television set. More about this further down in this article. To the best of my knowledge, the Colornet was never marketed in the United States but the remarkable resemblance to the Yaou black and white model tells me Philco may have been working on the Colornet.
Sony Chromatron 19C 80, (19C 90), 19C 100
* Update, July 21, 2014: Just found out from my online friend, Noriyoshi from Japan, that Sony manufactured two additional Chromatron models in 1967. They are the 19C 80 and 19C 100 both delta three gun, all tube televisions using the Chromatron wire selection grid. These two models were manufactured in 1967. The 19C 70 is also a delta three gun, all tube set. All three model use the same 19 inch CRT, 480AB22. Noriyoshi is currently repairing a 19C 100. Watch his progress here. See the below photos of the 19C 100, courtesy Noriyoshi Tezuka. More information to follow. Special Thanks to my friend Jerome for alerting me of this.
Update, July 22, 2014: A query to the Sony Archive Museum in Tokyo, Japan revealed the following:
“Chromatron color TV 19-c 80
Price:\179,000+tax (at that time)
Chromatron color TV 19-c 100
Price:\198,000+tax (at that time)”
Unfortunately, no original photos to display.
This is speculation, but we believe Sony marketed the 19C 80 and 19C 100 in Japan to appease the angry Sony dealers who did not have a Sony color set to sell, (Sony’s competition were selling shadow mask color sets years earlier) even while Sony was working behind the scene to develop the Trinitron.
(The Sony KV 7010U may have been an appeasement to U.S. dealers until the Trinitron was ready. More about the KV 7010U can be found below.)
Sony Chromatron Prototype
These two images were taken from my September 1967 issue of Popular Science magazine. In the first image, Sony co-founder Akio Morita on the right is demonstrating the newly developed Sony Chromatron 7 inch color television which main advantage is a very bright image, even under bright flood lights. Popular Science magazine reports this is to be the first Chromatron sold in the United States. The set was called “Microcolor”. * I believe the article is in error, because it it was well know that Sony gave up on the Chromatron in the fall of 1966. The Chromatron had production problems, yielding only 3 good tubes out every thousand. It sold for 198,000 yen ($550.00) in Japan, but cost Sony 400,000 yen to build each set. In Japan, plagued with problems, Sony sold only 18,000 Chromatrons from 1965 to 1966. (Information from the book “Sony”) I believe this television is a pre-production version of the 7 inch Trinitron introduced by Sony in 1968 and discussed below. You can see differences in the control arrangement, the carrying handle and smaller trim pieces on the sides from the final production version shown below.
* Update: The below images are indeed that of a Chromatron, however a modified redesign of the Chromatron. Because of the overwhelming problems of Sony’s Chromatron in Japan, financial losses from the Chromatron development and mounting pressure from Sony dealerships to introduce their first color set, Sony’s chief engineer and CEO launched an aggressive campaign to develop a new color tube. Sony took inspiration from the 1966 General Electric (GE) Portacolor and considered licensing the design, but in the end insisted that they design a new CRT which had the Chromatron benefits of high brightness. Early RCA color CRT’s and shadow masks blocked as much as 85% of the light energy. The Portacolor had a unique 3 beam, 3 gun, inline color CRT, but Sony engineers devised a way to create 3 inline beams within one gun for the first time. The three electron beams focused through the center of a newly developed single large lens instead of through three small lenses. This resulted in a much improved, focused image in the same way as a photographer closes the aperture of the lens, using just the center of the lens to obtain the sharpest image. The center of the lens is the sharpest. A side benefit is fewer convergence adjustments. In December of 1966, Sony developed the 7 inch Chromatron prototype as pictured below. Sony had to work out additional technical problems with the Chromatron, and it’s engineers worked day and night to meet a self imposed deadline: SUCCESSFULLY DEVELOP A NEW COLOR CRT FOR MARKET RELEASE BY OCTOBER 1968. They created a new type of shadow mask which had unbroken vertical slots or stripes instead of the round holes of a conventional shadow mask, allowing much more light to pass through. Sony called this mask the “aperture grill”. On the evening of October 15, 1967, the new tube, with the inline 3 beams, 1 gun, lens and aperture grill were assembled and tested. It was a success and a new color tube was born and named “Trinitron”. “Trini” for 3 electron beams, “tron” from Chromatron the original inspiration. On April 15, 1968, the Trinitron color television was announced at Sony corporate headquarters. Trinitron is the son, born from the Chromatron and the first color set to go on sale in the United States was the 7 inch KV 7010U Chromatron, followed shortly with the KV 7010UA which swapped out the Chromatron with the new Trinitron CRT, which is very similar to the Chromatron prototype as below. I wish to credit Sony and the author of the book “Sony” for some of this information. This writer had just graduated from high school in January, 1965 and went directly to work in his new career. I wanted to purchase my first color set in 1966. I spent months of evaluation on the color televisions available at that time. Zenith, Motorola, Magnavox, Slyvania, General Electric, RCA, Admiral, Packard Bell, Curtis Mathis and others were evaluated. Eventually, settled on the RCA as shown above, but was not satisfied with it. After seeing the first two Sony sets, a 7 inch and a 12 inch in 1968, I looked no further. They had the best color imaging available at the time and blew everything else away in my personal opinion. It was to me, a quantum leap improvement in quality.
