JPH06160804A - Illuminating device for liquid crystal display device - Google Patents
Illuminating device for liquid crystal display deviceInfo
- Publication number
- JPH06160804A JPH06160804A JP4318218A JP31821892A JPH06160804A JP H06160804 A JPH06160804 A JP H06160804A JP 4318218 A JP4318218 A JP 4318218A JP 31821892 A JP31821892 A JP 31821892A JP H06160804 A JPH06160804 A JP H06160804A
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- frequency
- crystal display
- inverter
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Liquid Crystal (AREA)
- Circuit Arrangements For Discharge Lamps (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は液晶TV、パソコン、ワ
ークステーション等に用いられる液晶表示装置用照明装
置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for a liquid crystal display device used in a liquid crystal TV, a personal computer, a workstation and the like.
【0002】[0002]
【従来の技術】近年、液晶を用いた表示装置は、各方面
に広く使用されている。2. Description of the Related Art In recent years, display devices using liquid crystals have been widely used in various fields.
【0003】以下に従来の液晶表示装置用照明装置につ
いて説明する。図2は従来の液晶表示装置用照明装置の
構成図を示すものである。図2において、21は液晶パ
ネル、22は透明導電性シート、23は拡散板、24は
蛍光管、25は反射板、26はインバータである。A conventional lighting device for a liquid crystal display device will be described below. FIG. 2 is a block diagram of a conventional lighting device for a liquid crystal display device. In FIG. 2, 21 is a liquid crystal panel, 22 is a transparent conductive sheet, 23 is a diffusion plate, 24 is a fluorescent tube, 25 is a reflector, and 26 is an inverter.
【0004】以上のように構成された液晶表示装置用照
明装置について、以下その動作について説明する。ま
ず、液晶パネル21には、図示しない手段により信号が
供給されており、文字や図形が表示される。蛍光管24
はインバータ26より高周波電流の供給を受け、蛍光を
発する。発光した光は、反射板25により所定の方向に
向けられ、拡散板23により均一な光線として、液晶パ
ネル21に達する。ここで、液晶パネル21の映像信号
と、インバータ26の高周波との間の干渉縞を防ぐため
に、接地電位に接続された透明導電性シート22を液晶
パネル21と蛍光管24の間に挿入している。The operation of the illuminating device for a liquid crystal display device constructed as above will be described below. First, a signal is supplied to the liquid crystal panel 21 by means not shown, and characters and figures are displayed. Fluorescent tube 24
Receives high-frequency current from the inverter 26 and emits fluorescence. The emitted light is directed in a predetermined direction by the reflection plate 25, and reaches the liquid crystal panel 21 as a uniform light beam by the diffusion plate 23. Here, in order to prevent interference fringes between the video signal of the liquid crystal panel 21 and the high frequency of the inverter 26, the transparent conductive sheet 22 connected to the ground potential is inserted between the liquid crystal panel 21 and the fluorescent tube 24. There is.
【0005】[0005]
【発明が解決しようとする課題】しかしながら上記の従
来の構成では、蛍光管24を高周波点灯させるためのイ
ンバータ26がコストや効率のために自励式発振器とな
っており、この発振周波数が、周囲温度の変動や電源電
圧の変動により緩やかに変動するため、映像信号等と干
渉を起こし、液晶パネル21の画面上でビート妨害とし
て干渉縞があらわれるという問題点を有していた。従来
は、この問題を解決するために、液晶パネル21と蛍光
管24の間にITO等の透明導電シート22を挿入して
対策していたが、パネルの大版化に伴いこの透明導電シ
ートのコストが高くなるという問題点を有していた。However, in the above conventional structure, the inverter 26 for lighting the fluorescent tube 24 at a high frequency is a self-excited oscillator for cost and efficiency, and the oscillation frequency is the ambient temperature. However, there is a problem in that interference fringes appear as beat interference on the screen of the liquid crystal panel 21 due to interference with video signals and the like because the fluctuations occur gradually due to fluctuations in the power supply voltage and power supply voltage. Conventionally, in order to solve this problem, a transparent conductive sheet 22 made of ITO or the like is inserted between the liquid crystal panel 21 and the fluorescent tube 24, and countermeasures are taken. It has a problem that the cost becomes high.
【0006】本発明は、上記従来の問題点を解決するも
ので、透明導電性シートを使用せずにビート妨害のない
パネルを提供することを目的とする。The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a panel without beat interference without using a transparent conductive sheet.
【0007】[0007]
【課題を解決するための手段】この目的を達成するため
に本発明の液晶表示装置用照明装置は、入力映像信号パ
ネルの照明手段である蛍光管の駆動用インバータの発振
周波数を同期させたものでる。In order to achieve this object, a lighting device for a liquid crystal display device according to the present invention is one in which the oscillating frequency of an inverter for driving a fluorescent tube which is a lighting means of an input video signal panel is synchronized. Out.
【0008】[0008]
【作用】この構成によって、ビート妨害のない液晶表示
装置用照明装置を提供することができる。With this configuration, it is possible to provide a lighting device for a liquid crystal display device without beat interference.
【0009】[0009]
【実施例】以下本発明の一実施例について、図面を参照
しながら説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
【0010】図1において、11は液晶パネルモジュー
ル、12は分周回路、13は蛍光管駆動インバータ回路
である。In FIG. 1, 11 is a liquid crystal panel module, 12 is a frequency dividing circuit, and 13 is a fluorescent tube drive inverter circuit.
