JPH0829801A - Reflection type liquid crystal projector - Google Patents

Reflection type liquid crystal projector

Info

Publication number
JPH0829801A
JPH0829801A JP16097994A JP16097994A JPH0829801A JP H0829801 A JPH0829801 A JP H0829801A JP 16097994 A JP16097994 A JP 16097994A JP 16097994 A JP16097994 A JP 16097994A JP H0829801 A JPH0829801 A JP H0829801A
Authority
JP
Japan
Prior art keywords
liquid crystal
light
display device
crystal display
writing
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.)
Granted
Application number
JP16097994A
Other languages
Japanese (ja)
Other versions
JP3071999B2 (en
Inventor
Noboru Yamaguchi
登 山口
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.)
Sharp Corp
Original Assignee
Sharp 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 Sharp Corp filed Critical Sharp Corp
Priority to JP6160979A priority Critical patent/JP3071999B2/en
Publication of JPH0829801A publication Critical patent/JPH0829801A/en
Application granted granted Critical
Publication of JP3071999B2 publication Critical patent/JP3071999B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PURPOSE:To correct the measure to the unequal gradation arising from the nonuniformity in the input and output characteristics of an optical writing type spatial optical modulator which arises without fail in reflection type liquid crystal projector with which supplying of reading out light with perfect parallel light beams is possible by changing the use voltage range (white and black voltages) of a liquid crystal display device. CONSTITUTION:Linear input video waveforms are inputted to the video signals of a liquid crystal writing device 11 composed of the liquid crystal display device 7, a liquid crystal display device driving circuit 8 and the video signals by a video signal generating section 9 as an input writing means to the optical writing type spatial optical modulator 10. After the use voltage range of the liquid crystal display device 7 is set, correction is executed in the liquid crystal display device driving circuit 8 in such a manner that the output video waveforms of the final stage via the voltage-transmittance characteristic possessed by the liquid crystal display device 7 attains linear characteristic waveforms.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、反射型液晶プロジェク
ターに関し、より詳細には、書き込み光によってインピ
ーダンスが変化する光導電体と、該光導電体のインピー
ダンス変化によりねじれ構造が変化して、読み出し光の
偏光状態を変化させるねじれネマティック液晶とを有す
る光書き込み型空間光変調素子を備え、書き込み光の情
報を読み出し光によって表示する液晶プロジェクターに
関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal projector, and more particularly to a photoconductor whose impedance is changed by writing light, and a twisted structure is changed by the impedance change of the photoconductor to read out. The present invention relates to a liquid crystal projector that includes an optical writing type spatial light modulator having a twisted nematic liquid crystal that changes a polarization state of light and that displays information of writing light by reading light.

【0002】[0002]

【従来の技術】図4は、従来の液晶プロジェクターの構
成図で、図中、21a,21bはガラス基板、22a,
22bは透明電極、23は光導電体層、24は遮光層、
25は反射ミラー層、26は液晶層、27は液晶表示装
置、28は液晶表示装置駆動回路、29は映像信号発生
部、30は光書き込み型空間光変調器、31は液晶書き
込み装置、32は入力光、33は書き込み情報、34は
読み出し光、35は出力情報である。
2. Description of the Related Art FIG. 4 is a block diagram of a conventional liquid crystal projector. In the figure, 21a and 21b are glass substrates, 22a and 22a.
22b is a transparent electrode, 23 is a photoconductor layer, 24 is a light shielding layer,
Reference numeral 25 is a reflection mirror layer, 26 is a liquid crystal layer, 27 is a liquid crystal display device, 28 is a liquid crystal display device drive circuit, 29 is a video signal generator, 30 is an optical writing type spatial light modulator, 31 is a liquid crystal writing device, and 32 is a liquid crystal writing device. Input light, 33 is write information, 34 is read light, and 35 is output information.

