JP3384722B2 - Rear projection type video projector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear projection type image projection device using a liquid crystal panel.

[0002]

2. Description of the Related Art FIG. 4 is a plan view showing a three-plate (R, G, B) type optical engine 60 in a rear projection type image projection apparatus. The light emitted from the lamp (halogen lamp or metal halide lamp) 62a is reflected by the condensing reflector 61, the ultraviolet rays and infrared rays are removed by the UV / IR filter 63, emitted from the light source device 62, and incident on the dichroic mirror 51. To do. The dichroic mirror 51 transmits red light (R) and reflects green light (G) and blue light (B). The red light separated by the dichroic mirror 51 is reflected by the total reflection mirror 52 and given to the red liquid crystal panel 53 for displaying a red image. The red light is passed through the liquid crystal panel 53 with its transmittance changed and then given to the dichroic prism 54 as a light combining means.

On the other hand, the green light and the blue light reflected by the dichroic mirror 51 are given to the dichroic mirror 55. This dichroic mirror 55 is green (G)
And transmits blue light (B). The green light separated by the dichroic mirror 55 is given to the green liquid crystal panel 56 that displays a green image. The green light is given a dichroic prism 54 after passing through the liquid crystal panel 56 with its transmittance changed.

The blue light transmitted through the dichroic mirror 55 is reflected by the total reflection mirrors 57 and 58 and given to the blue liquid crystal panel 59 for displaying a blue image.
The blue light is transmitted to the dichroic prism 54 after having its transmittance changed by the liquid crystal panel 59.

Each color light incident on the dichroic 54 is
They are combined and emitted as color image light (R, G, B). Then, the projected color image light is reflected by the prism 70.
The optical path is changed to the upward direction (vertical direction to the paper surface) and enters the projection lens 64.

The color image light emitted from the projection lens 64 is reflected by the mirror 71 and projected on the screen 72, as shown in FIG.

The above-mentioned liquid crystal panels 53, 56, 59 are provided with a mechanism for focus adjustment. For the liquid crystal panels 53, 59, further CG adjustment (for the pixels of the liquid crystal panel 56 for green color) is performed. LCD panel 53,
An adjustment mechanism for adjusting 59 pixels is provided.

6 to 9 show a liquid crystal panel 53 for red.
FIG. 6 is a view showing an adjusting mechanism of FIG.
FIG. 7 is a plan view, FIG. 8 is a view seen from the incident side of green light, and FIG.
FIG. 4 is a view seen from the incident side of red light. Member 81 in the figure,
The reference numeral 82 is fixed to the bottom surface of the housing 60a. The members 81 and 82 have holes 81a ..., 82a ...
Are formed. Further, the support piece 83 forming part of the support means for supporting the liquid crystal panel 53 is provided with notches 83a ... These holes 81a
... and the notch 83a, and also the hole 82a ... and the notch 83a.
And are overlapped with each other to form the adjustment cross hole. The liquid crystal panel 53 can be supported by inserting a minus driver as an adjusting tool into the adjusting cross hole and rotating the same.

Further, by rotating the CG adjusting screws 84a, the liquid crystal panel 53 can be moved up and down, left and right within the plane, and rotated. Specifically, the support piece 83 includes the first, second, and third Cs.
The G adjustment plates 84b, 84c, 84d are connected in this order. The liquid crystal panel 53 is the outermost third CG adjustment plate 8
It is fixed to 4d. The third CG adjustment plate 84d is the second C
The G adjustment plate 84c is provided so as to be rotatable in-plane, for example. The second CG adjustment plate 84c is provided so as to be vertically movable with respect to the first CG adjustment plate 84b. 1st CG
The adjustment plate 84b is provided so as to be movable in the left-right direction with respect to the support piece 83. Then, by turning the CG adjusting screws 84a ..., the three plates can be moved up and down, left and right, and rotated, whereby C of the liquid crystal panel 53 is rotated.
G adjustment is performed.

