System and method for driving a light delivery device

• US 6,963,440 B2
• Filed: 02/13/2004
• Issued: 11/08/2005
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Martin, Eric T., Ghozeil, Adam L, Gelhaus, Matthew
• Primary Examiner(s): Dang, Hung Xuan
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/779,260
• Publication Number:
  US 20050179979A1
• Time in Patent Office: 634 Days
• Field of Search: 359/238, 359/249, 359/290, 359/291, 359/292, 359/295, 359/296, 359/230, 359/214, 359/224, 359/239, 359/297, 345/204
• US Class Current: 359/290
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/147 the originated light output being determined for each pixel
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A light delivery device defining an optical path with a feedback device is disclosed. The feedback device dispatches actual illumination characteristics of the light delivery device to a control system, which compares the actual illumination characteristics with desired illumination characteristics to determine an offset for driving the light delivery device.

Claims

1. A light delivery device comprising:

a display device defining an optical path of light;

a system adapted to drive the display device with at least one predefined voltage intended to elicit at least one desired frequency of light from the display device;

a feedback device adapted to be positioned along the optical path of light;

wherein the system is adapted to receive information from the feedback device representing an actual frequency of light generated by the display device and to compare the actual frequency with the desired frequency to determine an offset; and

wherein the system is adapted to cause the display device to be driven based on the offset.

2. The light delivery device according to claim 1, further comprising:

an illumination source projecting light onto an array of optical modulation elements to define the optical path; and

wherein the display device is adapted to reflect desired frequencies of light based on the predefined voltage supplied from the system.

3. The light delivery device according to claim 1, wherein the system further includes:

a calibration control adapted to drive the display device with the predefined voltage;

an array driver circuitry;

wherein the calibration control device receives the information from the feedback device and receives driver information representing the desired frequency from the array driver circuitry;

wherein the calibration control determines the offset based on the information from the feedback device and the driver information; and

wherein the array driver circuitry is adapted to drive the display device with a new voltage based on the offset.

4. The light delivery device according to claim 1, wherein the information from the feedback device is intensity and frequency information of light read by the feedback device.

5. The light delivery device according to claim 4, wherein the system is adapted to determine a mean value of the frequency of light read by the feedback device based on the intensity and frequency information.

6. The light delivery device according to claim 1, wherein the feedback device is positioned along only a portion of a cross-section of the optical path to read only a portion of light emitted from the display device.

7. The light delivery device according to claim 1, further comprising:

a motor electrically connected to the system;

a mirror connected to the motor;

wherein the motor is adapted to move the mirror between a first position and a second position;

wherein the first position locates the mirror out of the optical path; and

wherein the second position locates the mirror in the optical path and directs light from the display device to the feedback device.

8. The light delivery device according to claim 7, wherein the system is adapted to:

initiate a timer;

instruct the motor to move the mirror to the second position after the timer passes a predetermined time;

determine the offset; and

instruct the motor to move the mirror to the first position after the offset has been determined.

9. The light delivery device according to claim 1, wherein the display device comprises a plurality of optical modulation elements organized into an array.

10. The light delivery device according to claim 9, wherein the system is adapted to instruct each of the optical modulation elements to emit a same desired frequency before determining the offset.

11. The light delivery device according to claim 1, wherein:

the display device comprises a plurality of optical modulation elements organized into an array, each of the optical modulation elements comprising;

an outer semitransparent plate;

a reflective middle plate positioned substantially parallel to and spaced from the semitransparent plate;

a lower plate connected to a first potential; and

at least one spring positioned between the at least one reflective middle plate and the lower plate;

wherein the reflective middle plate connects to the system to generate a capacitance between the reflective middle plate and the first potential and move the reflective middle plate to a position defining a distance between the reflective middle plate and the outer semitransparent plate; and

wherein the distance between the reflective middle plate and the outer semitransparent plate defines the desired frequency.

12. The light delivery device according to claim 1, wherein the system is adapted to effectuate calibration of the display device during a step of a manufacturing process.

13. The light delivery device according to claim 1, further comprising a thermal sensor in thermal contact with the display device.

14. The light delivery device according to claim 13, wherein the system is responsive to the thermal sensor to determine the offset when the thermal sensor detects that the display device has reached a predetermined temperature.

