JP3972915B2 - Image distortion correction mechanism for rear projection display - Google Patents

Description

  The present invention relates to a rear projection video apparatus (rear projector) that displays an image by reflecting an output image output from a projector or a projection unit by a mirror and projecting it from a rear surface onto a screen. The present invention relates to a video distortion correction mechanism for correcting distortion.

  FIG. 4 is an internal configuration diagram of a rear projection type image display apparatus 101 generally called a rear projector as viewed from the side. In FIG. 4, a projector or projection unit (hereinafter referred to as a projector) 103 arranged at a predetermined position in the lower part of the cabinet 102 outputs an image upward or obliquely upward from the projection lens 103a. The emitted output image is projected on a screen 105 disposed on the front surface of the cabinet 102 by changing the optical path by a reflection mirror 104 disposed at a predetermined position on the upper rear surface of the cabinet 102. In general, the relative position of the projected image projected on the screen 105 with respect to the screen 105 can be adjusted by an electrical correction function of the projector 103 or a position adjustment mechanism of the projector mount 106 on which the projector 103 is mounted. .

 FIG. 5 is a diagram showing a projected image 201 displayed on the screen 105 of the rear projection type image display apparatus 101. Each side of the projected image 201 has a pincushion-shaped image distortion called pincushion distortion. 201a, 201b, 201c, and 201d are generated. It is known that the pinkish distortions 201a, 201b 201c, and 201d are caused by the optical distortion of the projection lens 103a and the deflection 104a due to the weight of the reflection mirror 104.

 In FIG. 6, the self-weight deflections 104a and 104b when the reflection mirror 104 is viewed from the front generate the pinch distortions 201a and 201b in the projected image 201 of FIG. 5, and the self-weight deflection 104c viewed from the side is the pinion distortion in the projection image 201. 201c and 201d are generated. In particular, the size of the screen 105 is large, and in order to shorten the depth 102a of the rear projection display apparatus 101 itself, it is necessary to increase the size of the reflection mirror 104, and the deflection of the reflection mirror 104 due to its own weight greatly occurs. Become.

Conventionally, a CRT type projector having a circuit that can electrically correct pincushion distortion of an image is used in the projector 103 itself. However, a liquid crystal device or a digital mirror device called DMD, which is a mainstream in recent years, is displayed. In a projector used as a device, since the pixels of the display device are digitally fixed, there is a problem that the image quality of the display image is deteriorated by the method of electrically correcting the pinch distortions 201a, 201b, 201c, and 201d. Correction is considered difficult. Therefore, in order to eliminate the pintion distortions 201a, 201b, 201c, and 201d, a method such as adopting a high-performance projection lens with little optical distortion or adopting a reflection mirror with less bending and high rigidity is used. It was. Further, as described in Japanese Patent Application Laid-Open No. H10-260260, in a rear projection type image display device called a multi-projector having a relatively small screen size of 60 type or less and a relatively small reflecting mirror, the reflecting mirror has a trapezoidal aperture. And a supporting means for supporting the reflecting mirror disposed so as to cover the opening in the vicinity of the four corners of the opening of the base, and in the vicinity of each central portion of the four sides of the opening. There has been proposed a mechanism for correcting distortion by providing an adjusting means for pressing the mirror.
JP 2002-77777 A

  However, when the large reflecting mirror 104 is used for the purpose of shortening the depth of the rear projection type image display device 101 by increasing the size of the screen 105 to 70 type or more, the weight of the reflecting mirror 104 becomes heavy. In addition to the problem that the pinion distortions 201a, 201b, 201c, and 201d are greatly generated because the self-weight deflections 104a, 104b, and 104c of the reflection mirror 104 are greatly generated, the above-described method of Patent Document 1 makes the substrate itself large. As a result, the substrate itself may be bent due to its own weight or the weight of the reflection mirror 104, or distortion due to variations in assembly accuracy may occur, and distortion may not be corrected by pressing only the central part of each side of the reflection mirror 104. In addition, too much load is applied to the center of each side, and the reflection mirror 104 can be damaged. Has a problem of that is, fully taking the distortion has been difficult. Therefore, image distortion occurs on the four sides of the projected image, resulting in an unnatural image.

