LIGHT SOURCE UNIT AND PROJECTOR

• US 20150380898A1
• Filed: 09/04/2015
• Published: 12/31/2015
• Est. Priority Date: 03/06/2013
• Status: Active Grant

• Current Assignee: Ushio Denki Kabushiki Kaisha
• Original Assignee: Ushio Denki Kabushiki Kaisha
• Inventors: Okamoto, Masashi, Samejima, Takanori, Miura, Yuichi, Tsukamoto, Shohei, Yamada, Hirotaka
• Granted Patent: US 9,615,069 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: H01S 5/0683 by monitoring the optical output parameters
• 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 9/3182 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
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A light source unit includes: a plurality of elemental light sources each including one or more light emitting elements and one or more drive circuits; a control circuit; and a plurality of color band light characteristic measurement sections each configured to receive light to generate color band light characteristic measurement data. A plurality of the light emitting elements in the elemental light sources includes light emitting elements different in wavelength band of emission wavelength from one another. The color band light characteristic measurement sections are provided corresponding to a plurality of the wavelength bands. One or more of the color band light characteristic measurement sections include a first light intensity measurement section and a second light intensity measurement section. The control circuit generates light intensity indicating values and wavelength deviation indicating values, generates color phase indicating values, and performs first feedback control on the drive circuits.

Claims

1. A light source unit comprising:

a plurality of elemental light sources each including one or more light emitting elements and one or more drive circuits, and each configured to emit output luminous flux to outside, the one or more drive circuits being provided corresponding to the respective light emitting elements and each being configured to drive corresponding light emitting element, the output luminous flux being configured of radiated light from the one or more light emitting elements;

a control circuit configured to control the drive circuits; and

a plurality of color band light characteristic measurement sections each configured to receive light of a quantity correlated with light intensity of the output luminous flux to generate color band light characteristic measurement data, wherein

a plurality of the light emitting elements in the plurality of elemental light sources include a plurality of light emitting elements different in wavelength band of emission wavelength from one another,

the plurality of color band light characteristic measurement sections are provided corresponding to a plurality of the wavelength bands,

one or more of the plurality of color band light characteristic measurement sections include a first light intensity measurement section and a second light intensity measurement section, the first light intensity measurement section having first spectral sensitivity characteristics in a corresponding wavelength band and generating first light intensity measurement data as the color band light characteristic measurement data, and the second light intensity measurement section having second spectral sensitivity characteristics different in rate of sensitivity varying against wavelength varying from the first spectral sensitivity characteristics and generating second light intensity measurement data as the color band light characteristic measurement data,

the control circuit generates light intensity indicating values correlated with light intensity and wavelength deviation indicating values correlated with deviation from normal wavelength, with use of local color band spectral sensitivity information, based on the first light intensity measurement data and the second light intensity measurement data, the local color band spectral sensitivity information including sensitivity value at the normal wavelength and the rate of sensitivity varying against wavelength varying for each of the first and second spectral sensitivity characteristics, and

the control circuit generates color phase indicating values correlated with color of integrated light of the output luminous flux and performs first feedback control on the drive circuits to allow a difference between the color phase indicating values and target values to be small, with use of the wavelength deviation indicating values and local color band color matching function information, the local color band color matching function information including function values of a color matching function at the normal wavelength and rate of the color matching function output varying against wavelength varying.

2. The light source unit according to claim 1, wherein the control circuit generates a brightness indicating value that is correlated with brightness of integral light of the output luminous flux, and performs second feedback control on the drive circuits to allow a difference between the brightness indicating value and a target value.

3. The light source unit according to claim 1, wherein the control circuit determines coefficients of linear operation, the linear operation representing variation of the color phase indicating values when the light emitting intensity indicating values for the respective wavelength bands are slightly varied, with use of variation of the light emitting intensity indicating values, and determines the variation of the light emitting intensity indicating values for the respective wavelength bands through the coefficients to perform the first feedback control

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

the first light intensity measurement section includes a first optical sensor,

the second light intensity measurement section includes a second optical sensor, and

a light characteristic filter is provided on a front surface of one or both of the first optical sensor and the second optical sensor.

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

the first light intensity measurement section is realized by a light intensity measurement section provided with time-divisional characteristic variation,

the second light intensity measurement section is realized by the light intensity measurement section provided with time-divisional characteristic variation that is different from the time-divisional characteristic variation provided for the first light intensity measurement section,

the light intensity measurement section includes an optical sensor, and

when the light intensity measurement section functions as the second light intensity measurement section, a light characteristic filter different from a light characteristic filter when the light intensity measurement section functions as the first light intensity measurement section, is provided.

6. The light source unit according to claim 1, wherein one or both of an optical sensor included in the first light intensity measurement section and an optical sensor included in the second light intensity measurement section are image pickup elements.

7. A projector comprising:

the light source unit according to claim 1; and

an optical system configured to use the output luminous flux emitted from the light source unit, to project and display an image.