David Sarnoff, Display Industry Visionary
His many contributions to the display industry are closely linked to the pioneering of flat-panel displays and the invention and eventual success of the LCD.
by Larry Weber
FIFTY years ago, on May 28, 1968, the liquid-crystal display was born. On that day the Radio Corporation of America (RCA) held a press conference at Rockefeller Center in New York City, where inventor George Heilmeier taught the world about a new display technology that used a well-studied but little-known (outside a small research community) material called liquid crystals. A large number of newspapers and magazines published this exciting news, and the publicity aroused the interest of most of the scientists and engineers who contributed to the blossoming of the LCD technology in the following decade. This event is of such importance that Display Week 2018 will host a special session celebrating the 50th anniversary of the LCD on Tuesday, May 22, 2018, from 2 to 5:30 pm.
Another event of interest at this year’s Display Week will be the presentation of the first SID David Sarnoff Industrial Achievement Prize. This new SID award recognizes individuals for long-term and significant leadership and/or exceptional contributions to the advancement of the information display industry. The award is named after the late David Sarnoff, a pioneer of American radio and television who served as RCA’s president and chairman for many years.
Sarnoff’s many contributions to the advancement of the display industry are closely linked to the pioneering of flat-panel displays and the invention and eventual success of the LCD.
Courtesy Hagley Museum & Library © Yousuf Karsh
A Start in Radio
Sarnoff was born in Russia and emigrated to New York City in 1900 at the age of nine. By 1906, at age 15, he had found a job at the Marconi Wireless Telegraph Company of America, where he soon became a junior telegraph operator and rose to a management position by age 19. In 1919, RCA was founded by the General Electric Company (GE) through acquisition of the American division of Marconi. Sarnoff became an RCA commercial manager as part of that acquisition. By 1922 he had been promoted to RCA vice president and general manager. He became a good friend of radio pioneer Edwin H. Armstrong, and in the ’20s, with the help of Armstrong and his inventions, Sarnoff led RCA to become a major commercial success in the rapidly growing area of radio broadcasting. Sarnoff became RCA president in 1930.
Electronic TV Development
RCA’s great success in radio in the 1920s stimulated Sarnoff to look for other electronics development opportunities, which he found in the then-primitive mechanical-based television.1 He became intrigued by the potential for an all-electronic television, and
launched electronic TV R&D at RCA by recruiting television pioneer Vladimir Zworykin from Westinghouse in 1929. This was the start of a 40-year relationship between these two men, in which Sarnoff and RCA financially supported the many inventions of Zworykin.
In 1930 Sarnoff asked Zworykin to assemble a rather large team of 45 people just to research TV. Zworykin and his team had invented the Kinescope tube in 1929, which became the familiar TV picture tube. In 1933 Zworykin invented the Iconoscope, which became the practical TV camera tube used in most commercial TV broadcasts in the late ’30s and early ’40s. Sarnoff led RCA to develop a practical TV system during the Great Depression of the 1930s, when few companies had interest in TV or a budget to invest. Using a TV broadcast, Sarnoff personally announced at the opening of the 1939 New York World’s Fair the regularly scheduled TV broadcasting of NBC, the RCA subsidiary broadcasting network. By 1940 RCA had invested $9.25 million in TV, which was nine times as much as the nearest competitor, the pioneering television inventor Philo T. Farnsworth.
Television broadcasting was halted during World War II, but in 1943 the very sensitive Image Orthicon camera tube was developed at RCA by Albert Rose, Paul K. Weimer, and Harold B. Law. The Image Orthicon became the preferred TV camera tube for the next 20 years. After TV broadcasting began again after the war, RCA sold 5,400 TV sets in 1946 and 7 million TV sets in 1950. By 1959, 86 percent of US households had TVs. In that same year, commercial sponsors underwrote $1 billion in broadcasts.
