KR19990074085A - Projection TV's Screen Distortion Correction Device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a screen distortion correction apparatus for a projection television, which enables correction of the screen distortion in the horizontal direction as well as in the vertical direction which cannot be conventionally disassembled. The disclosed apparatus of the present invention includes a movable plate 32 on which the LCD engine 1 is mounted, a fixed plate 33 rotatably supporting the movable plate 32, and a height-adjustable support, and an eccentricity for horizontal position adjustment. A rotating cam 38 and a position fixing screw 40 and a height adjusting screw 41 for fixing the horizontal position are provided. The optical axis position of the LC engine 1 can be varied in the horizontal and vertical direction by the eccentric rotation cam 38 and the height adjustment screw 41. Therefore, the screen distortion can be corrected both horizontally and vertically with a simple operation.

Description

Projection TV's Screen Distortion Correction Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen distortion correction apparatus of a projection television. In particular, in order to correct distortion of a screen projected on a screen, the fine position adjustment with respect to an optical axis of an optical system for projecting an image can be easily adjusted in both horizontal and vertical directions. A distortion distortion correction device for a projection television.

Rear projection televisions have a screen installed in the front of the cabinet and an optical system projecting to the back of the screen within the cabinet. The optical system includes at least one image source. As the image source, a small projection type cathode ray tube or a liquid crystal light valve using a liquid crystal display panel is mainly used. Projection type cathode ray tubes directly project images with brightness, while liquid crystal light valves are installed together with a light source to modulate the light from the light source according to the image signal. 1 shows an optical system configuration of a so-called LCD engine equipped with such a liquid crystal light valve.

The LC engine 1 is first used for color separation of light via the light source 2 and the collimating lens 3 and the collimating lens 3, which propagate light emitted from the light source 2 in parallel. Infrared filter (4) for filtering the invisible region, total reflection reflector (5) for changing the light path, color liquid crystal display panel (6) for polarizing modulation of the light incident as the image source described above with red, green, and blue, color It consists of a power lens (7) which magnifies and modulates the modulated light passing through the liquid crystal display panel (6) onto the rear surface of the screen (9). For reference, the screen 9 is composed of a myriad of lenticular lenses, and reproduces a visible color image by diffusing the light projected on the back side to the front.

In the optical system of the LCD engine 1, all the optical parts from the light source 2 to the power lens 7 should be disposed on the same optical axis 8. The optical axis 8 also needs to be exactly coincident with the center of the screen 9. The reason is that when an optical axis offset occurs such that the optical axis 8 of the LC engine 1 is eccentric or tilted out of the center of the screen 9, the so-called screen is distorted at the edges of the screen appearing on the screen 9. This is because distortion occurs and image quality is greatly reduced. Therefore, it is very important to adjust the screen distortion correction to match the optical axis 8 of the LCD engine 1 to the center of the screen 9 at the time of shipment of the product. It is attached to the television cabinet in an adjustable state by the correction device.

2 shows a screen distortion correction apparatus for a rear projection type projection television according to the prior art. In the drawing, reference numeral 1 denotes an LCD engine. The LC engine 1 is mounted on the engine bracket 11. The movable plate 12 is installed under the engine bracket 11 and the fixed plate 13 is installed under the movable plate 12 to correct the screen distortion. The engine bracket 11 and the movable plate 12 are integrally coupled to each other by fastening screws (not shown). The movable plate 12 has a hinge hole 14 bored in one side corner and a straight long hole 15 and a plurality of circular arc holes 16 formed at opposite edges. The straight hole 15 accommodates an eccentric rotation cam 17 having an eccentric cam shaft 18 formed in a straight line passing through the center of the hinge hole 14, and moves in accordance with the rotation of the received eccentric cam 17. The plate 12 is formed to have the same width as the diameter of the eccentric rotation cam 17 so that the entire movement in the rotational direction. The circular arc holes 16 are formed on the same circular arc line centering on the hinge hole 14 and are clearance holes through which the position fixing screw 19 is allowed to pass. The fixing plate 13 is a cam support hole 21 for rotatably supporting the hinge protrusion 20 fitted into the hinge hole 14 of the movable plate 12 and the cam shaft 18 of the eccentric rotation cam 17. And a screw hole 22 for fastening the position fixing screw 19 that has passed through the circular arc hole 16 of the movable plate 12. This fixing plate 13 is fixedly mounted in a cabinet (not shown) of a television set.

