JPH02207221A - Liquid crystal display device - Google Patents

Liquid crystal display device

Info

Publication number
JPH02207221A
JPH02207221A JP1027915A JP2791589A JPH02207221A JP H02207221 A JPH02207221 A JP H02207221A JP 1027915 A JP1027915 A JP 1027915A JP 2791589 A JP2791589 A JP 2791589A JP H02207221 A JPH02207221 A JP H02207221A
Authority
JP
Japan
Prior art keywords
liquid crystal
crystal display
fluorescent lamps
display device
heater
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
Application number
JP1027915A
Other languages
Japanese (ja)
Inventor
Munetatsu Imamura
今村 宗立
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP1027915A priority Critical patent/JPH02207221A/en
Publication of JPH02207221A publication Critical patent/JPH02207221A/en
Pending legal-status Critical Current

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  • Liquid Crystal (AREA)

Abstract

PURPOSE:To obtain the highly reliable liquid crystal display device which is securely started and reaches target brightness speedily by incorporating a heater which heats fluorescent lamps and heating the fluorescent lamps at the start. CONSTITUTION:The heater 11 which heats the fluorescent lamps 2 is provided. In, for example, a low-temperature state, the inside and outside are almost at the same low temperature, so a start control circuit 12 starts the heater 11 and also drives an internal fan 4 to heat the fluorescent lamp 2 and stabilizers 3 and the fluorescent lamps 2 are turned on a constant warm-up time later. The fluorescent lamps 2 and stabilizers 3 are preheated and warmed up, so all the fluorescent lamps turn on at this point of time and never turn off. Consequently, the fluorescent lamps can easily be started even at low temperature and the target brightness can be obtained earlier than at the normal startup.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、液晶表示素子を多数配置して大画面を構成し
、バックライトとして蛍光灯を備えた液晶表示装置に関
するものである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device that has a large screen formed by arranging a large number of liquid crystal display elements and is equipped with a fluorescent lamp as a backlight.

〔従来の技術〕[Conventional technology]

第4図は従来の液晶表示装置を示す一部の断面図である
。図において、 (1)は液晶表示素子であり、多数連
結されて大画面を構成している。(2)はその光源(バ
ックライト)として各液晶表示素子(1)の背後に配置
された蛍光灯、(3)は蛍光灯(2)を点灯させるため
の安定器、(4)は給気ダクト(5)から蛍光灯(2)
に冷却用空気を送り、排気ダクト(6)およびリターン
ダクト(7)を通して循環させる内部ファン、(8)は
排気ダクh(6)の空気を冷却するためのヒートパイプ
、(9)はヒートパイプ(8)の放熱部を冷却する外部
ファンである。
FIG. 4 is a cross-sectional view of a part of a conventional liquid crystal display device. In the figure, (1) is a liquid crystal display element, which is connected in large numbers to form a large screen. (2) is a fluorescent lamp placed behind each liquid crystal display element (1) as its light source (backlight), (3) is a ballast for lighting the fluorescent lamp (2), and (4) is an air supply. Fluorescent light (2) from duct (5)
(8) is a heat pipe for cooling the air in the exhaust duct h (6), (9) is a heat pipe (8) This is an external fan that cools the heat radiation section.

次に動作について説明する。第4図において、液晶表示
素子(1)は自己発光型の素子ではないので、高い輝度
を得るためにはバックライトが必要であり、蛍光灯(2
)を光源として使用している。
Next, the operation will be explained. In Figure 4, since the liquid crystal display element (1) is not a self-luminous element, a backlight is required to obtain high brightness, and a fluorescent lamp (2) is required to obtain high brightness.
) is used as a light source.

上記液晶表示装置を駆動するには、安定器(3)により
蛍光灯(2)を始動点灯して蛍光灯(2)の輝度を一定
にしたままで、液晶制御回路(図示せず)により液晶表
示素子(1)に印加する電圧またはパルス幅を制御する
ことによって、所定の位置の液晶表示素子(1)の透過
率を変化させ、必要な画像を得ることができる。この液
晶表示装置は防塵のため、内気と外気の熱は交換するが
、直接空気の出入はないように構成されている。従って
蛍光灯(2)で発生した熱は、内部ファン(4)によっ
て循環する空気に吸収されてピー1〜パイプ(8)に送
られ、外部ファン(9)によって送られる外気(冷気)
と熱交換を行う。各構成要素(1)〜(9)の始動時の
シーケンスは第5図の始動フロー図に示す通りであり、
はぼ同時に各要素が始動する。
To drive the liquid crystal display device, the ballast (3) starts and lights up the fluorescent lamp (2), and while the brightness of the fluorescent lamp (2) remains constant, the liquid crystal control circuit (not shown) controls the liquid crystal display. By controlling the voltage or pulse width applied to the display element (1), the transmittance of the liquid crystal display element (1) at a predetermined position can be changed to obtain a desired image. To prevent dust, this liquid crystal display device is configured so that heat is exchanged between inside air and outside air, but air does not directly enter or exit. Therefore, the heat generated by the fluorescent lamp (2) is absorbed by the air circulating by the internal fan (4) and sent to the pipes (8), and the outside air (cool air) is sent by the external fan (9).
and performs heat exchange. The starting sequence of each component (1) to (9) is as shown in the starting flow diagram in FIG.
Each element starts at almost the same time.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

