JP2009063892A - Projector, optical element, and optical modulating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of improving illumination efficiency, and to provide an optical element and an optical modulating device therefor. <P>SOLUTION: The projector includes: an optical modulating means 30 capable of being modulated independently in every color; a micro-lens array 25 arraying, in the form of an array, a first cylindrical lens 27 projecting light to a sub-pixel 31 corresponding to different color light by being arranged on an optical path between a color separation means and the optical modulating means 30, and condensing incident light in a first direction arranging a plurality of kinds of the sub-pixels 31 in every color light, and a second cylindrical lens 28 projecting light to the sub-pixel 31 by condensing incident light in a second direction substantially orthogonal to the first direction; and a projection means for projecting light modulated with the optical modulating means 30. A first directional diameter L1 of the first cylindrical lens 27 is substantially equal to a first directional pitch P1 of a pixel 32. A second directional diameter L2 of the second cylindrical lens 28 is substantially equal to a second directional pitch P2 of the sub-pixel 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  The three-plate projector separates white light, and the resulting optical system (color separation system) that propagates the three primary colors of red, green, and blue, and a liquid crystal panel that modulates the intensity of the colored light and forms an image Are provided independently, and full-color display is performed by optically superimposing (color combining system) images of the respective colors. The configuration of this three-plate projector has the advantage that the light emitted from the white light source can be used effectively and the color purity is high. However, since the color separation system and the color synthesis system are necessary as described above, the number of parts of the optical system increases, which is disadvantageous compared to the single plate type in terms of cost reduction.

  On the other hand, a single-plate projector has a configuration using only one liquid crystal panel, and is classified into a delta arrangement, a stripe arrangement, and the like according to the arrangement of R, G, and B color filters. In the early single plate type, color separation was performed by a color filter, but the light utilization and light reflection by the color filter lowered the light use efficiency to about 1/3 of the three plate type, and there was a problem in practical use.

In order to solve this problem, a single-plate projector that separates light emitted from a white light source using three dichroic mirrors without using a color filter has been proposed (for example, see Patent Document 1). ).
The single-plate projector described in Patent Document 1 includes a light source that emits white light, a shape conversion optical system that converts the shape of light emitted from the light source, and three sheets that separate light emitted from the shape conversion optical system. Dichroic mirror and a liquid crystal panel.
This shape conversion optical system includes a convex cylindrical lens that converges incident light in the horizontal direction (color separation direction) and a concave cylindrical lens that collimates incident light. Thereby, the light incident on the shape converting optical system is converted into parallel light compressed only in the horizontal direction. The light converted into parallel light is color-separated into R (red) light, G (green) light, and B (blue) light by three dichroic mirrors arranged with an angle difference. The color-separated color lights enter the microlens array at different angles, and are condensed and modulated on the sub-pixels of the liquid crystal panel.
In this type of liquid crystal panel, in order to increase the brightness of the light that illuminates each pixel, the Fno. (F number) is increased, and illumination Fno. In the vertical direction (direction orthogonal to the color separation direction). Is made smaller. 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 2002-40416 A

  However, in the single-plate projector described in Patent Document 1, the microlens array has an illumination Fno. In the vertical direction, Fno. If the brightness is increased, the incident angle to the corresponding pixel increases. Thereby, the illumination light condensed by the microlens array deviates from the pixel, and the illumination efficiency is lowered.

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

In order to achieve the above object, the present invention provides the following means.
The projector according to the present invention supports 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 so that the emission directions are different for different color lights, and a plurality of types of color light. One pixel composed of a plurality of sub-pixels is arranged in an array and can be modulated independently for each incident color light, and on the optical path between the color separation means and the light modulation means A first cylindrical lens that collects incident light in a first direction in which a plurality of types of sub-pixels are arranged for each color light and enters the sub-pixels corresponding to different color lights, and incident light Microlens array in which second cylindrical lenses that are focused in a second direction substantially orthogonal to the first direction and incident on the sub-pixels are arranged in an array, respectively, and modified by the light modulation means. Projecting means for projecting the emitted light, and the diameter of the first cylindrical lens in the first direction is substantially equal to the pitch of the pixels in the first direction, and the second direction of the second cylindrical lens. The diameter of is substantially equal to the pitch of the sub-pixels in the second direction.