Sarnoff also drove RCA to pioneer the development, manufacturing, and broadcasting of color TV. In 1947, RCA’s Alfred Schroeder invented the shadow-mask cathode ray tube (CRT). This technology developed rapidly, and in 1950 RCA demonstrated a full-color TV system that was monochrome-TV compatible. This system was competing with the mechanical color-wheel field-sequential system promoted by the rival broadcasting network, CBS, which in 1950 was adopted as the United States color television standard by the Federal Communications Commission (FCC). But in 1953 the FCC reversed itself and approved the “RCA” all-electronic color TV standard. This paved the way for NBC to begin regular color broadcasts in 1954. In that same year, RCA sold its first color TV set.
Color TV had a rocky start. By 1956 all of RCA’s competitive color-TV-set manufacturers had dropped out due to poor sales. TIME magazine called color television “the most resounding industrial flop of 1956.” RCA endured years of poor color-set sales due to lack of color-TV programs. Sarnoff forced NBC to take big losses and develop innovative color programming such as “Disney’s Wonderful World of Color,” which went on the air in 1960. The first year of RCA break-even for color TV
sales was 1962. With the competitors having earlier dropped out, RCA became the sole supplier of shadow-mask color CRTs, selling to 20 OEM TV-set manufacturers in 1964. By 1965, the competitive networks ABC and CBS began regular color programming and the gross value of color sets sold finally exceeded that of monochrome sets.1
Flat-Panel Display Development
On September 27 of 1951, David Sarnoff made a speech directed to the technical staff at RCA Laboratories in Princeton, New Jersey (also dedicated this same day as the David Sarnoff Research Center [DSRC]). This was at an event celebrating the 45th anniversary of his first entry into the electronics industry as a junior telegraph operator back in 1906. During this speech he asked that in five years, during the celebration of his 50th anniversary, he be given three anniversary presents. One present he requested was a “light amplifier.” He said:
This speech inspired a response from the team at the DSRC that planted the seeds of the flat-panel display industry. The next five years saw the success of two significant development programs in response to Sarnoff’s dream. The first was a light amplifier developed by Ben Kazan (who later became the editor of the
Proceedings of the SID
, now known as the
Journal of the SID
) and Frederick Nicoll. This was a 12 × 12-in., 0.25-in.-thick flat-panel display that used a thick-film powder AC electroluminescent light-emitting phosphor placed in series with a thick-film powder cadmium sulfide (CdS) photoconductor. The working device with a gray-scale image, first demonstrated in 1954, is shown in
Fig. 1: This 12-in. × 12-in., 0.25-in.-thick flat-panel light amplifier was demonstrated by Ben Kazan and Frederick Nicoll in 1954. Source: IEEE and Proc. IRE.
Light from a rear optical slide-projector would cause the photoconductor to locally apply a spatially modulated AC voltage across the electroluminescent thick film, thereby emitting light for the flat-panel image. This early device could achieve light amplification factors of 60. David Sarnoff is seen standing next to this device in a 1955 photo shown in Fig. 2.
Fig. 2: In this 1955 photo, David Sarnoff stands next to the flat-panel light amplifier developed at RCA. Courtesy Hagley Museum & Library
The second and much more significant flat-panel development also used an AC thick-film electroluminescent phosphor as the light emitter. But in this case, the image was a live-TV gray-scale image generated electronically by active-matrix electronics. This was developed by Jan Rajchman, who had earlier worked with Zworykin at RCA to develop electron multipliers. Rajchman had also developed the magnetic-core memory at RCA in 1950, which became the dominant form of random-access memory used in digital computers in the 1960s and early ’70s. Rajchman wrote in 1952 in an internal RCA note:
Rajchman recognized that for each pixel “there should be a means 1) to store the level of display information, 2) to energize the EL cell according to the stored level, and 3) to establish the stored level by the coincidence of row and column excitations without affecting the stored level of any other element.” The AC electroluminescent (EL) pixels required driving with high-voltage bi-directionally conducting AC voltages, and so the transistors of the early ’50s would not work. However, through experience with core memories at RCA, a magnetic-core-based switching element called the transfluxor had been invented that could do the job. For Rajchman’s flat-panel display, this was organized like a core memory plane with a magnetic-core active-matrix switching element at each pixel. Rajchman made a 1,200-pixel prototype electroluminescent 14-in. × 18-in. at 1.5-in. thick display that was driven by an active matrix of 1,200 transfluxors in 1955. This prototype could achieve a moving video gray-scale image at 15 frames per second and is shown in
Fig. 3: A 14-in. × 18-in. at 1.5-in.-thick electroluminescent flat-panel live TV display with 1,200 pixels, developed in 1955, shows the face of its inventor, Jan Rajchman. Courtesy Hagley Museum & Library
While not as impressive as Kazan and Nicoll’s panel (Fig. 1), Rajchman’s prototype was of much greater technical significance since it demonstrated the fundamental building blocks found in today’s flat-panel displays. In his 1955 filed patent for this device is the vision of the “hang-on-the-wall” TV that we all enjoy today (Fig. 4).