従来の液晶表示装置は以上のように構成され、各要素が
ほぼ同時に始動するようになっているので、低温時には
液晶表示装置内の蛍光灯(2)が始動しにくく、全体が
同時に点灯しないため、例えば一部の蛍光灯(2)が点
灯しないまま画面を表示した場合、蛍光灯(2)がつい
ていない部分だけ、画像が見えないという問題点があっ
た。
Conventional liquid crystal display devices are constructed as described above, and each element starts almost at the same time. Therefore, at low temperatures, the fluorescent lamps (2) inside the liquid crystal display device are difficult to start, and the entire device does not light up at the same time. For example, if a screen is displayed with some of the fluorescent lights (2) not lit, there is a problem in that the image cannot be seen only in the portion where the fluorescent lights (2) are not lit.

また第6図に示す時間対輝度(白色面平均輝度)の特性
曲線から明らかなように、目標輝度に達するまでの時間
が長いという問題点があった。
Further, as is clear from the characteristic curve of luminance versus time (white surface average luminance) shown in FIG. 6, there is a problem in that it takes a long time to reach the target luminance.

この発明は上記のような問題点を解消するためになされ
たもので、低温時でも蛍光灯の始動を容易にできるとと
もに、通常の立上り時よりも早く目的の輝度を得ること
ができる液晶表示装置を得ることを目的とする。
This invention was made to solve the above-mentioned problems, and provides a liquid crystal display device that can easily start a fluorescent lamp even at low temperatures and can achieve the desired brightness earlier than the normal startup time. The purpose is to obtain.

〔課題を解決するための手段〕[Means to solve the problem]

この発明に係る液晶表示装置は、内部にヒーターを配置
し、蛍光灯、ファン等の始動時間にシーケンスをもたせ
たものである。
The liquid crystal display device according to the present invention has a heater arranged inside and has a sequence for starting times of fluorescent lamps, fans, etc.

すなわち本発明は、液晶表示素子を多数連結して大画面
を構成し、バックライトとして蛍光灯を備えた液晶表示
装置において、前記蛍光灯を加熱するヒーターを設け、
蛍光灯の始動時に加熱できるようにした液晶表示装置で
ある。
That is, the present invention provides a liquid crystal display device in which a large screen is constructed by connecting a large number of liquid crystal display elements and is provided with a fluorescent lamp as a backlight, and a heater for heating the fluorescent lamp is provided.
This is a liquid crystal display device that can be heated when starting a fluorescent lamp.

〔作 用〕[For production]

この発明の液晶表示装置においては、低温時の始動の際
、ヒーターによりあらかじめ蛍光灯および安定器を加熱
して点灯を容易にし、これによりすべての蛍光灯を始動
と同時に点灯して、液晶表示装置の全面に画像を表示さ
せることができる。
In the liquid crystal display device of the present invention, when starting at a low temperature, the fluorescent lamps and ballast are heated in advance using a heater to facilitate lighting, so that all the fluorescent lamps are turned on at the same time as starting, and the liquid crystal display device An image can be displayed on the entire surface of the screen.

また、ヒーターによって加熱することにより、目標輝度
に達するまでの時間が短縮される。
Furthermore, by heating with a heater, the time required to reach the target brightness is shortened.

〔実施例〕〔Example〕

以下、この発明の一実施例を図について説明する。第1
図は実施例の液晶表示装置を示す一部の断面図、第2図
はその始動フロー図、第3図は時間対輝度の特性図であ
る。第1図において、 (1)〜(9)は第4図と同一
または相当部分を示す。(11)は給気ダクト(5)に
設けられた蛍光灯(2)加熱用のヒーター、(12)は
始動制御回路である。
An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a cross-sectional view of a portion of the liquid crystal display device of the embodiment, FIG. 2 is a startup flow diagram thereof, and FIG. 3 is a characteristic diagram of luminance versus time. In FIG. 1, (1) to (9) indicate the same or equivalent parts as in FIG. 4. (11) is a heater for heating the fluorescent lamp (2) provided in the air supply duct (5), and (12) is a starting control circuit.

第1図に示した各要素の始動シーケンスを第2図により
説明する。
The starting sequence of each element shown in FIG. 1 will be explained with reference to FIG. 2.

低温時には、内部も外部もほぼ同じ温度の低温であるの
で、始動制御回路(12)によりヒーター(11)を始
動するとともに、内部ファン(4)を駆動させ、蛍光灯
(2)および安定器(3)を加熱する。
When the temperature is low, the temperature inside and outside is almost the same, so the starting control circuit (12) starts the heater (11), drives the internal fan (4), and turns on the fluorescent lamp (2) and the ballast ( 3) Heat.

定の暖気時間経過後、蛍光灯(2)を点灯させる。After the specified warm-up time has elapsed, the fluorescent lamp (2) is turned on.

