James R. "Bob" Biard (born May 20, 1931) is an American electrical engineer and inventor who holds 73 U.S. patents. Some of his more significant patents include the first infrared light-emitting diode (LED), the optical isolator, Schottky clamped logic circuits, silicon Metal Oxide Semiconductor Read Only Memory (MOS ROM), a low bulk leakage current avalanche photodetector, and fiber-optic data links. He has been on the staff of Texas AandM University as an Adjunct Professor of Electrical Engineering since 1980.
Bob grew up and attended school in Paris, TX. His father, James Christopher "Jimmy" Biard of Biardstown, worked as a farmer and a Dr. Pepper route salesman for the local Dr. Pepper company. Bob's mother, Mary Ruth Biard (née Bills), worked as a retail sales person at the Collegiate Shop in downtown Paris. She also sang in quartets at weddings and funerals. When Bob was a child, his pediatrician recommended a diet of mashed overripe bananas, stewed apples, and homemade dried cottage cheese as a remedy for digestive issues. As a Dr. Pepper salesman, Jimmy knew all of the local grocery store owners and they would save the overripe bananas for Bob. Mary would make the cottage cheese by placing unpasteurized milk in a cup towel and hanging it on an outdoor clothes line.
Jimmy eventually became manager of the local 7-Up company and ended up buying it from the former owner. He also sold used cars, worked as a master plumber at Camp Maxey (an army camp north of Paris) during and after WW-II, and did plumbing work for homes and businesses in the Paris area. While in high school, Bob worked for his father and an off duty fireman, who was also a plumber, during the summer as a plumber's assistant. Later in life, Jimmy became chief deputy sheriff in Lamar County, TX.
Bob attended Paris High School from 1944-48. After receiving an associate degree from Paris Junior College in 1951, he transferred to Texas AandM University in College Station, TX where he received a B.S. in Electrical Engineering (June 1954), an M.S. in Electrical Engineering (January 1956), and a Ph.D. in Electrical Engineering (May 1957). Among the scholarships he received were the Dow-Corning Award in 1953-54, and the Westinghouse and Texas Power and Light fellowships throughout his graduate work. He was also a member of IRE, Eta Kappa Nu, Tau Beta Pi, Phi Kappa Phi, and an associate member of Sigma Xi. From 1956-57, he worked part-time as an instructor of undergraduate Electrical Engineering courses. He also worked part-time as an Assistance Research Engineer for the Texas Engineering Experiment Station in charge of operation and maintenance of EESEAC, the Station's analog computer. During grad school, he also designed several vacuum tube DC amplifiers. His PhD dissertation was entitled, "Further Investigation of Electronic Multiplication of Voltages By Use of Logarithms". While a student at Texas AandM, he met his wife Amelia Ruth Clark. They married on May 23, 1952 and later moved to Richardson, TX.
On June 3, 1957, Dr. Biard was hired, along with his former Texas AandM professor Walter T. "Walt" Matzen, as an engineer for Texas Instruments Inc. in Dallas, TX. From 1957-59, as part of the Research and Development (RandD) Dept. of the Semiconductor Components (SC) Division, Dr. Biard worked with Walt to develop and patent one of the first low-drift DC amplifier circuits using transistors.
In the summer of 1958, Texas Instruments hired Jack Kilby (the inventor of the integrated circuit). According to Dr. Biard, during TI’s annual two-week summer shutdown, "At the time we were new, so we had to work while the others were on vacation. He would often come by and talk to us." Kilby held more than 60 U.S. patents, including two with Dr. Biard. Biard later stated, "I had the pleasure of being the co-inventor on two of his 60 patents. It was an honor to have my name with his."
In 1959-60, Dr. Biard collaborated with other engineers at Texas Instruments on the design, construction, and patent of one of the first completely automatic transistor testing facilities known as SMART, the Sequential Mechanism for Automatic Recording and Testing. He also developed, and later patented, a low-frequency reactance amplifier with undetectable "flicker" noise for seismic applications.
In 1959, Dr. Biard and Gary Pittman were assigned to work together in the Semiconductor Research and Development Laboratory (SRDL) on the creation of GaAs varactor diodes for X-band parametric amplifiers to be used in radar receivers. In September 1961, they discovered infrared light emission from a forward biased tunnel diode they had constructed on gallium arsenide (GaAs) semi-insulating substrate. Using an infrared image converter microscope recently brought in from Japan, they discovered all of the GaAs varactor diodes and tunnel diodes they had manufactured at the time emitted infrared light. In October 1961, they demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically isolated semiconductor photodetector.