Fig. 4: This conceptual drawing of a “hang-on-the-wall” TV appears in Jan Rajchman’s patent filed in 1955.
SID has very appropriately named its award for outstanding scientific or technical achievement in flat-panel displays the Jan Rajchman Prize.
On September 30, 1956, the day celebrating the 50th anniversary of his entry into the electronics business, David Sarnoff wrote in a New York Times article:
The flat-panel-friendly research environment Sarnoff stimulated at David Sarnoff Research Labs ultimately gave the display industry other critically important fundamental developments: the thin-film transistor, the LCD, and active-matrix addressing.
By 1960, RCA’s Paul Weimer had gained considerable experience with thin-film semiconductor deposition through his earlier development work on the RCA TV camera tubes such
as the Image Orthicon and the Vidicon. In this year he wanted to work in the exploding new field of solid-state electronics. He started work using single-crystal bulk silicon but soon realized that integrated circuits might be easier to make with an all thin-film planar structure. This led him to invent the first thin-film transistors, which he published in 1962.5 His first devices used cadmium sulfide as the semiconductor but Frank Shallcross in Weimer’s group found that cadmium selenide worked better. This DSRC group was able to make both n-type and p-type TFTs and used these to make the first CMOS logic gates – before this was done with bulk single-crystal silicon. The legendary inventor Peter Brody became aware of Weimer’s TFT achievements and soon began the very successful program at Westinghouse to also develop TFTs. Brody’s Westinghouse group was the first to make active-matrix displays using TFTs, in 1972, and that group became the major champions of the TFT technology for the display industry.
In the spring of 1962, Richard Williams, a researcher at the DSRC, was working on ways to modulate light. He placed a ~0.1-mm-thick layer of the liquid crystal para-azoxyanisole (PAA) between two glass plates coated with electrically conductive transparent tin oxide and applied a DC voltage to the electrodes. The microscope stage needed to be heated to 110-140 C in order to melt the PAA solid crystals to the liquid-nematic phase. His April 10, 1962, lab notebook entry states:
Fig. 5: These liquid-crystal display device patent figures were filed by RCA’s Richard Williams in 1962.
In 1964, George Heilmeier at the DSRC was looking for ways to use organic materials as an electro-optic modulator for lasers when he learned of the prior work of Williams. Heilmeier and his team used various dyes mixed with a liquid-crystal material sandwiched between the tin oxide-coated plates to make a successful guest-host light-modulator device. Heilmeier wrote in his lab notebook:
One of the biggest challenges was the very high temperatures (typically 100 C) needed to achieve nematic-phase liquid crystals. In 1965, DSRC organic chemist Joe Castellano discovered that the temperature could be significantly lowered with eutectic mixtures of liquid crystals.8 By 1966 ternary mixtures had achieved a nematic phase down to 25 C, which was a critical turning point toward practical LCDs.