[0010]

SUMMARY OF THE INVENTION In such a structure,
The focus adjustment is performed by inserting a driver into the adjustment cross hole.
Since the image light emission direction of 4 is the same and the adjusting cross hole and the projection lens 64 are close to each other, the optical path of the image light is blocked by the hand of the adjuster, and a shadow is formed on the screen image, which is appropriate. However, there is a drawback in that it cannot be adjusted. Especially, it is important to adjust the corners on the screen,
A shadow tends to appear in this corner portion. Further, when the adjuster tries to see the adjusting cross hole, he cannot see the image on the screen, and it is difficult to make the adjustment. Further, as shown in FIGS. 10A and 10B, when the adjustment direction is the lateral direction, the device 75 such as a power source and a fan exists in the lateral position of the optical engine 60, which is an obstacle. Becomes difficult to adjust.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a rear projection type image projection apparatus which allows easy adjustment of focus and the like.

[0012]

In order to solve the above-mentioned problems, the rear projection type image projection apparatus of the present invention changes the optical path of the image light obtained through the liquid crystal panel and guides it to the projection lens. Rear projection type image projection which is configured to project the image light passing through the projection lens from the rear side of the screen and has an adjustment mechanism for focus and / or CG adjustment with respect to the liquid crystal panel. In the device, the insertion direction of the adjustment tool with respect to the adjustment mechanism is set to be substantially parallel to the direction before changing the optical path of the image light obtained through the liquid crystal panel.

In the above arrangement, the inserting direction of the adjusting tool with respect to the adjusting mechanism is substantially parallel to the direction before changing the optical path of the image light obtained through the liquid crystal panel. That is, the inserting direction of the adjusting tool and the image light emitting direction of the projection lens are different. Therefore, the optical path of the image light is not blocked by the adjuster's hand, so that the image on the screen is not shaded and appropriate adjustment can be performed. In addition,
The direction before changing the optical path of the image light includes not only the direction intersecting with the screen but also the direction parallel to the screen.

The adjusting tool may be inserted into the adjusting mechanism from the front side of the screen.
With such a configuration, adjustment can be performed while watching the image on the screen. In addition, since the adjustment tool is not inserted in the lateral direction, even if a device such as a power source or a fan exists in the lateral position of the optical engine, it is not disturbed.

The adjusting tool may be inserted into the adjusting mechanism from the back side of the screen.
With such a configuration, the adjusting tool is not inserted in the lateral direction, so that even if a device such as a power source or a fan exists in the lateral position of the optical engine, it is not disturbed. Further, although various kinds of knobs and the like are arranged on the front side of the screen, since the knobs and the like are rarely arranged on the rear side of the screen, that is, the rear side of the image projection device, the adjustment tool There is also an advantage that it is easy to secure the insertion area.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a three-color image synthesizing section and an adjusting mechanism section in the rear projection type image projection apparatus of this embodiment. The dichroic prism 1 has
Image light that has passed through the liquid crystal panels for red, green, and blue (only the liquid crystal panel 3 for red is shown in the figure) is incident. The incident image lights of the respective colors are combined by the dichroic prism 1 and emitted as color image light.
The emitted color image light is passed through the optical path changing prism 2 and the optical path thereof is changed in the upward direction of the drawing to be given to a projection lens (not shown).

In this figure, the focus adjusting mechanism and the CG adjusting mechanism are shown only for the red liquid crystal panel 3. The vertically long L-shaped member 5 in the figure is fixed to the bottom of the casing of the optical engine (not shown). The horizontally long L-shaped member 6 in the figure is also fixed to the bottom of the housing. The members 5 and 6 have holes 5a and 6a each having a substantially convex shape.
Are formed. The support piece 7 connected to the member 5 is formed with a notch 7a having a substantially concave shape. The holes 5a and the cutouts 7a and the holes 6a and the cutouts 7a overlap with each other to form adjustment cross holes. The inserting direction of the adjusting tool (minus driver) into the adjusting cross hole is substantially parallel to the direction before changing the optical path of the color image light. By inserting an adjusting tool into the adjusting cross hole and rotating the adjusting tool, the liquid crystal panel 3 can be tilted and shifted in the optical axis direction, and the focus adjustment is performed by this tilting or shifting operation. After the focus adjustment, the lock screw 9 is tightened to fix the member 7 to the members 5 and 6, and the adjusted state is maintained.