On August 8, 1962, Biard and Pittman filed a patent describing a zinc diffused p-n junction LED with spaced cathode contacts to allow for efficient emission of infrared light under forward bias. After four years spent establishing the priority of their work based on engineering notebooks, the U.S. patent office determined their work predated submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs, and Lincoln Labs at MIT. As a result, the two inventors were issued U.S. patent 3,293,513 for the GaAs infrared (IR) light-emitting diode. Most other organized research seeking LEDs at the time used II-VI semiconductors like cadmium sulfide (CdS) and cadmium telluride (CdTe), while Biard and Pittman's patent used gallium arsenide (GaAs), a III/V semiconductor. After filing the patent, TI immediately began a project to manufacture infrared diodes. On Oct. 26th, 1962, TI announced the first commercial LED product, the SNX-100. It sold for a price of $130 per unit. The SNX-100 employed a pure GaAs crystal to emit a 900 nm light output. It used gold-zinc for the P-type contact and tin alloy for the N-type contact. TI gave Biard and Pittman $1.00 each for their patent.
The IBM Card Verifier was the first commercial device to use infrared LEDs. The LEDs replaced tungsten bulbs that controlled punched card readers. Infrared light was sent through the holes or blocked by the card, which not only significantly reduced the size and power required, but also improved the reliability. In November 1978, Tom M. Hyltin, a former engineering manager at Texas Instruments, published a book titled "The Digital Electronic Watch", in which he cited Dr. Biard and Gary Pittman's 1961 discovery as being fundamentally important to the creation of the digital wrist-watch.
In August 2013, during a recollection of the patent, Dr. Biard stated the following:
On November 29, 1963 Dr. Biard, Gary Pittman, Edward L. Bonin, and Jack Kilby filed a patent titled "Photosensitive Transistor Chopper Using Light Emissive Diode". Within the patent they described a phototransistor chopper consisting of an LED optically coupled with a dual emitter, photosensitive, silicon transistor. The arrangement provided a switching function in which the switch was completely electrically isolated from the LED that drove it. The transistor operated in response to light emitted from the LED when forward current bias was generated across the junction of the diode. When emitted light struck the surface of the transistor, it was absorbed in the regions of both the emitter-base and base-collector junctions causing the transistor to conduct. This photoconductive transistor could be rapidly turned on and off by intensity modulating the LED at a very high frequency using high frequency alternating voltage. Prior to their invention, complete electrical isolation of the switch element in a chopper from the driving source for opening and closing the switch element was not possible, even through use of isolation transformers. Using isolation transformers, which were bulky and expensive, in miniaturized circuits to separate the driving source and the switch element resulted in magnetic pick-up and spike feed-through due to the transformer winding capacitance. Optical isolators were ideal because they're very small and can be mounted to a circuit board. In addition, they offer protection against excessively high voltages, reduce noise levels, and make measurements more accurate. In March 1964, TI announced commercial chopper devices based on their patent bearing designations PEX3002 and PEX3003. In March 1965, TI announced the SNX1304 Optoelectronic Pulse Amplifier, which was conceived and developed by Dr. Biard and Jerry Merryman, the inventor of the first handheld digital calculator. The SNX1304 consisted of a GaAs p-n junction light emitter optically coupled to an integrated silicon photodetector feedback-amplifier circuit. The device is thought to be the first commercial optically coupled integrated circuit.
In the mid-1960s, Dr. Biard was placed in charge of both the Optoelectronic branch and the MOS branch in the Semiconductor Research and Development Lab (SRDL) at Texas Instruments (TI). In 1964, TI's Opto branch developed a monolithic visible LED element consisting of a 3x5 array of red LEDs capable of displaying the numbers 0-9. The device was lacking a means of driving the array, so Dr. Biard and Bob Crawford (from the MOS branch) designed a P-channel MOS circuit using binary coded decimal inputs to turn on the appropriate 15 output lines. The MOS circuit worked on the first pass and was implemented into a simulated cockpit altimeter. In March of that year, TI displayed the altimeter in a booth at the New York IEEE show and convention. At this convention, TI also demonstrated a hearing aid, which was the first consumer product using TI's integrated circuit. Biard and Crawford filed a patent for their device (U.S. Patent US3541543) on July 25, 1966, referred to as the "Binary Decoder". This was the first time a Read Only Memory had been made using MOS transistors. By the late 1970s, MOS ROM devices had become the most common example of nonvolatile memory used to provide the storage of fixed programs in digital equipment such as calculators and microprocessor systems.
In 1986, TI filed a complaint with the International Trade Commission (ITC) charging 19 different firms with violating US tariff laws by importing 256K and 64K dynamic RAM devices, which infringed numerous TI patents including US Patent 3,541,543. Per the request of Texas Instruments, Dr. Biard testified before the ITC in Washington D.C.; however, the judge determined that the firms did not violate TI's patent rights.