【0003】光書き込み型空間光変調器30は、光導電
体層23と遮光層24と反射ミラー層25と液晶層26
を透明電極22a,22bで挟み、該透明電極22a,
22bの両側をさらにガラス基板21a,21bで挟ん
だ構造をしている。液晶表示装置駆動回路28に入力さ
れた映像信号発生部29からの映像信号により動作して
いる液晶表示装置27を透過してきた入力光は、前記透
明電極22a,22bに交流バイアス電圧を加えると、
前記光書き込み型空間光変調器30にとっての入力とな
り、書き込み情報33として入力される。すると、該書
き込み情報33により、前記光導電体層23でインピー
ダンス変化が起こり、液晶層26内でねじれ構造が変化
し、読み出し光34の偏光状態を変化させて出力情報3
5となる。
The optical writing type spatial light modulator 30 includes a photoconductor layer 23, a light shielding layer 24, a reflection mirror layer 25 and a liquid crystal layer 26.
Is sandwiched between the transparent electrodes 22a and 22b,
22b has a structure in which both sides of 22b are further sandwiched between glass substrates 21a and 21b. The input light transmitted through the liquid crystal display device 27 operating according to the video signal from the video signal generator 29 input to the liquid crystal display device drive circuit 28, when an AC bias voltage is applied to the transparent electrodes 22a and 22b,
It becomes an input to the optical writing type spatial light modulator 30 and is input as writing information 33. Then, the write information 33 causes an impedance change in the photoconductor layer 23, the twisted structure is changed in the liquid crystal layer 26, and the polarization state of the read light 34 is changed to output information 3
It becomes 5.

【0004】図5〜図6は、光書き込み型空間光変調器
の書き込み光入射側からの入力光量と、読み出し光入射
側の出力光量との比が、読み出し光照射面内において均
一にならないことを説明するための図である。図6は、
光書き込み型空間光変調器30の読み出し光照射面内を
図5のように9分割し、それぞれの位置での液晶分子の
方向を示した図である。透明電極22a,22bに交流
バイアスを加わえると、液晶層26内でねじれ構造が変
化して45°読み出し光の偏光方向を変える。このよう
な動作をする光書き込み型空間光変調器30を実際の反
射型液晶プロジェクターに当てはめて考えると、図7の
ように、ある大きさをもった光源より読み出し光照射面
積内の分割ブロックの各ポイントに対する入射経路は、
それぞれ違った角度で入射している。
5 to 6 show that the ratio of the input light amount from the writing light incident side of the optical writing type spatial light modulator to the output light amount of the reading light incident side is not uniform in the reading light irradiation surface. It is a figure for explaining. FIG.
FIG. 6 is a diagram showing directions of liquid crystal molecules at each position by dividing the inside of the reading light irradiation surface of the optical writing type spatial light modulator 30 into nine as shown in FIG. 5. When an AC bias is applied to the transparent electrodes 22a and 22b, the twist structure is changed in the liquid crystal layer 26 to change the polarization direction of the 45 ° read light. When the optical writing type spatial light modulator 30 which operates as described above is applied to an actual reflection type liquid crystal projector, as shown in FIG. 7, a divided block within a reading light irradiation area is provided from a light source having a certain size. The incident path for each point is
They are incident at different angles.

【0005】より詳細には、図7に示すように、角度
→光源→と→光源→,→光源→と→光源→
,→光源→と→光源→,→光源→と→
光源→,それぞれ同じ広がり角度で入射しているが、
方向と入射した読み出し光照射面内の液晶分子軸とを併
させ考えると、いずれのポイントにおいても入射条件が
違っている。
More specifically, as shown in FIG. 7, angles → light source → and → light source →, → light source → and → light source →
, → light source → and → light source →, → light source → and →
Light source →, each incident with the same spread angle,
Considering both the direction and the liquid crystal molecular axis in the incident plane of the read-out light, the incident conditions are different at any point.

【0006】図8(a)〜(e)は、実際に光書き込み
型空間光変調器を備えた反射型液晶プロジェクターの各
部の主要特性グラフで、図8(a)は入力映像波形、図
8(b)はγ補正特性波形、図8(c)は液晶表示装置
の電圧−透過率(V−T)特性波形、図8(d)は光書
き込み型空間光変調器の入出力特性、図8(e)は出力
映像波形を各々示している。
FIGS. 8A to 8E are main characteristic graphs of respective parts of a reflection type liquid crystal projector actually equipped with an optical writing type spatial light modulator. FIG. 8A shows an input video waveform and FIG. 8B is a γ correction characteristic waveform, FIG. 8C is a voltage-transmittance (VT) characteristic waveform of the liquid crystal display device, and FIG. 8D is an input / output characteristic of the optical writing type spatial light modulator. 8 (e) shows output video waveforms.

