JPH02230129A - Reflection type liquid crystal display device - Google Patents
Reflection type liquid crystal display deviceInfo
- Publication number
- JPH02230129A JPH02230129A JP1050430A JP5043089A JPH02230129A JP H02230129 A JPH02230129 A JP H02230129A JP 1050430 A JP1050430 A JP 1050430A JP 5043089 A JP5043089 A JP 5043089A JP H02230129 A JPH02230129 A JP H02230129A
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- display device
- crystal display
- electrode
- reflective
- 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
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 31
- 239000010409 thin film Substances 0.000 claims abstract description 5
- 239000000758 substrate Substances 0.000 claims description 13
- 239000003990 capacitor Substances 0.000 claims 1
- 239000011159 matrix material Substances 0.000 claims 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 4
- 229910021417 amorphous silicon Inorganic materials 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Landscapes
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Liquid Crystal (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、プロジエクション表示デハイスに利用するア
クティブ素子を有した反射型液晶表示デバイスに関する
ものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reflective liquid crystal display device having an active element used in a projection display device.
従来の技術
近年、アクティブ素子を利用した液晶表示デバイスはポ
ケットテレビまたは情報端末として利用されるようにな
ってきた。2. Description of the Related Art In recent years, liquid crystal display devices using active elements have come to be used as pocket televisions or information terminals.
以下に従来の反射型液晶表示デバイスについて説明する
。A conventional reflective liquid crystal display device will be explained below.
第３図は従来の反射型液晶表示デバイスの断面図であり
、第４図は薄膜トランジスタ（以下、ＴＰＴ）の具備さ
れた基板の平面図である。ｌは絶縁基板、２はソース電
極、３はゲート電極、４は半導体部、５はドレイン電極
、６はゲート絶縁層、７は絶縁体層、８は反射画素電極
、９は液晶層、１０は対向共通電極、１ｌは対向透明基
板である。FIG. 3 is a sectional view of a conventional reflective liquid crystal display device, and FIG. 4 is a plan view of a substrate provided with a thin film transistor (hereinafter referred to as TPT). l is an insulating substrate, 2 is a source electrode, 3 is a gate electrode, 4 is a semiconductor section, 5 is a drain electrode, 6 is a gate insulating layer, 7 is an insulator layer, 8 is a reflective pixel electrode, 9 is a liquid crystal layer, 10 is The opposing common electrode, 1l, is an opposing transparent substrate.
以上のように構成された反射型液晶表示デバイスについ
て、以下その動作について説明する。The operation of the reflective liquid crystal display device configured as described above will be described below.
ゲート電極３に電圧が印加されトランジスタがオン状態
になるとソース電極２の信号電流がドレイン電極５に流
れ、反射画素電極９へと流れる。When a voltage is applied to the gate electrode 3 and the transistor is turned on, the signal current of the source electrode 2 flows to the drain electrode 5 and then to the reflective pixel electrode 9.
これにより、反射画素電極９上部に設けられた液晶を駆
動させて光をスイッチングし、画素間でコントラストを
取ることによって画像を得る。通常、一つの画素に信号
が書き込まれる時間は非常に短《、現行のテレビ放送（
例えば、ＮＴＳＣ方式）の場合、約６０分の１秒間であ
るのに対し、それ以外の時間は、ゲート電極には無印加
またはオン状態とは逆の極性の電圧が印加され、トラン
ジスタがオフ状態にある。こうして次にゲート電極が選
択され、新たにソース信号が書き込まれるまで、液晶に
加わった電圧を保持する。This drives the liquid crystal provided above the reflective pixel electrode 9 to switch light and obtain an image by taking contrast between pixels. Normally, the time for a signal to be written to one pixel is very short (current TV broadcasting (
For example, in the case of the NTSC system, this is about 1/60th of a second, whereas for the rest of the time, no voltage is applied to the gate electrode or a voltage of the opposite polarity to that in the on state is applied, and the transistor is in the off state. It is in. In this way, the voltage applied to the liquid crystal is held until the next gate electrode is selected and a new source signal is written.
発明が解決しようとする課題
しかしながら上記のようにＴＰＴのソース電極部分が反
射画素電極に重なっている構成では、ＴＰＴがオフ状態
の時、ソース電極と反射画素電極との間に容量が発生し
、ソースにかかる電位が変化すると液晶に加わっていた
電圧が変化する。（第５図）これによって、液晶ムこ印
加された電圧の保持が出来なくなる。これは、画像の輝
度むらおよびコントラストの低下をきたすという欠点を
有していた。Problems to be Solved by the Invention However, in the configuration in which the source electrode portion of the TPT overlaps the reflective pixel electrode as described above, when the TPT is in the off state, capacitance is generated between the source electrode and the reflective pixel electrode. When the potential applied to the source changes, the voltage applied to the liquid crystal changes. (FIG. 5) As a result, the voltage applied to the liquid crystal cannot be maintained. This has the disadvantage of causing uneven brightness and reduced contrast of the image.
