JP2009063893A - Projector, optical element, and light modulation device - Google Patents

Abstract

The present invention provides a projector, an optical element, and a light modulation device that are small in size and can improve illumination efficiency.
A light source that emits light including a plurality of types of color light, a color separation unit that separates light emitted from the light source into a plurality of types of color light, and a light that is color-separated by the color separation unit is modulated. A plurality of pixels 31 arranged in an array, arranged on each optical path between the plurality of light modulation means 30 provided for each color light, and between each of the color separation means and the plurality of light modulation means 30; A first cylindrical lens 34 that condenses incident light in a first direction that is an arrangement direction of the plurality of pixels 31 and enters the pixel 31, and a second direction that is substantially orthogonal to the first direction. A microlens array 33 in which second cylindrical lenses 35 that are focused on and incident on the pixels 31 are arranged in an array, and a projection unit that projects the light modulated by the light modulation unit 30. Features.
[Selection] Figure 4

Description

  The present invention relates to a projector, an optical element, and a light modulation device.

As a liquid crystal projector, a three-plate type liquid crystal projector using three liquid crystal panels is known (see, for example, Patent Document 1).
The projection-type liquid crystal display device described in Patent Document 1 includes a light source including red light, green light, and blue light, and a dichroic mirror that separates white light emitted from the light source into red light, green light, and blue light. And a liquid crystal panel that modulates light of each color and a cross prism that combines light modulated by the liquid crystal panel.
A microlens array is arranged on the front side of the liquid crystal panel. This microlens array has a convex lens surface on the incident side and a convex lens surface on the exit side, and is configured so that two lens surfaces are arranged in the optical axis direction for each dot. Yes. The incident light is condensed on each pixel of the liquid crystal panel by the two lens surfaces.
At this time, Fno. When the focal length of the microlens array is shortened to reduce the (F number), the microlens array has two lens surfaces, so the amount of light vignetting in the black matrix of the liquid crystal panel is reduced. Thus, it can be condensed. Here, Fno. Is a value obtained by dividing the focal length of the lens by the effective aperture of the lens. The smaller the is, the brighter the light illuminated by the lens.
JP 2002-148603 A

  However, in the projection-type liquid crystal display device described in Patent Document 1, the illumination distance Fno. Since the (F number) is reduced, the incident angle of light incident on each pixel of the liquid crystal panel is increased. This necessitates the use of a large projection lens for capturing the spread light emitted from the liquid crystal panel. Therefore, the thickness in the thickness direction of the device (vertical direction of the liquid crystal panel) is increased, and the entire device is increased in size.

  SUMMARY An advantage of some aspects of the invention is that it provides a projector, an optical element, and a light modulation device that are small in size and capable of improving illumination efficiency.

In order to achieve the above object, the present invention provides the following means.
The projector of the present invention includes a light source that emits light including a plurality of types of color light, a color separation unit that separates the light emitted from the light source into a plurality of types of color light, and light that has been color-separated by the color separation unit. A plurality of light modulating means provided for each color light, and arranged on respective optical paths between the color separating means and each of the plurality of light modulating means. A first cylindrical lens that collects incident light in a first direction that is an arrangement direction of the plurality of pixels and makes the incident light enter the pixel; and a second cylindrical lens that is substantially orthogonal to the first direction. A microlens array in which second cylindrical lenses that are condensed in a direction and incident on the pixels are arranged in an array, and a projection unit that projects the light modulated by the light modulation unit. And

In the projector according to the present invention, the light emitted from the light source is separated for each color light by the color separation unit and is incident on the microlens array. The light incident on the microlens array is condensed on the pixels of the respective light modulation means, modulated by the light modulation means, and projected by the projection means.
Here, by the first cylindrical lens of the microlens array of the present invention, the incident light is condensed in the first direction of the light modulation means and incident on each pixel. Further, the incident light is condensed in the second direction of the light modulation means by the second cylindrical lens and is incident on each pixel.
Therefore, since the first and second cylindrical lenses for condensing in the first direction and the second direction of the pixel arrangement direction of the light modulation means are provided separately, the focal lengths in the respective directions are designed separately. can do. That is, of the first direction and the second direction, for example, when the first direction is the thickness direction (short direction) of the projector, the focal length of the first cylindrical lens that collects light in the first direction. Can be designed longer. Thus, by increasing the focal length of the first cylindrical lens, the incident angle of the light incident on the pixel of the light modulator can be reduced. Therefore, since light does not spread in the thickness direction, it is possible to reduce the thickness in the first direction of the projection means arranged in the subsequent stage. In other words, since the thickness of the entire projector in the first direction can be reduced, the size can be reduced.
Furthermore, the illumination efficiency of the light modulation means can be improved by designing the focal length of the second cylindrical lens to be short.

