KR100219650B1 - Apparatus to control the center of lens unit for projector - Google Patents

Abstract

A barrel having a projection lens installed to enlarge and project the image generated by the image generator built in the case to the screen; A plate member on which the barrel is supported; A lead screw supported by a housing installed at the front of the image generating unit and screwed to the plate member; Projection lens system optical axis adjusting device including a rotary knob provided at the shaft end of the lead screw, and rotating the rotary knob, the plate member is moved in the height direction of the screen by the rotation of the lead screw to adjust the optical axis of the projection lens. To start.

Description

Projection lens system optical axis adjusting device

The present invention relates to a projector for projecting and displaying an image on a screen. More particularly, the present invention relates to a projection lens system optical axis adjusting device of a projector that is adjustable so that an optical axis of a projection lens system is variable for common use in a rear projection type and a front projection type. will be.

Today, as an apparatus for meeting the demand of reproducing images on a large screen with the development of the information industry, an image projection apparatus using a liquid crystal display device is in the spotlight. Such an image projecting device is generally composed of a screen and a projector that generates an image on the screen and enlarges the image, and is classified into two types, a rear projection type and a front projection type according to a method of projecting an image on the screen.

The rear-projection image projector is a projector mounted on a cabinet together with a screen so that the image projected from the projector is reflected by a reflector arranged obliquely in the cabinet and projected to the back of the screen. It is installed so that the image projected from the projector is directly projected on the screen to reproduce the image.

On the other hand, recently, a projector that is applicable to both types of front projection type and rear projection type image projection apparatus has been tried and widely used. That is, when the projector of the front projection type is mounted at a predetermined position inside the cabinet provided with the screen and the reflecting mirror, it functions as the rear projection type.

An example of the front projection type as the image projection apparatus is shown in FIG. 1, and as shown, in the front projection type image projection apparatus 1, the projector 10 is a wall 12 such as a theater or a home room, for example. In the position facing the front of the screen 121 installed in the (), the image projected from the projector 10 is to appear on the front of the screen 121. The projector 10 includes an image generator (not shown) built in the case 14 and a plurality of projection lenses 111 for enlarging and projecting the generated image onto the screen 121. A barrel 11 is provided and is mounted on a support 13 having a predetermined height to project an image onto the screen 121. However, in the front projection type image projection apparatus as described above, in order to obtain a clear image quality in which the focus is precisely adjusted, the focus position of the image projected from the projector 10 is incident perpendicularly to the center point A of the screen 121. It is desirable to. However, for this purpose, since the height of the support 13 on which the projector 10 is seated must also be increased as corresponding to the center point A position of the screen 20, a large amount of space must be occupied for the installation of the projector 10. There is a problem. This is inconvenient in that it is not easy to install the projector 10 in consideration of various equipment or wiring relations for installing the projector 10, and it is also useful for users who want to view the image projected on the screen 121. There is an inconvenience that the viewing space is limited. On the other hand, in order to lower the height of the support 13, when the projector 10 is installed at a low position and is inclined toward the center point A, the projected image is obliquely incident on the screen 121 and is focused. The adjustment is not done properly. Therefore, as shown in FIG. 1, the barrel 11 on which the projection lens 111 is mounted is installed to be spaced apart from the optical axis projected from the image generator by a predetermined interval, and passes through the projection lens 111. It is common for the image to be asymmetrically projected so that it is focused at approximately one quarter lower point B of the screen.

On the other hand, Figure 2 shows a rear projection type image projection, as shown, the cabinet 32 is provided with the screen 31, the projector 4 installed in the cabinet 32, and the projector 40 Reflector 33 is provided to reflect the image projected from the back of the screen 31. In the rear projection type image projection apparatus 3 having such a configuration, the angle of the reflector 33 is properly adjusted so that the focus of the image projected from the projector 40 is the center point A of the rear surface of the screen 31. To be located at

Therefore, in this case, the optical axis passing through the optical axis of the image generating unit (not shown) built in the projector case 42 and the projection lens 411 mounted on the barrel 41 are disposed in a straight line.

As described above, the projector 10 (FIG. 1) used for the front projection type image projection apparatus 1 (FIG. 1) and the projector 40 (FIG. 2) used for the rear projection type image projection apparatus 3 (FIG. 2) are images. The optical axis positions of the projection lenses 111 (FIG. 1) 411 and FIG. Therefore, the projector 10 used in the front projection type image projection apparatus 1 cannot be used in the rear projection type image projection apparatus 3, and conversely, the projector 40 used in the rear projection type image projection apparatus 3 is the front projection type. It cannot be used for the image projection apparatus 1. Therefore, when it is desired to use both the front and rear projection type, there is an inconvenience of having to separately provide a projector according to the projection method. This is in line with recent trends in which the projector is applicable to both types of front projection and rear projection image projection devices.