  The present invention provides a suitable image distortion correction mechanism that reduces the load on the mirror 104 at the time of image distortion correction and increases the degree of freedom of the correction amount, especially in the rear projection image display apparatus 101 using the large reflecting mirror 104. The purpose is to do.

According to the first aspect of the present invention, an image distortion correction mechanism using the reflection mirror is applied to a rear projection type image display apparatus that changes an optical path of an output image output from a projector or a projection unit by a reflection mirror and projects it from the back of the screen. An adjustment fitting that is attached to the support fitting that sandwiches and supports the upper side of the reflection mirror, an adjustment screw that connects the support fitting on the upper side of the reflection mirror and the adjustment fitting, and a nut, disposed on each side of the reflection mirror having a plurality of threaded holes adjustment screw is mounted, and a support bracket for supporting sandwich the reflecting mirror Kakuhen from front and back both sides by the adjusting screw, a plurality of attaching the threaded hole comprising of the adjusting screw, and adjusting the adjustment screw, and a support bracket of the reflecting mirror upper portion back and forth by a nut Together so as to correct the deflection of the reflection mirror, those with the plurality of image distortion correcting mechanism of a rear projection type image display device, wherein the changing the number and position of the adjusting screws attached to threaded holes This has the effect of reducing the load on the mirror during video distortion correction and increasing the degree of freedom of the correction amount.

The invention according to claim 2 is the image distortion correction mechanism of the rear projection type image display device according to claim 1, wherein a resin screw is used as the adjustment screw. It has the effect of reducing the load on the mirror at the time.

  According to the image distortion correction mechanism of the present invention, even in a rear projection image display apparatus using a large reflection mirror, the distortion of the reflection mirror, the distortion of the projection lens, and the distortion generated during assembly can be corrected finely. Therefore, it is possible to obtain a projected image free from pincushion distortion.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

(Embodiment 1)
FIG. 1 is a side view and a rear view of a first embodiment of a rear projection type image display apparatus 101 having a large reflecting mirror employing the image distortion correcting mechanism of the present invention.

  In FIG. 1, a rear projection type image display apparatus 101 includes a projector 103 disposed on a projector mount 106 having a position adjusting mechanism installed at a lower portion inside a cabinet 102, a screen 105 disposed on the front surface of the cabinet 102, and a cabinet 102. It is comprised from the support metal fitting 401 which can be attached attaching the reflection mirror 104 arrange | positioned from the upper part to the back of it, and a reflection mirror. The support fitting 401 is formed by a plurality of screw holes 401a to which adjustment screws 401b and 401c for adjustment are attached and adjustment screws 401b and 401c attached thereto, and the resin screws are preferable from the viewpoint of mirror protection. An adjustment fitting 403 that can adjust the position of the upper side of the support fitting 401 is disposed above the support fitting 401, and is connected by an adjustment fitting 402 and an adjustment bolt 404 that are attached to the cabinet 102 side.

  The operation of the rear projection image display apparatus 101 configured as described above will be described with reference to FIGS.

 First, the adjustment metal fitting 403 attached to the upper part of the support metal fitting 401 and the adjustment metal fitting 402 attached to the top surface of the cabinet 102 are connected by an adjustment screw 404 at the upper side of the reflection mirror 104 that is most bent by the weight of the reflection mirror 104. As shown in FIG. 3, the two adjustment fittings 403 and 404 are sandwiched between two nuts 601 and are connected by an adjustment screw 404 so that the support fitting 401 on the upper side of the reflection mirror 104 can be freely adjusted in the front-rear direction. .

 As shown in FIG. 6, since this portion is bent obliquely downward, it is preferable that the entire support fitting 401 is adjusted to be lifted obliquely rearward and upward. The reflection mirror 104 is attached so as to be sandwiched between the support fittings 401 on each side, and the attached reflection mirror 104 performs distortion correction using the screw holes 401a and adjustment screws 401b and 401c provided in the support fitting 401. In general, it is preferable to use a plurality of adjusting screws 401b and 401c around the center of the four sides and adjust the load in a distributed manner.