In 1969, while at the DSRC, theorist Wolfgang Helfrich conceived of a new type of LCD that we now know as the twisted-nematic LCD. He could not get anyone at RCA interested in it because it required two polarizers, making it costlier and more complicated than the dynamic-scattering LCD. After leaving RCA he joined experimentalist Martin Schadt at Hoffman-La Roche in Basel, Switzerland, in the fall of 1970. Helfrich explained his twisted-nematic idea to Schadt, and within a few weeks they had a working prototype. They quickly applied for a patent and published what is today the most successful LCD mode, making dynamic scattering obsolete.8
In 1966, a group at the DSRC led by Bernie Lechner (who later became SID president) started work on solving the problems of LCD addressing. The researchers soon realized that the LCD was indeed fast enough to achieve TV speeds but would need some sort of suitable switching device to drive each pixel at these speeds. Various methods were considered, including the following elements to drive each pixel: two diodes and a capacitor, silicon-on-sapphire metal-oxide semiconductor field-effect transistor (MOSFET), monolithic-silicon
MOSFET, and a Weimer TFT. From this work came the famous circuit seen in Fig. 6, which is now used in all active-matrix LCDs.9
Fig. 6: This classic active-matrix circuit for driving LC pixels with field-effect transistors was first published in 1969.9
By the time of the unveiling of the LCD at the 1968 RCA press conference, David Sarnoff’s health was failing, but his great interest in LCD developments was not. While
he was too sick to attend the public press conference, he did attend the private dress rehearsal held the day before, where he saw the presentations of George Heilmeier on dynamic scattering and Bernie Lechner on active-matrix addressing.1 He also heard James Hillier, VP of RCA Laboratories, explain how LCDs could be used as electronic clocks and wristwatches, automobile dashboard displays, scoreboards, stock tickers, and ultimately, pocket-size television receivers that could be viewed in bright sunlight. Unfortunately, David Sarnoff did not live to see the most significant results of his flat-panel dreams that were to unfold in the years to come. But during his lifetime he envisioned and promoted development of the everyday displays that we now all use, such as portable telephones with flat-panel displays that communicate wirelessly and large, flat color TVs that hang on the wall and receive signals from communication satellites.
Sarnoff was not an inventor of display technology, but for more than 40 years he drove RCA to become the dominant world company in the electronic TV and color-TV industries. Under his leadership, RCA planted the seeds that grew into the flat-panel display industry. (RCA, however, failed to become a dominant commercial success in flat panels.) One can only imagine what success RCA would have had in flat panels had Sarnoff been able to continue his leadership.
David Sarnoff remained RCA chairman until 1970 and died at age 80 in 1971. In Sarnoff’s eulogy, New York Governor Nelson Rockefeller said Sarnoff had a “capacity to look at the same things others were looking at but to see far more.”
1For more details, see Television: The Life Story of a Technology, Alexander B. Magoun, Greenwood, 2007.
2For the full speech, see http://www.davidsarnoff.org/kil-chapter08.html.
3For a detailed historical account of the development of the flat-panel display and LCDs at RCA see: “Crystalizing Innovation: The Emergence of the LCD at RCA, 1951–1976,” Princeton University Ph.D. dissertation, Benjamin H. Gross, 2011, available at http://dataspace.princeton.edu/jspui/handle/88435/dsp011g05fb62p Also see the just-released book: Benjamin Gross, The TVs of Tomorrow: How RCA’s Flat-Screen Dreams Led to the First LCDs, University of Chicago Press, 2018.
4D. Sarnoff, “Electronic Revolution, Present and Future,” The New York Times, Sep. 30 1956, 38, 42.
5P. K. Weimer, “The TFT – A New Thin-Film Transistor,” Proc. IRE 50(6), 1462–1469, 1962.
6R. Williams, “Domains in Liquid Crystals,” J. Chem. Phys. 39(2), 384–388, 1963.
7Bernie Lechner gives an interesting account of how he and his boss Jan Rajchman first saw the Williams LCD experiment in: B. J. Lechner, “History Crystallized: A First-Person Account of the Development of Matrix-Address LCDs for Television at RCA in the 1960s,” Information Display, January 2008.
8J. A. Castellano, Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry, World Scientific Publishing, Singapore, 2005.
9B. J. Lechner, “Liquid Crystal Displays,” presented at a conference on Pertinent Concepts in Computer Graphics held at the University of Illinois from March 31 to April 2, 1969, and published in Pertinent Concepts in Computer Graphics, edited by M. Faiman and J. Nievergelt, University of Illinois Press, 1969. Also: B. J. Lechner et al. “Liquid Crystal Matrix Displays,” Proc. IEEE 59, 1566, 1971. •