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 means and enters the microlens array. Each color light incident on the microlens array is condensed on sub-pixels corresponding to a plurality of types of color light of the light modulation means, then modulated by the light modulation means, and projected by the projection means.
Here, with 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 is incident on each subpixel corresponding to different color light. At this time, since the diameter of the first cylindrical lens in the first direction is substantially equal to the pitch in the first direction of the pixels, the first cylindrical lens efficiently separates a plurality of types of color light into opposing sub-pixels. Collect light. 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 sub-pixel. At this time, since the diameter of the second cylindrical lens in the second direction is substantially equal to the pitch of the sub-pixel in the second direction, a plurality of types of color light are condensed by the second cylindrical lens and applied to the opposing sub-pixels. Make it incident efficiently.

Therefore, since the first and second cylindrical lenses for condensing in the first direction and the second direction in the arrangement direction of the sub-pixels of the light modulation means are provided separately, the focal lengths in the respective directions are separately set. Can be designed. That is, for example, the illumination Fno. The second cylindrical lens can be designed to have a shorter focal length than the first cylindrical lens so that the light does not deviate from the sub-pixels in the second direction even when dark. Accordingly, it is possible to suppress a decrease in illumination efficiency of light incident on each subpixel of the light modulation unit.
Furthermore, since the light color-separated by the color separation means is condensed on each sub-pixel of the light modulation means by the first and second cylindrical lenses, for example, a lens having a shorter focal length than a lenticular lens is manufactured. It becomes easy to do. Therefore, in the present invention, when the pitch of the sub-pixels of the light modulation unit is narrow, a desired lens having a short focal length can be formed, so that it is possible to deal with the light modulation unit having fine sub-pixels. That is, since the focal length of the second cylindrical lens can be shortened corresponding to the pitch of the sub-pixels, the entire apparatus can be reduced in size.
Note that a sub-pixel is a minimum unit that constitutes one pixel, and one pixel is constituted by a plurality of adjacently arranged sub-pixels.

  In the projector according to the aspect of the invention, the first direction and the second direction may have different curvatures, and a reflection unit that reflects light emitted from the light source may be provided between the light source and the color separation unit. It is preferable to include a condensing unit that is disposed on the optical path, has a lens surface 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, for example, the light beam in the first direction can be thinned and the light beam in the second direction can be thickened. 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 subpixel of the light modulation device.
In this way, since the light beam in the first direction is thin and the light beam in the second direction is thick, it is possible to enter the light modulation device. In the second direction of illumination Fno. This makes it easier to design a lens that brightens the screen.

  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, the illumination Fno. In the second direction of illumination Fno. In order to brighten the light, the focal length of the first cylindrical lens that condenses the light in the first direction is lengthened, and the focal length of the second cylindrical lens that condenses the light in the second direction is shortened. 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 modulator 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 sub 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 pitch of the sub-pixels of the light modulation unit is narrow, it can be formed as a desired lens having a short focal length, so that it is possible to deal with the light modulation unit having fine sub-pixels. As described above, since the focal length of the second field lens can be shortened corresponding to the pitch of the sub-pixels, 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, the illumination Fno. In the second direction of illumination Fno. Is made longer, the focal length of the first field lens for condensing light in the first direction is lengthened, and the focal length of the second field lens for condensing light in the second 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. The lens can efficiently focus the light on the light modulation means.

  The optical element of the present invention is an optical element that makes light incident on each sub-pixel of the light modulation unit in which one pixel composed of a plurality of sub-pixels is arranged in an array, and the incident light is separated for each color light. A first cylindrical lens that condenses light in the first direction in which the plurality of types of sub-pixels are arranged and enters the sub-pixels corresponding to different color lights; and a first cylindrical lens that is substantially orthogonal to the first direction. A microlens array in which second cylindrical lenses that converge in two directions and enter the sub-pixels are arranged in an array, and a main optical axis of light emitted from the first cylindrical lens is the light The first field lens that is substantially perpendicular to the incident end face of the modulating means and the main optical axis of the light emitted from the second cylindrical lens are substantially perpendicular to the incident end face of the light modulating means. The first cylindrical lens has a first direction diameter substantially equal to a pitch of the pixel in the first direction, and the second cylindrical lens has a second direction diameter in the second direction. The pitch is substantially equal to the pitch of the sub-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 sub-pixels of the light modulation unit are separately provided. Therefore, the focal length in each direction can be designed separately. Accordingly, it is possible to provide an optical element capable of suppressing a decrease in illumination efficiency of light incident on each sub-pixel of the light modulation unit.
Further, since the light is condensed on each sub-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. Thereby, bright illumination to each sub-pixel of a light modulation means is attained.
Furthermore, 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 sub pixel of the light modulation means with bright illumination light.

