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US 2004/0061848 A1Published application
Angle detecting apparatus and projector having the same
AssigneeSeiko Precision Inc.
InventorsShiroshi Kanemitsu, Hirobumi Okuyama
Life of this patent
Estimating the term…
Abstract
A control circuit computes relative horizontal and vertical inclination angles between a screen and a projector by a line-type passive range-finding device. A display driving section adjusts a projection optical system including a condensing lens on the basis of the vertical and horizontal inclination angles computed by the control circuit, thereby correcting for a keystone distortion in an image projected.
Claims20
An angle detecting apparatus comprising:
- one or more line-type passive range-finding devices for performing a range-finding operation, each line-type passive range-finding device having a pair of lenses spaced apart from each other by a baseline length, a line sensor disposed behind the lenses so that a pair of images of an object are focused by the respective lenses onto the line sensor, and an operating section for performing the range-finding operation in a plurality of mutually different directions on the basis of an output of the line sensor;
- and an inclination-angle computing section for computing an inclination angle of the object relative to a direction of the baseline length on the basis of an output of the line-type passive range-finding device.
A projector comprising:
- an image generating section for generating an image to be projected and outputting display data;
- a display section having a projection optical system including a condensing lens and a display driving section for receiving the display data and driving the projection optical system to project the image onto a surface based on the display data;
- a pair of lenses spaced apart from each other by a baseline length;
- a sensor disposed behind each lens onto which images of the surface are focused;
- an operating section for performing a range-finding operation in a plurality of mutually different directions on the basis of outputs of the sensors;
- and a control circuit for computing an inclination angle of the surface relative to a direction of the baseline length on the basis of outputs of the sensors and controlling one of the image generating section and the projection optical system on the basis of the inclination angle to correct for keystone distortion in the projected image.
3 more elements
A projector according to claim 17;
- further comprising a second line-type passive range-finding device oriented perpendicularly with respect to the first line-type passive range-finding device;
- wherein the control circuit computes inclination angles based on outputs of the first and second line-type passive range-finding devices.
A projector comprising:
- an image generating section for generating an image to be projected and outputting display data;
- a display section having a projection optical system including a condensing lens and a display driving section for receiving the display data and driving the projection optical system to project the image onto a surface based on the display data;
- one or more line-type passive range-finding devices for performing a range-finding operation each having a pair of lenses spaced apart from each other by a baseline length, a line sensor disposed behind the lenses so that a pair of images of the surface are focused by the respective lenses onto the line sensor, and an operating section for performing the range-finding operation in a plurality of mutually different directions on the basis of an output of the line sensor;
- and a control circuit for computing an inclination angle of the surface relative to a direction of the baseline length on the basis of an output of the line-type passive range-finding device, and controlling one of the image generating section and the projection optical system on the basis of the inclination angle to correct for keystone distortion in the projected image.
1 more element
Dependencies are inferred from the claim text.