Bernard J. Lechner (25 January 1932 – 11 April 2014) was an

electronics The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considerin ...

and formerly vice president,

RCA The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...

Laboratories, where he worked for 30 years covering various aspects of television and information display technologies.

Biography

Lechner was born in

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

, NY, in 1932. He grew up and attended high school in

New Rochelle New Rochelle (; older french: La Nouvelle-Rochelle) is a city in Westchester County, New York, United States, in the southeastern portion of the state. In 2020, the city had a population of 79,726, making it the seventh-largest in the state o ...

, New York. According to his ''oral history'' recollections, he was already very interested in radio and TV receivers during his high school years. He built sets with commercially available kits. Then, he studied electrical engineering at the

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

, interrupted by two years service for the U.S. Army Signal Corps in the US and Germany. He received the B.S.E.E. degree in 1957. In 1957, he joined the

RCA Laboratories The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...

Princeton, New Jersey Princeton is a municipality with a borough form of government in Mercer County, in the U.S. state of New Jersey. It was established on January 1, 2013, through the consolidation of the Borough of Princeton and Princeton Township, both of w ...

, as Member of Technical Staff and worked on various aspects of video engineering such as a home video tape recorder, two-way cable TV services (pay-TV and interactive shopping), TV tuners and TV broadcast cameras. He headed various RCA research groups working on these developments. While already working at RCA, he did graduate work at

Princeton University Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the ...

and at the

Harvard School of Business Harvard Business School (HBS) is the graduate business school of Harvard University, a private research university in Boston, Massachusetts. It is consistently ranked among the top business schools in the world and offers a large full-time M ...

. Bernie died on April 11, 2014.

Active matrix Active matrix is a type of addressing scheme used in flat panel displays. In this method of switching individual elements (pixels), each pixel is attached to a transistor and capacitor ''actively'' maintaining the pixel state while other pixels ar ...
addressing

George H. Heilmeier, who had joined the RCA Laboratories a year after Lechner, started working with

liquid crystals Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. The ...

in 1964. A team led by Heilmeier developed the first liquid crystal displays (LCD). Lechner joined the efforts with the intention of applying LCDs to TV screens. For this purpose, Lechner's team studied simple matrix LCDs with a few lines and columns. It became obvious that there were tight limitations for the number of picture elements (

pixels In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the sm ...

) addressable by a direct-drive addressing scheme (

passive matrix addressing Passive matrix addressing is an addressing scheme used in early LCDs. This is a matrix addressing scheme meaning that only ''m'' + ''n'' control signals are required to address an ''m'' × ''n'' display. A pixel in a pass ...

) due to the limited contrast and response speed. Lechner was first to apply a ''

sample-and-hold In electronics, a sample and hold (also known as sample and follow) circuit is an analog device that samples (captures, takes) the voltage of a continuously varying analog signal and holds (locks, freezes) its value at a constant level for a ...

'' technique to this type of display by connecting a capacitor in parallel with each LCD pixel and controlling its charge through a

field-effect transistor The field-effect transistor (FET) is a type of transistor that uses an electric field to control the flow of current in a semiconductor. FETs ( JFETs or MOSFETs) are devices with three terminals: ''source'', ''gate'', and ''drain''. FETs cont ...

. Later-on, this technique was called active matrix addressing employing

thin-film transistor A thin-film transistor (TFT) is a special type of field-effect transistor (FET) where the transistor is thin relative to the plane of the device. TFTs are grown on a supporting (but non-conducting) substrate. A common substrate is glass, becaus ...

s (TFT). It helped, that the semiconductor operation of RCA was among the leaders of MOS-FET developments (

CMOS 4000 series The 4000 series is a CMOS logic family of integrated circuits (ICs) first introduced in 1968 by RCA. It had a supply voltage range of 5V to 20V, which is much wider than any contemporary logic family. Almost all IC manufacturers active during thi ...

). At a press conference at RCA Headquarters in New York, a demonstration of such an LC matrix display with 36 pixels, using discrete components, took place in 1968 and showed the feasibility of the concept for TV panels. A corresponding publication followed in 1969. RCA reduced the efforts on LCDs and sold the remaining operations in 1976. Lechner concentrated his work on advanced video systems. He became RCA staff vice president for these activities. In this capacity he was a member of the US delegation to the ''Comité Consultatif International pour la Radio'' (CCIR, now

ITU-R The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequency sp ...

