Image display apparatus and image distortion correction method of the same
View Patent ↗An image display apparatus includes a projector receiving an image signal and projecting image light and a screen including a projection plane of arbitrary shape. The projector and screen are connected with link mechanisms and link mechanisms. The relative position and posture between the projector and the screen are automatically or manually changeable. The relative position and posture between the projector and the screen are measured, and correction parameters for correcting distortion of image light projected from the projector onto the screen are calculated from the previously set viewing position of the viewer and the shape of the projection plane of the projector. Based on the calculated correction parameters, the image signal inputted into the projector is subjected to distortion correction processing. It is therefore possible to allow the viewer to see a clear image even if the position of the screen is changed.
1. An image display apparatus, comprising:
an image projector receiving an image signal and projecting image light;
an image display including a projection plane of an arbitrary shape, onto which the image light from the image projector is projected;
a connector including a plurality of arms which connect the image projector and the image display and a link mechanism which allows a relative position and posture between the image projector and the image display to one of manually and automatically change;
a measurer that measures the relative position and posture between the image projector and the image display; and
an image signal processor which calculates correction parameters for correction of distortion of the image light projected from the image projector onto the image display, wherein the correction parameters are calculated based on the relative position and posture measured by the measurer, the correction parameters are calculated further based on a previously set viewing position of a viewer, the correction parameters are calculated further based on the shape of the projection plane of the image display, the correction parameters are calculated further based on an angle of field of the image light projected from the image projector, and the correction parameters are calculated further based on a shift amount which is a distance between a point where a virtual projection plane intersects a previously set optical axis of the image projector and a center point of projected image on the virtual projection plane, and the image signal processor performs a distortion correction processing for the image signal inputted into the image projector based on the calculated correction parameters.
2. The image display apparatus according to claim 1 , wherein
the connector changes an image light projection direction of the image projector to match an optical axis of the image light projected from the image projector with a predetermined position of the projection plane of the image display,
the measurer measures the position and posture of the image display unit relative to the position and posture of the image projector in response to the change of the image light projection direction of the image projector by the connector, and
in response to a measurement of a new relative position and posture by the measurer, the image signal processor updates the correction parameters based on the new relative position and posture.
3. The image display apparatus according to claim 1 , further comprising:
a display condition judger which detects an image projection range of the image display and judges whether the image light is projected onto the entire image display, wherein
when it is judged by the display condition judger that an image is not projected onto the entire image display, the connector changes the relative position and posture between the image display and the image projector to allow the image light to be projected onto the entire image display; and
the image signal processor updates the correction parameters according to the changed relative position and posture between the image projector and the image display.
4. The image display apparatus according to claim 1 , further comprising:
a display condition judger which detects an image display condition in an edge portion of the image display and judges whether the image light is projected onto the entire image display, wherein
when it is judged by the display condition judger that an image is not projected onto the entire image display, the connector changes the relative position and posture between the image display and the image projector to allow the image light to be projected onto the entire image display; and
the image signal processor updates the correction parameters according to the changed relative position and posture between the image projector and the image display.
5. The image display apparatus according to claim 1 , wherein
a mirror capable of changing a reflection direction of the image light is provided between the image projector and the image display, and the image light of the image projector is projected onto the image display through the mirror.
6. The image display apparatus according to claim 1 , further comprising:
a viewing position measurer that measures the viewing position of the viewer, wherein
the connector controls a height of the image display to match a height of the viewing position measured by the viewing position measurer, and
the image signal processor updates the correction parameters according to a variation of the height of the image display.
7. The image display apparatus according to claim 1 , further comprising:
an instruction input which detects one of a speech and an operation of the viewer and inputs an instruction to change the position and posture of the image display unit based on the detected one of the speech and the operation, wherein
the connector changes the position and posture of the image display according to the instruction inputted by the instruction input, and
the image signal processor updates the correction parameters according to the changed position and posture of the image display.
8. The image display apparatus according to claim 7 , wherein
the instruction input detects one of a speech and an operation of the viewer and inputs an instruction to fix the position and posture of the image display based on one of the speech and the operation, and
the connector fixes the position and posture of the image display according to the instruction inputted by the instruction input.