蛍光灯(2)および安定器(3)はあらかじめ加熱して
暖めであるので、この時点で蛍光灯(2)は全て点灯し
、不点灯にはならない。その後、ヒーター(11)を停
止して外部ファン(9)を動作させ、液晶制御回路も動
作させることにより、全体の液晶表示素子(1)に画像
が得られる。
Since the fluorescent lamps (2) and the ballast (3) have been heated in advance to keep them warm, all the fluorescent lamps (2) are turned on at this point and do not turn off. Thereafter, by stopping the heater (11), operating the external fan (9), and operating the liquid crystal control circuit, an image can be obtained on the entire liquid crystal display element (1).

このときの時間対輝度の特性曲線は第3図のよ=4 うになり、低温時の始動特性が改善される上、目標輝度
に達する時間が短縮される。
At this time, the time versus brightness characteristic curve becomes 4 as shown in FIG. 3, and the starting characteristics at low temperatures are improved and the time required to reach the target brightness is shortened.

なお、上記実施例では、一定の暖気時間をあらかじめ決
めておいたが、外部に温度センサーを取りつけることに
より暖気時間を可変にし、幅広い温度変化に対応できる
In the above embodiment, a fixed warm-up time is determined in advance, but by attaching a temperature sensor to the outside, the warm-up time can be made variable to accommodate a wide range of temperature changes.

また、これと同様な考え方で、内部ファンと外部ファン
の回転数を変化させることによって熱交換の効率を変化
させ、目標輝度を可変とすることも可能となる。
Further, based on a similar idea, it is also possible to change the efficiency of heat exchange by changing the rotational speed of the internal fan and the external fan, thereby making it possible to make the target brightness variable.

〔発明の効果〕〔Effect of the invention〕

以上のように、この発明によれば、蛍光灯を加熱するヒ
ーターを内蔵し、始動時に加熱できるようにしたので、
始動が確実で、速く目標輝度まで達する高い信頼度の液
晶表示装置を得られるという効果がある。
As described above, according to the present invention, the heater for heating the fluorescent lamp is built-in and can be heated at the time of startup.
This has the effect of providing a highly reliable liquid crystal display device that starts reliably and quickly reaches the target brightness.

【図面の簡単な説明】[Brief explanation of the drawing]

第1−図はこの発明の一実施例による液晶表示装置を示
す一部の断面図、第2図はその始動フロー図、第3図は
時間対輝度の特性図、第4図は従来の液晶表示装置を示
す一部の断面図、第5図はその始動フロー図、第6図は
時間対輝度の特性図である。 各図中、同一符号は同一または相当部分を示し、(1)
は液晶表示素子、(2)は蛍光灯、(3)は安定器、(
4)は内部ファン、(8)はヒートパイプ、 (9)は
外部ファン、(11)はヒーター、(12)は始動制御
回路である。
Fig. 1 is a cross-sectional view of a portion of a liquid crystal display device according to an embodiment of the present invention, Fig. 2 is a startup flow diagram thereof, Fig. 3 is a characteristic diagram of luminance versus time, and Fig. 4 is a conventional liquid crystal display device. FIG. 5 is a sectional view of a part of the display device, FIG. 5 is a startup flow diagram thereof, and FIG. 6 is a characteristic diagram of luminance versus time. In each figure, the same reference numerals indicate the same or corresponding parts, (1)
is a liquid crystal display element, (2) is a fluorescent lamp, (3) is a ballast, (
4) is an internal fan, (8) is a heat pipe, (9) is an external fan, (11) is a heater, and (12) is a starting control circuit.

Claims (1)

【特許請求の範囲】[Claims] (1)液晶表示素子を多数連結して大画面を構成し、バ
ックライトとして蛍光灯を備えた液晶表示装置において
、前記蛍光灯を加熱するヒーターを設け、蛍光灯の始動
時に加熱できるようにしたことを特徴とする液晶表示装
置。
(1) In a liquid crystal display device in which a large screen is constructed by connecting a large number of liquid crystal display elements and is equipped with a fluorescent lamp as a backlight, a heater is provided to heat the fluorescent lamp so that it can be heated when the fluorescent lamp is started. A liquid crystal display device characterized by:
JP1027915A 1989-02-07 1989-02-07 Liquid crystal display device Pending JPH02207221A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1027915A JPH02207221A (en) 1989-02-07 1989-02-07 Liquid crystal display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1027915A JPH02207221A (en) 1989-02-07 1989-02-07 Liquid crystal display device

Publications (1)

Publication Number Publication Date
JPH02207221A true JPH02207221A (en) 1990-08-16

Family

ID=12234179

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1027915A Pending JPH02207221A (en) 1989-02-07 1989-02-07 Liquid crystal display device

Country Status (1)

Country Link
JP (1) JPH02207221A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6352356B1 (en) 1998-10-26 2002-03-05 Mannesmann Vdo Ag Illuminating device for a display

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6352356B1 (en) 1998-10-26 2002-03-05 Mannesmann Vdo Ag Illuminating device for a display

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