 Furthermore, a highly flexible correction is performed by adjusting the location and number of the adjusting screws 401b and 401c for the difference in distortion due to the variation in the reflection mirror 104 and the variation in assembly accuracy.

 FIG. 2 is a cross-sectional view of a main part when a cross section including an instruction line 400 passing through the center line of the adjusting screw 401b of FIG. 1 is viewed from the arrow A side.

 By pressing the adjustment screw 401b from the front side of the cabinet 102 and pressing the adjustment screw 401c from the rear surface of the cabinet as shown in FIGS. Finer adjustments can be made.

  As described above, according to the present embodiment, in the rear projection display apparatus 101 having the large reflection mirror 104, a plurality of adjustment screws 401b and 401c can be attached to the support fitting 401 itself that supports the reflection mirror 104. By providing adjustment screws 401b and 401c for adjustment that can be arbitrarily attached to the screw holes 401a, and adjustment fittings 402 and 403 that can adjust the upper side of the support fitting 401 and an adjustment screw 404, a large reflection Even in a rear projection display device using a mirror, it is possible to finely correct the distortion of the reflection mirror, the distortion of the projection lens, and the distortion that occurs in the support bracket of the reflection mirror, so that a projection image without pincushion distortion can be obtained. Obtainable.

  The image distortion correcting mechanism of the rear projection image display apparatus according to the present invention is such that the distortion of the reflection mirror, the distortion of the projection lens, and the reflection mirror support metal fitting occur in the rear projection image display apparatus using a large mirror. Distortion can be finely corrected, and even a large rear projection type image display device of 100 type or more has the effect of obtaining a projection image without pincushion distortion, and is useful in the field of large image display systems. is there.

The internal block diagram which looked at Embodiment 1 of the rear projection type video display apparatus which has the large reflective mirror 104 which employ | adopted the image distortion correction mechanism by this invention from the side surface and the rear surface 1 is a cross-sectional view of the main part when a cross section including an instruction line 400 passing through the center line of the adjustment screw 401b in FIG. 1 is viewed from the arrow A side. FIG. 1 is an enlarged detail view of the adjustment fitting 402 and the vicinity of the adjustment fitting 402. Internal configuration diagram of a general rear-projection image display device (rear projector) seen from the side The figure which shows the projection image 201 displayed on the screen 105 of the rear projection type video display apparatus 101. The figure which shows the bending generate | occur | produced with the dead weight of the reflective mirror 104

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Rear projection type image display apparatus 102 Cabinet 102a Depth of rear projection type image display apparatus 103 Projector or projection unit 103a Projection lens 104 Reflection mirror 104a-104c Reflective mirror 104 self-deflection 105 Screen 106 Projector mount 201 Projection image 201a-201d Pin Cushion distortion 401 Support bracket 401a Screw hole 401b Adjustment screw (pressed from the mirror front side)
401c Adjustment screw (pressed from the back of the mirror)
402 Adjustment bracket 403 Adjustment bracket 404 Adjustment screw 601 Nut

Claims (2)

An image distortion correction mechanism by the reflection mirror adapted to a rear projection type image display device that changes an optical path of an output image output from a projector or a projection unit by a reflection mirror and projects it from the back of the screen,
An adjustment fitting attached to support the support fitting to sandwich and support the upper side of the reflection mirror;
An adjustment screw that connects the support fitting on the upper side of the reflection mirror and the adjustment fitting, and a nut;
A plurality of screw holes that are arranged on each side of the reflection mirror and to which an adjustment screw is attached, and a support bracket that sandwiches and supports each side of the reflection mirror from the front and back surfaces by the adjustment screw ;
A plurality of adjusting screws attached to the screw holes;
With
While adjusting the support bracket on the upper side of the reflection mirror with the adjustment screw and nut, back and forth,
Wherein to correct deflection of the reflection mirror, said plurality of image distortion correcting mechanism of a rear projection type image display apparatus characterized by changing the number and position of the adjusting screws attached to threaded holes. 2. The image distortion correcting mechanism for a rear projection image display device according to claim 1, wherein a resin screw is used as the adjustment screw.

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