  Further, since the light color-separated by the color separation means is condensed on each pixel of the light modulation means by the first and second cylindrical lenses, for example, the focal length can be made shorter than that of the lenticular lens. . Therefore, when the pixel pitch of the light modulation means is narrow, it can be formed as a desired lens having a short focal length, and therefore it is possible to cope with the light modulation means having fine pixels. That is, since the focal length of the second cylindrical lens can be shortened in accordance with the pixel pitch, the entire apparatus can be reduced in size.

  In the projector according to the aspect of the invention, the first direction and the second direction have different curvatures, and the reflection unit reflects light emitted from the light source, and the light between the light source and the color separation unit. It is preferable to include a condensing unit that is disposed on the road and has lens surfaces having different curvatures in the first direction and the second direction, and condenses the light reflected by the reflection unit.

In the projector according to the present invention, the light emitted from the light source is reflected by the reflecting portion. At this time, since the curvatures of the first direction and the second direction of the reflecting portion are different, the light emitted from the reflecting portion, for example, narrows the light flux in the first direction and changes the light flux in the second direction. Can be thick. And the light reflected by the reflection part is condensed by the condensing means which has a lens surface from which the curvature of a 1st direction and a 2nd direction differs, and becomes a substantially parallel light. The light emitted from the condensing means is condensed in the first direction by the first cylindrical lens, condensed in the second direction by the second cylindrical lens, and enters each pixel of the light modulation device.
That is, of the first direction and the second direction, for example, when the first direction is the thickness direction (short direction) of the projector, it is necessary to increase the focal length in order to reduce the thickness. At this time, by narrowing the light beam in the first direction, it is possible to suppress an increase in the incident angle of light incident on each pixel of the light modulation means even if the focal length is increased. Therefore, since the thickness of the whole projector in the first direction can be further reduced, it is possible to further reduce the size.

  In the projector according to the aspect of the invention, it is preferable that the first cylindrical lens and the second cylindrical lens are arranged in this order from the light source side.

  In the projector according to the present invention, for example, when the first direction is the thickness direction (short direction) of the projector, the focal length of the first cylindrical lens is increased and the focal length of the second cylindrical lens is decreased. Accordingly, the first cylindrical lens having a long focal length is arranged on the light source side, and the second cylindrical lens having a short focal length is arranged on the light modulation means side, whereby the light emitted from the light source is changed to the first and second cylindrical lenses. Light can be efficiently collected by the lens.

  In the projector according to the aspect of the invention, the first field lens that makes the main optical axis of the light emitted from the first cylindrical lens substantially perpendicular to the incident end surface of the light modulation unit, and the second cylindrical lens. It is preferable that the second field lens has a main optical axis of the light that is substantially perpendicular to the incident end face of the light modulation unit, and the first field lens and the second field lens are cylindrical lenses.

  In the projector according to the present invention, the first field lens that collects light in the first direction so that the main optical axis of the light emitted from the microlens array is substantially perpendicular to the incident end surface of the light modulation unit, and the microlens array And a second field lens that condenses light in the second direction so that the main optical axis of the light emitted from the light modulation means is substantially perpendicular to the incident end face of the light modulation means. That is, the incident angle of the light incident on the light modulation means is increased by the first field lens and the second field lens. Therefore, it becomes possible to irradiate each pixel of the light modulation means with bright illumination light.

  Furthermore, since the first field lens and the second field lens are cylindrical lenses, the focal length can be shortened as compared with, for example, a lenticular lens. Therefore, when the pixel pitch of the light modulation means is narrow, it can be formed as a desired lens having a short focal length, and therefore it is possible to cope with the light modulation means having fine pixels. As described above, since the focal length of the second field lens can be shortened in accordance with the pixel pitch, it is possible to reduce the size of the entire apparatus even if the first and second field lenses are used.

