Drive methods of array-type light modulation element and flat-panel display

• US 6,327,071 B1
• Filed: 10/18/1999
• Issued: 12/04/2001
• Est. Priority Date: 10/16/1998
• 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): Ben, Loha
• Application Number:
  US09/421,316
• Time in Patent Office: 778 Days
• Field of Search: 359/290, 359/291, 359/295, 359/298, 359/254, 359/214, 359/224, 359/230, 359/293, 358/241, 358/59
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G09G 2300/0473 Use of light emitting or modulating elements having two or more stable states when no power is applied
• 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 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0254 Control of polarity reversal in general, other than for liquid crystal displays
• 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
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: G09G 3/3473 based on light coupled out of a light guide, e.g. due to scattering, by contracting the light guide with external means

Abstract

In an array-type light modulation element drive method comprising the steps of arranging electromechanical light modulation elements for executing light modulation by displacement operation of a flexible section by an electrostatic force and elastic restoration operation of the flexible section like a two-dimensional matrix, selecting each pixel according to a scan electrode signal Vg, and giving a data signal Vb to a pixel electrode for driving the pixel, a basic frame is divided into an odd frame and an even frame and the polarity of an applied signal Vgs is inverted in the odd frame and the even frame for executing AC drive of the light modulation element.

Claims

1. An array-type light modulation element drive method comprising steps of:

arranging a plurality of electromechanical light modulation elements for executing light modulation by displacement operation of respective flexible sections of the light modulation elements by an electrostatic force and elastic restoration operation of the flexible sections, selecting a pixel associated with one of the plurality of the electromechanical light modulation elements, giving a data signal to an electrode of the selected pixel for driving the selected pixel, and providing an AC signal to an electrode of said one of the plurality of electromechanical light modulation elements for executing AC drive of said one light modulation element.

2. The array-type light modulation element drive method as claimed in claim 1 wherein the AC drive of the light modulation element is provided by dividing a basic period of a scan drive signal into an odd frame and an even frame and a polarity of the scan drive signal is inverted in the odd and even frames.

3. The array-type light modulation element drive method as claimed in claim 2 wherein the AC drive of the light modulation element is AC drive in an active matrix structure of pixels.

4. The array-type light modulation element drive method as claimed in claim 3 wherein the active matrix structure is any of a mechanical conductive switch type active matrix structure, a mechanical switch type active matrix structure, or a semiconductor switch type active matrix structure.

5. The array-type light modulation element drive method as claimed in claim 1 wherein the AC drive of the light modulation element is AC drive in a simple matrix structure of pixels.

6. The array-type light modulation element drive method as claimed in claim 5 wherein the AC drive of the simple matrix structure is to set voltage across electrodes in an even frame, Veven, to the difference between applied voltage maximum value Vmax and voltage across electrodes in an odd frame, Vodd.

7. A drive method of a flat-panel display comprising an array-type light modulation element, a surface light source placed facing the array-type light modulation element, and a phosphor disposed on the opposite side to the surface light source with the array-type light modulation element between, said method comprising the steps of driving the array-type light modulation element by a drive method as claimed in any one of claims 1 to 6 and causing the phosphor to emit light for producing display by light emitted from the array-type light modulation element.

8. The flat-panel display drive method as claimed in claim 7 wherein the surface light source is a light source for emitting ultraviolet rays for exciting the phosphor.

9. The array-type light modulation element drive method as claimed in claim 1 wherein the AC drive of the light modulation element is AC drive in an active matrix structure of pixels and wherein the active matrix structure is any of a mechanical conductive switch type active matrix structure, a mechanical switch type active matrix structure, or a semiconductor switch type active matrix structure.

10. A drive method of a flat-panel display comprising an array-type light modulation element, a surface light source placed facing the array-type light modulation element, and a phosphor disposed on an opposite side to the surface light source with the array-type light modulation element between, said method comprising the steps of driving the array-type light modulation element by a drive method as claimed in claim 9 and causing the phosphor to emit light for producing display by light emitted from the array-type light modulation element.

11. The flat-panel display drive method as claimed in claim 10 wherein the surface light source is a light source for emitting ultraviolet rays for exciting the phosphor.

12. An array-type light modulation element drive method comprising steps of:

arranging a plurality of electromechanical light modulation elements in a two-dimensional matrix for executing light modulation by displacement operation of respective flexible sections of the electromechanical light modulation elements, providing a scan electrode signal to select a pixel associated with one of the plurality of the electromechanical light modulation elements, and giving an AC data signal to an electrode of the selected pixel for driving the selected pixel using AC drive.