JPH02102693U

JPH02102693U -

Info

Publication number: JPH02102693U
Application number: JP1017189U
Authority: JP
Priority date: 1989-01-31
Filing date: 1989-01-31
Publication date: 1990-08-15

Description

[Brief explanation of drawings]

第１図は本考案の１実施例の調光表示装置のブ
ロツク図、第２図は本考案の原理を示す表示輝度
と外光強度との関係を示した図、第３図は第１図
の装置の動作を説明する各部の波形図、第４図は
第１図の装置の基準電圧信号生成回路から出力さ
れる信号の特性波形を示した図、第５図は第４図
の信号波形を出力するための本考案の他の実施例
の回路のブロツク図、第６図は第５図の回路の各
部の出力波形図、第７図は第４図の信号波形を出
力するための本考案のさらに他の実施例の回路の
ブロツク図、第８図及び第９図は第７図の回路の
各部の出力波形図、第１０図は従来の調光表示装
置の表示輝度特性を説明するための図である。１……基準電圧信号選択回路、２……基準信号
生成回路、３……比較回路、４……外光強度検出
部、５……表示駆動回路、６……表示部、７……
正弦波発振器、８……全波整流回路、９……負電
圧変換回路、１０……比較回路、１１……入力端
子、１２……デジタルＩＣ、１３……Ａ／Ｄ変換
器、１４……ＲＯＭ、１５……Ｄ／Ａ変換器、１
６……出力端子。 Fig. 1 is a block diagram of a dimming display device according to an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between display brightness and external light intensity showing the principle of the present invention, and Fig. 3 is similar to Fig. 1. 4 is a diagram showing the characteristic waveform of the signal output from the reference voltage signal generation circuit of the device in FIG. 1, and FIG. 5 is the signal waveform in FIG. 4. 6 is an output waveform diagram of each part of the circuit of FIG. 5, and FIG. 7 is a block diagram of a circuit of another embodiment of the present invention for outputting the signal waveform of FIG. 4. A block diagram of a circuit according to still another embodiment of the invention, FIGS. 8 and 9 are output waveform diagrams of various parts of the circuit of FIG. 7, and FIG. 10 explains display brightness characteristics of a conventional dimming display device. This is a diagram for DESCRIPTION OF SYMBOLS 1...Reference voltage signal selection circuit, 2...Reference signal generation circuit, 3...Comparison circuit, 4...External light intensity detection section, 5...Display drive circuit, 6...Display section, 7...
Sine wave oscillator, 8...Full wave rectifier circuit, 9...Negative voltage conversion circuit, 10...Comparison circuit, 11...Input terminal, 12...Digital IC, 13...A/D converter, 14... ROM, 15...D/A converter, 1
6...Output terminal.

Claims

[Scope of utility model registration request]

A dimmable display device that adjusts the display brightness of the display device according to the intensity of external light detected from the surrounding brightness, which detects the surrounding brightness and compares a voltage proportional to the intensity of external light. an external light intensity detection section that outputs a voltage signal; a reference signal generation circuit that generates at least two types of waveform signals among a triangular waveform signal, a full-wave rectified waveform signal, and an inverted waveform signal thereof as a reference voltage signal; A reference voltage signal selection circuit that selects and outputs only one type of signal from at least two types of reference voltage signals generated by the signal generation circuit; A dimming display device comprising a comparison circuit that outputs a rectangular wave signal according to a comparison between the positive and negative signals, and a display drive circuit that controls the display brightness of the display device based on the duty ratio of the rectangular wave signal of the comparison circuit.