  In the projector according to the aspect of the invention, it is preferable that the first field lens and the second field lens are arranged in this order from the light source side.

  In the projector according to the present invention, for example, when the first direction is the thickness direction (short direction) of the projector, the focal length of the first field lens that collects light in the first direction is increased, and the second direction The focal length of the second field lens that collects light in the direction is shortened. Accordingly, the first field lens having a long focal length is arranged on the light source side, and the second field lens having a short focal length is arranged on the light modulation means side, whereby the light emitted from the light source is changed to the first and second fields. Light can be efficiently collected by the lens.

  The optical element of the present invention is an optical element that causes light to enter each pixel of the light modulation unit having a plurality of pixels in an array, and the incident light is directed in a first direction that is an arrangement direction of the plurality of pixels. A first cylindrical lens that condenses and enters the pixel, and a second cylindrical lens that condenses incident light in a second direction substantially orthogonal to the first direction and enters the pixel, respectively. And the first cylindrical lens has a first direction diameter substantially equal to a pitch of the pixels in the first direction, and a second direction of the second cylindrical lens. The diameter is substantially equal to the pitch of the pixels in the second direction.

In the optical element according to the present invention, as described above, the first and second cylindrical lenses for condensing light in the first direction and the second direction in the arrangement direction of the pixels of the light modulation unit are separately provided. , The focal length in each direction can be designed separately. Thereby, the optical element which can suppress the fall of the illumination efficiency of the light which injects into each pixel of a light modulation means can be provided.
The diameter of the first cylindrical lens in the first direction is substantially equal to the pitch in the first direction of the pixel, and the diameter of the second cylindrical lens in the second direction is substantially equal to the pitch in the second direction of the pixel. equal. Thereby, since one 1st, 2nd cylindrical lens can be made to respond | correspond to 1 pixel of a light modulation means, it becomes possible to condense light efficiently to each pixel of a light modulation means.
Furthermore, since the light is condensed on each pixel of the light modulation means by the first and second cylindrical lenses, for example, the focal length can be made shorter than that of the lenticular lens. Thereby, bright illumination to each pixel of a light modulation means is attained.

  The optical element of the present invention includes a first field lens that makes a main optical axis of light emitted from the first cylindrical lens substantially perpendicular to an incident end surface of the light modulation unit, and the second cylindrical lens. A second field lens that makes the main optical axis of the emitted light substantially perpendicular to the incident end face of the light modulator, and the first field lens and the second field lens are preferably cylindrical lenses. .

  In the optical element according to the present invention, by providing the first field lens and the second field lens, the incident angle of the light incident on the light modulation means is increased. Therefore, it becomes possible to irradiate each pixel of the light modulation means with bright illumination light.

  The light modulation device of the present invention preferably includes a plurality of pixels in an array, and includes a light modulation unit that modulates incident light and the optical element described above.

In the light modulation device according to the present invention, as described above, the first and second cylindrical lenses for condensing light in the first direction and the second direction in the arrangement direction of the pixels of the light modulation means are separately provided. Therefore, the focal length in each direction can be designed separately. Accordingly, it is possible to suppress a decrease in illumination efficiency of light incident on each pixel of the light modulation unit.
Further, since the light is concentrated on each pixel of the light modulation means by the first and second cylindrical lenses, for example, the focal length can be shortened as compared with the lenticular lens. Therefore, as described above, since the focal lengths of the second cylindrical lens and the second field lens can be shortened in accordance with the pixel pitch, it is possible to reduce the size of the entire light modulation device.

  Hereinafter, embodiments of a projector, an optical element, and a light modulation device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First Embodiment]
The projector according to the present embodiment is a three-plate projection type color liquid crystal projector provided with a transmissive liquid crystal light valve for each color light of R (red), G (green), and B (blue), and the image is displayed on the screen. Projected.

  As shown in FIG. 1, the projector 1 according to the present embodiment includes a light source unit 10, a color separation unit (color separation unit) 20, a microlens array (optical element) 33, and a liquid crystal light valve (light modulation device). 30 and a projection lens (projection means) 40.

  The light source unit 10 includes a light source 11, a cylindrical lens 12, first and second fly array lenses 13 a and 13 b, a polarization conversion element 14, and a superimposing lens 15. The light source 11 emits white light including red light (hereinafter referred to as “R light”), green light (hereinafter referred to as “G light”), and blue light (hereinafter referred to as “B light”). It is to be ejected.