【0007】映像信号に図8(a)に示すような入力映
像波形を入力し、プロジェクターの場合、R,G,B各液
晶表示装置27の映像を合成してスクリーン上に拡大投
写することでカラー映像を得るようになっているため、
液晶表示装置27が3枚必要となる。液晶表示装置27
の液晶材料やその製造上、また液晶ドライバー等のバラ
ツキ,偏光板調整誤差や入射光波長特性の違い等、さま
ざまな要因からR,G,B各液晶表示装置27のもってい
る電圧−透過率特性がそれぞれ異なってしまうため、図
8(e)に示すようなリニアな出力映像波形を得るため
に、液晶表示装置駆動回路28内でγ補正を行い、さら
に階調での色度ズレを無くすようにしている。
By inputting an input video waveform as shown in FIG. 8 (a) to a video signal, and in the case of a projector, the videos of the R, G and B liquid crystal display devices 27 are combined and projected on a screen in an enlarged manner. Since I am getting color images,
Three liquid crystal display devices 27 are required. Liquid crystal display 27
The voltage-transmittance characteristics of the R, G, and B liquid crystal display devices 27 due to various factors such as the liquid crystal material and its manufacturing, variations in the liquid crystal driver, polarization plate adjustment error, and difference in incident light wavelength characteristics. However, in order to obtain a linear output video waveform as shown in FIG. 8E, γ correction is performed in the liquid crystal display drive circuit 28 to further eliminate the chromaticity deviation in gradation. I have to.

【0008】図8(a)に示すような完全リニアな入力
映像波形を液晶表示装置27の電圧−透過率特性に基づ
いて作成した図8(b)に示すγ補正特性波形を介して
光書き込み型空間光変調器30に入射させると、図8
(e)に示す出力映像波形として出力する。光書き込み
型空間光変調器30の特性として、入力−出力特性があ
り、図中のa曲線を介せば、図8(e)に示す出力映像
波形のa′曲線、つまりリニアな特性になる。
Optical writing is performed through the .gamma.-correction characteristic waveform shown in FIG. 8B in which a completely linear input image waveform as shown in FIG. 8A is created based on the voltage-transmittance characteristic of the liquid crystal display device 27. When the light is incident on the spatial light modulator 30 of FIG.
It is output as the output video waveform shown in (e). There is an input-output characteristic as a characteristic of the optical writing type spatial light modulator 30, and if it goes through the a curve in the figure, it becomes an a'curve of the output video waveform shown in FIG. 8E, that is, a linear characteristic. .

【0009】これが、図5〜図7の説明でわかるよう
に、光書き込み型空間光変調器30の読み出し光照射面
積内において、光源から各ポイントへの入射角度のちが
いで、入出力特性が不均一となる。つまり、読み出し光
照射面内において、b曲線,c曲線に該当するポイント
があれば、それぞれ図8(e)に示すような出力映像波
形としてb′曲線,c′曲線となって出力される。
As can be seen from the description of FIGS. 5 to 7, this is because the incident angle from the light source to each point is different within the reading light irradiation area of the optical writing type spatial light modulator 30, and thus the input / output characteristics are unsatisfactory. Be uniform. That is, if there are points corresponding to the b curve and the c curve on the reading light irradiation surface, the b'curve and the c'curve are output as the output video waveforms shown in FIG. 8E, respectively.

【0010】[0010]

【発明が解決しようとする課題】ある大きさを持った光
源より完全な平行光で読み出し光を供給することのでき
ない反射型液晶プロジェクターに、光書き込み型空間光
変調器を採用するシステムにおいて、書き込み光入射側
からの入力光量と読み出し光入射側からの出力光量との
比が、読み出し光照射面内において均一でない特性を持
ち、その特性により出力映像波形も読み出し光照射面内
において均一でなくなり、スクリーンへの投写映像に輝
度差が生じるという問題点があった。
In a system adopting an optical writing type spatial light modulator in a reflection type liquid crystal projector which cannot supply a reading light as a perfect parallel light from a light source having a certain size, writing is performed in a system. The ratio of the input light amount from the light incident side and the output light amount from the reading light incident side has a characteristic that the reading light irradiation surface is not uniform, and due to the characteristic, the output image waveform is also not uniform in the reading light irradiation surface, There is a problem in that there is a brightness difference in the projected image on the screen.

【0011】本発明は、このような実情に鑑みてなされ
たもので、完全な平行光で読み出し光を供給することの
できない反射型液晶プロジェクターにおいて、必ず発生
する光書き込み型空間光変調器の面内入出力特性の不均
一からくる階調ムラの対策を、液晶表示装置の使用電圧
範囲(白・黒電圧)を変えることにより補正するように
した反射型液晶プロジェクターを提供することを目的と
している。
The present invention has been made in view of the above circumstances, and is a surface of an optical writing type spatial light modulator which is always generated in a reflection type liquid crystal projector which cannot supply readout light with perfect parallel light. It is an object of the present invention to provide a reflection type liquid crystal projector in which a countermeasure against gradation unevenness caused by non-uniformity of internal input / output characteristics is corrected by changing a working voltage range (white / black voltage) of a liquid crystal display device. .