  The light modulation device according to the present invention includes a light modulation unit that includes a plurality of sub-pixels arranged in an array and can independently modulate each incident color light, and the optical element described above. It is characterized by.

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 of the arrangement direction of the sub-pixels of the light modulation unit 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 subpixel of the light modulation unit.
In addition, since the first and second cylindrical lenses are focused on each sub-pixel of the light modulation unit, for example, the focal length can be shortened as compared with a lenticular lens. Therefore, as described above, the focal lengths of the second cylindrical lens and the second field lens can be shortened corresponding to the pitch of the sub-pixels, so that the entire light modulation device can be reduced in size.

  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 single-plate projection type color liquid crystal projector having one transmission type liquid crystal light valve for different color lights of R (red), G (green), and B (blue). It is projected onto the screen.
In the present embodiment, in the spatial separation method of illuminating the pixels of the transmissive liquid crystal panel corresponding to R, G, and B, the illumination Fno. In the second direction of illumination Fno. It becomes the composition which brightens.
As shown in FIG. 1, the projector 1 according to the present embodiment includes a light source unit 10, a dichroic prism (color separation unit) 20, a microlens array (optical element) 25, and a liquid crystal light valve (light modulation device) 30. And a projection lens (projection means) 35.

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 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.
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.

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).
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 dichroic prism 20 is a prism that separates the light superimposed by the superimposing lens 15 into R light, G light, and B light. Specifically, the dichroic prism 20 has two dichroic films 20a and 20b arranged so as to be substantially orthogonal to each other. The first dichroic film 20a has characteristics of reflecting R light and transmitting G light and B light. On the other hand, the second dichroic film 20b has characteristics of reflecting B light and transmitting R light and G light. As a result, the R light reflected by the first dichroic film 20 a of the dichroic prism 20 and bent by 90 degrees with respect to the optical axis O is reflected by the reflecting mirror 21 toward the optical axis O. Further, the B light reflected by the second dichroic film 20 b of the dichroic prism 20 and bent by 90 degrees with respect to the optical axis O is reflected toward the optical axis O by the reflection mirror 22. That is, the R light reflected by the reflecting mirror 21 and the B light reflected by the reflecting mirror 22 are reflected toward the liquid crystal light valve 30.

Next, the microlens array 25 will be described with reference to FIG. FIG. 2 is a perspective view showing a part of the microlens array 25 taken out.
As shown in FIG. 2, the microlens array 25 is arranged in a plurality of arrays in the vertical direction, the first cylindrical lenses 27 for condensing incident light in the vertical direction, and a plurality of arrays in the horizontal direction. And a second cylindrical lens 28 that condenses incident light in the lateral direction. Further, the longitudinal diameter of the first cylindrical lens 27 is L1, and the lateral diameter of the second cylindrical lens 28 is L2.
Further, an adhesive member 26a made of, for example, a resin is provided between the first cylindrical lens 27 and the second cylindrical lens 28. Then, the first cylindrical lens 27 and the second cylindrical lens 28 are fixed by the adhesive member 26a. Further, an adhesive member 26b made of, for example, a resin is also provided on the surface of the second cylindrical lens 28 on the liquid crystal light valve 30 side. By this adhesive member 26b, the emission end face 25b of the microlens array 25 is made flat. ing.
It is preferable that the refractive index of the adhesive members 26a and 26b has a larger difference from the refractive index of the material constituting the first and second cylindrical lenses 27 and 28.