Update July 11, 2012: I am now convinced that the below two black and white images are not that of a true Chromatron. Why? I recently acquired a copy of Sony’s 1967 annual report. Sony states that the below television is a Chromatron and was shown in the United States in June, 1967 and would be marketed in the United States in summer, 1968. We know that Sony gave up on the Chromatron in Japan in 1966 and set out to re-engineer the tube. We are looking at a modified Chromatron television in the two photos below which is the Trinitron. Sony called it a Chromatron in the Popular Science article and in their annual report, because it was not officially named a Trinitron until their April, 1968 announcement. You can see that in the 1968 color publicity photo, it was called Micro Color same as the prototype in the two black and white photos from 1967. You can see that the color 1968 publicity photo is virtually identical to the final released version of July, 1968, which was called a Trinitron.
* Update January 28, 2013: I was wrong. Just found a working Sony KV 7010U Chromatron! The set is being repaired and I will provide detailed information and photos soon.
After the Chromatron, nineteen years later, Sony succeeded in developing the first commercially available index beam television in the form of a one tube projection TV and rightfully renamed it the Indextron. After that, three years later in 1988 the first stand alone consumer available beam index color television called the WatchCube. You can read about it on the INDEXTRON PAGE.
The integrated antenna/handle design was carried forward in the 5 inch Sony Trinitron KV 5200 introduced in 1980 and shown on Page Two.
This 1968 Sony publicity photo with live screen shot appears to be Model KV-7010U. It was photographed from my copy of the December, 1968 issue of Popular Mechanics. This is the earliest production model, later changed to the Model KV-7010UA with minor changes. This photo shows “Micro Color” with no three-color logo above the viewing screen. The sales brochure below, shows “Trinitron Color” with rectangular three-color logo above the viewing screen. A later version changed the three-color logo to the ellipse design.
Some interesting information can be gleamed from the magazine article.
1. The set is described as “Micro Color” not the Trinitron.
2. A diagram of the CRT shows a wire grid and described as such instead of the Aperture Grill.
3. The text of the article says “it has a grid of fine wires that give the tube high transparency.”
4. The article describes the CRT as being an “improved Chromatron developed by Dr. Lawrence.”
5. The article states “Sony took the Chromatron and added a raft of improvements that licked the production problems … and christened the tube Trinitron”.
6. The article further states “Sets currently on the market carry a list price of $429.95.”
This December, 1968 issue hit the news stands in November and we know magazine articles are usually prepared a month or two in advance of publication. Given that, we can say this particular model was on the market at least as early as September or October, 1968.
Question? Is the magazine article reviewing the KV 7010U Chromatron or the KV 7010UA Trinitron? I know of one set owned by a collector which is designated “Micro Color” without the three color logo, but is confirmed to be model KV 7010UA with a Trinitron CRT inside. Curiously in the October 31, 1968 Sony Annual Report, Sony states that a 7 inch Micro Color television was marketed in the United States July, 1968. They are silent as to whether it was the Chromatron or the Trinitron, but interestingly, in the previous year Sony Annual Report dated October 31, 1967, they stated that “a 7 inch Micro Color Chromatron will be marketed before Summer, 1968.”