【0012】[0012]

【課題を解決するための手段】本発明は、上記課題を解
決するために、(1)書き込み光によってインピーダン
スが変化する光導電体と、該光導電体のインピーダンス
変化によりねじれ構造が変化して、読み出し光の偏光状
態を45°変化させるねじれネマティック液晶とを有す
る光書き込み型空間光変調器を備え、書き込み光の情報
を読み出し光によって表示する液晶プロジェクターにお
いて、前記光書き込み型空間光変調器の書き込み光入射
側からの入力光量と、読み出し光入射側の出力光量との
比が、前記光書き込み型空間光変調器の読み出し光照射
面内において均一になるように、書き込み光量を制御す
る制御手段を設けたこと、更には、(2)前記(1)に
おいて、前記光書き込み型空間光変調器の読み出し光照
射面内を、任意の数にマトリックス分割し、分割された
各ブロック毎に書き込み光量を制御する制御手段を設け
たこと、更には、(3)前記制御手段は、書き込み光の
情報に映像信号で表示駆動する液晶表示装置を用い、該
液晶表示装置を駆動させるための映像信号を制御するこ
とを特徴としたものである。
In order to solve the above-mentioned problems, the present invention provides (1) a photoconductor whose impedance is changed by writing light, and a twist structure which is changed by the impedance change of the photoconductor. A liquid crystal projector comprising a twisted nematic liquid crystal that changes the polarization state of the reading light by 45 ° and displaying information of the writing light by the reading light. Control means for controlling the writing light amount so that the ratio of the input light amount from the writing light incident side and the output light amount on the reading light incident side becomes uniform in the reading light irradiation surface of the optical writing type spatial light modulator. Further, (2) In (1) above, the inside of the reading light irradiation surface of the optical writing type spatial light modulator is arbitrarily set. And a control means for controlling the writing light quantity for each of the divided blocks. Further, (3) the control means is a liquid crystal display device for displaying and driving the writing light information by a video signal. It is characterized by controlling a video signal for driving the liquid crystal display device.

【0013】[0013]

【作用】光書き込み型空間光変調器の読み出し光照射面
内をマトリックス状に分割し、その分割された各ブロッ
クに相当する液晶表示装置側の各ブロックにおいて、液
晶表示装置の印加動作電圧(白電圧,黒電圧)を変える
ことが、光書き込み型空間光変調器の書き込み光を制御
することになり、読み出し光によって得た出力情報がリ
ニアな特性となる。
The reading light irradiation surface of the optical writing type spatial light modulator is divided into a matrix, and in each block on the liquid crystal display device side corresponding to each divided block, the applied operating voltage (white Changing the voltage, the black voltage) controls the writing light of the optical writing type spatial light modulator, and the output information obtained by the reading light has a linear characteristic.

【0014】[0014]

【実施例】実施例について、図面を参照して以下に説明
する。図1は、本発明による反射型液晶プロジェクター
の一実施例を説明するための構成図で、光書き込み型空
間光変調器を備え、書き込み光の情報に映像信号で表示
駆動する液晶表示装置を使った液晶プロジェクターの構
成図である。図中、1a,1bはガラス基板、2a,2
bは透明電極、3は光導電体層、4は遮光層、5は反射
ミラー層、6は液晶層、7は液晶表示装置、8は液晶表
示装置駆動回路、9は映像信号発生部、10は光書き込
み型空間光変調器、11は液晶書き込み装置、12は入
力光、13は書き込み情報、14は読み出し光、15は
出力情報、16は制御部である。
Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a reflection type liquid crystal projector according to the present invention, which uses a liquid crystal display device including an optical writing type spatial light modulator and driving a display by a video signal for writing light information. It is a block diagram of a liquid crystal projector. In the figure, 1a and 1b are glass substrates, 2a and 2
Reference numeral b is a transparent electrode, 3 is a photoconductor layer, 4 is a light shielding layer, 5 is a reflection mirror layer, 6 is a liquid crystal layer, 7 is a liquid crystal display device, 8 is a liquid crystal display device drive circuit, 9 is a video signal generator, and 10 is a video signal generator. Is an optical writing spatial light modulator, 11 is a liquid crystal writing device, 12 is input light, 13 is write information, 14 is read light, 15 is output information, and 16 is a control unit.