The present invention has been made to solve the above problems, and is easy to install the projector, while the projection lens system optical axis adjustment of the projector to adjust the optical axis of the projector projection lens system to be applicable to two types of image projection apparatus of front projection type and rear projection type The object is to provide a device.

1 is a schematic diagram illustrating an image projection state of a conventional front projection type projector,

2 is a schematic diagram illustrating an image projection state of a conventional rear projection type projector;

Figure 3 is a schematic perspective view showing a projection lens system optical axis adjustment device of the projector according to the present invention,

4 is a schematic cross-sectional view for explaining an operating state of the projection lens system optical axis adjusting device of FIG. 3;

5 is a schematic perspective view showing a projection lens system optical axis adjusting device of a projector according to another embodiment of the present invention.

Explanation of symbols for the main parts of the drawings

21. Body barrel 211. Plate member

211a.Connector 211b.Guide

212 Projection 22 Screen

23. Housing 24. Lead screw 241. Rotating knob 241a.

25.Guide rail 26.Compression coil spring

29. Case 291. Knob seat

29a..insertion groove

Projection lens system optical axis adjustment apparatus of a projector according to the present invention for achieving the above object, and the barrel provided with a projection lens for projecting the image generated by the image generation unit built in the case on the screen; A plate member on which the barrel is supported; And a conveying means installed in the case so as to adjust the optical axis of the projection lens by linearly reciprocating the plate member in the height direction of the screen.

The conveying means includes a housing installed on the front surface of the image generating unit, a lead screw supported on the housing in the height direction of the screen, and a connection member connected to the plate member and coupled to move along an axis of the lead screw. Preferably, the rotary knob is provided on the shaft end of the lead screw, the guide means for guiding the transfer of the plate member, the guide rail installed in the housing parallel to the lead screw and the guide rail is coupled It is preferable to have a guide part provided in the plate member as much as possible.

Preferably, the plate member has a conveyance distance determined by a positioning means provided in the knob seating portion formed in the case to accommodate the rotary knob and the rotary knob, and the positioning means has an insertion groove formed on an outer circumferential surface of the rotary knob. And, it is preferably made of a projection formed on the knob seating portion to be complementary to the insertion groove.

The case is preferably provided with an opening formed to allow the conveyance of the barrel, the plate member is preferably elastically biased in one direction of the top and bottom of the screen.

Hereinafter, a preferred embodiment of a projection lens system optical axis adjusting device of a projector according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, the projection lens system optical axis adjusting device of the projector according to the present invention has an optical axis while the barrel 21 on which the projection lens 212 is installed is moved a predetermined distance in the height direction (Z-axis direction) of the screen 22. This is to be adjusted.

The barrel 21 receives an image generated by an image generator (not shown) built into the case 29 and enlarges and projects the image onto the screen 22 through the projection lens 212, and is installed on the front of the image generator. It is supported by the plate member 211 slidably provided on one surface of the housing 23. Although not shown in the drawings, the image generating unit refers to a housing for supporting a plurality of optical members and optical members disposed on the projector case 29 to generate an image through a light source and light emitted from the light source. (23) Points to the one including all of the above.

A lead screw 24 is installed on one surface of the housing 23 to be parallel to the height direction (Z-axis direction) of the screen 22, and the lead screw 24 is formed on one side of the plate member 211. The connecting member 211a is screwed in. Therefore, when the lead screw 24 rotates, the plate member 211 is moved forward and backward. In addition, one side of the housing 23 is provided with a guide rail 25 to be parallel to the conveying direction of the plate member 211. It supports the other side opposite to the lead screw 24 has a function of guiding the sliding of the plate member 211. In FIG. 3, reference numeral 211b is provided on both sides of the plate member 211 to show guide parts coupled to the lead screw 24 and the guide rail 25, respectively. Reference numeral 292 denotes an opening provided in the case 29 so that the conveyance of the barrel 21 supported by the plate member 211 is guided according to the sliding of the plate member 211.

In the projection lens system optical axis adjusting device of the present invention, it is preferable that the plate member 211 is elastically biased in any one direction. The means for elastically biasing the plate member 211 is, for example, the compression coil spring 26, so that the lead screw 24 and the guide rail 25 to be located between the plate member 211 and the housing 23. It is provided along the plate member 211 is elastically biased in one direction (-Z direction) of the screen 22. Since the plate member 211 is elastically biased by the compression coil spring 26, the plate member 211 is buffered so that the barrel 21 supported by the plate member 211 is not smoothly moved, such as shaking the optical axis. .

The projector to which the projection lens system optical axis adjusting device is applied may adjust the focus position of the projection lens 212 to the selected mode by sliding the barrel 21 according to a mode to be used, either front projection type or rear projection type. . That is, when the projector is used as the front projection type, the barrel 21 is transferred so that the optical axis of the projection lens 212 is spaced apart from the optical axis of the housing 23 by a predetermined interval.

