Image processing apparatus employing a spatial light modulator

• US 5,327,263 A
• Filed: 05/20/1993
• Issued: 07/05/1994
• Est. Priority Date: 12/18/1989
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Katagiri, Masayuki, Kako, Noritoshi, Noguchi, Yoji
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Rogers, Scott A.
• Application Number:
  US08/063,780
• Time in Patent Office: 411 Days
• Field of Search: 358/471, 358/213.13, 359/72, 359/250, 359/252, 359/103-106
• US Class Current: 358/471
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence
• CPC Class Codes: G02F 1/1357 Electrode structure
• CPC Class Codes: G03B 27/725 Optical projection devices wherein the contrast is controlled electrically (e.g. cathode ray tube masking)
• CPC Class Codes: G03H 1/0005 Adaptation of holography to specific applications holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042
• CPC Class Codes: G03H 2001/261 in optical contact
• CPC Class Codes: G03H 2270/22 Disc shaped
• CPC Class Codes: H04N 1/00249 with a photographic apparatus, e.g. a photographic printer or a projector photographic apparatus per se G03B, G03D
• CPC Class Codes: H04N 1/10 using flat picture-bearing surfaces H04N1/113, H04N1/195 take precedence
• CPC Class Codes: H04N 1/113 using oscillating or rotating mirrors
• CPC Class Codes: H04N 1/407 Control or modification of tonal gradation or of extreme levels, e.g. background level
• CPC Class Codes: H04N 1/508 using the same reproducing head for two or more colour components

Abstract

An image processing apparatus comprises a liquid modulator having a photoconductive material including an image-writing plane, a liquid crystal layer laminated on the photoconductive material, a pair of electrodes sandwiching the photoconductive material and the liquid crystal layer, and a spacer inserted between the photoconductive material and one of the electrodes. Also provided are an analog writing system for analogously writing an original image in the light modulator; a digital reading system for digitally reading the image written in the light modulator; a processing section for image-processing the read image data; a digital writing system for digitally writing processed image data in the light modulator; and, an analog reading system for analogously reading an image written in the light modulator. The liquid crystal layer is either a phase-transition type liquid crystal, a p-type smectic A liquid crystal providing a storage function, or a ferroelectric liquid crystal providing a storage function. The phase-transition type liquid crystal is selected from a group consisting of (1) a p-type cholesteric liquid crystal and (2) a mixture of p-type cholesteric liquid crystal and p-type nematic liquid crystal. The ferroelectric liquid crystal is selected from a group consisting of (1) a chiral smectic C liquid crystal, (2) a mixture of chiral smectic C liquid crystal and non-chiral smectic C liquid crystal, and (3) a mixture of chiral smectic C liquid crystal and a photoactive material.

Claims

1. An image processing apparatus comprising:

a liquid modulator having a photoconductive material including an image-writing plane, a liquid crystal layer laminated on said photoconductive material, a pair of electrodes sandwiching said photoconductive material and said liquid crystal layer, and a spacer inserted between said photoconductive material and one of said electrodes surrounding said liquid crystal layer;

an analog writing system for analogously writing an original image in said liquid modulator;

a digital reading system for digitally reading the image written in said liquid modulator by emitting a laser beam for scanning said light modulator in two dimensions;

a processing section for image-processing the read image data;

a digital writing system for digitally writing processed image data in said light modulator by applying said laser beam for scanning on said light modulator in two dimensions; and

an analog reading system for analogously reading an image written in said light modulator,

wherein said liquid crystal layer comprises a liquid crystal which is selected from a group consisting of;

(1) a phase-transition type liquid crystal providing a storage function,

(2) a p-type smectic A liquid crystal providing a storage function, and

(3) a ferroelectric liquid crystal providing a storage function;

wherein the phase-transition type liquid crystal is selected from a group consisting of;

a p-type cholesteric liquid crystal,

a mixture of p-type cholesteric liquid crystal and p-type nematic liquid crystal, and

wherein the ferroelectric liquid crystal is selected from a group consisting of;

a chiral smectic C liquid crystal,

a mixture of chiral smectic C liquid crystal and non-chiral smectic C liquid crystal, and

a mixture of chiral smectic C liquid crystal and a photoactive material.

2. An apparatus according to claim 1, wherein said apparatus further comprises means for variably controlling a scanning density of said laser beam to a desired value and means for adjusting a beam spot diameter of said laser beam according to said scanning density controlled by said means for variably controlling a scanning density of said laser beam to a desired value.

3. An apparatus according to claim 1, wherein said apparatus further comprises means for sensing brightness of an image written on said light modulator by said analog writing system and means for adjusting input sensitivity of said light modulator.

4. An apparatus according to claim 1, wherein said light modulator includes a film heater consisting of a plurality of micro-heaters ranged in a pattern, said film heater serving to apply temperature distributed in a matrix to said liquid crystal layer.

5. An apparatus according to claim 1, wherein at least one of said electrodes are divided into a plurality of areas to be independently driven.

6. An apparatus according to claim 1, wherein said apparatus further comprises a plurality of light modulators, and an original image is decomposed into a plurality of color-component images and said color-component images are analogously and digitally written in or read our of said light modulators.

7. An apparatus according to claim 1, wherein said light modulator is divided into a plurality of regions and said analog writing system for decomposing an original image is decomposed into a plurality of color-component images and said color-component images are analogously and digitally written in or read out of said regions.

8. An apparatus according to claim 6, wherein a dichroic mirror is used for decomposing said original image into of said color-component images.