【0015】光導電体層3と遮光層4と反射ミラー層5
と液晶層6とを透明電2a,2bで挟み、さらにその両
側をガラス基板1a,1bで挟んだ構造の光書き込み型
空間光変調器において、透明電極2a,2bに交流バイ
アス電圧を加え動作させた場合、液晶表示装置駆動回路
8に入力された映像信号発生部9からの映像信号により
動作している液晶表示装置7を透過してきた入力光が、
光書き込み型空間光変調器10にとっての入力となり、
書き込み情報13として光書き込み型空間光変調器10
に入力される。すると、書き込み情報13により光導電
体層3でインピーダンス変化が起こり、液晶層6内でね
じれ構造が変化し、読み出し光14の偏光状態を変化さ
せて出力情報15となる。制御部16で液晶表示装置7
の印加動作電圧を変えることにより、光書き込み型空間
光変調器10の書き込み情報13を制御する。
The photoconductor layer 3, the light shielding layer 4, and the reflection mirror layer 5
In the optical writing type spatial light modulator having a structure in which the liquid crystal layer 6 and the liquid crystal layer 6 are sandwiched between the transparent electrodes 2a and 2b, and both sides thereof are sandwiched between the glass substrates 1a and 1b, an AC bias voltage is applied to the transparent electrodes 2a and 2b to operate. In this case, the input light transmitted through the liquid crystal display device 7 operating by the video signal from the video signal generator 9 input to the liquid crystal display device drive circuit 8 is
It becomes an input to the optical writing type spatial light modulator 10,
Optical writing type spatial light modulator 10 as writing information 13
Is input to Then, the write information 13 causes an impedance change in the photoconductor layer 3, the twisted structure is changed in the liquid crystal layer 6, and the polarization state of the read light 14 is changed to be output information 15. The control unit 16 controls the liquid crystal display device 7
The write information 13 of the optical write type spatial light modulator 10 is controlled by changing the applied operating voltage of the.

【0016】図2は、光書き込み型空間光変調器の書き
込み入射光からの入力光量と、読み出し光入射側の出力
光量との比が、読み出し光照射面内において均一になる
ことを説明するための図で、図中の参照番号は、図1と
同じである。光書き込み空間光変調器10の読み出し光
照射面内を任意の数にマトリックス分割(〜の9分
割)し、読み出し光源から光書き込み型空間光変調器1
0の読み出し光照射面内に対しての入射角により、光書
き込み型空間光変調器10の持つ入力−出力特性が変化
するため、読み出し光照射面内を細分化し、細分化され
たブロックに書き込み光量を制御部16により制御す
る。
FIG. 2 is for explaining that the ratio of the input light amount from the writing incident light of the optical writing type spatial light modulator and the output light amount on the reading light incident side becomes uniform in the reading light irradiation surface. In the figure, reference numerals in the figure are the same as those in FIG. The reading light irradiation surface of the optical writing spatial light modulator 10 is divided into an arbitrary number of matrixes (9 divisions of up to 9), and the reading light source is changed to the optical writing spatial light modulator 1.
Since the input-output characteristic of the optical writing type spatial light modulator 10 changes depending on the incident angle of 0 with respect to the reading light irradiation surface, the reading light irradiation surface is subdivided and writing is performed in the subdivided blocks. The light amount is controlled by the control unit 16.

【0017】そこで、光書き込み型空間光変調器10の
読み出し光照射面内を細分化した各ブロックに相当する
ように、液晶表示装置7の表示面も細分化し、細分化さ
れた9ブロックごとに、液晶表示装置7の使用電圧範囲
(白電圧,黒電圧)を可変にしてやると、その変化に伴
い、書き込み光量が、光書き込み型空間光変調器10の
出力が一定になる方向に制御部16により制御できる。
Therefore, the display surface of the liquid crystal display device 7 is also subdivided so as to correspond to the subdivided blocks of the reading light irradiation surface of the optical writing type spatial light modulator 10, and each subdivided block is divided. When the operating voltage range (white voltage, black voltage) of the liquid crystal display device 7 is made variable, the amount of writing light is changed so that the output of the optical writing type spatial light modulator 10 becomes constant. Can be controlled by.

