Beam scanning type display apparatus

Patent metadata

Field	Value
Publication number	US-9459448-B2
Application number	US-201314105318-A
Country	US
Kind code	B2
Filing date	Dec 13, 2013
Priority date	Feb 27, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A beam scanning type display apparatus includes a reflection angle variable mirror that scans a beam light, at least two light detectors disposed at a predetermined distance in a beam scanning direction of the mirror that detects a light amount of screen reflection light, a distortion correction calculation unit that obtains a drive correction value of the mirror by calculating an irradiation distance and a screen inclination, from a light amount of a reflection light detected by the light detectors at two different scanning timings and an inclination angle of the mirror at this time, and a mirror driving unit that controls an inclination angle of the mirror by the drive correction value. A drive correction value of the mirror driving unit is obtained at a plurality of timings of a scanning period of beam light, and beam light is scanned at the corrected inclination angle of the mirror.

First claim

What is claimed is:

1. A beam scanning type display apparatus which performs an image display on a screen by two-dimensionally scanning a beam light from a light source, comprising:
a light source driving unit that drives the light source;
a reflection angle variable mirror that performs beam scanning by reflecting a beam light from the light source;
at least two light detectors which detect a light amount of screen reflection light of the beam light, the light detectors being disposed at a predetermined distance in a beam scanning direction of the reflection angle variable mirror, the at least two light detectors being disposed at opposite sides of a scanning direction of an emitting unit that emits a beam light reflected by the reflection angle variable mirror;
a distortion correction calculation unit that obtains a drive correction value of the reflection angle variable mirror by calculating an irradiation distance to an irradiation point and a screen inclination of the irradiation point, from the light amount of the reflection light which is detected by the light detectors at two different scanning timings and a mirror inclination angle of the reflection angle variable mirror at this time; and
a mirror driving unit that controls an inclination angle of the reflection angle variable mirror by the drive correction value,
wherein the drive correction value is obtained at a plurality of timings of a scanning period of beam light, and the beam light is scanned by the reflection angle variable mirror controlled based on the drive correction value.

2. The beam scanning type display apparatus according to claim 1 , wherein the mirror drive correction is performed by changing an angle of the reflection angle variable mirror at a predetermined timing by changing a mirror angular speed.

3. The beam scanning type display apparatus according to claim 1 , wherein the mirror drive correction is performed by changing an angle of the reflection angle variable mirror at a predetermined timing by changing a deflection angle range of the reflection angle variable mirror.

4. The beam scanning type display apparatus according to claim 1 , wherein there are a detection period in which beam light is scanned and a drive correction value of the reflection angle variable mirror is obtained, and a display scanning period in which an image display is performed by scanning a beam light by controlling an inclination angle of the reflection angle variable mirror based on the drive correction value obtained in the detection period.

5. The beam scanning type display apparatus according to claim 4 , wherein the reflection angle variable mirror is driven by slowing down a scanning speed in the detection period, and
different operations of the reflection angle variable mirror are driven in the detection period and the display scanning period.

6. The beam scanning type display apparatus according to claim 1 , wherein the distortion correction calculation unit further calculates a light intensity value from the light amount of reflection light detected by the light detectors, and
the light source driving unit is corrected and driven based on the calculated light intensity value.

7. The beam scanning type display apparatus according to claim 6 , wherein the distortion correction calculation unit calculates the light intensity value for each of RGB colors, and
the light source driving unit respectively corrects and drives RGB light sources based on the calculated light intensity value for each of RGB colors.

8. The beam scanning type display apparatus according to claim 4 , wherein the detection period includes an external light removal period for detecting an external light amount, and
a drive correction value of the reflection angle variable mirror is obtained by a light intensity of reflection light which is obtained by subtracting a light intensity of the external light from a light intensity of screen reflection light of beam light.

9. The beam scanning type display apparatus according to claim 8 , wherein the distortion correction calculation unit includes an external light value storage unit that stores a light intensity of an external light detected in the external light removal period,
the light intensity of the external light detected by the light detectors is stored in the external light storage unit in the external removal period, and
a drive correction value of the reflection angle variable mirror is obtained by a light intensity of a screen reflection light which is obtained by subtracting the light intensity of the external light stored in the external light storage unit from a light intensity of a screen reflection light of beam light detected by the light detectors in the detection period in which beam light is scanned and the drive correction value of the reflection angle variable mirror is obtained.

10. The beam scanning type display apparatus according to claim 1 , wherein the light source includes RGB light sources and an infrared laser, and
the light detector includes a light receiving element that detects light of an infrared wavelength region, and detects a distance to an irradiation point and an inclination by scanning the infrared laser.

11. The beam scanning type display apparatus according to claim 10 , wherein the reflection angle variable mirror performs scanning only in one-dimensional direction when a distance and an inclination are detected.

Assignees

• Hitachi Maxell

Inventors

• Yamamoto Shoji
• Seo Yoshiho
• Betsui Keiichi

Classifications

• G02B26/0858

  the reflecting means being moved or deformed by piezoelectric means · CPC title

• H04N9/3182

  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 title

• G02B27/0031

  for scanning purposes · CPC title

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G02B26/105

  with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence) · CPC title