Update, June 19, 2014: Because of the recent find of the KV 7010U service manual and other information recently found, we are now convinced that the author of this article was auditioning and reviewing a Sony Chromatron KV 7010U. The service manual recites: “7 inch, 90 degree deflection Chromatron system incorporating “Trinitron”. We now know that the KV 7010U Chromatron was released April, 1968 and the KV 7010UA was released approximately 3 months later.
As you will see below and on page one, Vintage Micro Television of this site, I found an actual Sony Chromatron Model KV 7010U.
(Note: We are showing information on the Sony KV 7010UA because it’s an improved Chromatron, renamed Trinitron and because cosmetically, it looks identical to the KV 7010U except for the the identity tag above the screen. In fact, the very first production run identified the KV 7010UA as Micro Color. The only way you would know the difference is by looking at the tag placed at the rear of the set. This photo shows that this set was a KV 7010UA Trinitron Receiver. On a KV 7010U, the tag reads “Transistor TV Receiver” Model KV 7010U)
Sales Brochure 1968 The Worlds Smallest Color Television
In April, 1968, Sony introduced their first Chromatron and soon thereafter (July) Trinitron color TV for the U.S. market and the world’s smallest color TV at the time. It had a revolutionary new 7 inch CRT described in detail on PAGE ONE.
This is an original four page sales brochure of the first Sony Trinitron television sold in the United States, the seven inch KV 7010UA. It became available for sale in the Summer of 1968. I purchased new in spring of 1969.
Scans of vintage analogue 35 mm color print photographs taken shortly after acquisition of my original Sony KV 7010UA purchased in 1969.
Live Screen shots from the moon photographed August 2, 1971 taken off the Sony KV 7010UA. The mission, Apollo 15, carried two astronauts, Commander David R. Scott and LM pilot James B. Irwin, the seventh and eighth men to walk on the Moon. These images are photos of the actual 35mm color prints I took on that day.
Two digital photos of original analogue 35 mm prints photographed 1971. Actual screen shots off the Sony KV 7010UA from the Tonight show in 1971, the first Carol Wayne, the second, George Burns. The original images were much sharper, these shots are photographs of photographs. Keep in mind these images were produced with 42 year old studio cameras, since then technowledgy has progressed considerably. Having both the KV 7010UA and the KV 1210U in my possession at the same time, I will say the 1210U had a brighter, better focused image. I started taking screen shots back in 1969, being impressed with the picture quality of the Trinitron system.
Original Sony KV 7010UA 4 color service manual, block diagrams, wave forms, etc. Drop me a line if you would like a copy.
In 1967, Sony demonstrated a 7 inch Chromatron prototype according to a Sony press release on June 20, 1967. In Sony’s Annual Report dated October 31, 1967, Sony stated that a 7 inch Chromatron would be marketed in the United States before the Summer of 1968 and in Sony’s Annual Report dated October 31,1968, Sony confirmed that a 7 inch micro color was marketed in July, 1968. It appears that prior to the launch of the famed Trinitron CRT, an actual hybrid Chromatron with a 7 inch CRT was introduced in the United States as the model KV 7010U and then quickly replaced (within 3 months) by the model KV 7010UA with a Trinitron CRT. In January, 2013, a working Sony KV 7010U was found by this editor, currently in his possession and confirmed to be a hybrid Chromatron 7 inch CRT. The television was opened and among other things, a label was attached to the CRT bell reciting “SONY CHROMATRON Licensed under Patents of Paramount Pictures Corporation”.
A bit of mystery surrounds the introduction of the Sony KV 7010U Chromatron in April, 1968, only to be replaced so quickly (July, 1968) by the KV 7010UA with Trinitron CRT.
*Update February 17, 2014:
Broadcasting Magazine January 15, 1968, reports: Gulf Western parent company of Paramount Pictures Corporation, holder of the Chromatron patent announced that Sony Corporation of Japan, would begin selling a 7 inch Chromatron color television in April, 1968.
In the the April 29, 1968 Volume 41 Number 9 issue of Electronics Abroad magazine it is reported that Sony has decided to drop the Chromatron CRT from the Sony 7 inch television and starting in June, 1968 would instead begin shipping a set “useing a tube right out of the laboratory” (the Trinitron model KV 7010UA). The reason given was that the one gun Chromatron requires hard-to-make color switching grids.
