Hiro Moriyasu

Hiro Moriyasu (b. 1935 in Kure, Hiroshima, Japan – d. 17 July 2005 in Portland, OR) was an engineer who joined Tektronix in 1959 for a career spanning more than 25 years.

He pioneered the digital oscilloscope and other advanced computer technologies, and held more than 20 U.S. patents.

In the early 1970s, Hiro became the general manager of a new division of Tektronix focused on scientific graphic computing.

Upon leaving Tektronix, Hiro spent two years at Electro Scientific, Inc., co-founded Zeelan Technology in 1990 (acquired by Mentor in 1996) and founded of Acumar Technology in 1998 (acquired by Lafayette Instruments in 2006).

Moriyasu was born in Kure, Hiroshima, Japan. He came to the United States in 1953 as an electrical engineering student at Oregon State University. He died in Portland, Oregon on 17 July 2005, aged 70.

Products

• Key designer of 4051 computer
• Key designer of P7001 digitizer
• Likely designer of X381 plug-in (history uncertain)
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Products by Hiro Moriyasu

Manufacturer	Model	Description	Designers	Introduced
Tektronix	X381	Experimental timebase plug-in	Hiro Moriyasu	(not released)
Tektronix	321	Portable single channel scope	Oz Svehaug • Oliver Dalton • Hiro Moriyasu	1960
Tektronix	Q	Strain gauge preamp plug-in	Hiro Moriyasu	1960
Tektronix	O	Dual opamp plugin	Hiro Moriyasu	1962
Tektronix	321A	Portable single channel scope	Oz Svehaug • Oliver Dalton • Hiro Moriyasu	1964
Tektronix	P7001	Digitizer for the 7704A oscilloscope	Hiro Moriyasu • Luis Navarro • Bruce Hamilton • Jack Gilmore • Bob Shand • Bruce Hamilton • Jack Robinson • Bill Lucas • Jack Grimes • Dennis Keldsen • Mohamed Saba • Dick Beatty • Wayne Eshelman • George Rhine • Bill Markwart • Marlow Butler • Carl Dalby • Colin Doward • Gale Byers	1973
Tektronix	4051	Graphics-capable desktop microcomputer	Hiro Moriyasu	1975

Patents

• US3325742A: Hybrid amplifier circuit (filed 1963-08-06, granted 1967-06-13)
• US3441863A: Drift compensated direct coupled amplifier circuit having adjustable d.c. output voltage level (filed 1965-08-02, granted 1969-04-29)
• US3439282A: Time base generator with automatic rate control (filed 1965-08-20, granted 1969-04-15)
• US3473044A: Monostable comparator circuit (filed 1965-12-13, granted 1969-10-14)
• US3408580A: Oscilloscope device exhibiting reduced jitter (filed 1966-03-17, granted 1968-10-29)
• US4225940: Oscilloscope system for acquiring, processing, and displaying information (filed 1978-10-02, granted 1980-09-30) (Tektronix, with Jack Gilmore, Willem Velsink, Luis Navarro)
• US5444459: Signal acquisition system utilizing ultra-wide time range time base (filed 1993-06-22, granted 1995-08-22) (Zeelan Technology)
• US5349539: Behavioral model parameter extractor (filed 1991-10-28, granted 1994-09-20) (Zeelan Technology)
• US5243343: Signal acquisition system utilizing ultra-wide time range time base filed 1990-12-03, granted 1993-09-07) (Zeelan Technology)
• US5034698: Dual-path wideband and precision data acquisition system filed 1990-01-22, granted 1991-07-23)
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Links

• Tek inventors recognized at banquet (1984)
• Digital oscilloscope inventor Moriyasu dies (AP, 2005)
• Hiro Moriyasu : Engineering Hall of Fame - 2006
• Barrie Gilbert, The Gears of Genius, in IEEE SCCS News, 2007