JPH11352451A - Liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obscure the shadows caused by obstacles, such as lead wires, by arranging respective convex lenses in such a manner that the shades formed in the plural convex lenses in multilens arrays are formed in the positions varying on a light valve by the obstacles in a reflector. SOLUTION: The convex lenses 9, 9 of the multilens arrays 6, 8 are properly arranged, by which the positions of the shapes of the lead wires 4 are generated in the positions varying with the plural convex lenses 9a to 9d. The secondary light source images of the convex lenses 9 are made incident in superposition on a liquid crystal panel but if the positions of the plural generated shades vary with each of the respectively convex lenses 9a to 9d, the shades are dispersed without overlapping on one point and the shades projected onto a screen are entirely obscured. Then, the effect of the shades of the shielding objects may be lessened by properly arranging the convex lenses 7, 9 on the multilens arrays 6, 7 with respect to the shapes and positions of the lead wires 4, i.e., the obstacles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector and the like, and more particularly to a liquid crystal projector useful for making a shadow of an obstacle of a high-intensity discharge lamp added to the liquid crystal projector inconspicuous.

[0002]

2. Description of the Related Art There is known a liquid crystal projector which forms an image by transmitting light emitted from a light source through a transmission type liquid crystal panel which is a kind of light valve. In this liquid crystal projector device, as a light beam serving as projection irradiation light, a high-efficiency discharge lamp such as a high-pressure mercury lamp or a metal halide lamp generally called a high-intensity discharge lamp is widely used as a light source lamp. Also, since the light source lamp used is close to a point light source, the emitted light from the light source lamp is made parallel by a reflector or the like, and a multi-lens array, also called a fly-eye integrator, is used.
By inserting the light valve in the light path, the light valve is irradiated with uniform light.

FIG. 7 shows a simplified block diagram of a liquid crystal projector using the above-mentioned lamp and a multi-lens array. The light source lamp unit 51 includes a light source lamp 52 and a reflector 53. A first flat multi-lens array 55 is disposed in front of the light source lamp unit 51. On the surface of the multi-lens array 55, a plurality of convex lenses 56 having a similar outer shape equal to the aspect ratio of an irradiation area of the liquid crystal panel 61 described later are arranged in a square. Further, a flat second multi-lens array 57 in which a plurality of convex lenses 58 are formed is disposed so as to face the focal point of each convex lens 56 of the first multi-lens array 55. FIG. 8A shows the light source lamp unit 51, the first multi-lens array 55, and the second
8B is a front view of the multi-lens array 57 shown in FIG. 8B, which is projected from the line AA in FIG. 8A through the second multi-lens array 57 to look into the reflector 53. FIG. The AA line in FIG. 7 shows the same positional relationship as the AA line in FIG.

The light emitted from the light source lamp 52 is converted into substantially parallel light beams by a reflector 53, and is incident on a plurality of convex lenses 56 on a first multi-lens array 55. Further, the light is converged by the plurality of convex lenses 58 on the second multi-lens array 57 and becomes a plurality of light sources that emit the respective convex lenses 58. Here, this is called a secondary light source image.

[0005] Each secondary light source image is converted to a plano-convex lens 59.
Then, the light is converged in a predetermined direction, and is irradiated through the plano-convex lens 60 so as to be superimposed on the liquid crystal panel 61 so as to become parallel light. Then, in the liquid crystal panel 61, the transmitted light is modulated based on a video signal supplied from a path (not shown), and an image is formed. LCD panel 61
Is modulated and projected on a screen 63 via a projection lens 62.

The liquid crystal panel 61 and the vicinity of the convex lens 56 on the first multi-lens array 55 are in an optically conjugate relationship, and the image of the rectangular aperture of each convex lens 56 is located at the effective aperture of the liquid crystal panel 61. It is designed to be enlarged and projected. That is, the secondary light source images of the light emitting portions of the light source lamps 52 formed on the convex lenses 56 on the first multi-lens array 55 are all incident on the liquid crystal panel 61 in a stacked manner.