Update March 26, 2014: I think we solved the mystery. Sony’s purchase of a Chromatron non-exclusive license with Paramount Pictures read in part: to provide “technical assistance in the production of a chromatron tube and color television receiver utilizing it.” (Source, Sony History website) If we can find and read the entire agreement, we may find that Sony was contractually obligated to manufacture a Chromatron for the United States market and share technical information with Paramount who we know wanted to license to other U.S. manufactures.
Sony quietly dropped the Chromatron tube within 3 months of introduction and re-engineered the KV 7010 chassis with the Trinitron tube. (Source, Broadcasting Magazine)
Sony KV 7010U Chromatron also known as the Chromagnetron
Probably the rarest and most intriguing television in my collection, combining the Trinitron one gun with the Chromatron wire selection grid CRT, thereby simplifying the complicated, expensive color switching. Trinitron one gun, three inline cathodes with Chromatron wire selection grid CRT. Technically know as the * Chromagentron, but referred to in the press as Chromatron.
* Chromagnetron described in Electronics magazine, April 29, 1968, The History Of Television 1942 to 2000 and in New Scientist magazine.
Update January 16, 2013: I finally found a replacement model after a 4 year search. My original model the KV 7010UA, was given mistakenly to Goodwill by my wife. The KV-7010U is the earliest production model using a Chromatron CRT and later modified by the Sony KV-7010UA with minor cosmetic changes, and swapping out the Chromatron CRT for the newly developed Trinitron CRT. See page one of the timeline, “Vintage Micro TV” for the story, then come back here for repair information.
February 14, 2013: I asked Andy Cuffe who recapped my two Indextrons to try and restore the Sony KV 7010U.
When found, it had a blue screen with no image and static sound. After opening the cabinet, it was a great surprise to see this:
A Sony Chromatron licenced under patents of Paramount Pictures Corporation! I was estatic. Prior to this time, a Chromatron in a U.S. production KV 7010U was rumored but never verified to my knoweldge. I have never seen a single piece of information to verify this other then Sony’s 1967 Annual Report which stated that a 7 inch Micro Color Chromatron would go on sale before the Summer of 1968 and a photo of a prototype was published in a Popular Science September, 1967 issue.
After Andy’s examination, he wrote: “This is just speculation,
but I think instead of an aperture grill it uses fine wires to focus
the beams onto the correct phosphor stripes. I expect that there is a
pair of fine wires running vertically behind each set of three
phosphor stripes. The wires form a lens that focuses the beams onto
the correct phosphor. It would need a second HV supply because there
needs to be a difference of maybe 500-1000v between the adjacent
After further exanination Andy wrote:
“I can’t see much inside the CRT, but there is a small gap where there is clear glass near the front of the CRT. You can see a little of where the aperture grill would be. It looks very similar to an aperture grill, but the wires are much finer. I will try to photograph it, but I don’t think it will turn out because there are a lot of obstructions and the glass isn’t completely smooth.”
“I suspect they are applying a DC voltage to the wire mesh and only using
it to focus the electron beams onto the correct phosphor stripes. This
is simpler than trying to switch a single beam from stripe to stripe.
Since the wires focus the beams onto the correct stripes (rather than
just blocking them from hitting the wrong ones) it should make the
I found the Sam’s folder for the 7010UA which has lots of pictures in
it. Most of the boards look identical. The HV circuit lacks the second
HV rectifier, and the CRT bell is a different shape. It also has a
standard set of purity rings instead of the electronic control. The
purity control on your set is probably varying the bias on the wire mesh.”
Andy performed a test on the CRT and found all three beams weak, the red especially so. Andy said a good beam emission should test at .85 on the meters, see next photo:
“I’ve fully recapped both the main circuit boards, and the picture has improved (see the attached screen shot). I still need to replace a few more caps on the main chassis, but probably nothing that will make much difference the picture.
The severe color noise is gone, and the picture has better contrast. There’s still virtually no red though. Each color has two controls. Background works like the brightness control, and drive works like the contrast control. I have the red drive and background controls at maximum. The green drive is at minimum, and the blue drive is turned up just enough to balance the green. The blue and green backgrounds are set to produce proper black level. I think this is about as good as it will get with the bad red gun. I could try to rejuvenate just the red. The red is so bad that I think it will either do nothing at all, or improve it slightly. The only risk is that something unforeseen could happen to the blue, or green in the process.