本発明は上記の問題点を解決するものでディスプレイ画
面の輝度むらおよびコントラストの低下を解消すること
のできる反射型液晶表示デバイスを提供することを目的
とする。The present invention solves the above-mentioned problems and aims to provide a reflective liquid crystal display device that can eliminate uneven brightness and decrease in contrast of a display screen.
課題を解決するための手段
この目的を解決するために本発明の反射型液晶表示デバ
イスは、ＴＰＴを構成しているソース電極を反射画素電
極に重ならないよう反射画素電極の外側に形成した構成
となっている。Means for Solving the Problem In order to solve this object, the reflective liquid crystal display device of the present invention has a structure in which the source electrode constituting the TPT is formed outside the reflective pixel electrode so as not to overlap with the reflective pixel electrode. It has become.
作用
この構成によって、ＴＰＴがオフ状態の時にソース電極
と反射画素電極間に発生ずる容量を軽減することができ
、ソース電極の電位が変化しても画素に加わった電位の
変化が少なく、表示における輝度むらまたはコントラス
トの低下を押えることができる。Effect: With this configuration, it is possible to reduce the capacitance that occurs between the source electrode and the reflective pixel electrode when the TPT is in the off state, and even if the potential of the source electrode changes, there is little change in the potential applied to the pixel, which improves display performance. It is possible to suppress uneven brightness or decrease in contrast.
実施例
以下本発明の一実施例の反射型液晶表示デバイスについ
て、図面を参照しながら説明する。EXAMPLE Hereinafter, a reflective liquid crystal display device according to an example of the present invention will be described with reference to the drawings.
第１図は本発明の一実施例における反射型液晶表示デバ
イスの断面図であり、第２図は本発明の一実施例におけ
る反射型液晶表示デバイスのＴＰＴが具備された基板の
平面構造を示すものである。FIG. 1 is a cross-sectional view of a reflective liquid crystal display device according to an embodiment of the present invention, and FIG. 2 shows a planar structure of a substrate provided with TPT of a reflective liquid crystal display device according to an embodiment of the present invention. It is something.
２Ｉは絶縁基板としてガラス基板、２２はソース電極、
２３はゲート電極、２４は半導体部として非品質珪素、
２５はドレインｔ極、２６はゲート絶縁層として非晶質
窒化珪素層、２７は絶縁体層として非品質窒化珪素、２
８は反射画素電極、２９は液晶、３０は酸化インジウム
・スズ（ＩＴＯ）、３１はガラス基板である。2I is a glass substrate as an insulating substrate, 22 is a source electrode,
23 is a gate electrode, 24 is non-quality silicon as a semiconductor part,
25 is a drain t pole, 26 is an amorphous silicon nitride layer as a gate insulating layer, 27 is a non-quality silicon nitride layer as an insulator layer, 2
8 is a reflective pixel electrode, 29 is a liquid crystal, 30 is indium tin oxide (ITO), and 31 is a glass substrate.
以上のように構成された反射型液晶表示デバイスについ
て、その動作は従来例の動作と同様である。The operation of the reflective liquid crystal display device configured as described above is similar to that of the conventional example.
以上のように本実施例によれば、ＴＰＴを構成している
ソース電極が反射画素電極１８と重なっていないために
、ＴＰＴがオフ状態の時にソース電極と反射画素電極間
に発生する容量を軽減することができ、ソース電極の電
位が変化しても画素に加わった電位の変化が少なく、表
示における輝度むらまたはコントラストの低下を抑える
ことができる。As described above, according to this embodiment, since the source electrode constituting the TPT does not overlap with the reflective pixel electrode 18, the capacitance generated between the source electrode and the reflective pixel electrode when the TPT is in the off state is reduced. Therefore, even if the potential of the source electrode changes, the potential applied to the pixel does not change much, and it is possible to suppress uneven brightness or decrease in contrast in display.
発明の効果
以上のように本発明は反射型液晶表示デバイスにおいて
、薄膜トランジスタを構成しているソース電掻を反射画
素電極と重ならないように反射画素電極間の外側に位置
するような構成にすることにより、ＴＰＴがオフ状態の
時にソース電掻と反射画素電極間に発生する容量を軽減
することができ、ソース電極の電位が変化しても画素に
加わった電位の変化が少なく、すなわち、液晶に加わる
電位が保持され、ディスプレイ表示における輝度むらま
たはコントラストの低下を抑えることができる反射型液
晶表示デバイスを実現できるものである。Effects of the Invention As described above, the present invention provides a reflective liquid crystal display device in which the source electrode constituting the thin film transistor is located outside between the reflective pixel electrodes so as not to overlap with the reflective pixel electrodes. This makes it possible to reduce the capacitance generated between the source electrode and the reflective pixel electrode when the TPT is off, and even if the potential of the source electrode changes, there is little change in the potential applied to the pixel. It is possible to realize a reflective liquid crystal display device in which the applied potential is maintained and uneven brightness or deterioration in contrast in display can be suppressed.