The light source 11 includes a high-pressure mercury lamp 11a that emits light, and a reflector (reflecting portion) 11b that reflects the light emitted from the high-pressure mercury lamp 11a. The reflector 11b has a vertical direction (first direction, vertical direction of the liquid crystal light valve 30: X direction shown in FIG. 1) and a horizontal direction (second direction, horizontal direction of the liquid crystal light valve 30: Y shown in FIG. 1). Direction) and an anamorphic reflector having a different shape (curvature). In the present embodiment, the casing (not shown) in which the projector 1 is housed has a short vertical direction and a long horizontal direction. Hereinafter, the vertical direction is appropriately referred to as the thickness direction.
The reflector 11b according to the present embodiment is formed such that the vertical direction and the horizontal direction have different curvatures, the vertical direction of the light beam emitted from the reflector 11b is thin, and the horizontal direction is thick.
The cylindrical lens (condensing means) 12 is a concave lens having different curvatures in the vertical direction and the horizontal direction, and has a long focal length on the vertical surface and a short focal length on the horizontal surface. As a result, the cylindrical lens 12 emits light having a narrow vertical luminous flux emitted from the reflector 11b and a thick lateral luminous flux as parallel light.

The first and second fly array lenses 13a and 13b are lenses that uniformize the illuminance distribution of light emitted from the high-pressure mercury lamp 11a. Further, as shown in FIG. 2, the first and second fly array lenses 13a and 13b are shorter in the vertical direction (X direction) than in the horizontal direction (Y direction).
The polarization conversion element 14 is an element that converts the uniform light with an indefinite polarization state into light with a specific polarization direction.

As shown in FIG. 1, the color separation unit 20 reflects an R light reflecting dichroic mirror 21 that reflects R light and transmits G light and B light out of light emitted from the high-pressure mercury lamp 11 a, and G light. A G light reflecting dichroic mirror 22 that reflects and transmits B light is provided.
Of the light emitted from the high pressure mercury lamp 11 a, the R light is bent 90 degrees in the R light reflecting dichroic mirror 21 and enters the reflecting mirror 25. The optical path of the R light is bent 90 degrees by the reflecting mirror 25 and is incident on the R light liquid crystal light valve (spatial light modulation means) 30R.
Further, a condenser lens 37 is disposed on the optical path between the reflection mirror 25 and the R light liquid crystal light valve 30R. The condenser lens 37 makes the R light incident on the R light liquid crystal light valve 30R uniform.

Of the light emitted from the high pressure mercury lamp 11a, the G light is transmitted through the R light reflecting dichroic mirror 21, and the optical path of the G light is bent by 90 degrees at the G light reflecting dichroic mirror 22. Then, the G light is incident on the G light liquid crystal light valve (spatial light modulation means) 30G.
Further, a condenser lens 38 is disposed on the optical path between the G light reflecting dichroic mirror 22 and the G light liquid crystal light valve 30G. The condenser lens 38 makes the G light incident on the G light liquid crystal light valve 30G uniform.
Of the light emitted from the high-pressure mercury lamp 11 a, the B light passes through the R light reflecting dichroic mirror 21 and the G light reflecting dichroic mirror 22 and enters the reflecting mirror 27 via the relay lens 26. The B light incident on the reflection mirror 27 is incident on the reflection mirror 29 via the relay lens 28 with the optical path bent by 90 degrees. The light incident on the reflection mirror 29 has its optical path bent by 90 degrees and is incident on a B light liquid crystal light valve (spatial light modulation means) 30B.
A condenser lens 39 is disposed on the optical path between the reflection mirror 29 and the B light liquid crystal light valve 30B. With this condenser lens 39, the G light incident on the B light liquid crystal light valve 30B becomes uniform light.
The R light, G light, and B light incident on the liquid crystal light valves 30R, 30G, and 30B are telecentric illumination light.