I suppose if you’re really serious, you could see if RACS in France can rebuilt it. It would be similar in complexity to rebuilding a 15GP22 (minus the leaking problem).”
We decided against rejuvenation, deeming it to risky with little chance of improvement.
46 capacitors were replaced.
The next series of photos (a summary of 178) were taken by Andy in his shop. I have many more to numerous to post, but if you are interested, I can send you full size, detailed images, just drop me a line.
Sony service manual found by Andy Cuffe on June 14, 2014. Tap or click on image for enlarged view.
I want to thank Andy Cuffe for his expertise and help in restoring this television.
Now you can read about the design of the 1965 Sony Chromatron 19C 70 in the below 15 page PDF file. Some of the information applies to the design of the Sony KV 7010U. I want to thank the staff at Sony Archive History Museum in Tokyo, Japan for sharing this document. I know it will be of interest to television and history enthusiasts worldwide.
Click or tap on below image to view PDF.
Now jump back to the Time Line on page one “Vintage Micro TV“ to read the story with photos and screen shots of the Sony KV 7010U.
This New York Times article dated September 9, 1964, corresponds to the above Sony press release, courtesy New York Times.
The one gun 17 inch Sony Chromatron went into pilot production. * In 1965, the following year, Sony decided to market a 3 gun, 19 inch Chromatron. This set sold in Japan only, during 1965 and 1966, and shown above on this page, as model 19C 70. Also, it is widely reported that this model sold only 13,000 units. I found a 1994 IEEE interview with one of Sony’s chief engineers of the Chromatron/Trinitron, Susumo Yoshida, which said, in part: “It was beautiful. The Chromatron is beautiful, bright, and sharp, if it works. If it can be mass-produced, it is a fantastic product. They only produced EIGHTEEN THOUSAND SETS, and it was nice, bright, clear, and sharp. People really appreciated the product. There was even a lifetime guarantee by the Sony Corporation. If it was broken, customers could ask Sony to fix it for free.”
What we have learned is that Sony continued to have technical problems. It was a manufacturing nightmare and nearly drove Sony to bankruptcy. Masaru Ibuka, Sony’s co-founder and President refused to give up on the Chromatron. He did not want to copy RCA’s shadow mask system, which he deemed inferior. “We must produce something different. We do not copy … We are a company of engineers.” Indeed it was written in the company’s founding prospectus which Mr. Ibuka drew up in 1946.
Mr. Ibuka finally thew in the towel in Fall, 1966. He looked for a new solution to the Chromatron, and assembled a core group of engineers who were given the task of correcting the Chromatron’s problems. They worked 24/7 and experimented with various techniques. This led to the developement of the Trinitron CRT. In many ways, the Trinitron resembled the Chromatron. It had one gun, but this time with 3 inline beams within the single gun structure. It had the vertical phospher stripes etched across the screen like the Chromatron. The new “Aperture Grill” was aligned with unbroken vertical slits, much like the Chromatron’s wire selection grid. The Aperture grill was not as efficient as the Chromatron wire selection grid, but still was 3 times brighter then the shadow mask dots and holes system. The Trinitron required only 2 convergence adjustments, instead of the 12 used in the shadow mask system. This made the Trinitron an instant success, together with superior beam focusing through one large lens instead of three small lenses, less parts, and lower power consumption. The superior image was instantly recognized by all who saw it for the first time.
Some will say, that if Sony does not copy, well then why did they introduce the Lawrence Chromatron? Possibly one could say they imitated, and brought to consumers the Chromatron system, which no other company was willing or able to achieve before them. That was approximately 18,000 units brought to market with a lifetime gurantee, not to mention the Chromatrons sold in the United States as the KV 7010U. This led to a very similar Trinitron CRT becoming the most successful color television in history with a 40 year production run.
* Citation: It is noted that the orginal Lawrence Chromatron CRT was specified in both one and three gun versions. “Described in this paper is a single gun and three gun version of a simple color cathode-ray tube developed by Chromatic Television Laboratories, Inc., based on the ideas of Dr. Ernest O. Lawrence of the University of California. Both types utilize post deflection focusing (PDF) and acceleration as will be discussed in the body of this paper. The principles described are quite general and may be applied to other cathode-ray tube and camera tube designs. The single and three gun types discussed below will operate with any of the presently proposed color television transmission systems.”
