Image displaying apparatus and method

• US 6,008,929 A
• Filed: 06/30/1998
• Issued: 12/28/1999
• Est. Priority Date: 07/02/1997
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tanaka, Yoshinori, Akimoto, Osamu
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/107,143
• Time in Patent Office: 546 Days
• Field of Search: 359/264, 359/290, 359/298, 345/59, 345/87, 345/88, 345/89, 345/98, 345/102, 348/770, 348/771
• US Class Current: 359/264
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3629 using liquid crystals having memory effects, e.g. ferroelectric liquid crystals

Abstract

An image displaying apparatus and method is provided which can provide a satisfactory display with a gradation of intensity even with a spatial light modulator which provides a binary light modulation. A light from a light source 1 is modulated by a spatial light modulator 3 which modulates a light at each pixel thereof correspondingly to a pixel data of an image to be displayed. When the pixel state of the spatial light modulator 3 is being changed, the light source 1 is turned off. When the pixel state of the spatial light modulator 3 is steady, a light pulse is irradiated from the light source 1 to the spatial light modulator 3 to display the image.

Claims

1. An image displaying apparatus, comprising:

a spatial light modulator having a plurality of pixels formed therein and modulating a light at each pixel thereof in a binary manner correspondingly to a pixel data of an image to be displayed; and

a light source which is turned off during changing in state of a pixel formed in the spatial light modulator, and irradiates a light pulse to the spatial light modulator while the pixel state is steady;

the light pulse from the light source being modulated by the spatial light modulator at each pixel to display the image.

2. The apparatus as set forth in claim 1, wherein the light source irradiates to the spatial light modulator a light pulse having a width varied correspondingly to the intensity of an image to be displayed.

3. The apparatus as set forth in claim 2, wherein the light source irradiates more than two light pulses for a period for which the pixel is held in the state steady.

4. The apparatus as set forth in claim 1, wherein the spatial light modulator holds the pixel thereof in the steady state for a period varied correspondingly to the intensity of an image to be displayed.

5. The apparatus as set forth in claim 1, wherein the light source irradiates to the spatial light modulator a number of light pulses which is variable depending on the intensity of an image to be displayed.

6. The apparatus as set forth in claim 5, wherein the spatial light modulator holds the pixel thereof in the steady state for a period varied correspondingly to the intensity of an image to be displayed.

7. The apparatus as set forth in claim 5, wherein the light source emits a light pulse at time points generally evenly distributed over a period for which the pixel state is held in the steady state.

8. The apparatus as set forth in claim 1, wherein the light source irradiates to the spatial light modulator a quantity of light pulse adjusted based on a product of an irradiation length of time and intensity.

9. A method of displaying an image, comprising the steps of:

modulating a light from a light source at each pixel of a spatial light modulator which modulates a light in a binary manner correspondingly to a pixel data of an image to be displayed;

turning off the light source during changing in pixel state of the spatial light modulator; and

irradiating a light pulse from the light source to the spatial light modulator while the pixel state of the spatial light modulator is steady.

10. The method as set forth in claim 9, wherein the light source irradiates to the spatial light modulator a light pulse having a width varied correspondingly to the intensity of an image to be displayed.

11. The method as set forth in claim 10, wherein the spatial light modulator holds the pixel thereof in the steady state for a period varied correspondingly to the intensity of an image to be displayed.

12. The method as set forth in claim 10, wherein the light source irradiates more than two light pulses for a period for which the pixel is held in the state steady.

13. The method as set forth in claim 9, wherein the light source irradiates to the spatial light modulator a number of light pulses which is variable depending on the intensity of an image to be displayed.

14. The method as set forth in claim 13, wherein the spatial light modulator holds the pixel thereof in the steady state for a period varied correspondingly to the intensity of an image to be displayed.

15. The method as set forth in claim 13, wherein the light source emits a light pulse at time points generally evenly distributed over a period for which the pixel state is held in the steady state.

16. The method as set forth in claim 9, wherein the light source irradiates to the spatial light modulator a quantity of light pulse adjusted based on a product of an irradiation length of time and intensity.