Next, the configuration of the liquid crystal light valve 30 and the positional relationship between the microlens array 25 and the liquid crystal light valve 30 will be described with reference to FIG.
In FIG. 3, the light emitted from the dichroic prism 20 is actually condensed by the microlens array 25. However, in order to avoid making the figure complicated, the light passes through the center of the microlens array 25. Only the main optical axis of the light is shown. Further, in FIG. 3, the liquid crystal light valve 30 actually has a plurality of sub-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. In addition, the liquid crystal light valve 30 has a plurality of types of sub-pixels 31 that have different wavelength selectivity and can independently modulate R light, G light, and B light color-separated by the dichroic prism 20 in an array. Have. Specifically, the liquid crystal light valve 30 includes a plurality of red light sub-pixels 30R on which R light is incident, a plurality of green light sub-pixels 30G on which G light is incident, and blue light on which B light is incident. And a plurality of sub-pixels 30B. The sub-pixel 31 is a minimum unit constituting one pixel, and a plurality of sub-pixels 31 (three sub-pixels 31 in the present embodiment) arranged adjacent to each other constitute one pixel 32.
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 27 is substantially the same as the pitch P1 of the three sub-pixels 30R, 30G, and 30B (one pixel 32) in the vertical direction of the liquid crystal light valve 30. The horizontal diameter L2 of the second cylindrical lens 28 is substantially the same as the pitch P2 of the one sub-pixels 30R, 30G, 30B in the horizontal direction of the liquid crystal light valve 30.
That is, as shown in FIG. 3, one sub-pixel 31 in the vertical direction of the liquid crystal light valve 30 corresponds to one first cylindrical lens 27, and the side of the liquid crystal light valve 30 corresponds to one second cylindrical lens 28. One sub-pixel 31 in the direction corresponds.

Further, since the microlens array 25 is arranged on the optical path of the G light that has passed through the dichroic prism 20, as shown in FIG. 3, the R light and the B light are symmetrical with respect to the G light. The light is incident on the incident end face 25a of the array 25 at an angle θ.
Accordingly, the R light and G light incident on the microlens array 25 are color-separated by the first cylindrical lens 27 so that the emission directions are different in the vertical direction, and are incident from the openings 30c of the sub-pixels 30R, 30G, and 30B. To do.
In addition, the R light, G light, and B light emitted from the first cylindrical lens 27 and incident on the second cylindrical lens 28 are condensed in the lateral direction by the second cylindrical lens 28, and are condensed on the sub-pixels 30R, 30G, and 30B. Incidence is efficient.

As shown in FIG. 1, a condenser lens 29 is disposed on the optical path between the dichroic prism 20 and the microlens array 25. The condenser lens 29 becomes telecentric illumination light.
The projection lens 35 enlarges and projects the light modulated in the liquid crystal light valve 30 toward the screen 40.

  Since the projector 1 according to the present embodiment includes the first cylindrical lens 27 that condenses in the vertical direction and the second cylindrical lens 28 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, the vertical illumination Fno. The second cylindrical lens 28 can be designed to have a shorter focal length than the first cylindrical lens 27 so that the light in the lateral direction does not deviate from the sub-pixels 31 even if the light is darkened. Accordingly, it is possible to suppress vignetting due to the black matrix 30b or the like between the openings 30c, and thus it is possible to suppress a decrease in illumination efficiency of light incident on each sub-pixel 31 of the liquid crystal light valve 30.

  Furthermore, since the light color-separated by the dichroic prism 20 is condensed on each sub-pixel 31 of the liquid crystal light valve 30 by the first and second cylindrical lenses 27 and 28, 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 sub-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 sub-pixels 31 can be handled. . That is, since the focal length of the second cylindrical lens 28 can be shortened corresponding to the pitch P1 of the sub-pixels 31, it is possible to reduce the size of the entire apparatus.

  Further, the vertical illumination Fno. Is darkened and the lateral illumination Fno. In order to brighten the light, the focal length of the first cylindrical lens 27 that condenses the light in the vertical direction is lengthened, and the focal length of the second cylindrical lens 28 that condenses the light in the horizontal direction is shortened. Accordingly, the first cylindrical lens 27 having a long focal length is arranged on the light source 11 side, and the second cylindrical lens 28 having a short focal length is arranged on the liquid crystal light valve 30 side, whereby the light emitted from the light source 11 is The first and second cylindrical lenses 27 and 28 can efficiently collect light.

  Further, since the R light, G light, and B light incident on the liquid crystal light valve 30 are telecentric illumination light, especially when the liquid crystal light valve 30 is used as the light modulation means, Light can be incident perpendicular to the incident end face 30a. 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 26a and 26b between the first cylindrical lens 27 and the second cylindrical lens 28.
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.
Further, although the first cylindrical lens 27 and the second cylindrical lens 28 are arranged in this order from the light source 11 side, the present invention is not limited to this, and the second cylindrical lens 28 and the first cylindrical lens 27 may be arranged in this order.
Further, in FIG. 3, the microlens array 25 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.
Further, although the light emitted from the light source 11 is divided into three colors of R light, G light, and B light, the present invention is not limited to this, and it may be divided into four or more colors. In this case, the first cylindrical lens 27 may be formed so that the vertical diameter thereof is substantially equal to the pitch of one pixel 32 in the vertical direction.