[0007]

By the way, in a high-intensity discharge lamp used as an arc tube, a lead wire 54 of the lamp is taken out across an effective opening of a reflector 53 as shown in FIG. Is common. Since the lead wire 54 becomes an obstacle for blocking light from the light source lamp, the shadow of the lead wire 4 enters the bright light emitting portion of the light source lamp as a dark streak in the secondary light source image. In many cases, as shown in FIG. 8B, the lead wire blocks the effective light beam of the plurality of convex lenses 58 to form a shadow.
Lenses 58a, 58 on the multi-lens array 57 of
Shadows are reflected at almost the same positions of b and 58c. If there is a shadow of the lead wire 54 at the same position of the plurality of convex lenses 58,
On the liquid crystal panel 61, a plurality of shadows are piled up at the same place to form a dark shadow, which is enlarged and projected on the screen.

As another example, as shown in FIG. 9, there is a multi-lens array 67 in which convex lenses 68 forming a fly's eye are arranged in a staggered manner.
In a, 68b, and 68c, the lead wire 74 blocks at the same position, and shadows cannot be avoided. The shadow projected on the screen in an enlarged manner impairs the projection effect and degrades the quality of the image, which has been a serious problem. Not only the lead wire but also a support for supporting the light source lamp 72 that crosses the effective opening of the reflector 53 causes a similar shadow. Here, the lead wire in the reflector, the support member of the arc tube, and the like that cause such a shadow of the projected image are referred to as obstacles.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention reflects a light source lamp and a light emitted from the light source lamp and emits the light as a parallel or convergent light flux. A reflector, a multi-lens array composed of a number of convex lenses arranged corresponding to the reflector irradiation surface, and separating and demodulating a light beam transmitted through the multi-lens array into at least three primary colors, In a liquid crystal projector having a light valve that modulates a light beam, shadows formed in a plurality of convex lenses in the multi-lens array by obstacles in the reflector are located at different positions on the light valve. And a liquid crystal projector, wherein each of the convex lenses is arranged. Also, a shadow created by an obstacle placed in the reflector,
The liquid crystal projector having the obstacle formed so as to be located at the boundary between the convex lenses constituting the multi-lens array, and the multi-lens array having a shadow caused by the obstacle disposed in the reflector. Provided is a liquid crystal projector in which a constituent convex lens is shielded from light or the transmittance of the convex lens is reduced.

[0010]

FIG. 1 is a block diagram of a transmission type liquid crystal projector according to an embodiment of the present invention. In this figure, a lamp 1 is composed of a light source lamp 2 and a reflector 3, and a halogen lamp, a metal halide lamp, or the like is used as the light source lamp 2, and is disposed at a focal position of the reflector 3 composed of a paraboloid. A lead wire 4 for supplying power to the light source lamp 2 is disposed inside the reflector 3. The light emitted from the light source lamp 2 is emitted as light substantially parallel to the optical axis of the reflector 3 and is emitted forward from the opening.

[0011] Of the light emitted from the reflector 3, unnecessary light invisible in the infrared and ultraviolet regions is UV-I
The light is cut off by the R-cut filter 5 and only light effective for forming an image can be used.

In the subsequent stage of the UV-IR cut filter 5,
A first flat multi-lens array 6 is arranged, and then a second flat multi-lens array 8 is arranged. On the surface of the first multi-lens array 6, a plurality of convex lenses 7 having a similar external shape equal to the aspect ratio of the illuminated areas of the liquid crystal panels 17, 21 and 26 described later are arranged in a square. . A plurality of convex lenses 9 are formed on the surface of the second multi-lens array 8 so as to face the respective focal points of the convex lenses 7.
In addition, the shape of the irradiated area of the liquid crystal panels 17, 21, and 26,
All sizes are equal.

The light that has passed through the second lens array 8 is
The light converged by each convex lens 9 of the multi-lens array by the plano-convex lens 10 is applied to the liquid crystal panels 17, 21,
It is made to overlap at 26. That is, only the R light of the light emitted from the plano-convex lens 10 is reflected by the dichroic mirror 14, the path of the light is changed by the reflecting mirror 15, and then enters the liquid crystal panel 17 via the convex lens 16. The transmitted light is modulated in the liquid crystal panel 17 based on a video signal supplied from a path (not shown), and an R image is formed.

