Light source unit and projector

• US 10,191,362 B2
• Filed: 02/06/2017
• Issued: 01/29/2019
• Est. Priority Date: 08/08/2014
• Status: Active Grant

• Current Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Original Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Inventors: Okamoto, Masashi, Samejima, Takanori, Oda, Fumihiko
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Sathiraju, Srinivas
• Application Number:
  US15/425,780
• Publication Number:
  US 20170146897A1
• Time in Patent Office: 722 Days
• Field of Search: None
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129
• CPC Class Codes: H04N 9/3164 using multiple light sources
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607
• CPC Class Codes: H04N 9/3194 including sensor feedback
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A light source unit includes: elemental light sources each including light emitting elements and drive circuits; an integrated control circuit that controls the drive circuits; and band optical characteristic acquisition sections that receive light of an amount correlated with a total light amount of output luminous fluxes to acquire light emitting intensity indicating values and wavelength deviation indicating values. The integrated control circuit at least intermittently acquires band optical characteristic acquisition data to generate the light emitting intensity indicating values and the wavelength deviation indicating values. The integrated control circuit holds light emitting intensity indicating value target variation information, and determines the variation of the light emitting intensity indicating values, in accordance with the light emitting intensity indicating value target variation information belonging to one appearance mode of the wavelength deviation indicating values assumed on a basis of an actual mode of the generated wavelength deviation indicating values.

Claims

1. A light source unit, comprising:

a plurality of elemental light sources each including light emitting elements and drive circuits, the light emitting elements that emit light of an emission wavelength including a plurality of different wavelength bands, and the drive circuits respectively driving the light emitting elements;

an integrated control circuit that controls the drive circuits; and

band optical characteristic acquisition sections that receive light of an amount correlated with a total light amount of output luminous fluxes, acquire light emitting intensity indicating values correlated with light intensity for the respective different wavelength bands and acquire wavelength deviation indicating values correlated with deviation from a reference wavelength for one or more of the different wavelength bands, the output luminous fluxes being collection of light beams emitted from light emitting elements,

wherein the integrated control circuit at least intermittently acquires band optical characteristic acquisition data and generate the light emitting intensity indicating values and the wavelength deviation indicating values, the band optical characteristic acquisition data being generated by the band optical characteristic acquisition sections,

the integrated control circuit holds light emitting intensity indicating value target variation information, the light emitting intensity indicating value target variation information being used to reduce difference between color phase indicating values correlated with the integrated light color of the output luminous fluxes and target color phase indicating values by feedback control of the drive circuits, the feedback control being performed to reduce difference between the light emitting intensity indicating values and target light emitting intensity indicating values for the respective different wavelength bands, and the light emitting intensity indicating value target variation information being used for determination of variation of the light emitting intensity indicating values with respect to the target light emitting intensity indicating values for the respective different wavelength bands matched to each of assumed appearance modes of the wavelength deviation indicating values, and

the integrated control circuit determines the variation of the light emitting intensity indicating values for the respective different wavelength bands, in accordance with the light emitting intensity indicating value target variation information belonging to one appearance mode assumed on a basis of an actual mode of the generated wavelength deviation indicating values, out of the appearance modes of the wavelength deviation indicating values.

2. The light source unit according to claim 1, wherein the light emitting intensity indicating value target variation information held by the integrated control circuit is calculated and generated by solving an equation, the equation representing, using the variation of the light emitting intensity indicating values, variation of the color phase indicating values when the light emitting intensity indicating values are slightly varied for the respective different wavelength bands.

3. The light source unit according to claim 1, wherein the integrated control circuit determines the variation of the light emitting intensity indicating values for the respective different wavelength bands to reduce difference between brightness indicating values and target brightness indicating values, the brightness indicating values being correlated with total brightness of light of the output luminous fluxes.

4. The light source unit according to claim 1, wherein

the band optical characteristic acquisition sections each include:

a wavelength dispersive optical element that changes a traveling direction of light included in a received measurement-use output luminous flux on a basis of a wavelength of the light, and

an imaging element that detects a distribution pattern formed rearward by the light of which the traveling direction is changed by the wavelength dispersive optical element, and

the band optical characteristic acquisition sections each generate the band optical characteristic acquisition data with use of the wavelength dispersive optical element and the imaging element.

5. The light source unit according to claim 1, wherein

one of the band optical characteristic acquisition sections for one or more of the different wavelength bands includes:

a first light amount measurement section having first spectral sensitivity characteristics relating to spectral sensitivity characteristics of the one or more of the wavelength bands, and

a second light amount measurement section having second spectral sensitivity characteristics that are different in variation rate of sensitivity with respect to wavelength variation from the first spectral sensitivity characteristics, and

the integrated control circuit holds local band spectral sensitivity information that includes variation rates of the sensitivity with respect to the wavelength variation and a sensitivity value at a reference wavelength of the first spectral sensitivity characteristics and the second spectral sensitivity characteristics, and

the integrated control circuit acquires first light amount measurement data serving as the band optical characteristic acquisition data generated by the first light amount measurement sections and second light amount measurement data serving as the band optical characteristic acquisition data generated by the second light amount measurement sections, and uses the local band spectral sensitivity information to generate and acquire the light emitting intensity indicating values and the wavelength deviation indicating values on a basis of the first light amount measurement data and the second light amount measurement data.

6. The light source unit according to claim 1, wherein

the band optical characteristic acquisition sections each include:

a light amount detector that detects a light amount of the received measurement-use output luminous flux, and

a temperature detector that detects temperature of the light emitting elements,

the band optical characteristic acquisition sections each generate the band optical characteristic acquisition data with use of the light amount detector and the temperature detector, and

the integrated control circuit estimates the wavelength deviation indicating values on a basis of the detected temperature of the light emitting elements.

7. The light source unit according to claim 1, wherein

the band optical characteristic acquisition sections each include:

a light amount detector that detects a light amount of the received measurement-use output luminous flux, and

a power detector that detects an amount correlated with power supplied to the light emitting elements,

the band optical characteristic acquisition sections each generate the band optical characteristic acquisition data with use of the light amount detector and the power detector, and

the integrated control circuit estimates the wavelength deviation indicating values on a basis of the detected power supplied to the light emitting elements.

8. The light source unit according to claim 6, wherein the light amount detector is an imaging element.

9. A projector comprising the light source unit according to claim 1 and a projection display section that projects an image using the light source unit.