【0018】図3(a)〜(e)は、本発明の反射型液
晶プロジェクターの各部の主要特性グラフを示す図で、
図3(a)は入力映像波形、図3(b)はγ補正特性波
形、図3(c)は液晶表示装置の電圧−透過率(V−
T)特性波形、図3(d)は光書き込み型空間変調器の
入出力特性、図3(e)は出力映像波形である。
FIGS. 3A to 3E are graphs showing main characteristic graphs of respective parts of the reflection type liquid crystal projector of the present invention.
3A is an input video waveform, FIG. 3B is a γ correction characteristic waveform, and FIG. 3C is a voltage-transmittance (V−) of the liquid crystal display device.
T) characteristic waveform, FIG. 3D is an input / output characteristic of the optical writing type spatial modulator, and FIG. 3E is an output video waveform.

【0019】光書き込み型空間光変調器10への入力書
き込み手段として、液晶表示装置7と液晶表示装置駆動
回路8と映像信号発生部9とから構成される液晶書き込
み装置11において、図3(a)に示すようなリニアな
入力映像波形を映像信号に入力し、液晶表示装置7の使
用電圧範囲(白電圧,黒電圧)を設定した後に、図3
(c)に示すような液晶表示装置7の持つ電圧−透過率
特性を介した最終段の出力映像波形が、図3(e)に示
すようなリニアな特性波形になるように、液晶表示装置
駆動回路8内で、図3(b)に示す波形の補正(γ補
正)を行う。
As a means for inputting and writing data to the optical writing type spatial light modulator 10, a liquid crystal writing device 11 composed of a liquid crystal display device 7, a liquid crystal display device driving circuit 8 and a video signal generator 9 is used as shown in FIG. 3) after inputting a linear input video waveform as shown in FIG. 4) to the video signal and setting the operating voltage range (white voltage, black voltage) of the liquid crystal display device 7.
The liquid crystal display device as shown in FIG. 3C is such that the final stage output video waveform via the voltage-transmittance characteristic of the liquid crystal display device 7 has a linear characteristic waveform as shown in FIG. In the drive circuit 8, the waveform shown in FIG. 3B is corrected (γ correction).

【0020】反射型液晶プロジェクターの場合、液晶表
示装置7を透過した入力光12が書き込み情報13とな
り、光書き込み型空間光変調器10へ入力され、読み出
し光14により出力されて最終出力映像となるが、特性
波形の流れを考えると、図3(c)に示すような液晶表
示装置7の電圧−透過率特性を介した後に、図3(d)
に示すような光書き込み型空間光変調器10の持つ入力
−出力特性をさらに介し、その出力特性が最終の出力映
像となる光書き込み型空間光変調器10の読み出し光照
射面内をマトリックス状に分割(ここでは説明のため9
分割とする)し、読み出し光源から光書き込み型空間光
変調器10の読み出し光照射面内に対しての入射角によ
り、図3(d)に示すような、光書き込み型空間光変調
器10の持つ入力−出力特性が変化するため、読み出し
光照射面内を細分化することで、細分化した各ブロック
毎に次のような補正手段を設ける。
In the case of the reflection type liquid crystal projector, the input light 12 transmitted through the liquid crystal display device 7 becomes the writing information 13, which is input to the optical writing type spatial light modulator 10 and is output by the reading light 14 to be the final output image. However, considering the flow of the characteristic waveform, after passing through the voltage-transmittance characteristic of the liquid crystal display device 7 as shown in FIG.
The input-output characteristic of the optical writing type spatial light modulator 10 as shown in FIG. 2 is further passed, and the output light irradiation surface of the optical writing type spatial light modulator 10 becomes the final output image in a matrix form. Split (here 9 for explanation)
3), and the incident angle of the reading light source with respect to the reading light irradiation surface of the optical writing spatial light modulator 10 causes the optical writing spatial light modulator 10 as shown in FIG. Since the input-output characteristics that it has change, the following correction means is provided for each subdivided block by subdividing the reading light irradiation surface.

【0021】光書き込み型空間光変調器10の出力は、
最終段の出力映像となるため、これを一定とするために
は、入力側のいずれかを補正対象としなければならない
が、まず、γ補正を対象にした場合、液晶表示装置7に
おいても、光書き込み型空間光変調器10の読み出し光
照射面内を細分化した各ブロックに相当するよう、液晶
表示装置7も細分化した上で9個のブロック全てを個別
にγ補正しなければならず、処理能力やメモリ容量等、
非常に莫大な規模になり、現実的でない。
The output of the optical writing type spatial light modulator 10 is
Since the output image is the final stage, in order to make it constant, one of the input sides must be the correction target. First, when the γ correction is targeted, the liquid crystal display device 7 also has The liquid crystal display device 7 must be subdivided and all 9 blocks must be individually γ-corrected so as to correspond to each subdivided block in the reading light irradiation surface of the writing type spatial light modulator 10. Processing capacity, memory capacity, etc.
It will be very huge and unrealistic.

