Display control system for spatial light modulators

• US 7,545,553 B2
• Filed: 08/18/2007
• Issued: 06/09/2009
• Est. Priority Date: 08/30/2006
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Endo, Taro, Nishino, Hirokazu, Maeda, Yoshihiro, Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Choi; William C
• Application Number:
  US11/894,247
• Publication Number:
  US 20080074563A1
• Time in Patent Office: 661 Days
• Field of Search: 359/198, 359/213, 359/224, 359/237, 359/290
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• 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: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/312 Driving therefor driving of electronic spatial light modulators in displays other than projection devices G09G3/34, G09G3/36; control of liquid crystal elements G02F1/133; control of micromechanical modulators G02B26/08

Abstract

A display control system, comprises: a spatial light modulator (SLM) constituted by a plurality of pixel elements placed in array; a first control unit for controlling each of the plurality of pixel elements under a state of ON or OFF; a second control unit for controlling each of the plurality of pixel elements under a state other than the ON or OFF states; a control changeover unit for dividing one frame period, for each pixel element of the plurality thereof, into a period of the first control unit controlling and that of the second control unit controlling, and also changing over between a control of the first control unit and that of the second control unit for each pixel element of the plurality thereof; and a data division unit for dividing input data to each of the plurality of pixel elements into first control unit-use data, which is input to the first control unit, and second control unit-use data which is input to the second control unit in accordance with the content of the present input data.

Claims

1. A display system including a spatial light modulator (SLM) having a plurality of pixel elements for modulating a light to project an image comprising:

a first control unit for controlling each of the plurality of pixel elements for modulating said light under a state of ON or OFF;

a second control unit for controlling each of the plurality of pixel elements for modulating said light under a state other than the ON or OFF states; and

a control changeover unit for changing over from one of said first or second control unit to another control unit in modulating said light to project an image from each of said pixel elements.

2. The display system according to claim 1 wherein:

said control changeover unit further dividing a frame period for each of said pixel elements into a period for the first control unit and second control unit for controlling each of said pixel elements for modulating said light according to an ON/OFF state modulation and an intermediate state modulation.

3. The display system according to claim 2, wherein

the division data change unit changing the first control unit-data by subtracting a predetermined change value from said first control unit data and also changing the second control unit data by adding the change value to said second control unit data if a value of the second control unit data is smaller than a predetermined change threshold value.

4. The display system according to claim 1 further comprising:

a data division unit for dividing an input data for each of the plurality of pixel elements into first control unit data for inputting to the first control unit, and second control unit data for inputting to the second control unit depending on contents of said input data.

5. The display system according to claim 4, further comprising:

a data conversion process unit provided for applying a first data conversion process to the first control unit data in compliance with the first control unit and also applying a second data conversion process to the second control unit data in compliance with the second control unit, and

a division data change unit for checking the first control unit data and the second control unit data for determining whether to change a division of said first and second control unit data depending on data contents of said first and second control unit data as checked by said division data change unit.

6. The display control system according to claim 5, wherein

the division data change unit providing different data division ratios to the data division unit and said data division unit applying said different data division ratios for dividing the input data again;

and

the data conversion process unit applying said first and second data conversion processes again to covert said first and second control unit data after said data division dividing the input data by applying said different data dividing ratios.

7. The display system according to claim 1, wherein

the first control unit is a pulse width modulation (PWM) control unit for generating a display light intensity according to a total length of time each of said pixel elements is controlled at said ON state.

8. The display control system according to claim 7, wherein

the PWM control unit controls each of said pixel elements of the SLM at an ON state continuously for a period with a length of time equal to a value obtained by multiplying an integer to a predetermined control unit time duration in accordance with an input data.

9. The display control system according to claim 1, wherein

the second control unit is an intermediate state control unit for controlling a display light intensity according to an intermediate control process.

10. The display system according to claim 9, wherein

the SLM is a micromirror device comprising a plurality of mirror elements placed in array, and

the intermediate state control unit controls each of said mirror elements to operate in an oscillation state.

11. The display system according to claim 9, wherein

the intermediate state control unit controls each of said mirror elements to oscillate for a predefined time period in accordance with contents of received data.

12. The display control system according to claim 9, wherein

the intermediate state control unit controls each of said mirror elements to oscillate in a predefined time period according to a plurality of control unit time durations.

13. The display control system according to claim 9, wherein

the intermediate state control unit controls each of said mirror elements to oscillate a predefined number of times in accordance with contents of received data.