Similarly, the BG light transmitted through the dichroic mirror 14 transmits the B light through the dichroic mirror 19, and the G light is reflected and enters the liquid crystal panel 21 via the convex lens 20. Also, the dichroic mirror 19
The B light transmitted through passes through the convex lens 22, the reflecting mirror 27, the convex lens 23, the reflecting mirror 24, and the convex lens 25 and enters the liquid crystal panel 26. Similarly to the R image, a G image is formed by the liquid crystal panel 21 and a B image is formed by the liquid crystal panel 26. The convex lenses 22 and 23 are relay lenses.

R passing through the liquid crystal panels 17, 21, 26
Each of the GB light beams enters the cross prism 18. An interference filter 18 is provided inside the cross prism 18.
a and the interference filter 18b are adhered to each other.
In a, R light is reflected and B light is transmitted. The B light is reflected by the interference filter 18b, and the R light is transmitted. The G light passes through both the interference filters 18a and 18b. Therefore RG
The respective light beams of B are combined by the cross prism 18, and the combined image is enlarged by the projection lens 30 and projected on a screen (not shown).

FIG. 2B is a plan view of the light source lamp section 1 seen from the multi-lens array 8 side. FIG. 2 (a)
Is the same as that seen from the AA line in FIG. The effective light flux is blocked by the lead wires 4 arranged to be inclined to the lower left, and among a plurality of convex lenses 9 on the multi-lens array 8, a plurality of convex lenses 9 (a, b, c, d) are formed. The shadow of the lead wire 4 is reflected. However, multi-lens
By appropriately arranging the convex lenses 7, 9 on the arrays 6, 8, the position of the shadow of the lead wire 4 can be adjusted by a plurality of convex lenses 9.
Each of (a, b, c, d) occurs at a different position. As described above, the secondary light source images of the convex lens 9 are incident on the liquid crystal panels 17, 21, and 26 in a superimposed manner. , D), the shadows on the liquid crystal panels 17, 21, and 26 are dispersed without being overlapped at one place, and the shadows projected on the screen become completely inconspicuous. By appropriately arranging the convex lenses on the multi-lens array with respect to the shape and position of the lead wire 4, that is, the obstacle, as in this example, the influence of the shadow of the shield can be reduced.

In the example shown in FIG. 3, the convex lenses 32, 34 on the multi-lens arrays 31, 33 are arranged in a staggered arrangement with respect to the lead wires 4, which are arranged at the lower left as in FIG. The convex lenses 34 (a, b, c, d,
The positions of the shadows of the lead wires 4 generated at e and f) are all different positions in each of the six convex lenses 34 (a, b, c, d, e, and f). Obstacle shadows appearing in the image projected on the screen have been successfully reduced by appropriate arrangement of convex lenses on the multi-lens array.

FIG. 4 shows a lower three-stage arrangement of convex lenses constituting a multi-lens array with respect to an obstacle in which the lead wire 4 and a light source lamp support, that is, a light source lamp support member 36 are integrated. It is staggered. That is, as shown in FIG. 4B, the multi-lens arrays 37 and 39
The lower three steps of the upper convex lenses 38 and 40 are moved horizontally in the figure, and the positions of the convex lenses 40 (a, b, c) where the shadows of the lead wire 4 and the support member 36 appear are different for each convex lens. I have to.

Further, by deforming the shape of the obstacle which may cause a shadow, or by appropriately moving the position of the obstacle,
It is also conceivable to reduce the influence of the generated shadow. An example is shown in FIG. The multi-lens arrays 6, 8 shown in the plan view of FIG. 5B are the same as the multi-lens arrays 6, 8 shown in FIG. As shown in the plan view of FIG. 5B, the shape of the lead wire 4 is bent stepwise so that the shadow of the lead wire 4 is located on the boundary between the adjacent convex lenses 9a and 9b. 4 on the boundary between the adjacent convex lenses 9b and 9c.
Is on the boundary between the adjacent convex lenses 9c and 9d. If the shadow of the obstacle is on the boundary of the convex lens 9 as described above, the shadow appears only on the outer periphery of the screen on the screen, so that the influence of the shadow of the obstacle is almost inconspicuous.

