Color display apparatus

• US 7,944,605 B2
• Filed: 03/26/2009
• Issued: 05/17/2011
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Endo, Taro, Maeda, Yoshihiro, Shirai, Akira, Ishii, Fusao
• Primary Examiner(s): HASAN, MOHAMMED A
• Application Number:
  US12/383,711
• Publication Number:
  US 20090190045A1
• Time in Patent Office: 782 Days
• Field of Search: 359/318, 359290-298, 359/224.1
• US Class Current: 359/295
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• CPC Class Codes: H04N 9/3123 using pulse width modulation

Abstract

A color display apparatus includes a color changeover unit for changing over colors of an illumination light or a projection light, and a control circuit for applying a video signal for generating a control signal for controlling a spatial light modulator, wherein the control circuit further applying the video signal for generating a control signal during a transition period when the illumination and/or the projection light are projected with a first color coexisting with a second color as the color changeover unit changing over the colors of the illumination light or projection light from the first color to the second color.

Claims

1. A color display apparatus, comprising:

a color changeover unit for changing over colors of an illumination light or a projection light, and

a control circuit for applying a video signal for generating a control signal for controlling a spatial light modulator, wherein the control circuit generating the control signal corresponding to a first color or a second color during a transition period immediately at the end of a display frame period in transition to a next display frame period when the illumination and/or the projection light are projected with a first color overlapping with a second color as the color changeover unit changes over the colors of the illumination light or projection light from the first color to the second color at a beginning or an end point of the transition period.

2. The apparatus according to claim 1, wherein:

said control circuit further receives the video signal as binary data for generating the control signal comprising non-binary data.

3. The apparatus according to claim 1, wherein:

the spatial light modulator applies data of a lower bit of the video signal to modulate the illumination light during the transition period when the color changeover unit changing the colors.

4. The apparatus according to claim 1, wherein:

the spatial light modulator comprising a mirror device comprising a plurality of micromirrors wherein each of said micromirrors is controlled to operate in three states for modulating and reflecting the illumination light having a maximum light intensity, an intermediate light intensity and a minimum light intensity.

5. The apparatus according to claim 1, wherein:

the spatial light modulator includes a plurality of pixel elements, wherein each of the pixel elements is controlled for generating an intermediate light intensity during the transition period when the color changeover unit changing the colors of the illumination light and/or the projection light.

6. The apparatus according to claim 1, wherein:

the spatial light modulator, including the plurality of pixel elements is implemented as a mirror device including a plurality of micromirrors, wherein each of the micromirrors is controlled to operate in an intermediate state between an ON state and an OFF state, when each of the pixel elements is controlled to generate an intermediate light intensity during a transition period when the color changeover unit changing the colors of the illumination light and/or the projection light.

7. The apparatus according to claim 1, wherein:

the color changeover unit comprises a color wheel or a wavelength selection switch element for changing over a wavelength transmitted through the element in the transition period immediately at the end of the display frame period in transition from the display frame period to the next display frame period.

8. The apparatus according to claim 1, wherein:

the color changeover unit comprises a rotation wheel comprising a plurality of wavelength-selective polarization element.

9. The apparatus according to claim 1, further comprising:

a plurality of semiconductor light sources for emitting illumination lights of different wavelengths, and

the color changeover unit comprises a light source control circuit for sequentially changing over lights emitted from each of the plurality of semiconductor light sources.

10. A color display apparatus, comprising:

a polarizing direction changeover unit for changing over a polarizing direction of an illumination light or a projection light,

a control circuit for applying a video signal for generating a control signal in accordance with the polarizing direction; and

a spatial light modulator, wherein the spatial light modulator applying the control signal generated by the control circuit corresponding to the polarization direction to modulate the illumination light in a transition modulation state during a transition period immediately at the end of a display frame period in transition to next display frame period for controlling when the polarizing direction changeover unit changes over the polarizing directions of the illumination light or projection light from a first polarizing direction to a second polarizing direction at a beginning or an end point of the transition period.

11. The apparatus according to claim 10, wherein:

said control circuit further receives the video signal as binary data for generating the control signal comprising non-binary data.

12. The apparatus according to claim 10, wherein:

the polarizing direction changeover unit comprises a polarization element or an element comprising a wave plate.

13. The apparatus according to claim 10, further comprising:

a light source for projecting the illumination light of different colors with each of said color projected with a different polarizing direction.

14. A method to display a color video image from a display apparatus comprising a spatial light modulator comprising:

applying a control signal corresponding to a first color or a second color to modulate the spatial light modulator during a first transition period when a light of a first color coexists with a second color in changing over from the first color to second color; and

the step of controlling the spatial light modulator further comprising a step of applying a second control signal corresponding to the second color different from the control signal to modulate the spatial light modulator when the light of the second color coexists with a third color when the light is changed over from the second color to the third color.

15. A method to display a color video image from display apparatus comprising a spatial light modulator comprising:

applying a second control signal corresponding to the second color generated in a first transition period when changing from a first color to a second color to control the spatial light modulator when a light of the first color coexists with the light of the second color in changing over from the first color to the second color, and

applying the second control signal generated in a second transition period when changing from the second color to a third color to control the spatial light modulator when the light of the second color coexists with the third color in changing over from the second color to the third color.

16. A method to display a color video image from a display apparatus comprising a spatial light modulator having a plurality of pixel elements comprising:

applying a video signal for controlling each of said pixel elements during a transition period immediately at the end of a display frame period in transition to next display frame period when changing from a first color with the light of the first color overlaps with the second color in changing over from the first color to the second color if a brightness of the video signal for the pixel element is greater than or equal to a predefined value, and

controlling the pixel element to operate in an OFF state during the transition period immediately at the end of the display frame period in transition to next display frame period if the brightness of the video signal for the pixel element is smaller than the predefined value.

17. The method according to claim 16, wherein:

The step of applying the video signal further comprising a step of applying a video signal comprising binary data, and

generating non-binary data from the binary data, wherein

the step of applying the video signal to control the spatial light modulator further comprising a step of applying the non-binary data to control the spatial light modulator.

18. A color display apparatus, comprising:

a color changeover unit for changing over the colors of an illumination light or projection light, and

a spatial light modulator for applying a video signal to modulate the illumination light by modulating the illumination light of different colors in synchronization with the color changeover unit in changing between light of the different colors, and wherein the color changeover unit further changes between the different colors in synchronization with a beginning or an end point of a transition period immediately at the end of a display frame period in transition from the display frame period to a next display frame period with at least two of said different colors overlapping with each other.

19. The color display apparatus according to claim 18, wherein:

the color changeover unit further controls the colors of the illumination light or projection light to adjust a timing of color changeover to synchronize with the spatial light modulator depending on a changeover of the different colors.

20. A method to display a color video image from a display apparatus comprising a spatial light modulator having a plurality of pixel elements comprising:

applying a first control signal corresponding to a first color to modulate the spatial light modulator during a first transition period when a light of a first color overlaps with a second color in changing over from the first color to second color; and

applying a second control signal corresponding to a third color to modulate the spatial light modulator during a second transition period when a light of the second color overlaps with the third color in changing over from the second color to third color.