Display apparatus using pulsed light source

• US 7,869,115 B2
• Filed: 10/01/2008
• Issued: 01/11/2011
• Est. Priority Date: 11/01/2003
• Status: Expired due to Fees

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Endo, Taro, Maeda, Yoshihiro, Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Thomas; Brandi N
• Application Number:
  US12/286,805
• Publication Number:
  US 20090128883A1
• Time in Patent Office: 832 Days
• Field of Search: 259/290, 259/291, 259/242, 259/295, 259/298
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

The present invention provides a display apparatus, comprising: a light source; at least one spatial light modulator for modulating a luminous flux emitted from the light source; and controller for processing video image information, which is input, and controlling the light source and the spatial light modulator, wherein the controller controls the light source and the spatial light modulator so as to perform pulse emission of the light source during a period shorter than a period in which the spatial light modulator is controlled under a modulation state and also controls the light source so as to modulate the pulse emission during a period shorter than a period in which the spatial light modulator is controlled under a modulation state.

Claims

1. A display apparatus for displaying an image, comprising:

a light source;

at least one spatial light modulator (SLM) for modulating a luminous flux emitted from the light source; and

a controller for processing inputted video image data for controlling the light source and the spatial light modulator, wherein

the controller controls the light source to emit pulse emissions of different frequencies from the light source wherein at least two of said pulse emissions of two different frequencies are controlled to emit with a pulse width shorter than a minimum controllable period of an ON state of the spatial light modulator and at least two of the pulsed emissions with the two different frequencies are controlled to emit in at least two different and separated time periods within a same frame period of the spatial light modulator.

2. The display apparatus according to claim 1, wherein:

the controller applies the inputted video image data to generate a light source profile control signal to emit the pulsed emissions of the different frequencies from the light source in the two different time periods within the same frame period of the spatial light modulator controllable by the controller by applying a least significant bit (LSB) of the video image data.

3. The display apparatus according to claim 1, wherein:

the controller controls the light source to emit the pulse emissions with at least two of said pulse emissions having a pulse width shorter than the minimum controllable period of the ON state of the spatial light modulator (SLM) by applying a least significant bit (LSB) of the video image data and

wherein the controller controls the light source and the SLM to project a minimum controllable brightness increment of an image pixel smaller than an amount of brightness projected by said SLM when applying the LSB of the video image data when a constant pulse emission is projected from the light source through the entire period of the ON state of the SLM.

4. The display apparatus according to claim 1, wherein:

the light source further comprising a light emitting diode (LED) or a laser light source.

5. The display apparatus according to claim 1, wherein:

the spatial light modulator is controlled to operate in a plurality of modulation states comprising the ON state, an OFF state and intermediate states with amounts of brightness modulated by the SLM between the ON state and the Off state in accordance with a control signal received from the controller.

6. The display apparatus according to claim 1, further comprising:

a projector, wherein

the spatial light modulator comprising a mirror device further comprising a plurality of micromirrors, and

the projector projects a modulated light reflected from and modulated by the micromirrors of the spatial light modulator.

7. The display apparatus according to claim 6, wherein:

the spatial light modulator is controlled by a control signal received from the controller to operate in an ON state for guiding the pulsed emissions emitted from the light source to the projector, or an OFF state for guiding the pulsed emissions emitted from the light source away from the or an oscillation state when the micromirror is controlled to oscillate between the ON state and OFF state.

8. The display apparatus according to claim 1, wherein:

the controller receives the inputted video image data as binary data and converts the binary data into non-binary video image signal, wherein the spatial light modulator is controlled by applying the non-binary video image signal.

9. The display apparatus according to claim 1, wherein:

the controller controls the light source to emit the pulsed emissions of the different frequencies in different time periods during a period when the SLM is operated in a stable ON state.

10. The display apparatus according to claim 1, wherein:

the controller controls the light source to emit the pulsed emissions by modulating a pulse intensity of the pulsed emissions.

11. The display apparatus according to claim 1, wherein:

the controller controls the light source to emit the pulsed emissions by modulating a pulse cycle of the pulsed emissions.

12. The display apparatus according to claim 11, wherein:

the light source emits the pulsed emissions wherein each of said pulsed emission having a different frequency in a different subfield within a display frame period.

13. The display apparatus according to claim 1, wherein:

the controller generates a light source control profile signal according to the inputted video image data by controlling and switching on and off the light source at a flashing rate greater than a modulation rate of the spatial light modulator.

14. The display apparatus according to claim 1 wherein:

the controller further comprises a video image analyzer for analyzing the inputted video image data for generating a light source control profile signal according to the inputted video image data.

15. The display apparatus according to claim 13, wherein:

the controller adjusts a gamma correction of an input/output characteristic for displaying the image.