LASER PROJECTION DISPLAY DEVICE, AND METHOD FOR CONTROLLING LASER LIGHTSOURCE DRIVING UNIT USED FOR SAME

• US 20180013994A1
• Filed: 01/05/2016
• Published: 01/11/2018
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: Hitachi-Lg Data Storage Incorporated (Hitachi, Ltd.)
• Original Assignee: Hitachi-Lg Data Storage Incorporated (Hitachi, Ltd.)
• Inventors: OGI, Yuya, SEO, Yoshiho, NONAKA, Tomoyuki
• Granted Patent: US 10,051,249 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 2380/10 Automotive applications
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 5/028 Circuits for converting colour display signals into monochrome display signals
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3135 Driving therefor
• 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

Abstract

The laser projection display device includes: a photo-sensor for detecting the quantity of laser light generated by the laser light source; and an image processing unit for processing a drive signal on the basis of the quantity of light of the detected laser light and supplying the processed drive signal to a driving unit for the laser light source. Right after the dimming, the image processing unit supplies the drive signal to the driving unit for the laser light source on the basis of the quantity of light of the detected laser light within a second execution cycle shorter than a first execution cycle which is the execution cycle used during the normal operation.

Claims

1. A laser projection display device that projects laser light beams of a plurality of colors corresponding to image signals and displays an image corresponding to the image signals, comprising:

a laser light source that generates the laser light beams of the plurality of colors;

a laser light source driving unit that drives the laser light source;

an optical sensor that detects the amount of light of the laser light beams which are generated by the laser light source; and

an image processing unit that processes the image signals on the basis of the amount of light of the laser light beams detected by the optical sensor, and supplies a drive signal to the laser light source driving unit,

wherein the image processing unit performs a process of determining the drive signal in a first execution cycle and a second execution cycle that is shorter than the first execution cycle.

2. The laser projection display device according to claim 1, further comprising:

an illuminance sensor that detects brightness at the periphery of the laser projection display device,

wherein the image processing unit changes luminance of an image that is displayed from first luminance to second luminance in accordance with brightness that is detected by the illuminance sensor.

3. The laser projection display device according to claim 1,

wherein the image processing unit changes the luminance of the image that is displayed from first luminance to second luminance in accordance with an instruction of a user of the laser projection display device.

4. The laser projection display device according to claim 2,

wherein in the case of changing the first luminance to the second luminance, the image processing unit supplies a drive signal, which is updated in the first execution cycle, to the laser light source driving unit when the luminance of the image is the first luminance, and supplies a drive signal, which is updated in the second execution cycle, to the laser light source driving unit in a predetermined period after the luminance of the image is changed from the first luminance to the second luminance.

5. The laser projection display device according to claim 3,

wherein in the case of changing the first luminance to the second luminance, the image processing unit supplies a drive signal, which is updated in the first execution cycle, to the laser light source driving unit when the luminance of the image is the first luminance, and supplies a drive signal, which is updated in the second execution cycle, to the laser light source driving unit in a predetermined period after the luminance of the image is changed from the first luminance to the second luminance.

6. The laser projection display device according to claim 4,

wherein the drive signal is a current value corresponding to a threshold current value, a current gain, and each of the image signals, and

the image processing unit performs a process of determining the threshold current value with respect to the laser light source driving unit in the first execution cycle and the second execution cycle that is shorter than the first execution cycle.

7. The laser projection display device according to claim 4,

wherein the drive signal is a current value corresponding to a threshold current value, a current gain, and each of the image signals, and

the image processing unit performs a process of determining the current gain with respect to the laser light source driving unit in the first execution cycle and the second execution cycle that is shorter than the first execution cycle.

8. The laser projection display device according to claim 1, further comprising:

an image capturing element that captures an ambient image of the laser projection display device; and

an image analyzing unit that analyzes the image that is captured by the image capturing element,

wherein the image processing unit changes the luminance of the image, which is displayed in correspondence with an analysis result detected by the image analyzing unit, from the first luminance to the second luminance through third luminance.

9. The laser projection display device according to claim 1,

wherein the image processing unit drives the laser light source driving unit so that among the lasers of the plurality of colors, any one laser light beam is generated when changing luminance of the image that is displayed from first luminance to second luminance.

10. A laser projection display device that projects laser light beams of a plurality of colors corresponding to image signals and displays an image corresponding to the image signals, comprising:

a laser light source that generates the laser light beams of the plurality of colors;

a laser light source driving unit that drives the laser light source;

an optical sensor that detects the amount of light of the laser light beams which are generated by the laser light source; and

an image processing unit that processes the image signals on the basis of the amount of light of the laser light beams detected by the optical sensor, and supplies a drive signal to the laser light source driving unit,

wherein the image processing unit performs setting of the drive signal in a first setting cycle and a second setting cycle that is shorter than the first setting cycle with respect to the laser light source driving unit.

11. A method for controlling a laser light source driving unit that drives a laser light source of a laser projection display device that projects laser light beams of a plurality of colors corresponding to image signals and displays an image,

wherein a process of determining a drive signal of the laser light source driving unit is performed in a first execution cycle and a second execution cycle that is shorter than the first execution cycle.

12. The method for controlling a laser light source driving unit according to claim 11,

wherein in the case of changing luminance of the image that is displayed from first luminance to second luminance, a drive signal, which is updated in the first execution cycle, is supplied to the laser light source driving unit when the luminance of the image is the first luminance, and a drive signal, which is updated in the second execution cycle, is supplied to the laser light source driving unit in a predetermined period after the luminance of the image is changed from the first luminance to the second luminance.

13. The method of controlling a laser light source driving unit according to claim 11,

wherein the drive signal is a current value corresponding to a threshold current value, a current gain, and each of the image signals, and

a process of determining the threshold current value is performed with respect to the laser light source driving unit in the first execution cycle and the second execution cycle that is shorter than the first execution cycle.

14. The method for controlling a laser light source driving unit according to claim 12,

wherein the drive signal is a threshold current value of the laser.