Proceedings of the IRE (Volume:41 , Issue: 7 )
Date of Publication: July 1953
851 – 858
Digital Object Identifier :
Date of Current Version :
08 January 2007
Issue Date :
Update April 6, 2014:
On January 27, 1969, Gulf Western Industries, who purchased Paramount Pictures, sued Sony for alleged failure to share technical information pursuant to the 1964 license agreement and also on the Trinitron. (In 1961, Sony secured an exclusive license to develop the Chromatron in Japan only. In 1964, Sony obtained a non-exclusive license for the rest of the world.) We reviewed the case in the U.S. District Court Southern District of New York and read the Complaint and Sony’s Answer. Sony alleged that Great Western breached the Agreement by licensing the Chromatron Patents to Philco-Ford in 1967 without notice to Sony per the 1964 Agreement. Both the 1964 and 1967 Agreements were made part of the case as exhibits. The case was settled and discontinued with prejudice by both parties, by Stipulation filed December 9, 1969.
The 1964 license agreement did not contractually require Sony to manufacture a Chromatron in the United States or anywhere else as I had speculated.
The 1964 license agreement outlined that Paramount would be keeping track of the numbers of Sony Chromatrons sold for royalty purposes. Today Viacom is the successor in interest to Gulf Western and Paramount Pictures is a division of Viacom, so we may find the actual production numbers of the Sony KV 7010U (which I suspect is less then 1000 units) if we are allowed to check the archives of Paramount Pictures Corporation.
Interesting to note that Philco proposed another one gun system called the Apple tube now known as the Indextron in the early 1950′s. They worked on this tube for over 10 years without success.
So in 1967, Philco was still interested in an alternative to RCA’s shadow mask system, this time working on the Chromatron. I had not known this until reading the lawsuit.
To summarize, at the dawn of color broadcasting in 1953, the Chromatron CRT was one of the competing systems along with CBS and RCA. RCA won the competition with it’s compatible color dot and shadow mask system and introduced it’s first color television, the CT 100 in April, 1954. Ironically 14 years later, Sony introduced the Trinitron system which is an improved Chromatron and this system became the the most successful television product in the world with a 40 year production run. After pioneering the color television industry, it was sad to see the demise of RCA in 1986. The Radio Corporation of America deserves great credit for all their endeavors and *inventions to enhance the entertainment experiences of the American people and abroad.
* Actually for history, Philo Farnsworth was awarded priority of inventions for both his image dissector, (1934) dating back to 1927 and the image orthicon (1933) by the U.S. Patent office. Because RCA was determined to go forward with the commercial manufacturing of television equipment, RCA reluctantly entered into a cross-license/royalty agreement with Farnsworth in 1939 after their loss in court, spending years of litigation fighting Farnsworth’s inventions. Farnsworth was honered at the 2002 Emmy Award Show in this clip. In March, 2013, Philo Farnsworth was posthumously inducted into the Television Hall of Fame by the Academy Of Television Arts & Sciences for his invention of the all electronic television.
Editors commentary: Unfortunately, now the powerful Sony Corporation is in decline. It is sad to see that Sony’s vision was lost after the passing of co-founder Akio Morita, and earlier this year, (February, 2014) Sony announced the end of their Vaio computers and the spinoff of their television business. Sony hired their second CEO to stop the bleeding, but it hasn’t helped. It has been my long belief that to succeed you need to stay aggressive and innovate. Maybe Sony became to big in spite of themselves. Sony did innovate in their early years. Masaru Ibuka, co-founder was an engineering genius and Akio Morita was a marketing and financial genius. They did things the “SONY WAY” and proved all the naysayers wrong. They brought us outstanding new products we could not even imagine. (Apple is doing the same thing now) The inspiring story behind the Chromatron/Trinitron and the “never give up” attitude, serves as a business model for all. Sony needs to re-examine themselves and return to their core values. I hope it’s not to late.
Will the same thing happen to Apple? Time will tell.
See the VINTAGE MICRO TV page for additional photos, press clippings and information on the Sony KV 7010U Chromatron.