That is, in the state of being assembled and mounted in the set, the position of the LC engine 1 can be finely adjusted by rotating the eccentric rotation cam 17 before tightening and fixing the position fixing screw 19. When the eccentric rotary cam 17 is rotated, the angle of the micro-elevation with the LC engine 1 mounted on the movable plate 12 on the hinge protrusion 20 of the fixed plate 13 is corresponding to the displacement according to the rotational position thereof. Rotate to After adjusting the position of the LC engine 1, the fixing screw 19 is tightened to fix the adjusted position.

Here, the movement of the movable plate 12 moves the optical axis 8 of the LCD engine 1 in the horizontal direction. Therefore, the conventional screen distortion correction can correct the screen distortion in the horizontal direction. However, the problem is that the optical axis of the LC engine 1 needs to be precisely adjusted not only in the horizontal direction but also in the vertical direction. However, the conventional apparatus cannot adjust the optical axis position in the vertical direction. In the conventional apparatus, the vertical position of the optical axis is determined at the initial stage of assembly only by the overlapping state between the movable plate 12 and the stationary plate 13. Therefore, in order to compensate for a vertical offset in the optical axis position due to a shock that may occur during transportation, installation, or use after shipment of the product, the movable plate including the LC engine 1 in the set ( 12) and all the fixing plates (13) must be disassembled to perform the cumbersome work of reassembly and adjustment from the beginning.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to project an optical axis such as an LCD system or the like into an optical system in a state where an optical system such as an LCD engine is assembled in a set. It is to provide a screen distortion correction device that can be adjusted.

1 is a profile showing the optical configuration of an LCD engine used in a projection television.

Figure 2 is an exploded perspective view showing a screen distortion correction apparatus of a projection television according to the prior art.

Figure 3 is an exploded perspective view showing the screen distortion correction apparatus of the projection television according to the present invention.

Fig. 4 is a cross-sectional view showing the screen distortion correction device of the projection television according to the present invention assembled in a cabinet in a set (indoor view).

Fig. 5 is a plan view showing a screen distortion correction apparatus of the projection television according to the present invention assembled in a cabinet in a set.

6A and 6B are plan views showing a state in which the horizontal position is maximally moved and adjusted by the screen distortion correction apparatus of the projection television according to the present invention;

7A and 7B are cross-sectional views of principal parts showing height adjustment by a screen distortion correction apparatus of a projection television according to the present invention;

Explanation of symbols on the main parts of the drawings

1: LCD engine 8: Optical axis

32: movable plate 33: fixed plate

34: hinge hole 34: hinge protrusion

35: straight long hole 36: arc long hole

37,44: screw hole 38: eccentric rotation cam

40: position fixing screw 41: height adjustment screw

The present invention to achieve the above object,

In constructing an apparatus for correcting screen distortion of a projection television having an optical system for projecting an image in a cabinet of the projection television set,

A movable plate equipped with an optical system, a fixed plate fixedly mounted in a cabinet and rotatably supporting the movable plate, a rotating means for rotating the movable plate on the fixed plate, and a fixing for fixing the movable plate to the fixed plate at any rotational position. It further comprises a means, and further comprising a height adjustment means for adjusting the height of the movable plate relative to the fixed plate.

Here, the rotating means and the fixing means form a straight hole having a constant width in a straight line passing through the center of rotation of the movable plate, and form a cam support hole in the fixed plate and have the same diameter as the straight hole width of the movable plate. An eccentric rotary cam having an eccentric camshaft accommodated in the straight hole and rotatably fitted in the cam support hole of the fixed plate, and at least one circular arc long on an arc of a certain radius from the center of rotation of the movable plate; Forming a long hole, and the fixing plate has at least one screw hole formed at a position corresponding to the circular hole of the movable plate, and has at least one position fixing screw that is fastened to the corresponding screw hole of the fixed plate by passing through the circular hole of the movable plate. Can be implemented.

On the other hand, in the height adjustment means that can adjust the height of the movable plate relative to the fixed plate, the projection portion for forming a screw hole in the vicinity of the one side edge of the movable plate, the support plate to support the other side edge of the movable plate at a constant height And a height adjusting screw fastened to the screw hole of the movable plate to configure the height of the movable plate according to the fastening depth of the height adjuster.