9. The image display apparatus according to claim 1 , wherein
the connector includes:
a first arm which is placed in parallel to the optical axis of the image light projected from the image projector and fixed to the image projector;
a plurality of second arms which are connected to different positions of the first arm in the optical axis direction and are vertically linked to a ground plane;
a plurality of third arms which are connected to different positions of each second arm, in the plurality of second arms, in the vertical direction and are parallel to the optical axis of the image light; and
a fourth arm vertically linked to the ground plane from the plurality of third arms and connected to the image display, and
connection points of the first arm and the plurality of second arms, connection points of the plurality of second arms and the plurality of third arms, and connection points of the plurality of third arms and the fourth arm freely rotate to allow the optical axis of the image light projected from the image projector to be projected onto an arbitrary position of the projection plane of the image display.
10. The image display apparatus according to claim 9 , wherein
the connector includes an extension mechanism which changes a length of the plurality of second arms and the extension mechanism is one of automatically and manually one of extended and contracted to change a distance between the display projector and the image display.
11. The image display apparatus according to claim 9 , comprising:
a fifth arm which fixes the projection plane of the image display at a predetermined angle of the projection plane with respect to the image projector and is connected to the image display in parallel to the optical axis of the image light.
12. The image display apparatus according to claim 9 , wherein
the fourth arm includes a rotation mechanism allowing the posture of the projection planar relative to the image projector to freely rotate around a predetermined position of the projection plane.
13. The image display apparatus according to claim 9 , wherein
any one of the connection points of the first arm and the plurality of second arms, the plurality of second arms and the plurality of third arms, and the plurality of third arms and the fourth arm includes a stopper mechanism fixing rotation of the connection point to allow the optical axis of the image light projected from the image projector to be projected onto an arbitrary position of the projection plane of the image display.
14. The image display apparatus according to claim 9 , comprising:
a counter weight generating force holding the posture of the image projector at a predetermined posture to hold the position of the image display relative to the image projector at a predetermined position.
15. The image display apparatus according to claim 1 , wherein
the image projector projects image light rays with a parallax therebetween from at least one of a plurality of image light projecting sections to cause the image display to display a stereoscopic image.
16. The image display apparatus according to claim 1 , comprising:
a point-of-view monitor which monitors the viewing position of the viewer and detects that the monitored viewing position is deviated from a previously set viewing position; and
an informer that informs if the point-of-view monitor detects that the monitored viewing position is deviated from the previously set viewing position.
17. The image display apparatus according to claim 16 , wherein
the informer is a sound output outputting sound to the viewer, and
the point-of-view monitor informs that the monitored viewing position is deviated from the previously set viewing position by causing the sound output to output sound.
18. The image display apparatus according to claim 17 , wherein
the point-of-view monitor varies a state of the sound outputted from the sound output according to one of an amount and a direction that the monitored viewing position is deviated from the previously set viewing position.
19. The image display apparatus according to claim 16 , wherein
the image projector serves as the informer, and the point-of-view monitor informs that the monitored viewing position is deviated from the previously set viewing position by varying a color of the image light projected from the image projector.
20. The image display apparatus according to claim 19 , wherein
the point-of-view monitor varies the color of the image light projected from the image projector according to one of an amount and a direction that the monitored viewing position is deviated from the previously set viewing position.
21. The image display apparatus according to claim 16 , wherein
the informer is a light emitter emitting light to the viewer, and
the point-of-view monitor informs that the monitored viewing position is deviated from the previously set viewing position by causing the light emitter to emit light.
22. The image display apparatus according to claim 21 , wherein
the point-of-view monitor varies the light emitted by the light emitter according to one of an amount and a direction that the monitored viewing position is deviated from the previously set viewing position.
23. An image distortion correction method for an image display apparatus, including:
an image projector receiving an image signal and projecting image light; an image display including a projection plane of arbitrary shape, onto which the image light from the image projector is projected; a connector including a plurality of arms which connect the image projector and the image display and a link mechanism which allows a relative position and posture between the image projector and the image display to one of manually and automatically change; and a measurer measuring that measures the relative position and posture between the image projector and the image display, the image distortion correction method comprising:
calculating correction parameters for correcting a distortion of the image light projected from the image projector onto the image display, wherein the correction parameters are calculated based on the relative position and posture measured by the measurer, the correction parameters are calculated further based on a previously set viewing position of the viewer, the correction parameters are calculated further based on the shape of the projection plane of the image display, the correction parameters are calculated further based on an angle of a field of the image light projected from the image projector, and the correction parameters are calculated further based on a shift amount which is a distance between a point where a virtual projection plane intersects a previously set optical axis of the image projector and a center point of a projected image on the virtual projection plane; and
performing a distortion correction processing for the image signal inputted into the image projector based on the correction parameters.