Next, the microlens array 33 will be described with reference to FIG. FIG. 3 is a perspective view showing a part of the microlens array 33 taken out.
A microlens array 33 is disposed on the optical path between the condenser lenses 37, 38, 39 and the liquid crystal light valves 30R, 30G, 30B.
As shown in FIG. 3, the microlens array 33 is arranged in a plurality of arrays in the vertical direction, the first cylindrical lenses 34 for converging incident light in the vertical direction, and a plurality of arrays in the horizontal direction. And a second cylindrical lens 35 that condenses incident light in the lateral direction. Further, the longitudinal diameter of the first cylindrical lens 34 is L1, and the lateral diameter of the second cylindrical lens 35 is L2.
In addition, an adhesive member 32a made of, for example, a resin is provided between the first cylindrical lens 34 and the second cylindrical lens 35. Then, the first cylindrical lens 34 and the second cylindrical lens 35 are fixed by the adhesive member 32a. Further, an adhesive member 32b made of, for example, a resin is also provided on the surface of the second cylindrical lens 35 on the liquid crystal light valve 30 side, and the injection end surface 33b of the microlens array 33 is made flat by the adhesive member 32b. ing.
It is preferable that the refractive index of the adhesive members 32a and 32b has a larger difference from the refractive index of the material constituting the first and second cylindrical lenses 34 and 35.

Next, the configuration of the liquid crystal light valve 30 and the positional relationship between the microlens array 33 and the liquid crystal light valve 30 will be described with reference to FIG.
In FIG. 4, the liquid crystal light valve 30 actually has pixels 31 arranged in a matrix, but only one column is shown in the X direction.

  The liquid crystal light valve 30 is a transmissive liquid crystal panel using a high-temperature polysilicon TFT. The liquid crystal light valves 30R, 30G, and 30B modulate R light, G light, and B light incident on the liquid crystal light valves 30R, 30G, and 30B, respectively, and have a plurality of pixels 31 in an array. Further, each opening 30 c of the black matrix (BM) 30 b becomes a light transmission region of each sub-pixel 31.

The vertical diameter L1 of the first cylindrical lens 34 is substantially the same as the pitch P1 of one pixel 31 in the vertical direction of the liquid crystal light valve 30. The horizontal diameter L2 of the second cylindrical lens 35 is substantially the same as the pitch P2 of one pixel 31 in the horizontal direction of the liquid crystal light valve 30.
That is, as shown in FIG. 4, one pixel 31 in the vertical direction of the liquid crystal light valve 30 corresponds to one first cylindrical lens 34, and the horizontal direction of the liquid crystal light valve 30 corresponds to one second cylindrical lens 35. Corresponds to one pixel 31.
Thus, the light incident on the microlens array 33 is condensed in the vertical direction by the first cylindrical lens 34 and is incident from the opening 30c of each pixel 31 of each liquid crystal light valve 30R, 30G, 30B.
In addition, the light emitted from the first cylindrical lens 34 and incident on the second cylindrical lens 35 is condensed in the horizontal direction by the second cylindrical lens 35 and efficiently applied to each pixel 31 of each liquid crystal light valve 30R, 30G, 30B. Incident.

  As shown in FIG. 1, the dichroic prism (color light combining means) 36 has a configuration in which two dichroic films 36a and 36b are arranged orthogonally in an X shape. The dichroic film 36a reflects B light and transmits R light and G light. The dichroic film 36b reflects R light and transmits G light and B light. In this manner, the dichroic prism 36 combines the R light, G light, and B light modulated in the liquid crystal light valves 30R, 30G, and 30B, respectively. Then, the combined light is enlarged and projected toward the screen 45 by the projection lens (projection means) 40.

  Since the projector 1 according to this embodiment includes the first cylindrical lens 34 that condenses in the vertical direction and the second cylindrical lens 35 that condenses in the horizontal direction, the focal length between the vertical direction and the horizontal direction is set. Can be designed separately. That is, it is possible to design a long focal length of the first cylindrical lens 34 that collects light in the vertical direction, which is the thickness direction (short direction) of the projector 1. Thus, by increasing the focal length of the first cylindrical lens 34, the incident angle of the light incident on the pixels 31 of the liquid crystal light valves 30R, 30G, and 30B can be reduced. Therefore, since light does not spread in the thickness direction, it is possible to reduce the thickness in the vertical direction of the projection lens 40 disposed in the subsequent stage. That is, since the thickness of the entire projector 1 in the vertical direction can be reduced, the size can be reduced.

