Thin film EL display panel drive circuit

Claim 2

A thin-film matrix display panel drive circuit comprising: driving voltage means for providing a driving voltage to said matrix display panel; first switching elements connected to scan side electrodes; second switching elements connected to scan side electrodes and said driving voltage means, first activating mans for activating said first switching elements to apply write pulses to picture elements on said scan side electrodes to which said first switching elements are connected; second activating means for activating said second switching elements to apply write pulses to picture elements on said scan side electrodes to which said second switching elements are connected; voltage compensating means for compensating for voltage drops in said second switching elements by adding voltage to said driving voltage supplied by said driving voltage means, said compensation being determined in accordance with variations in the number of emitting picture elements.

Claim 3

The thin-film matrix display panel drive circuit of claim 1, wherein said second switching elements and said first switching elements are alternately activated or deactivated.

Claim 4

The thin-film matrix display panel drive circuit of claim 2, wherein said voltage for compensating the voltage drop is stored in said driving voltage means while said first switching elements are activated.

Claim 5

The thin-film matrix display panel drive circuit of claim 2, wherein said compensation voltage is added to the drive voltage supplied by said driving voltage means when said second switching elements are activated.

Claim 6

A drive system for a thin-film matrix display panel comprising: data side electrodes formed on one major surface of the thin-film matrix display panel and generally extending in a first direction; scanning side electrodes formed on the opposing major surface of said thin-film matrix display panel in a second direction substantially perpendicular to said first direction, said scanning side electrodes being alternately divided into odd number scanning electrodes and even number scanning electrodes; a pull-up driving circuit; a precharge driving circuit; a write driving circuit for providing first and second write pulses; a source level switching circuit; an odd side first driving circuit connected to said odd number scanning electrodes at one end thereof, the other end of said odd side first driving circuit being connected to said source level switching circuit; an odd side second driving circuit connected to said odd number scanning electrodes at one end thereof, the other end of said odd side second driving circuit being connected to said pull-up charge driving circuit and said write driving circuit; an even side first driving circuit connected to said even number scanning electrodes at one end thereof, the other end of said even side first driving circuit being connected to said source level switching circuit; an even side second driving circuit connected to said even number scanning electrodes at one end thereof, the other end of said even side second driving circuit being connected to said pull-up charge driving circuit and said write driving circuit; and a data side first driving circuit connected to said data side electrodes at one end thereof, the other end of said data side first driving circuit being connected to said precharge driving circuit; said driving circuits collectively driving said data side electrodes and said scanning side electrodes to define a number of emitting elements; detecting means for detecting the number of emitting elements for each scan side emitting line in a first driving period; voltage compensating means connected to said write driving circuit for compensating for voltage drops in said odd and even side second driving circuits by adding a voltage in a second driving period to said second write pulse based upon the variations int he number of emitting elements detected in said first driving period; said odd side second driving circuit providing said first write pulse to said odd number scanning electrodes when an even number scanning electrode is selected in said first driving period and providing said second write pulse to a selected odd number scanning electrode when in said second driving period. said even-side second driving circuit providing said first write pulse to said even number scanning electrodes when an odd number scanning electrode is selected in said first driving period and providing said second write pulse to a selected even number scanning electrode in said second driving period; said first write pulse provided being of a polarity opposite to said second write pulse which is provided.

Claim 7

A drive system for a thin-film matrix display panel comprising: data side electrodes formed on one major surface of the thin-film matrix display panel and generally extending in a first direction; scanning side electrodes formed on the opposing major surface of said thin-film matrix display panel in a second direction substantially perpendicular to said first direction, said scanning side electrodes being alternately divided into odd number scanning electrodes and even number scanning electrodes; a pull-up driving circuit; a precharge driving circuit; a write driving circuit for providing first and second write pulses; a source level switching circuit; an odd side first driving circuit connected to said odd number scanning electrodes at one end thereof, the other end of said odd side first driving circuit being connected to said source level switching circuit; an odd side second driving circuit connected to said odd number scanning electrodes at one end thereof, the other end of said odd side second driving circuit being connected to said pull-up charge driving circuit and said write driving circuit; an even side first driving circuit connected to said even number scanning electrodes at one end thereof, the other end of said even side first driving circuit being connected to said source level switching circuit; an even side second driving circuit connected to said even number scanning electrodes at one end thereof, the other end of said even side second driving circuit being connected to said pull-up charge driving circuit and said write driving circuit; and a data side first driving circuit connected to said data side electrodes at one end thereof, the other end of said data side first driving circuit being connected to said precharge driving circuit; said driving circuits collectively driving said data side electrodes and said scanning side electrodes to define a number of emitting elements; detecting means for detecting the number of emitting elements for each scan side emitting line in a first driving period; voltage compensating means connected to said write driving circuit for compensating for voltage drops in said odd and even side second driving circuits by adding a voltage in a second driving period to said second write pulse based upon the variations int he number of emitting elements detected in said first driving period; said odd side second driving circuit providing said first write pulse to said odd number scanning electrodes when an even number scanning electrode is selected in said first driving period and providing said second write pulse to a selected odd number scanning electrode when in said second driving period. said even-side second driving circuit providing said first write pulse to said even number scanning electrodes when an odd number scanning electrode is selected in said first driving period and providing said second write pulse to a selected even number scanning electrode in said second driving period; said first write pulse provided being of a polarity opposite to said second write pulse which is provided.

Claim 8

The thin-film matrix display panel drive circuit of claim 1, wherein said compensating means adds a compensating voltage to said driving voltage supplied by said driving voltage means so as to apply a substantially constant voltage to said scan side electrodes.

Claim 9

The thin-film matrix display panel drive circuit of claim 6, wherein said compensating voltage increases as the number of picture emitting elements increases.

Claim 10

The thin-film matrix display panel drive circuit of claim 5, wherein the voltage added to said second write pulse of said voltage compensation means is used to develop a total voltage which is substantially constant.

Claim 11

The thin-film matrix display panel driver circuit of claim 8, wherein the voltage added to said second write pulse by said voltage compensation means increases as the number of emitting elements increases.

Claim 12

A driver circuit, as claimed in claim 1, wherein said driver circuit drives a thin-film EL display panel.

Claim 13

A driver circuit, as claimed in claim 1, wherein said first and second driving circuits comprise first type channel MOS transistors and second type channel MOS transistors, respectively.

Claim 14

A drive system, as claimed in claim 5, wherein said drive system drives a thin-film electroluminescent (EL) display panel.

Claim 15

A drive system, as claimed n claim 5, wherein said odd side first and second driving circuits and said even side first and second type driving circuits comprise odd side first and second type channel high voltage MOS drivers and even side first and second type channel high voltage MOS drivers, respectively.