Integrated synchronized optical sampling and control element

• US 7,812,297 B2
• Filed: 06/10/2008
• Issued: 10/12/2010
• Est. Priority Date: 06/26/2007
• Status: Expired due to Fees

• Current Assignee: Polaris PowerLED Technologies, LLC (Microchip Technology Incorporated)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Ferentz, Alon, Blaut, Roni, Korcharz, Dror, Jacubovski, Migel, Peker, Arkadiy
• Primary Examiner(s): Le; Que T
• Assistant Examiner(s): BENNETT, JENNIFER D
• Application Number:
  US12/136,095
• Publication Number:
  US 20090001253A1
• Time in Patent Office: 854 Days
• Field of Search: 250/205, 250/214.AL, 250/208.1, 250/214.R, 250/226, 315/219, 315/185.S, 315/224, 315/149, 315/155, 315/246, 315/247, 315/291, 315/294, 315/185.R, 345204-215, 345690-699, 345 87- 88, 345/99, 345/102, 345 83- 84, 362/227, 362/612, 362/800
• US Class Current: 250/205
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• 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 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

An optical sampling and control element for use with a luminaire exhibiting a cycle and a frame, the optical sampling and control element being constituted of a color sensor in optical communication with the luminaire; and a sampler connected to the outputs of the color sensor, the sampler comprising an integrator arranged to integrate the outputs of the color sensor over a predetermined period less than the frame.

Claims

1. An optical sampling and control element for use with a luminaire exhibiting a cycle and a frame, the optical sampling and control element comprising:

a color sensor in optical communication with the luminaire;

a synchronizer; and

a sampler connected to the outputs of said color sensor, said sampler comprising;

an integrator; and

an analog to digital converter in communication with said color sensor,

said analog to digital converter arranged to sample said color sensor, responsive to said synchronizer, at a plurality of adjacent cycles of said luminaire during a single frame, each of said plurality of adjacent cycles sampled at an offset from the previous cycle, and

said integrator arranged to sum the converted outputs of said analog to digital converter over a predetermined period less than the frame and normalize said sum.

2. An optical sampling and control element according to claim 1, further comprising a color manager arranged to receive the output of said sampler.

3. An optical sampling and control element according to claim 2, wherein said color manager comprises a pulse width modulation signal generator.

4. An optical sampling and control element according to claim 2, further comprising a light emitting diode driver arranged to receive the output of said color manager.

5. An optical sampling and control element according to claim 1, further comprising a color manager arranged to receive the output of said sampler, and wherein said color manager comprises:

a means for receiving a luminance setting input signal defining a luminance, on an individual frame basis, of the luminaire;

a means for receiving a color reference value;

a feedback controller requiring a plurality of frames to converge;

a modulated signal generator immediately responsive to said received luminance setting input signal and said feedback controller;

a scaler arranged to scale a first one of said received reference value and said output signal of said sampler, to be consonant with a second one of said received reference value and said output signal of said sampler; and

a difference circuit, arranged to output a signal representative of the difference between the output of said scaler and the output of said second one of said received reference value and said output signal of said sampler,

said feedback controller responsive to said output signal of said difference circuit to reduce said difference.

6. A method of optical sampling and control for use with a luminaire exhibiting a cycle and a frame, the method comprising:

receiving a tristimulus output representative of the luminaire;

periodically sampling said received tristimulus output at a predetermined period so as to sample said received tristimulus output at a plurality of adjacent cycles of said luminaire during a single frame, wherein said periodically sampling of each of said plurality of adjacent cycles is at an offset from the previous cycle;

digitizing each of said periodic samples to a digital representation; and

integrating said received tristimulus output over a predetermined period comprising at least one cycle and less than one frame by summing said digitized periodic samples over the predetermined period and normalizing said sum.

7. A method according to claim 6, further comprising controlling a color loop responsive to said integrated tristimulus output.

8. A method according to claim 7, further comprising generating a pulse width modulation signal responsive to said controlled color loop.

9. A method according to claim 8, further comprising driving said luminaire responsive to said generated pulse width modulation signal.

10. A method according to claim 6, further comprising:

receiving a luminance setting input signal defining the luminance of the luminaire on an individual frame basis;

receiving a color reference value;

scaling a first one of said received reference value and said integrated tristimulus output, to be consonant with a second one of said received reference value and said integrated tristimulus output; and

calculating a difference between said first one of said received reference value and said integrated tristimulus output, and said second one of said received reference value and said integrated tristimulus output.