Projector and control method

• US 10,015,456 B2
• Filed: 01/17/2017
• Issued: 07/03/2018
• Est. Priority Date: 01/20/2016
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Toyooka, Takashi, Iguchi, Tatsuya
• Primary Examiner(s): Tran, Trang U
• Application Number:
  US15/408,176
• Publication Number:
  US 20170208303A1
• Time in Patent Office: 532 Days
• Field of Search: 348762, 348744, 362260
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• 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 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197
• 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 9/3158 for controlling the spectrum
• CPC Class Codes: H04N 9/3164 using multiple light sources
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A projector includes a light-emitting element that outputs light of a first wavelength band which is in a first polarization state; a retardation plate that converts a portion of the light into a second polarization state; a polarization separation element that separates the light into a first flux of light in the first polarization state and a second flux of light in a second polarization state; a phosphor, which outputs a third flux of light of a second wavelength band; an optical modulator that modulates the light in accordance with a video signal; a light-emitting element control unit that controls brightness of the light-emitting element in accordance with brightness information; and a retardation plate control unit that controls a rotation angle of the retardation plate in accordance with the brightness information.

Claims

1. A projector comprising:

a light-emitting element that outputs light of a first wavelength band which is in a first polarization state;

a retardation plate that converts a portion of the light output from the light-emitting element into a second polarization state in accordance with a rotation angle of the retardation plate;

a polarization separation element that separates the light from the retardation plate into a first flux of light in the first polarization state and a second flux of light in a second polarization state;

a phosphor, excited by the first flux of light, which outputs a third flux of light of a second wavelength band different from the first wavelength band;

an optical modulator that modulates the light in accordance with a video signal;

an integration unit that integrates a plurality of pieces of brightness information;

a light-emitting element control unit that controls brightness of the light-emitting element in accordance with the integrated plurality of pieces of brightness information; and

a retardation plate control unit that controls a rotation angle of the retardation plate in accordance with the brightness information.

2. The projector according to claim 1, wherein the brightness information includes brightness information which is set in accordance with a user'"'"'s instruction input.

3. The projector according to claim 1, further comprising a setting unit that sets the brightness information in accordance with an analysis result of the video signal.

4. The projector according to claim 1, further comprising:

a sensor that detects illuminance of the light which is output from the light-emitting element; and

a setting unit that sets the brightness information in accordance with an output of the sensor.

5. The projector according to claim 1,

wherein the retardation plate control unit controls the rotation angle of the retardation plate in accordance with brightness information integrated by the integration unit.

6. The projector according to claim 1, further comprising a color correction unit that performs color correction in accordance with the brightness information,

wherein the retardation plate control unit controls the rotation angle of the retardation plate in accordance with a correction result of the color correction unit.

7. The projector according to claim 6, further comprising a generation unit that generates a table for the color correction in accordance with input and output characteristics of the light-emitting element.

8. A control method comprising:

causing a light-emitting element to output light of a first wavelength band which is in a first polarization state;

causing a retardation plate to convert a portion of the light output from the light-emitting element into a second polarization state in accordance with a rotation angle of the retardation plate;

separating the light from the retardation plate into a first flux of light in the first polarization state and a second flux of light in a second polarization state;

causing a phosphor excited by the first flux of light to output a third flux of light of a second wavelength band different from the first wavelength band;

causing an optical modulator to modulate the light in accordance with a video signal;

integrating a plurality of pieces of brightness information;

controlling brightness of the light-emitting element in accordance with the integrated plurality of pieces of brightness information; and

controlling the rotation angle of the retardation plate in accordance with the brightness information.