According to the present invention, by rotating the eccentric rotation cam, the movable plate on which the optical system is mounted is moved in the horizontal direction with respect to the stationary plate by a small distance, and the screen fixing in the horizontal direction is corrected by tightening and fixing the position fixing screw at a desired position. can do. It is also possible to adjust the height of the movable plate by varying the depth of engagement of the above-mentioned height adjusting screw in the horizontally adjusted state or before. By adjusting the horizontal position and height of the movable plate in this way, the horizontal and vertical positions of the optical axis of the optical system mounted thereon can be finely adjusted. Therefore, the screen distortion can be corrected in both horizontal and vertical directions without disassembling the optical system, the movable plate, the fixed plate, and the like from the television set. The screen distortion correction apparatus of the projection television according to the present invention will be described in more detail with reference to the accompanying drawings showing preferred embodiments thereof.

In a preferred embodiment of the screen distortion correction apparatus of the rear projection type television according to the present invention, an LCD system as an image projection optical system used in the rear projection type television will be described with reference to FIG. 1) is mounted on the engine bracket 31, the movable plate 32 is placed under the engine bracket 31 and the fixed plate 33 is placed below the movable plate 32. The engine bracket 31 and the movable plate 32 are integrally coupled to each other by fastening screws (not shown). The movable plate 32 has a hinge hole 34 drilled in one side corner, a linear long hole 35 formed at the opposite edge, a plurality of circular arc holes 36, and a height adjusting screw hole 37 formed at one side edge. Here, the straight hole 35 is formed in a straight line passing through the center of the hinge hole 34, and accommodates the eccentric rotation cam 38 having the eccentric cam shaft 39 to rotate the received eccentric rotation cam 38. Accordingly, the entire movable plate 32 is opened in the same width as the diameter of the eccentric rotation cam 38 so as to interlock so as to move in the rotational direction (see FIG. 4). The arc holes 36 of the movable plate 32 are formed on the same arc line centering on the hinge hole 34, and are the clearance holes which respectively pass the position fixing screw 40 as it is. On the other hand, the height adjustment screw 41 is fastened to the screw hole 37 of the movable plate 32. The fixing plate 33 is a cam support hole 43 for rotatably supporting the hinge protrusion 42 fitted into the hinge hole 34 of the movable plate 32 and the cam shaft 39 of the eccentric rotation cam 38. And the screw hole 44 for fastening the position fixing screw 40 passing through the circular arc hole 36 of the movable plate 32 and the edge portion thereof opposite to the screw hole 37 of the movable plate 32. It has a protrusion 45 that protrudes long along its edge to support it. This fixing plate 33 is fastened and fastened with a separate screw 47 to the cabinet 46 of the television set as shown in FIGS. 4 and 5.

The operation for screen distortion correction in the above embodiment will be described below.

5 is a plan view of the assembled state of the above-described embodiment, the movable plate 32 is not rotated to any one side of the horizontal direction on the fixed plate 33, Figures 6a and 6b is the movable plate 32 to both sides, respectively Each rotates as much as possible. In the state where the movable plate 32 is rotated as far as possible to one side, the eccentric rotation cam 38 accommodated in the straight hole 35 is rotated such that the cam shaft 39 is eccentrically to the left or right with respect to the center line. do. Then, the optical axis 8 of the LC engine 1 shown in FIG. 5 is also rotated left or right to change its horizontal position. That is, when the eccentric rotation cam 38 is rotated, the movable plate 32 is reciprocated in a fixed angle range around the hinge protrusion 42 on the fixed plate 33, and the horizontal axis of the optical axis 47 depends on the rotational position thereof. By adjusting the position, the screen distortion in the horizontal direction can be corrected. When the horizontal position is determined, the fixing plate 40 may be tightened to fix the movable plate 32 to the fixing plate 33.

Next, the screen distortion in the vertical direction may be adjusted by loosening or tightening the height adjusting screw 41 fastened to the screw hole 37 formed at one side of the movable plate 33 as shown in FIGS. 7A and 7B. As shown in the figure, the movable plate 32 is at a certain height from the fixing plate 33 at the portion supported by the protrusion 45 of the fixing plate 33, while the portion having the screw hole 37 is height-adjusted. The fastening depth of the screw 41, that is, the length protruding from the fixing plate 33 to the fixing plate 33 is increased. When the tightening depth is changed by tightening or loosening the height adjusting screw 41, one side of the movable plate 32 is rotated in the vertical direction with the portion supported by the protrusion 45 on the other side as a point, and thus the movable plate 32 Since the height of the optical axis 8 of the LC engine 1 mounted above the variable is variable, it is possible to adjust the height that can correct the screen distortion in the vertical direction.