Furthermore, since the light color-separated by the color separation unit 20 is condensed on each pixel 31 of the liquid crystal light valve 30 by the first and second cylindrical lenses 34 and 35, for example, the focal length compared to the lenticular lens. It is easy to produce a short lens. Therefore, when the pitch P1 of the pixels 31 of the liquid crystal light valve 30 is narrow, it can be formed as a desired lens having a short focal length, so that the liquid crystal light valve 30 having the fine pixels 31 can be handled. That is, since the focal length of the second cylindrical lens 35 can be shortened corresponding to the pitch P1 of the pixels 31, the overall size of the projector 1 can be reduced.
Furthermore, the illumination efficiency of the liquid crystal light valve 30 can be improved by designing the focal length of the second cylindrical lens 35 to be short.

  In addition, since the R light, G light, and B light incident on the liquid crystal light valves 30R, 30G, and 30B are telecentric illumination light, the liquid crystal light valves 30R, 30G, and 30B are particularly used as the light modulation means. In this case, it is possible to make light incident perpendicularly to the incident end face 30 a of the liquid crystal light valve 30. Thereby, the contrast of the light passing through the liquid crystal light valve 30 can be improved.

Note that an air layer may be provided without providing the adhesive members 32 a and 32 b between the first cylindrical lens 34 and the second cylindrical lens 35.
Further, although the light beam in the vertical direction is thinned and the light beam in the horizontal direction is thickened by the reflector 11b of the light source 11, the shape of the light emitted from the light source 11 is not limited to this.
In addition, the first cylindrical lens 34 and the second cylindrical lens 35 are arranged in this order from the light source 11 side, but the present invention is not limited to this, and the second cylindrical lens 35 and the first cylindrical lens 34 may be arranged in this order.
Further, in FIG. 4, the microlens array 33 and the liquid crystal light valve 30 are illustrated with a space therebetween, but are preferably arranged as close as possible and may be in contact with each other.

[Modification of First Embodiment]
This modification includes an optical element 50 having a first field lens 51 and a second field lens 52 on the optical path between the microlens array 33 and the liquid crystal light valve 30. Such a modification will be described with reference to FIG.
As shown in FIG. 5, a plurality of first field lenses 51 are arranged in the vertical direction (X direction) as in the first cylindrical lens 34, and the main optical axis of the light emitted from the first cylindrical lens 34. Is incident substantially perpendicularly to the longitudinal direction of the incident end face 30 a of the liquid crystal light valve 30.
Similarly to the second cylindrical lens 35, a plurality of second field lenses 52 are arranged in the lateral direction (Y direction), and the liquid crystal light valve 30 uses the main optical axis of the light emitted from the second cylindrical lens 35. Is incident substantially perpendicularly to the lateral direction of the incident end face 30a. The first and second field lenses 51 and 52 are cylindrical lenses.
Further, the first field lens 51 is provided on the second cylindrical lens 35 side, and the second field lens 52 is provided on the liquid crystal light valve 30 side.

Further, an adhesive member 56a made of, for example, a resin is provided between the second cylindrical lens 35 and the first field lens 51, and the second cylindrical lens 35, the first field lens 51, and the like are provided by the adhesive member 56a. Is fixed. In addition, an adhesive member 56b made of, for example, resin is provided between the first field lens 51 and the second field lens 52, and the first field lens 51 and the second field lens 52 are provided by the adhesive member 56b. And fixing. Further, an adhesive member 56c made of, for example, a resin is also provided on the surface of the second field lens 52 on the liquid crystal light valve 30 side, and the emission end face 50b of the optical element 50 is made flat by the adhesive member 56c. Yes.
It is preferable that the refractive indexes of the adhesive members 56a, 56b, and 56c have a large difference from the refractive indexes of the materials constituting the second cylindrical lens 35 and the first and second field lenses 51 and 52.

In this modification, the first field lens 51 and the second field lens 52 increase the incident angle of light incident on the liquid crystal light valve 30. Therefore, each pixel 31 of the liquid crystal light valve 30 can be irradiated with bright illumination light.
In addition, since the first field lens 51 and the second field lens 52 allow light to enter the liquid crystal light valve 30 perpendicularly, the contrast of light passing through the liquid crystal light valve 30 can be improved. Can be projected onto the screen 45.