【0022】そこで、液晶表示装置7の使用電圧範囲
(白電圧,黒電圧)を細分化した各ブロック毎に可変し
てやれば、図3(c)に示すように、液晶表示装置7の
電圧−透過率特性波形が変化するため、その変化に伴
い、書き込み光量が、光書き込み型空間光変調器10の
出力が、図3(e)に示すように一定になる方向に、制
御部16により制御できる。
Therefore, if the operating voltage range (white voltage, black voltage) of the liquid crystal display device 7 is varied for each subdivided block, the voltage-transmission of the liquid crystal display device 7 as shown in FIG. 3C. Since the rate characteristic waveform changes, the writing light amount can be controlled by the control unit 16 in such a direction that the output of the optical writing type spatial light modulator 10 becomes constant as shown in FIG. .

【0023】このように、光書き込み型空間光変調器の
任意の数に分割された読み出し光照射面内の各ブロック
毎に液晶表示装置の印加動作電圧(白電圧,黒電圧)を
変えることで、液晶表示装置の電圧−透過率特性(V−
T特性)波形が変わり、その結果、光書き込み型空間光
変調器に入射する書き込み光量が制御され、分割された
いかなるブロックにおける出力映像も均一となり、スク
リーンに投写した映像の輝度が均一になる。
In this way, by changing the applied operating voltage (white voltage, black voltage) of the liquid crystal display device for each block in the reading light irradiation surface divided into an arbitrary number of the optical writing type spatial light modulator. , Voltage-transmittance characteristics (V-
(T characteristic) The waveform changes, and as a result, the amount of writing light incident on the optical writing type spatial light modulator is controlled, the output image in any divided block becomes uniform, and the brightness of the image projected on the screen becomes uniform.

【0024】[0024]

【発明の効果】以上の説明から明らかなように、本発明
によると、完全な平行光で読み出し光を供給することの
できない反射型液晶プロジェクターに、光書き込み型空
間光変調器を採用するシステムにおいて、光書き込み型
空間光変調器の書き込み光入射側からの入力光量と、読
み出し光入射側の出力光量との比が、前記光書き込み型
空間光変調器の読み出し光照射面内において均一になる
ように、書き込み光量を制御する制御手段を設けたの
で、スクリーンに投写した最終の出力映像が部分的な輝
度ムラや色度ムラ等発生せず、均一な映像を提供するこ
とができる。
As is apparent from the above description, according to the present invention, in a system that employs an optical writing type spatial light modulator in a reflection type liquid crystal projector that cannot supply reading light with perfect parallel light. , The ratio of the input light quantity from the writing light incident side of the optical writing type spatial light modulator to the output light quantity of the reading light incident side is uniform in the reading light irradiation surface of the optical writing type spatial light modulator. In addition, since the control means for controlling the writing light amount is provided, it is possible to provide a uniform image without causing partial uneven brightness or chromaticity in the final output image projected on the screen.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明による反射型液晶プロジェクターの一実
施例を説明するための図である。
FIG. 1 is a diagram for explaining an embodiment of a reflective liquid crystal projector according to the present invention.

【図2】本発明のより具体的な説明図である。FIG. 2 is a more specific explanatory diagram of the present invention.

【図3】本発明の反射型液晶プロジェクターの各部の主
要特性グラフを示す図である。
FIG. 3 is a diagram showing a main characteristic graph of each part of the reflective liquid crystal projector of the present invention.

【図4】従来の液晶プロジェクターの構成図である。FIG. 4 is a configuration diagram of a conventional liquid crystal projector.

【図5】従来例を説明するための図である。FIG. 5 is a diagram for explaining a conventional example.

【図6】従来例を説明するための図である。FIG. 6 is a diagram for explaining a conventional example.

【図7】従来例を説明するための図である。FIG. 7 is a diagram for explaining a conventional example.

【図8】従来例の反射型液晶プロジェクターの各部の主
要特性グラフを示す図である。
FIG. 8 is a diagram showing a main characteristic graph of each part of a conventional reflective liquid crystal projector.

