Scanning device, image display device, and method for controlling image display device
AssigneeNEC Corporation
InventorHiroshi Imai
Life of this patent
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Abstract
A scanning device that scans a beam emitted from a light source, includes: a beam condensing unit that condenses the beam emitted from the light source; a beam diverging unit that is arranged on an output side of the beam condensing unit, and diverges the beam condensed by the beam condensing unit; a first scanning unit that is arranged between the beam condensing unit and the beam diverging unit, and scans the beam condensed by the beam condensing unit; and a moving unit that moves at least one of the beam condensing unit and the beam diverging unit along respective optical axis directions thereof, in accordance with a scan angle of the first scanning unit.
Claims7
A scanning device that scans a beam emitted from a light source, the scanning
- device comprising:
- a beam condensing unit that condenses the beam emitted from the light source;
- a beam diverging unit that is arranged on an output side of the beam condensing unit, and diverges the beam condensed by the beam condensing unit;
- a first scanning unit that is arranged between the beam condensing unit and the beam diverging unit, and scans the beam condensed by the beam condensing unit;
- a moving unit that moves at least one of the beam condensing unit and the beam diverging unit along respective optical axis directions thereof, in accordance with a scan angle of the first scanning unit;
- a polarizing beam splitter that is arranged between the beam condensing unit and the first scanning unit;
- and
- a ¼ wavelength plate that is arranged between the polarizing beam splitter and the first scanning unit.
A scanning device that scans a beam emitted from a light source, the scanning device comprising:
- a beam condensing unit that condenses the beam emitted from the light source;
- a beam diverging unit that is arranged on an output side of the beam condensing unit, and diverges the beam condensed by the beam condensing unit;
- a first scanning unit that is arranged between the beam condensing unit and the beam diverging unit, and scans the beam condensed by the beam condensing unit;
- a moving unit that moves at least one of the beam condensing unit and the beam diverging unit along respective optical axis directions thereof, in accordance with a scan angle of the first scanning unit;
- and
- a mirror that is arranged between the beam condensing unit and the first scanning unit, wherein the mirror is arranged so that an incident angle to the first scanning unit is less than 45 degrees.
A method for controlling an image display device which displays an image by scanning a beam on an external projection plane, the method comprising:
- emitting a beam from a light source;
- condensing the emitted beam by using a beam condensing unit;
- diverging the condensed beam by using a beam diverging unit that is arranged on an output side of the beam condensing unit;
- reflecting the diverged beam by using a mirror so that an incident angle to a first scanning unit is less than 45 degrees, the minor being arranged between the beam condensing unit and the beam diverging unit;
- moving at least one of the beam condensing unit and the beam diverging unit along respective optical axis directions according to a scan angle of the first scanning unit;
- and
- changing a distance between the beam condensing unit and the first scanning unit so as to position a beam focus point within a predetermined projection plane.
Dependencies are inferred from the claim text.