Optical data processing device

• US 5,268,679 A
• Filed: 05/31/1991
• Issued: 12/07/1993
• Est. Priority Date: 06/29/1990
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Shannon, John M.
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): Saras, Steven J.
• Application Number:
  US07/708,606
• Time in Patent Office: 921 Days
• Field of Search: 364/713, 364/822, 364/837, 364/845, 364/841, 359/53, 359/72, 359/73, 359/79, 359/107, 359/108, 359/15, 359/41, 359/58-60, 340/784, 340/783, 340/793, 340/779, 340/716, 340/717, 250/214 LS
• US Class Current: 345/4
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 3/00 Optical logic elements; Optical bistable devices
• CPC Class Codes: G06E 1/02 operating upon the order or content of the data handled

Abstract

An optical data processing device has successive light intensity modulating levels, each level including a matrix of cells (35), each cell having therein an element (31) of electrically controllable light transmissivity and a control device (32) which is responsive to signals supplied thereto to control the transmissivity of the element (31) in accordance with such signals. The matrix cells in at least one level also each include a light responsive element (34), such as a photodiode, for controlling the pattern of transmissivities at that level in accordance with the light received from the preceding level, thereby permitting optical as well as electrical modulation of the input image, formed at the first level. The final level (n) includes a display screen which, when an input light beam is incident on the first level, produces an output image corresponding to the input image as modified by the sequence of levels in accordance with the supplied data signals. Since there may typically be 350,000 matrix cells in each level, very high parallel data processing capability is achieved.

Claims

1. An optical data processing device comprising:

a sequence of light modulating levels, each such level consisting of a substrate carrying a matrix of elements of controllable light transmissivity, each light transmissive element having control means associated therewith for controlling the transmissivity thereof in accordance with signals supplied to such control means;

means for supplying input data signal to the control means of the light transmissive element in the first modulating level so as to form a pattern of transmissivities at said first level which, when a light beam is incident thereon, results in formation at that level of a two-dimensional input image representing the input data signals;

the control means of the light transmissive elements in at least one of the modulating levels comprising switching elements for modifying the transmissivities of the associated light transmissive elements in accordance with electrical data signals supplied to such switching elements;

control means of the light transmissive elements in at least one of the further modulating levels following the first modulating level comprising light responsive elements for modifying the transmissivities of the associated light transmissive elements in accordance with the light pattern incident on such at least one modulating level and which was formed by the immediately preceding modulating level; and

the final modulating level comprising a display screen on which is formed, in response to a light beam incident on the first modulating level, a two-dimensional output image corresponding to said input image as modified by the pattern of light transmissivities of all of the sequence of modulating levels.

2. A device according to claim 1, wherein the first level comprises light responsive elements for modifying the light transmissivity of the light transmissive elements in response to light incident on the first level.

3. A device according to claim 2, where each light transmissive element of the first level has associated therewith a respective light responsive element and means are provided for causing the pattern to be stored at the first level in response to an input light beam incident on the light responsive areas.

4. A device according to claim 1, wherein at least one of the further levels after the first level has a group of light responsive elements for providing a signal to modulate the light transmissivity of at least one light transmissive element in response to the light incident on said group of light transmissive elements.

5. A device according to claim 1, wherein at least one of the further levels after the first level has at least one light transmissive element associated with a light responsive element and means are provided for controlling the transmissivity of the said at least one light transmissive element of that level in response only to the light incident on the said light responsive element.

6. A device according to claim 1, wherein each level comprises a matrix of cells and each cell comprises a controllable light transmissive element and an area of predetermined transmissivity for allowing passage of the operating light beam.

7. A device according to claim 6, wherein a deflection layer is provided between selected ones of the further levels after the first level for deflecting the portion of the input light beam passing through the area of predetermined transmissivity of a matrix cell onto the light transmissive element of the corresponding matrix cell of the next further level.

8. A device according to claim 7, wherein a light sensing level comprising light responsive elements is provided between one selected further level and the deflection layer for sensing a pattern stored at the one selected level and for providing data signals to the light transmissivity control elements of the other selected further level for enabling the pattern stored at the one selected further level to be produced at the other selected further level.