【符号の説明】[Explanation of symbols]

1a,1b…ガラス基板、2a,2b…透明電極、3…
光導電体層、4…遮光層、5…反射ミラー層、6…液晶
層、7…液晶表示装置、8…液晶表示装置駆動回路、9
…映像信号発生部、10…光書き込み型空間光変調器、
11…液晶書き込み装置、12…入力光、13…書き込
み情報、14…読み出し光、15…出力情報、16…制
御部。
1a, 1b ... Glass substrate, 2a, 2b ... Transparent electrode, 3 ...
Photoconductor layer, 4 ... Light shielding layer, 5 ... Reflection mirror layer, 6 ... Liquid crystal layer, 7 ... Liquid crystal display device, 8 ... Liquid crystal display device drive circuit, 9
... video signal generator, 10 ... optical writing type spatial light modulator,
11 ... Liquid crystal writing device, 12 ... Input light, 13 ... Writing information, 14 ... Read light, 15 ... Output information, 16 ... Control part.

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 書き込み光によってインピーダンスが変
化する光導電体と、該光導電体のインピーダンス変化に
よりねじれ構造が変化して、読み出し光の偏光状態を4
5°変化させるねじれネマティック液晶とを有する光書
き込み型空間光変調器を備え、書き込み光の情報を読み
出し光によって表示する液晶プロジェクターにおいて、
前記光書き込み型空間光変調器の書き込み光入射側から
の入力光量と、読み出し光入射側の出力光量との比が、
前記光書き込み型空間光変調器の読み出し光照射面内に
おいて均一になるように、書き込み光量を制御する制御
手段を設けたことを特徴とする反射型液晶プロジェクタ
ー。
1. A photoconductor whose impedance is changed by writing light, and a twist structure is changed by the impedance change of the photoconductor, thereby changing the polarization state of the reading light to 4
A liquid crystal projector that includes an optical writing type spatial light modulator having a twisted nematic liquid crystal that changes by 5 ° and displays information of writing light by reading light,
The ratio of the input light amount from the writing light incident side of the optical writing type spatial light modulator and the output light amount from the reading light incident side is
A reflection type liquid crystal projector comprising a control means for controlling the writing light quantity so that the reading light irradiation surface of the optical writing spatial light modulator becomes uniform.
【請求項2】 前記光書き込み型空間光変調器の読み出
し光照射面内を、任意の数にマトリックス分割し、分割
された各ブロック毎に書き込み光量を制御する制御手段
を設けたことを特徴とする請求項1記載の反射型液晶プ
ロジェクター。
2. A control means for dividing the reading light irradiation surface of the optical writing type spatial light modulator into an arbitrary number of matrixes and controlling the writing light quantity for each of the divided blocks. The reflective liquid crystal projector according to claim 1.
【請求項3】 前記制御手段は、書き込み光の情報に映
像信号で表示駆動する液晶表示装置を用い、該液晶表示
装置を駆動させるための映像信号を制御することを特徴
とする請求項1又は2記載の反射型液晶プロジェクタ
ー。
3. The liquid crystal display device, wherein the control means uses a liquid crystal display device for displaying and driving a write light information by a video signal, and controls a video signal for driving the liquid crystal display device. The reflective liquid crystal projector according to 2.
JP6160979A 1994-07-13 1994-07-13 Reflective LCD projector Expired - Fee Related JP3071999B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6160979A JP3071999B2 (en) 1994-07-13 1994-07-13 Reflective LCD projector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6160979A JP3071999B2 (en) 1994-07-13 1994-07-13 Reflective LCD projector

Publications (2)

Publication Number Publication Date
JPH0829801A true JPH0829801A (en) 1996-02-02
JP3071999B2 JP3071999B2 (en) 2000-07-31

Family

ID=15726270

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6160979A Expired - Fee Related JP3071999B2 (en) 1994-07-13 1994-07-13 Reflective LCD projector

Country Status (1)

Country Link
JP (1) JP3071999B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005221953A (en) * 2004-02-09 2005-08-18 Fuji Xerox Co Ltd Optical writing device
JP2009540342A (en) * 2006-06-02 2009-11-19 フューリ テクノロジーズ コーポレイション Pulse width drive method using multiple pulses

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009072563A1 (en) 2007-12-05 2009-06-11 Hamamatsu Photonics K.K. Phase modulating apparatus and phase modulating method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005221953A (en) * 2004-02-09 2005-08-18 Fuji Xerox Co Ltd Optical writing device
JP2009540342A (en) * 2006-06-02 2009-11-19 フューリ テクノロジーズ コーポレイション Pulse width drive method using multiple pulses

Also Published As

Publication number Publication date
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