The present invention is not limited to the above described and illustrated in the drawings, and the rear projection type is modified or modified in various forms to be used for optical axis offset adjustment of various similar optical systems including the optical system in the projection television as well as the front projection television. It can be transformed.

As described above, according to the screen distortion correction apparatus of the projection television according to the present invention, the screen distortion can be easily corrected in both the horizontal and vertical directions in the state where the optical system is mounted on the set. Therefore, the trouble of disassembling the optical system from the set to correct the screen distortion is eliminated. Thus, it is possible to reduce the time and manpower waste for screen distortion correction before and after the shipment of the product, and to improve the quality and reliability of the product. It can contribute.

Claims (9)

A projection television screen distortion correction apparatus having an optical system for projecting an image in a cabinet of a projection television set, the apparatus comprising: a movable plate on which the optical system is mounted, and fixedly mounted in the cabinet and rotatably supporting the movable plate. A fixed plate, a rotating means for rotating the movable plate on the fixed plate, a fixing means for fixing the movable plate to the fixed plate at an arbitrary rotation position, and a height adjusting means for adjusting the height of the movable plate relative to the fixed plate. Screen distortion correction device for a projection television, characterized in that. 2. The movable plate according to claim 1, wherein the rotating means forms a straight hole having a constant width on a straight line passing through the center of rotation of the movable plate, and forms a cam support hole in the fixed plate. And an eccentric rotating cam having an eccentric cam shaft which is formed in the same diameter as the long hole width and is accommodated in the straight hole and rotatably fitted in the cam support hole of the fixed plate. 2. The fixing plate according to claim 1, wherein the fixing means forms at least one arc long hole on the movable plate which is long on a circular arc having a predetermined radius from the center of rotation, and the fixing plate corresponds to the arc long hole of the movable plate. At least one screw hole formed at the position of the movable plate and having at least one position fixing screw which passes through at least one arc hole of the movable plate and is fastened to the corresponding screw hole of the fixed plate. Compensator. The movable plate according to claim 1, wherein the height adjusting means forms a screw hole near one edge of the movable plate, and the fixing plate forms a protrusion for supporting the vicinity of the other edge of the movable plate at a predetermined height. And a height adjusting screw fastened to the screw hole, the height of the movable plate being adjusted according to the fastening depth of the height adjusting screw. 2. The movable plate according to claim 1, wherein the rotating means forms a straight hole having a constant width on a straight line passing through the center of rotation on the movable plate, and the cam holding hole is formed in the fixed plate. An eccentric rotary cam having an eccentric camshaft which is formed with a diameter equal to the width of the straight slot and is received in the straight slot and rotatably fitted in the cam support hole of the fixed plate, wherein the fixing means is operated as described above. At least one arc hole is formed on the plate in a circular arc line having a certain radius from the center of rotation, and the fixing plate forms at least one screw hole at a position corresponding to the arc hole of the movable plate. At least one position fixing screw which is passed through at least one arc hole and fastened to a corresponding screw hole of the fixing plate; The adjusting means forms a screw hole near one edge of the movable plate, and the fixing plate forms a protrusion for supporting the vicinity of the other edge of the movable plate at a predetermined height, and a height adjusting screw fastened to the screw hole of the movable plate. And a movable plate height adjusted according to the fastening depth of the height adjuster. 6. The movable plate and the fixed plate according to any one of claims 1 to 5, wherein a hinge hole and a hinge protrusion fitted to the hinge hole are formed in the movable plate and the fixed plate, respectively, so that the movable plate can be rotated about the hinge protrusion. Screen distortion correction device for a projection television, characterized in that. The projection distortion correction apparatus according to claim 3 or 5, wherein a plurality of the circular arc holes and the screw holes are formed on the same circular arc line at a predetermined interval, respectively. The apparatus for correcting distortion of a projection television according to claim 3 or 5, wherein the protrusion is formed to extend in a straight line along an edge. The projection distortion correction apparatus according to claim 1, wherein the optical system is fixed to a separate bracket and the bracket is fixed to the movable plate.