When the vertical direction is the thickness direction (short direction) of the projector, the focal length of the first cylindrical lens 34 is increased and the focal length of the second cylindrical lens 35 is decreased. Accordingly, in order to increase the focal length of the first field lens 51 that collects light in the vertical direction and shorten the focal length of the second field lens 52 that collects light in the horizontal direction, By arranging the second field lens 52 having a short focal distance on the liquid crystal light valve 30 side, which is arranged on the second cylindrical lens 35 side on the light source 11 side, the light emitted from the light source 11 is changed to the first and second field lenses. Thus, the light can be efficiently condensed on the liquid crystal light valve 30.
In this modification, the first field lens 51 and the second field lens 52 are provided separately in the vertical direction and the horizontal direction, but a configuration in which one lens having a field lens function is provided in the vertical direction and the horizontal direction. It may be.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, although the dichroic prism is used as the color light combining means, the present invention is not limited to this. As the color light synthesizing means, for example, a dichroic mirror having a cross arrangement to synthesize color light, or a dichroic mirror arranged in parallel to synthesize color light can be used.

1 is a schematic configuration diagram illustrating a projector according to a first embodiment of the present invention. It is a top view which shows the fly array lens of FIG. It is a perspective view which shows the structure of the micro lens array of FIG. It is a perspective view which shows the relationship between the micro lens array of FIG. 1, and a liquid crystal light valve. It is a perspective view which shows the modification of the projector of FIG.

Explanation of symbols

  L1, L2 ... Diameter, P1, P2 ... Pitch, 1 ... Projector, 11 ... Light source, 11b ... Reflector (reflective part), 12 ... Cylindrical lens, 20 ... Color separation part (color separation means), 30 ... Liquid crystal light valve ( (Light modulation means), 30a ... incident end face, 33 ... microlens array, 34 ... first cylindrical lens, 35 ... second cylindrical lens, 40 ... projection lens (projection means), 50 ... optical element, 51 ... first field lens 52 ... second field lens,

Claims (8)

A light source that emits light including multiple types of color light;
Color separation means for separating the light emitted from the light source into a plurality of types of color light;
A plurality of light modulation means provided for each color light, having a plurality of pixels that modulate light separated by the color separation means in an array;
Arranged on the respective optical paths between the color separation means and each of the plurality of light modulation means, and condenses incident light in a first direction that is an arrangement direction of the plurality of pixels, to the pixels. A first cylindrical lens to be incident and a second cylindrical lens that collects incident light in a second direction substantially orthogonal to the first direction and enters the pixel are arranged in an array. A lens array;
A projector comprising: projection means for projecting light modulated by the light modulation means. The first direction and the second direction have different curvatures, and a reflection unit that reflects the light emitted from the light source;
A lens surface disposed on an optical path between the light source and the color separation unit, having a different curvature in the first direction and the second direction, collects the light reflected by the reflection unit. The projector according to claim 1, further comprising a light collecting unit.   The projector according to claim 1, wherein the first cylindrical lens and the second cylindrical lens are arranged in this order from the light source side. A first field lens that makes a main optical axis of light emitted from the first cylindrical lens substantially perpendicular to an incident end face of the light modulation unit;
A second field lens that makes the main optical axis of the light emitted from the second cylindrical lens substantially perpendicular to the incident end face of the light modulator;
The projector according to any one of claims 1 to 3, wherein the first field lens and the second field lens are cylindrical lenses.   The projector according to claim 4, wherein the first field lens and the second field lens are arranged in this order from the light source side. An optical element that makes light incident on each pixel of a light modulation unit having a plurality of pixels in an array,
A first cylindrical lens that collects incident light in a first direction, which is an arrangement direction of the plurality of pixels, and enters the pixel, and a second direction that is substantially orthogonal to the first direction. And a microlens array in which second cylindrical lenses that are condensed and incident on the pixels are arranged in an array,
The diameter of the first cylindrical lens in the first direction is substantially equal to the pitch of the pixels in the first direction;
An optical element, wherein a diameter of the second cylindrical lens in the second direction is substantially equal to a pitch of the pixels in the second direction. A first field lens that makes a main optical axis of light emitted from the first cylindrical lens substantially perpendicular to an incident end face of the light modulation unit;
A second field lens that makes the main optical axis of the light emitted from the second cylindrical lens substantially perpendicular to the incident end face of the light modulator;
The optical element according to claim 6, wherein the first field lens and the second field lens are cylindrical lenses. A light modulation means for modulating incident light having a plurality of pixels in an array;
An optical modulation device comprising the optical element according to claim 6.

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