Source: https://patents.google.com/patent/JPH0424611A/en
Timestamp: 2019-05-21 20:54:37
Document Index: 409752376

Matched Legal Cases: ['art 4', 'art 4', 'art 5', 'art 5', 'art 6', 'art 6']

JPH0424611A - Liquid crystal display device with automatic contrast adjusting function - Google Patents
Liquid crystal display device with automatic contrast adjusting function
JPH0424611A
JPH0424611A JP12976590A JP12976590A JPH0424611A JP H0424611 A JPH0424611 A JP H0424611A JP 12976590 A JP12976590 A JP 12976590A JP 12976590 A JP12976590 A JP 12976590A JP H0424611 A JPH0424611 A JP H0424611A
JP12976590A
Toshimasa Ike
1990-05-18 Application filed by Seiko Instr Inc filed Critical Seiko Instr Inc
1990-05-18 Priority to JP12976590A priority Critical patent/JPH0424611A/en
1992-01-28 Publication of JPH0424611A publication Critical patent/JPH0424611A/en
PURPOSE: To adjust contrast to an optimum value automatically by providing a liquid crystal cell for contrast detection at one part of a liquid crystal display, detecting the quantity of light passing through this cell, and feeding it back to a voltage to be impressed to a liquid crystal display panel.
CONSTITUTION: Optical sensors 3a and 3b outputs voltages or currents corresponding to the intensity of respectively received beams to a contrast detection part 4, and this contrast detection part 4 detects difference between the inputted voltages or currents, converts them to electric signals corresponding to the difference and outputs the signals to a voltage control part 5. Corresponding to the inputted electric signals, this voltage control part 5 controls the output voltage of a stabilizing power supply circuit part 6 and is equipped with a function to detect the peak values of the electric signals, and the stabilizing power supply circuit part 6 is the supplying source of the voltage to be supplied to liquid crystal. Difference is detected between the quantity of light passing through an ON cell 2a and an OFF cell 2b of the liquid crystal, and the liquid crystal impressing voltage is controlled so that the difference can be almost maximum. Thus, the optimum contrast can be automatically obtained.
JP12976590A 1990-05-18 1990-05-18 Liquid crystal display device with automatic contrast adjusting function Pending JPH0424611A (en)
JP12976590A JPH0424611A (en) 1990-05-18 1990-05-18 Liquid crystal display device with automatic contrast adjusting function
US07/695,443 US5153756A (en) 1990-05-18 1991-05-03 Liquid crystal display device with automatic constrast control
JPH0424611A true JPH0424611A (en) 1992-01-28
ID=15017654
JP12976590A Pending JPH0424611A (en) 1990-05-18 1990-05-18 Liquid crystal display device with automatic contrast adjusting function
US (1) US5153756A (en)
JP (1) JPH0424611A (en)
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1990-05-18 JP JP12976590A patent/JPH0424611A/en active Pending
1991-05-03 US US07/695,443 patent/US5153756A/en not_active Expired - Lifetime
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