Array-type light modulating device and method of operating flat display unit

• US 6,356,254 B1
• Filed: 09/24/1999
• Issued: 03/12/2002
• Est. Priority Date: 09/25/1998
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kimura, Koichi
• Primary Examiner(s): Jherpe, Richard
• Assistant Examiner(s): Eisen, Alexander
• Application Number:
  US09/404,541
• Time in Patent Office: 900 Days
• Field of Search: 345/84, 345/85, 345/108, 345/109, 345/211-214, 348/203, 348/205, 348/800, 359/196, 359/201, 359/202, 359/209, 359/212, 359/223, 359/290, 359/291
• US Class Current: 345/108
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/062 Waveforms for resetting a plurality of scan lines at a time
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

It is an object to provide an array-type light modulating device and a method of operating a flat display unit with which even electromechanical light modulating devices, which require a long time to restore the original positions, are able to significantly shorten substantial response time without deterioration in the image quality and loss occurring owning to the restoring time.

An array-type light modulating device incorporating electromechanical light modulating devices which are arranged to perform light modulation by using an operation for displacing flexible portions by dint of electrostatic force and an elastic restoring operation of the flexible portions and which are disposed into a two-dimensional matrix configuration, wherein a resetting operation of the light modulating devices is performed simultaneously with a writing operation period for scanning lines except for the present scanning lines so that the resetting operation is completed before the writing operation for the light modulating devices to continuous perform the writing operation for each scanning line.

Claims

1. A method of operating an array-type light modulating device incorporating electromechanical light modulating devices which are arranged to perform light modulation by using an operation for displacing flexible portions by dint of electrostatic force and an elastic restoring operation of said flexible portions and which are disposed into a two-dimensional matrix configuration, said method of operating an array-type light modulating device comprising the steps of:

performing a resetting scan operation which restores said light modulating devices for scanning lines; and

performing a writing scan operation for selecting either of an operation for displacing said devices or an operation for maintaining the present state for scanning lines,

wherein the resetting scan operation for selected scanning lines is performed within writing scan operation period for scanning lines except for the selected scanning lines.

2. A method of operating an array-type light modulating device according to claim 1, wherein the resetting scan operation for selected scanning lines is performed simultaneously with writing scan operation for scanning lines except for the selected scanning lines so that the writing scan operation of each scanning line is continuously performed.

3. The method of claim 2, wherein within each scanning line of the two-dimensional matrix, the resetting scan operation precedes the writing scan operation in time.

4. A method of operating an array-type light modulating device according to claim 1, wherein reset scanning operation time is set to be longer than time required for each flexible portion to elastically restore the original position.

5. A method of operating an array-type light modulating device according to any one of claims 1, wherein the elastic restoring operation of each light modulating device is an operation which realizes a light shielded state after the restoration has been completed.

6. The method of claim 5, wherein within each scanning line of the two-dimensional matrix, the resetting scan operation precedes the writing scan operation in time.

7. A method of operating an array-type light modulation device according to claim 1, said array-type light modulation device forming a flat display unit, said flat display unit incorporating said array-type light modulating device, a flat light source disposed opposite to said array-type light modulating device and fluorescent members disposed opposite to said flat light source such that said array-type light modulating device is interposed, said method of operating a flat display unit further comprising:

using light emitted from said array-type light modulating device to cause fluorescent members to emit light to perform display.

8. A method of operating a flat display according to claim 7, wherein said flat light source is a light source for emitting ultraviolet rays for exciting said fluorescent members.

9. The method of claim 1, wherein within each scanning line of the two-dimensional matrix, the resetting scan operation precedes the writing scan operation in time.

10. A method of operating an array-type light modulating device incorporating electromechanical light modulating devices which are arranged to perform light modulation by using an operation for displacing flexible portions by dint of electrostatic force and an elastic restoring operation of said flexible portions and which are disposed into a two-dimensional matrix configuration, said method of operating an array-type light modulating device comprising the steps of:

performing a resetting scan operation which restores said light modulating devices for scanning lines; and

performing a writing scan operation for selecting either of an operation for displacing said devices or an operation for maintaining the present state for scanning lines,

wherein the resetting scan operation for selected scanning lines is performed within writing scan operation period for scanning lines except for the selected scanning lines,

wherein reset scanning operation time is set to be an integer multiple of writing scan time.

11. The method of claim 10, wherein the resetting scan operation for selected scanning lines is performed simultaneously with writing scan operation for scanning lines except for the selected scanning lines so that the writing scan operation of each scanning line is continuously formed.

12. The method according to claim 10, wherein reset scanning operation time is set to be longer than time required for each flexible portion to restore the original position.

13. The method of claim 10, wherein the elastic restoring operation of each light modulating device is an operation which realizes a light shielded state after the restoration has been completed.