In 1964, Dr. Biard designed linear transimpedance amplifiers (TIA) to work with silicon photodiodes for receiving optical signals generated by LEDs. When the signal current from the silicon photodiode was too large, the input stage of the amplifier would saturate and cause undesirable delays when the optical signal was removed. Dr. Biard solved this problem by connecting a silicon HP Schottky diode across the collector-base junction of the input transistor. Since the Schottky diode had a lower forward drop than the transistor PN junction, the transistor did not saturate and the undesirable delay time was eliminated. The engineer in the next office at the SRD Lab was developing Diode Transistor Logic (DTL) ICs and also having saturation problems. Dr. Biard decided to use what he learned with the optical receiver amplifiers and apply that to the bipolar logic circuits. On December 31, 1964, Dr. Biard filed a patent for the Schottky transistor (U.S. Patent US3463975), a.k.a. the Schottky-clamped transistor, which consisted of a transistor and an internal metal-semiconductor Schottky-barrier diode. The patent was filed based on Schottky Clamped DTL monolithic integrated logic circuits using aluminum-silicon Schottky diodes across the collector-base junctions of the transistors and in the input to adjust the logic levels. The diode prevented the transistor from saturating by minimizing the forward bias on the collector-base transistor junction, thus reducing the minority carrier injection to a negligible amount. The Schottky diode could be integrated on the same die, it had a compact layout, it had no minority carrier charge storage, and it was faster than a conventional junction diode. Dr. Biard's patent was filed before Transistor–transistor logic (TTL) circuits had been invented, yet it was written broadly enough to cover the Schottky clamped TTL ICs using platinum silicide Schottky diodes, which were much more predictable and manufacturable than the aluminum Schottky diodes he originally used. His patent ultimately improved the switching speed of saturated logic designs, such as the Schottky-TTL, at a low cost. In 1985, Dr. Biard received the Patrick E. Haggerty Innovation Award for this patent.
In the 1960s, during the ongoing development of integrated circuit related technologies, avalanche photodiodes were afflicted by a relatively high bulk leakage current, which was amplified by the avalanche gain. The leakage current resulted from holes and electrons thermally generated in the device. This leakage current restricted the photodiode's use, unless a cooling apparatus was used conjunctively. On February 15, 1968 Dr. Biard filed a patent titled "Low Bulk Leakage Current Avalanche Photodiode" (U.S. Patent US3534231), which presented the design of an avalanche photodiode to reduce the bulk leakage currents without having to be cooled. The design consisted of three semiconductor layers, located one on the other, with a barrier layer below the photosensitive junction in the form of a reverse biased second junction. The first two layers constituted the photosensitive junction and the third layer constituted a highly doped semiconductor back region present at a distance from the photosensitive junction smaller than a diffusion length of the thermally generated carriers.
In May 1969, Dr. Biard left Texas Instruments to join Spectronics, Inc., when the company was founded, as Vice President of Research. While at Spectronics, Dr. Biard worked on the design of many of their standard products including silicon photodiodes, phototransistors, photodarlington devices, and GaAs light-emitting diodes. In 1973, he designed and patented a cylindrical edge-emitting LED for efficient coupling to fiber optic bundles. In 1974, he worked on the development of optical couplers used in a data bus developed for airborne avionics systems. With J. E. Shaunfield and R. S. Speer, he co-invented a passive star coupler for use in fiber optic bundle data buses. During this time, he also designed and set up the Spectronics, Inc. optical standards lab and most of the special test equipment for component calibration and evaluation such as a spot scan microscope, a radiation pattern plotter, and constant temperature burn-in racks for LEDs. He also contributed to the development of infrared detector test equipment and design of the Spectronics, Inc. Long Wavelength Infrared Test Set. He also directed RandD activities on the InAs Phototransistor and P-N Junction Cold Cathodes. In 1978, he worked on integrated circuits consisting of an LED driver and pin diode receiver used for digital fiber optic communications.
In 1978, Spectronics was acquired by Honeywell. From 1978 to 1987, Dr. Biard worked as Chief Scientist of the Honeywell Optoelectronics Division in Richardson, TX. Dr. Biard started their MICROSWITCH IC and Sensor Design Center and served as a member of the Components Group Sensor Planning Team. He was also the Components Group representative on the Honeywell Technology Board (HTB), which was concerned with the development and transfer of technology throughout the Honeywell corporate structure. Dr. Biard's product development responsibilities included optoelectronic components (light emitting diodes and photodetectors), fiber optic components, transmitter and receiver modules, silicon Hall effect sensors, and pressure sensors.
In 1987, Dr. Biard became Chief Scientist of the Honeywell MICRO SWITCH Division. He then retired in December 1998 only to be hired back on as a consultant. As a consultant, he became part of a team developing Vertical Cavity Surface Emitting Lasers (VCSELs). He was also involved in the interface between the MICRO SWITCH division, the Honeywell Corporate RandD Laboratory, and universities.
Complete article available at this page.
This post have 0 komentar
EmoticonEmoticon