[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 25 and the liquid crystal light valve 30. Such a modification will be described with reference to FIG.
In the present embodiment, the vertical illumination Fno. Is used to increase the brightness in the space separation system that illuminates the sub-pixels 30R, 30G, and 30B of the liquid crystal light valve 30 corresponding to R, G, and B. Is darkened and the lateral illumination Fno. It becomes the composition which brightens.
In FIG. 4, the light emitted from the dichroic prism 20 is actually condensed by the optical element 50, but the light passing through the center of the optical element 50 in order to avoid complication of the drawing. Only the main optical axis is shown. Furthermore, although the liquid crystal light valve 30 has subpixels 31 arranged in a matrix, only one column is shown in the X direction.

As shown in FIG. 4, the first field lens 51 is arranged in a plurality in the vertical direction (X direction) similarly to the first cylindrical lens 27, and the main optical axis of the light emitted from the first cylindrical lens 27. 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 28, a plurality of second field lenses 52 are arranged in the horizontal direction (Y direction), and the liquid crystal light valve 30 uses the main optical axis of the light emitted from the second cylindrical lens 28. 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 28 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 28 and the first field lens 51, and the second cylindrical lens 28, 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 28, 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 sub-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 40.

Further, the vertical illumination Fno. Is darkened and the lateral illumination Fno. Is made longer, the focal length of the first field lens 51 that condenses the light in the vertical direction is increased, and the focal length of the second field lens 52 that condenses the light in the horizontal direction is shortened. Accordingly, the first field lens 51 having a long focal length is arranged on the second cylindrical lens 28 side on the light source 11 side, and the second field lens 52 having a short focal length is arranged on the liquid crystal light valve 30 side, whereby the light source 11 Can be efficiently condensed on the liquid crystal light valve 30 by the first and second field lenses 51 and 52.
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 a dichroic prism is used as a color separation method, incident light may be separated by changing the angles of three dichroic mirrors.

1 is a schematic configuration diagram illustrating a projector according to a first embodiment of the present invention. 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 (reflecting part), 12 ... Cylindrical lens, 20 ... Dichroic prism (color separation part), 25 ... Micro lens array, 27 DESCRIPTION OF SYMBOLS 1st cylindrical lens, 28 ... 2nd cylindrical lens, 30 ... Liquid crystal light valve (light modulation means), 30a ... Incident end face, 35 ... Projection lens (projection means), 50 ... Optical element, 51 ... 1st field lens, 52. Second field lens,

Claims (7)

A light source that emits light including multiple types of color light;
Color separation means for separating the light emitted from the light source so that the emission direction differs for each different color light;
A light modulation means in which one pixel composed of a plurality of sub-pixels corresponding to a plurality of types of color light is arranged in an array and can be modulated independently for each incident color light;
It is arranged on the optical path between the color separation unit and the light modulation unit, and incident light is condensed in a first direction in which a plurality of types of the sub-pixels are arranged for each color light to correspond to different color lights. A first cylindrical lens that is incident on the sub-pixel and a second cylindrical lens that collects incident light in a second direction substantially orthogonal to the first direction and is incident on the sub-pixel are arrayed, respectively. An array of microlens arrays;
Projecting means for projecting light modulated by the light modulating means,
The diameter of the first cylindrical lens in the first direction is substantially equal to the pitch of the pixels in the first direction;
The diameter of the second cylindrical lens in the second direction is approximately equal to the pitch of the sub-pixels in the second direction. 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 causes light to be incident on each sub-pixel of the light modulation unit in which one pixel composed of a plurality of sub-pixels is arranged in an array,
A first cylindrical lens that condenses incident light in a first direction in which a plurality of types of sub-pixels are arranged for each color light and enters the sub-pixels corresponding to different color lights; and A microlens array in which second cylindrical lenses that are condensed in a second direction substantially orthogonal to the direction of the light and incident on the sub-pixels are arranged in an array,
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 diameter of the first cylindrical lens in the first direction is substantially equal to the pitch of the pixels in the first direction;
The diameter of the second cylindrical lens in the second direction is substantially equal to the pitch of the sub-pixels in the second direction. A light modulation means in which one pixel composed of a plurality of sub-pixels is arranged in an array and can be modulated independently for each incident color light;
An optical modulation device comprising the optical element according to claim 6.

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