第１図は本発明の一実施例における反射型液晶表示デバ
イスの断面図、第２図は一実施例における反射型液晶表
示デバイスＴＰＴの具備されている基板の平面図、第３
図は従来の反射型液晶表示デバイスの断面図、第４図は
従来の反射型液晶表示デバイスのＴＰＴが具備されてい
る基板の平面図、第５図は従来の反射型液晶表示デバイ
スにおける等価回路図である。
２１・・・・・・ガラス基板、２２・・・・・・ソース
電極、２３・・・・・・ゲート電極、２４・・・・・・
非晶質珪素、２５・・・・・・ドレイン電極、２６・・
・・・・非品質窒化珪素層、２７・・・・・・非晶質窒
化珪素、２８・・・・・・反射画素電極。
代理人の氏名 弁理士 粟野重孝 はか１名図
ど１．３Ｉ
一ガラス基孜
３０−ＺＴｏ
／−−一絶揉１Ｌ抜
１／ −一一肘間透腑１款
第
図
第
図FIG. 1 is a cross-sectional view of a reflective liquid crystal display device according to an embodiment of the present invention, FIG. 2 is a plan view of a substrate provided with a reflective liquid crystal display device TPT according to an embodiment, and FIG.
The figure is a cross-sectional view of a conventional reflective liquid crystal display device, FIG. 4 is a plan view of a substrate equipped with a TPT of a conventional reflective liquid crystal display device, and FIG. 5 is an equivalent circuit in a conventional reflective liquid crystal display device. It is a diagram. 21...Glass substrate, 22...Source electrode, 23...Gate electrode, 24...
Amorphous silicon, 25...Drain electrode, 26...
. . . Non-quality silicon nitride layer, 27 . . . Amorphous silicon nitride, 28 . . . Reflective pixel electrode. Name of agent Patent attorney Shigetaka Awano Haka 1 figure 1.3I Ichigarasu Motoki 30-ZTo /--Ittetsumasu 1L removal 1/-11 Hijima Tokan 1 clause Figure 1
Claims (3)
れている反射画素電極群と、前記画素電極に信号を供給
するための逆スタッガー型薄膜トランジスタからなるス
イッチング素子群とを具備した基板と、液晶を介して一
定の間隔を有して前記基板と対向し、共通電極を有して
いる基板とで構成されており、前記薄膜トランジスタを
構成しているソース電極部分が反射画素電極と重ならな
いような構成としたことを特徴とする反射型液晶表示デ
バイス。(1) A substrate comprising a group of reflective pixel electrodes arranged in a matrix for displaying liquid crystal, a group of switching elements consisting of inverted staggered thin film transistors for supplying signals to the pixel electrodes, and and a substrate having a common electrode, which faces the substrate with a certain distance therebetween, and has a configuration in which the source electrode portion forming the thin film transistor does not overlap with the reflective pixel electrode. A reflective liquid crystal display device characterized by:
ことを特徴とする請求項（１）記載の反射型液晶表示デ
バイス。(2) The reflective liquid crystal display device according to claim (1), wherein a plurality of switching elements are formed in each pixel.
れていることを特徴とする請求項（１）記載の反射型液
晶表示デバイス。(3) The reflective liquid crystal display device according to claim (1), wherein an auxiliary capacitor is formed in each display pixel of the reflective pixel electrode group.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1050430A JPH02230129A (en) | 1989-03-02 | 1989-03-02 | Reflection type liquid crystal display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1050430A JPH02230129A (en) | 1989-03-02 | 1989-03-02 | Reflection type liquid crystal display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02230129A true JPH02230129A (en) | 1990-09-12 |
Family
ID=12858653
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1050430A Pending JPH02230129A (en) | 1989-03-02 | 1989-03-02 | Reflection type liquid crystal display device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02230129A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008083731A (en) * | 2000-01-26 | 2008-04-10 | Semiconductor Energy Lab Co Ltd | Semiconductor device |
| US8017456B2 (en) | 2000-01-26 | 2011-09-13 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and manufacturing method thereof |
-
1989
- 1989-03-02 JP JP1050430A patent/JPH02230129A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008083731A (en) * | 2000-01-26 | 2008-04-10 | Semiconductor Energy Lab Co Ltd | Semiconductor device |
| US8017456B2 (en) | 2000-01-26 | 2011-09-13 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and manufacturing method thereof |
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