) in Geneva for a new

HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...

standard from 1989 to 1990.

Lechner distance

The Lechner Distance chart illustrates the optimal viewing distances at which the human eye can best process the details a HDTV resolution has to offer. For example, the optimal viewing distance for a 42inch (110 cm) Full HD TV (1080p) is . Lechner researched the typical distance between a viewer and their television screen by taking measurements in many American homes. The median distance compiled from all his data came out to . Given this distance, a Full HD TV (1080p) with a screen size of would deliver the optimal viewing resolution. When GE acquired RCA and gave the David Sarnoff Research Center to SRI International in 1987, Lechner took early retirement. Lechner continued his work as independent consultant serving on standard committees and in related organizations as well as an expert witness in patent cases.

Memberships and awards

Lechner was a Fellow of the

IEEE The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operat ...

, the Society for Information Display (SID) and the

Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the m ...

(SMPTE). He was a member of the honor societies Tau Beta Pi,

Eta Kappa Nu Eta Kappa Nu () or IEEE-HKN is the international honor society of the Computer Science and Institute of Electrical and Electronics Engineers (IEEE). "The organization promotes excellence in the profession and in education through an emphasi ...

and

Sigma Xi Sigma Xi, The Scientific Research Honor Society () is a highly prestigious, non-profit honor society for scientists and engineers. Sigma Xi was founded at Cornell University by a junior faculty member and a small group of graduate students in 1886 ...

. In 1971, he was named the first recipient of the SID Frances Rice Darne Award for his outstanding contributions to matrix displays and in 1983, he was named the first recipient of the Beatrice Winner Award for his contributions to SID. He was awarded the David Sarnoff Medal in 1996 and the Progress Medal in 2001 by the

(SMPTE) for his many contributions to the technologies essential to today's television systems. Lechner received two RCA Laboratories Outstanding Achievement Awards and a David Sarnoff Team Award in Science. In 2000, the

Advanced Television Systems Committee The Advanced Television Systems Committee (ATSC) is an international nonprofit organization developing technical standards for digital terrestrial television and data broadcasting. ATSC's 120-plus member organizations represent the broadcast, ...

(ATSC) established the Bernard J. Lechner Award in his honor. In 2011, he received the IEEE Jun-ichi Nishizawa Medal for conceiving the principle of active matrix LCDs (

AMLCD An active-matrix liquid-crystal display (AMLCD) is a type of flat-panel display, the only viable technology for high-resolution TVs, computer monitors, notebook computers, tablet computers and smartphones with an LCD screen, due to low weight, ...

)

Selected publications

Lechner has widely published in the areas of displays and television systems. He also holds ten United States

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

s. * Lechner, B.J.: ''Testing HDTV terrestrial broadcasting systems,'' IEEE Transactions on Broadcasting, Vol. 37 (1991), No. 4, pp. 148–151 * Kressel H. and Lechner, B. J. (guest editors): ''Scanning the issue-Special issue on consumer electronics'', Proc. IEEE, Vol. 82 (1994), No. 4, pp. 445–458 * Lechner, B.J.; Chernock, R.; Eyer, M.K.; Goldberg, A.; Goldman, M.S.: '' The ATSC Transport Layer, Including Program and System Information Protocol (PSIP),'' Proceedings of the IEEE, Vol. 94 (2006), No. 1, pp. 77–101 * Lechner, B.J.: Guest Editorial, ''It's a High-Definition World,'', Information Display, Vol. 23, No. 11, November 2007 * Lechner, B.J.: ''History Crystallized: A First-Person Account of the Development of Matrix-Addressed LCDs for Television at RCA in the 1960s,'' Information Display, Vol. 24, No. 1, January 2008

References

External links

TV Viewing Distance versus Screen Size

BBC R&D White Paper WHP092
''Tests of visual acuity to determine the resolution required of a television transmission system'', J.O. Drewery and R. Salmon, 2004. {{DEFAULTSORT:Lechner, Bernard J. American electrical engineers Fellow Members of the IEEE 1932 births 2014 deaths People from New Rochelle, New York Harvard School of Engineering and Applied Sciences alumni Engineers from New York (state)