Further, if it is desired to reduce the shadow of an obstacle even if the image on the screen is somewhat dark, a multi-lens
Among the convex lenses on the array, a convex lens that produces a shadow of an obstacle can be shielded. As shown in FIG. 6B, among the many convex lenses 44 on the multi-lens array 43, the convex lens 4 in which the shadow of the lead wire 4 is generated
4a, 44b, and 44c may be covered to some extent with a light-blocking material that blocks light, or the convex lenses 44a, 44c
For example, b and 44c may be made of a material having a reduced light transmittance. Even if about three of the many convex lenses constituting the multi-lens array are completely shielded from light as in this example, the light amount is reduced by 10% or less, and the light amount reduction is not a serious problem.

Although the present invention has been described with reference to a transmissive liquid crystal projector as an example, the present invention can be applied to a reflective liquid crystal projector as it is. In addition, a high-intensity discharge lamp is used as the light source lamp, and a multi-lens
The present invention can be applied to any device using an array. The shape of the reflector may be not only a parabolic surface but also an elliptical surface on which a light beam converges.

[0022]

As described above, according to the present invention, it is possible to easily remove or reduce the influence of a shadow of a shield which lowers the image quality of an image. Therefore, it is possible to effectively contribute to the improvement of the quality of the image projected on the screen. When the present invention is used for an actual product, no additional members are required,
There are few factors that increase the processing cost, and it is also economical.

[Brief description of the drawings]

FIG. 1 is a block diagram of a liquid crystal projector to which the present invention has been applied.

FIG. 2 is a diagram showing an example of the arrangement of convex lenses on a multi-lens array to which the present invention has been applied.

FIG. 3 is a diagram showing another arrangement example of convex lenses on a multi-lens array to which the present invention is applied.

FIG. 4 is a diagram showing a third arrangement example of convex lenses on a multi-lens array to which the present invention has been applied.

FIG. 5 is a diagram showing an application example in which the shape and arrangement of obstacles are changed.

FIG. 6 is a diagram showing a multi-lens array in which some convex lenses are shielded from light.

FIG. 7 is a block diagram illustrating a schematic light path of a conventional liquid crystal projector.

FIG. 8 is a diagram showing an example of the arrangement of convex lenses on a conventional multi-lens array.

FIG. 9 is a diagram showing another example of arrangement of convex lenses on a conventional multi-lens array.

[Explanation of symbols]

1 light source lamp section, 2 light source lamps, 3 reflectors,
4 lead wire, 8 multi-lens array, 9 convex lens, 17 liquid crystal panel (R), 21 liquid crystal panel (G), 26 liquid crystal panel (B), 36 light source lamp support member

Claims (4)

[Claims] 1. A light source lamp, a reflector that reflects light emitted from the light source lamp and emits the light as a parallel or convergent light beam, and a number of convex lenses arranged corresponding to the irradiation surface of the reflector A multi-lens array comprising: a light valve that modulates the luminous flux while separating and demodulating the luminous flux transmitted through the multi-lens array into at least three primary colors; A liquid crystal projector, wherein each of the convex lenses is arranged such that shadows formed by the objects in the plurality of convex lenses in the multi-lens array are different positions on the light valve. 2. A light source lamp; a reflector that reflects light emitted from the light source lamp and emits the light as a parallel or convergent light flux; and a number of convex lenses arranged corresponding to the irradiation surface of the reflector. And a light beam transmitted through the multi-lens array is separated into at least three primary colors and demodulated, and a light valve that modulates the light beam is disposed in the reflector. A liquid crystal projector, wherein the obstacle is formed such that a shadow created by the obstacle is located at a boundary between the convex lenses constituting the multi-lens array. 3. A light source lamp; a reflector for reflecting light emitted from the light source lamp and emitting it as a parallel or converging light flux; and a plurality of reflectors arranged corresponding to the irradiation surface of the reflector. A liquid crystal projector having a multi-lens array composed of convex lenses, and a light valve that separates and demodulates a light beam transmitted through the multi-lens array into at least three primary colors and modulates the light beam; A liquid crystal projector characterized in that a convex lens constituting the multi-lens array, which has a shadow caused by an arranged obstacle, is shielded from light or the transmittance of the convex lens is reduced. 4. The liquid crystal projector according to claim 1, wherein the obstacle is a lead line of the light source lamp.