The support piece 7 has a first, second and third C
The G adjustment plates 11, 12, and 13 are connected in this order.
The liquid crystal panel 3 is fixed to the outermost third CG adjustment plate 13. The third CG adjustment plate 13 is the second CG adjustment plate 12
For example, it is provided so as to be rotatable in-plane. The second CG adjustment plate 12 is provided so as to be movable in the vertical direction with respect to the first CG adjustment plate 11, for example. The first CG adjustment plate 11 is provided so as to be movable in the left-right direction with respect to the support piece 7. And
By rotating the CG adjusting screws 15 ..., the three plates can be moved up and down, left and right, and rotated, whereby the CG adjustment of the liquid crystal panel 3 is performed.

FIG. 2 is an explanatory diagram showing the positional relationship among the optical engine 21 having the adjusting mechanism of FIG. 1, the mirror 22 and the screen 23. The color image light emitted from the projection lens of the optical engine 21 is reflected by the mirror 22 and projected on the back side of the screen 23. Then, as shown in this figure, the inserting direction of the adjusting tool into the cross adjusting hole in the focus adjusting mechanism is from the front side of the screen 23.

With the above arrangement, the inserting direction of the adjusting tool with respect to the focus adjusting mechanism is substantially parallel to the direction before changing the optical path of the color image light obtained through the dichroic prism 1. That is, the inserting direction of the adjusting tool and the image light emitting direction of the projection lens are different. Therefore, since the optical path of the color image light is not blocked by the adjuster's hand, the image on the screen 23 will not be shaded and appropriate adjustment can be performed. Further, since the adjusting tool is inserted into the focus adjusting mechanism from the front side of the screen 23, the adjustment can be performed while watching the image on the screen 23. Further, since the direction in which the adjusting tool is inserted is not the horizontal direction (the direction from the side surface of the image projection device), even if a device such as a power supply or a fan exists in the lateral position of the optical engine 21, it is disturbed. Never.

Regarding the CG adjusting mechanism, the above-mentioned C
If a universal joint that is connected to the head of the G adjustment screw 15 and reaches the front side of the screen is provided and a hexagonal hole is formed at the tip of this universal joint, an adjustment tool (hexagonal) can be used for this CG adjustment. The insertion direction of the wrench is substantially parallel to the direction before changing the optical path of the color image light, and the adjustment tool is inserted from the front side of the screen.

Although only the adjusting mechanism for the liquid crystal panel 3 for red light is shown in FIG. 1, the adjusting mechanism for the liquid crystal panel for blue can be realized with the same configuration. On the other hand, the focus adjusting mechanism of the liquid crystal panel for green light cannot adopt the same configuration as the adjusting mechanism of the liquid crystal panel 3 (note that the CG adjusting mechanism is not necessary). It is possible to adopt a conventional configuration for the focus adjustment mechanism of the liquid crystal panel for green light. Even in this case, the adjustment can be performed easily and properly as compared with the case where all the three focus adjustments are performed by the conventional configuration. Further, regarding the focus adjusting mechanism of the liquid crystal panel for green light, it may be considered that the focus adjusting mechanism when assembled in the housing of the optical engine is unnecessary by providing the mechanism for supporting the dichroic prism.

In the example shown in FIG. 1, the member 6 is used.
The bent piece portion in which the hole 6a is formed is bent to the dichroic prism 1 side. However, if the structure is bent to the side opposite to the side where the dichroic prism 1 is located, the member 6 and the dichroic prism can be adopted. It is possible to reduce the distance from the unit 1 and achieve compactness.