3 and 4, the operation of the projection lens system optical axis adjusting device according to the present invention will be described.

The optical axis of the projection lens 212 is positioned on the other side of the screen 22 in the other direction (Z direction) while the barrel 21 is located on one side in the height direction of the screen 22, that is, the position shown in the solid line in FIG. 4. If the user wants to move it, the user can grasp the rotary knob 241 formed at the end of the lead screw 24 and protrude out of the case 20 and rotate it in the clockwise direction (A direction, Fig. 3), for example. The screw 24 also rotates in the same direction. Accordingly, the connecting member 211a screwed with the lead screw 24 moves along the length direction of the lead screw 24. At this time, the plate member 211 formed with the bracket portion 211a is also moved together, such that the barrel 21 installed on the plate member 211 is moved to the position shown by the virtual line in FIG. 4. Accordingly, the position of the projection lens 212 in the barrel 21 is changed. At this time, since the distance from which the barrel 21 is conveyed is very small, the image emitted from the image generating unit does not occur outside the projection area of the projection lens 212 provided in the barrel 21.

On the contrary, when the projector used as the front projection type is to be used as the rear projection type, the user may operate the rotary knob 241 to rotate in the counterclockwise direction (B direction, FIG. 3). Then, as the lead screw 24 rotates in the opposite direction as described above, the barrel 21 is transferred to the position shown by the solid line in FIG. Then, the case 29 of the projector may be mounted on a predetermined mounting portion inside a cabinet (not shown) where the screen is installed. Therefore, in this state, the optical axis of the image generating unit and the optical axis of the projection lens 212 are located on the same line.

On the other hand, in the projection lens system optical axis adjusting device of the present invention, it is preferable that positioning means for determining the position of the barrel 21 in the state in which the optical axis is adjusted in one of the longitudinal directions of the screen is provided.

Fig. 5 is a schematic view showing the projection lens system optical axis adjusting device of the projector according to another embodiment of the present invention, showing an example in which the above-mentioned positioning means is provided.

Referring to FIG. 5, the positioning means includes a protrusion 241a protruding from the outer circumferential surface of the rotary knob 241 and a knob seating portion 291 provided in the case 29 to accommodate the knob 241. The protrusion 241a is provided with an insertion groove 291a formed to be hooked. The insertion groove 291a is provided such that the protrusion 251 is inserted at a position where the optical axis is adjusted so that the plate member 211 is transferred. Accordingly, as shown in FIG. 5, the transfer distance of the plate member 211 may be determined by one insertion groove 291a, and another insertion groove (not shown) may be further provided. This is sufficient if the screw formed in the lead screw 24 is designed to have a predetermined pitch, which is well known in the art. When the projection part 241a is inserted into the insertion groove 291a in the state where the optical axis of the projection lens 212 is adjusted as described above, reverse rotation of the rotary knob 241 due to external impact or the like is prevented. Since the position of 21 is fixed, the image projection range is prevented from changing while the projector is projecting the image on the screen 22.

As described above, according to the projection lens system optical axis adjusting device of the projector according to the present invention, the projector can be applied to two types of front projection type and rear projection type by allowing the optical axis of the projection lens to be adjusted in the height direction of the screen, and the installation of the projector is easy. Become.

Claims (7)

A barrel having a projection lens installed to enlarge and project the image generated by the image generator built in the case to the screen; A plate member on which the barrel is supported; And a conveying means installed in the case so that the plate member is linearly reciprocated in the height direction of the screen to adjust the optical axis of the projection lens. The method of claim 1, The transfer means, A housing installed in front of the image generating unit; A lead screw supported by the housing in a height direction of the screen; A connection member connected to the plate member and coupled to move along an axis of the lead screw; And a rotary knob installed at the shaft end of the lead screw. The method of claim 2, The transfer means, A guide means for guiding the transfer of the plate member, the projection lens system optical axis of the projector, characterized in that it has a guide rail provided in the housing parallel to the lead screw and the guide portion provided in the plate member to be coupled to the guide rail Adjuster. The method of claim 2, The plate member is a projection lens system optical axis adjusting device of the projector, characterized in that the conveying distance is determined by the positioning means provided in the knob seating portion formed in the case to accommodate the rotary knob and the rotary knob. The method of claim 4, wherein The positioning means, And a projection formed on the knob seating portion to be complementarily coupled to the insertion groove, and an insertion groove formed on an outer circumferential surface of the rotary knob. The method of claim 1, The case is provided with an opening formed to allow the conveyance of the barrel, the projection lens system optical axis adjustment apparatus of the projector. The method of claim 1, And the plate member is elastically biased in one direction of the top and bottom of the screen.

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