【0011】以上のように構成された液晶表示装置用照
明装置について、図1を用いてその動作を説明する。ま
ず、液晶モジュール11より映像信号のクロック信号を
取り出し分周回路12に接続する。分周回路12は、カ
ウンター等を使用した公知の回路で、例えば、クロック
周波数:fo=20MHz、分周比N:500とするとイ
ンバータ13の発振周波数は40kHzとなり、映像信号
と同期するのでビート妨害の原因となる蛍光管騒動イン
バータ回路13の発振周波数の緩やかな変動は見られな
い。The operation of the illuminating device for liquid crystal display device constructed as described above will be described with reference to FIG. First, the clock signal of the video signal is taken out from the liquid crystal module 11 and connected to the frequency dividing circuit 12. The frequency dividing circuit 12 is a known circuit using a counter or the like. For example, assuming that the clock frequency is fo = 20 MHz and the frequency dividing ratio is N: 500, the oscillation frequency of the inverter 13 is 40 kHz, which is in synchronization with the video signal, thus causing beat interference. There is no gradual change in the oscillation frequency of the fluorescent tube disturbance inverter circuit 13 that causes the above.
【0012】以上のように本実施例によれば、分周回路
12を設けて、蛍光管駆動インバータ回路13の発振周
波数を映像信号のクロック信号と同期させることによ
り、ビート妨害をなくすことができる。As described above, according to this embodiment, by providing the frequency dividing circuit 12 and synchronizing the oscillation frequency of the fluorescent tube driving inverter circuit 13 with the clock signal of the video signal, beat interference can be eliminated. .
【0013】なお、本実施例において分周する基になる
信号をクロック信号としたが、水平同期信号、あるいは
垂直同期信号としてもよいことは言うまでもない。In this embodiment, the signal on which frequency division is based is the clock signal, but it goes without saying that it may be a horizontal synchronizing signal or a vertical synchronizing signal.
【0014】[0014]
【発明の効果】以上のように本発明は、映像信号と同期
したインバータ回路を設けることにより、透明導電性シ
ートを使用せずにビート対策をすることができる優れた
液晶表示装置用照明装置を実現できるものである。As described above, according to the present invention, by providing an inverter circuit synchronized with a video signal, an excellent illuminating device for a liquid crystal display device capable of taking beat countermeasures without using a transparent conductive sheet. It can be realized.
【図1】本発明の一実施例の液晶表示装置用照明装置の
概念図FIG. 1 is a conceptual diagram of a lighting device for a liquid crystal display device according to an embodiment of the present invention.
【図2】従来の液晶表示装置用照明装置の分解斜視図FIG. 2 is an exploded perspective view of a conventional lighting device for a liquid crystal display device.
11 液晶パネルモジュール(クロック周波数:fo) 12 分周回路(分周比:1/N) 13 蛍光管駆動インバータ回路 11 liquid crystal panel module (clock frequency: fo) 12 frequency dividing circuit (frequency dividing ratio: 1 / N) 13 fluorescent tube drive inverter circuit
Claims (1)
バータの発振周波数を、入力映像信号と同期させたこと
を特徴とする液晶表示装置用照明装置。1. A lighting device for a liquid crystal display device, wherein an oscillation frequency of an inverter for driving a lighting means of the liquid crystal display device is synchronized with an input video signal.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4318218A JPH06160804A (en) | 1992-11-27 | 1992-11-27 | Illuminating device for liquid crystal display device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4318218A JPH06160804A (en) | 1992-11-27 | 1992-11-27 | Illuminating device for liquid crystal display device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06160804A true JPH06160804A (en) | 1994-06-07 |
Family
ID=18096754
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4318218A Pending JPH06160804A (en) | 1992-11-27 | 1992-11-27 | Illuminating device for liquid crystal display device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06160804A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004326091A (en) * | 2003-04-21 | 2004-11-18 | Samsung Electronics Co Ltd | Liquid crystal display and its driving method |
KR20190031487A (en) | 2016-07-29 | 2019-03-26 | 다이니폰 인사츠 가부시키가이샤 | A method of supplying a light adjusting film, a light control member, a vehicle, and a light adjusting film |
-
1992
- 1992-11-27 JP JP4318218A patent/JPH06160804A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004326091A (en) * | 2003-04-21 | 2004-11-18 | Samsung Electronics Co Ltd | Liquid crystal display and its driving method |
KR20190031487A (en) | 2016-07-29 | 2019-03-26 | 다이니폰 인사츠 가부시키가이샤 | A method of supplying a light adjusting film, a light control member, a vehicle, and a light adjusting film |
EP3822699A1 (en) | 2016-07-29 | 2021-05-19 | Dai Nippon Printing Co., Ltd. | Vehicle with light control film attached to its sunroof |
KR20220070346A (en) | 2016-07-29 | 2022-05-30 | 다이니폰 인사츠 가부시키가이샤 | Light control film, light control member, vehicle, and electricity supply method for light control film |
US11541731B2 (en) | 2016-07-29 | 2023-01-03 | Dai Nippon Printing Co., Ltd. | Light control film, light control member, vehicle, and electricity supply method for light control film |
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