15. A method for calibrating a display device, comprising:

positioning a feedback device along an optical path from the display;

reading illumination characteristics from the display device with the feedback device;

determining a desired frequency of light projected from the display device;

determining an actual frequency of light projected from the display device based on the illumination information;

determining an offset based on a difference between the desired frequency and the actual frequency; and

driving the display device based on the offset.

16. The method according to claim 15, wherein the illumination information is an intensity and frequency of light projected from the display device.

17. The method according to claim 16, wherein the step of determining the actual frequency of light further comprises:

determining a peak value of the intensity of the illumination characteristics;

determining a frequency range of the illumination characteristics; and

determining a mean value of the actual frequency based on the intensity and the frequency.

18. The method according to claim 15, wherein the step of positioning further comprise moving a mirror into the optical path to direct light from the display device to the feedback device.

19. The method according to claim 18, further comprising:

initiating a timer;

moving the mirror into the optical path after a predetermined amount of time has elapsed;

determining the offset; and

moving the mirror out of the optical path.

20. The method according to claim 18, further comprising:

sensing a temperature of the display;

moving the mirror into the optical path when the temperature of the display reaches a predetermined temperature;

determining the offset; and

moving the mirror out of the optical path.

21. The method according to claim 15, wherein the display device comprises a plurality of optical modulation elements organized into an array.

22. The method according to claim 21, wherein the system instructs each of the optical modulation elements to emit a same desired frequency before determining the offset.

23. The method according to claim 15, wherein:

the display device comprises a plurality of optical modulation elements organized into an array, each of the optical modulation elements comprising;

an outer semitransparent plate;

a reflective middle plate positioned substantially parallel to and spaced from the semitransparent plate;

a lower plate connected to a first potential; and

at least one spring positioned between the at least one reflective middle plate and the lower plate;

wherein the reflective middle plate connects to the system to generate a capacitance between the reflective middle plate and the first potential and move the reflective middle plate to a position defining a distance between the reflective middle plate and the outer semitransparent plate; and

wherein the distance between the reflective middle plate and the outer semitransparent plate defines the desired frequency.

24. The method according to claim 15, wherein the step of positioning is performed during a step in a manufacturing process.

25. The method according to claim 15, wherein the reading step is performed on only a portion of light along a cross-section of the optical path generated by the display.

26. The method according to claim 15, wherein the display device comprises a plurality of diffractive based light devices.

27. A light delivery device comprising:

a display device means for defining an optical path of light;

a system means for driving the display device means with at least one predefined voltage to elicit at least one desired frequency of light from the display device means;

a feedback device means positioned along the optical path of light for reading a frequency of light from the display device means;

wherein the system means is for receiving information from the feedback device means representing a actual frequency of light read from the display device means and comparing the actual frequency with the desired frequency to determine an offset; and

wherein the system means is for effectuating calibration of the display device means to drive the display device means based on the offset.

28. The light delivery device according to claim 27, further comprising:

an illumination source means for projecting light onto an array of optical modulation elements to define the optical path; and

wherein the display device means is for reflecting desired frequencies of light based on the predefined voltage supplied from the system means.

29. The light delivery device according to claim 27, wherein the system means further includes:

a calibration control means for driving the display device means with the predefined voltage;

an array driver circuitry means for generating driver information representing a desired frequency for display by the display device means;

wherein the calibration control means is for receiving the information from the feedback device means and receiving the driver information from the array driver circuitry and determining the offset; and

wherein the array driver circuitry means is for driving the display device with a new voltage based on the offset.

30. The light delivery device according to claim 27, wherein the information from the feedback device means is intensity and frequency information of light read by the feedback device.

31. The light delivery device according to claim 30, wherein the system means is for determining a mean value of the frequency of light read by the feedback device means based on the intensity and frequency information.

32. The light delivery device according to claim 27, wherein the feedback device means is positioned along only a portion of a cross-section of the optical path to read only a portion of light emitted from the display device means.

33. The light delivery device according to claim 27, further comprising to a mirror means for directing light between a first direction not at the feedback device and a second direction toward the feedback device.

34. The light delivery device according to claim 33, wherein the display device means comprises a plurality of optical modulation element means organized into an array and for generating light.

35. The light delivery device according to claim 27, further comprising a thermal sensor means for determining the offset.