Image displaying apparatus with control over the output ratio of a plurality of light sources

• US 7,675,013 B2
• Filed: 05/05/2006
• Issued: 03/09/2010
• Est. Priority Date: 05/12/2005
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Soeda, Yashuhiro, Ishihara, Keiichiro, Kobayashi, Shuichi
• Primary Examiner(s): Epps; Georgia Y
• Assistant Examiner(s): Legasse, Jr.; Francis M
• Application Number:
  US11/429,608
• Publication Number:
  US 20060255243A1
• Time in Patent Office: 1,404 Days
• Field of Search: 250/204, 250/205, 250/208.1, 359/201, 359/202, 359/204, 359/618, 359/629, 359/201.1, 359/201.2, 359/202.1, 359/204.4, 345/213
• US Class Current: 250/205
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 27/102 for generating a colour image from monochromatic image signal sources
• CPC Class Codes: G02B 27/104 for use with scanning systems scanning systems G02B26/10
• CPC Class Codes: G02B 27/108 for sampling a portion of a beam or combining a small beam in a larger one, e.g. wherein the area ratio or power ratio of the divided beams significantly differs from unity, without spectral selectivity
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• 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

Abstract

An image displaying apparatus displays a color image with favorable quality on a predetermined surface. A light source unit emits light beams within different wavelength ranges optically modulated by image information. A light combining unit combines light beams from the light source unit into a light beam. A scanning unit scans a scanned surface with the light beam from the light combining unit and forms an image thereon. A controlling unit synchronously controls the scanning unit and the light source unit. A dividing unit divides a light beam into more than one light beam within an arbitrary optical path on light-incident side of the scanning unit. A receiving unit and adjustment unit adjust quantity of light emission of one or more light source units based on the light quantity received by the receiving unit on one of the optical paths divided by the dividing unit.

Claims

1. An image displaying apparatus comprising:

a plurality of light source units for emitting light beams within wavelength ranges different from each other that are modulated based on image information;

a light combining unit for combining a plurality of light beams from the plurality of light source units into a single white light beam;

a scanning unit for scanning a scanned surface with the single white light beam from the light combining unit and forming image information on the scanned surface;

a light beam dividing unit, provided along an optical path between the light combining unit and the scanning unit, for dividing a single light beam into a plurality of light beams;

a light receiving unit for receiving a beam divided by the light beam dividing unit;

a controlling unit for synchronously controlling the scanning unit and the plurality of light source units, wherein the controlling unit controls the plurality of light source units so that light beams emitted therefrom are sequentially incident on the light receiving unit at sequential timings or at different timings; and

an adjustment unit for adjusting a quantity of light emission of at least one light source unit among the plurality of light source units based on light quantities of the light beams received by the light receiving unit,

wherein the light receiving unit is configured to receive light beams from a red light source unit and a green light source unit among the plurality of light source units but not a blue light beam from a blue light source unit among the plurality of light source units,

wherein the light combining unit includes;

a first dichroic mirror which reflects a part of light beam from the red light source unit and transmits a part of light beam from the green light source unit; and

a mirror which transmits the light beam from the red light source unit which has been reflected on the first dichroic mirror and the light beam from the green light source unit which has been transmitted through the first dichroic mirror, and reflects the light beam from the blue light source unit,

wherein the light beam dividing unit includes the first dichroic mirror,

wherein the light receiving unit is configured to sense the light beam from the red light source unit which has been transmitted through the first dichroic mirror and the light beam from the green source unit which has been reflected on the first dichroic mirror.

2. The image displaying apparatus according to claim 1, wherein a first scan region in which an image is formed by scanning with a light beam by the scanning unit, and a second scan region other than the first scan region exists on the scanned surface, and the adjustment unit performs light quantity adjustment of the at least one light source unit, wherein the quantity of light emission is adjusted based on light quantity received by the light receiving element when the scanning unit scan the second scan region.

3. The image displaying apparatus according to claim 1, wherein the light combining unit combines light beams from at least first and second light source units among the plurality of light source units into a single combined light beam, the light receiving unit is disposed on an optical path of the single combined light beam, and the adjustment unit performs light quantity adjustment of the first and second light source units using a signal from the light receiving unit.

4. An image pickup apparatus, wherein an image obtained through an image pickup portion that pickups images of an object is displayed on the image displaying apparatus according to claim 1.

5. The image displaying apparatus according to claim 1, wherein the green light source unit comprises an infrared light source unit configured to emit infrared light and a wavelength conversion element configured to perform wavelength conversion from the infrared light emitted form the infrared light source unit to green light.