(Embodiment 2) FIG. 3 is an explanatory diagram showing a positional relationship among an optical engine 31, a mirror 32, and a screen 33 in a rear projection type image projection apparatus according to Embodiment 2. The color image light emitted from the projection lens of the optical engine 31 is reflected by the mirror 32 and projected on the back side of the screen 33. Optical engine 31
An adjusting mechanism 34 is provided in the. This adjusting mechanism 34
Has the same structure as that shown in the first embodiment, but the adjusting tool is inserted into the cross adjusting hole from the back side of the screen 33 opposite to the first embodiment. There is.

With such a configuration, the adjusting tool is not inserted in the lateral direction, so that even if a device such as a power source or a fan exists in the lateral position of the optical engine 31, it is not disturbed. Further, although various knobs and the like are arranged at the position on the screen 33 side, that is, the front surface side of the image projection apparatus, the knobs and the like are arranged on the rear surface side of the screen 33, that is, the rear surface side of the image projection apparatus. Since it is rare that the adjustment tool is inserted, it is easy to secure the insertion area of the adjustment tool.

[0027]

As described above, according to the present invention, the inserting direction of the adjusting tool and the image light emitting direction of the projection lens are different. Therefore, the adjuster does not block the optical path of the image light with his / her hand, the image on the screen is not shaded, and appropriate adjustment can be performed. If the adjustment tool is inserted from the front side of the screen, the adjustment can be performed while watching the image on the screen, while the adjustment tool is inserted from the back side of the screen. With such a configuration, it becomes easy to secure the insertion area of the adjustment tool. The adjustment from the front side / rear side of the screen is disturbed even if a device such as a power source or a fan exists in the lateral position of the optical engine because the direction in which the adjusting tool is inserted is not the lateral direction. It has the effect of never happening.

[Brief description of drawings]

FIG. 1 is a perspective view showing an adjusting mechanism and the like in a rear projection type image projection apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between an optical engine including the mechanism of FIG. 1, a screen, and the like.

FIG. 3 is an explanatory diagram showing an arrangement relationship of an optical engine, a screen and the like in a rear projection type image projection apparatus according to Embodiment 2 of the present invention.

FIG. 4 is a plan view showing an optical engine portion of a conventional rear projection type image projection apparatus.

FIG. 5 is an explanatory diagram showing a positional relationship of an optical engine, a screen and the like in a conventional rear projection type image projection apparatus.

FIG. 6 is a perspective view showing a conventional adjusting mechanism.

FIG. 7 is a plan view showing a conventional adjusting mechanism.

FIG. 8 is a view of a conventional adjusting mechanism as viewed from the incident side of green light.

FIG. 9 is a view of a conventional adjusting mechanism as viewed from the incident side of red light.

FIG. 10 is a diagram showing another conventional example.

[Explanation of symbols]

1 dichroic prism 2 Optical path changing prism 3 LCD panel 5 members 6 members 7 Support piece 9 Lock screw 15 CG adjustment screw 21 Optical engine 22 mirror 23 screen 31 Optical engine 32 mirror 33 screens 34 Adjustment mechanism

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-195382 (JP, A) JP-A-7-218890 (JP, A) Actually open 5-4149 (JP, U) Actually open 5- 15035 (JP, U) Actual Kaihei 5-6440 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03B 33/12 G03B 21/10 G02F 1/1335

Claims (3)

(57) [Claims] 1. The liquid crystal panel is configured so that the optical path of image light obtained through a liquid crystal panel is changed and guided to a projection lens, and the image light that has passed through the projection lens is projected from the rear side of the screen. In a rear projection type image projection device having an adjustment mechanism for focus and / or CG adjustment, the optical path of image light obtained by passing the adjustment tool into the adjustment mechanism through the liquid crystal panel is changed. A rear projection type image projection device, which is set to be substantially parallel to the front direction. 2. The rear projection type image projection apparatus according to claim 1, wherein the adjusting tool is inserted into the adjusting mechanism from the front side of the screen. 3. The rear projection type image projection apparatus according to claim 1, wherein an adjusting tool is inserted into the adjusting mechanism from a rear side of the screen.