JP2010276757A - Projector and electro-optical device - Google Patents

Abstract

Provided are a projector and an electro-optical device that can obtain a high-luminance image with high use efficiency of light from a light source.
A projector 1 of the present invention includes light sources 7R, 7G, and 7B, a light guide rod 8, a microlens array 4, liquid crystal light valves 3R, 3G, and 3B, and a projection optical system 6. The liquid crystal light valves 3R, 3G, and 3B have an effective light modulation region configured by repeating a unit pixel pattern including at least one pixel, and the horizontal / vertical dimension ratio of the incident end face of the light guide rod 8 is the liquid crystal light. The horizontal / vertical dimension ratio of the unit pixel pattern of the bulbs 3R, 3G, 3B and the horizontal / vertical dimension ratio of the exit end face of the light guide rod 8 are effective light modulation regions of the liquid crystal light valves 3R, 3G, 3B. It corresponds to the horizontal / vertical dimension ratio.
[Selection] Figure 1

Description

  The present invention relates to a projector and an electro-optical device.

  There is known an electro-optical device using an illumination method in which a plurality of light beams emitted from a point light source array are focused on a pixel opening of a liquid crystal panel by a microlens array and the liquid crystal panel is illuminated by the focused light ( For example, see Patent Documents 1 and 2 below). In this illumination method, most of the light emitted from the point light source array can be used for display. Therefore, for example, when applied to a projector or an electro-optical device, the light is highly efficient and can display a bright image. Optical devices and projectors can be realized.

JP 2002-236287 A JP 2002-357826 A

However, when the above-described illumination method is employed in a projector or an electro-optical device, there are the following problems with respect to the configuration of the light source.
A point light source array is configured by arranging light emitting elements such as light emitting diodes (hereinafter abbreviated as LEDs) and lasers in an array shape, and illuminates in accordance with a plurality of pixel openings of a liquid crystal panel. It is desirable that the number of light emitting elements is as large as possible. In order to make the illuminance distribution of the light illuminating the liquid crystal panel uniform, it is desirable that the intensity of light emitted from each light emitting element is as uniform as possible.
However, in reality, it is extremely difficult to realize a point light source array having a large number of light emitting elements with high brightness and high efficiency that can be used in a device such as a projector and uniform intensity. Therefore, conventionally, this type of light source is not in the form of an array, and can only be realized by a single light emitting element, and a sufficient amount of light cannot be obtained.

  In addition, since the shape of a light modulation element such as a liquid crystal panel is generally rectangular, in order to increase the light use efficiency, after the light emitted from the light source is converted into a rectangular shape with uniform illuminance, the liquid crystal panel It is desirable to illuminate. However, in the configurations of Patent Documents 1 and 2, it is difficult to convert the light from the light source into a rectangular shape with uniform illuminance, resulting in uneven illuminance or light from the light source leaking outside the liquid crystal panel. There was a risk of becoming. In addition, fly eye integrators and rod integrators have been conventionally used as means for uniformly converting light from a light source into a rectangular shape. However, when these are used in combination with a point light source array, the light from the point light source array is Disturbed by eye integrators and rod integrators. As a result, it becomes difficult for the subsequent microlens array to condense in accordance with the pixel aperture, so that the light utilization efficiency cannot be increased.

  SUMMARY An advantage of some aspects of the invention is that it provides a projector and an electro-optical device that have high use efficiency of light from a light source and can obtain a high-luminance image.

  In order to achieve the above object, a projector according to the present invention includes a light source that emits light, a rectangular incident end surface on which light emitted from the light source is incident, and a reflective side surface that reflects incident light. A light guide having a rectangular emission end surface for emitting light reflected by the reflective side surface, and a lens array in which a plurality of lenses are arranged in an array and light emitted from the light guide is incident And a light modulation element that modulates the light emitted from each of the plurality of lenses constituting the lens array, and a projection optical system that projects the light modulated by the light modulation element onto a projection surface. The light modulation element includes an effective light modulation region in which a plurality of pixels are arranged in a matrix and is configured by repeating a unit pixel pattern including at least one of the pixels. A plurality of corresponding pixel openings, a horizontal / vertical dimension ratio of the incident end face of the light guide coincides with a horizontal / vertical dimension ratio of the unit pixel pattern of the light modulation element, and the light guide The horizontal / vertical dimension ratio of the exit end face of the light body is equal to the horizontal / vertical dimension ratio of the effective light modulation area of the light modulation element.

  In the projector of the present invention, when light from the light source is incident on the light guide and is reflected a plurality of times on the reflective side surface of the light guide, a virtual image of the light source repeatedly appears on the outside of the reflective side surface. A matrix-like light source image pattern composed of a plurality of positioned virtual images is formed. That is, even when only one light source is used, a light source image pattern is formed as if a plurality of light sources are arranged in a matrix. In this way, even if it is difficult to form a high-brightness and uniform light source array by arranging a plurality of actual light sources, a single light source is used to form a high-brightness and uniform light source image pattern. Can do.

  In addition, since the horizontal / vertical dimension ratio of the incident end face of the light guide matches the horizontal / vertical dimension ratio of the unit pixel pattern of the light modulation element, the above-described light source image pattern composed of a real image and a virtual image is This is substantially similar to the pattern of pixels in the effective light modulation region of the light modulation element. And since the light from each light source image (real image, virtual image) is condensed on the pixel opening of the light modulation element by the lens array, most of the light from the light source passes through the pixel opening and becomes an effective light beam. Contributes to image formation. On the other hand, since the horizontal / vertical dimension ratio of the exit end face of the light guide coincides with the horizontal / vertical dimension ratio of the effective light modulation area of the light modulation element, light leakage outside the effective light modulation area is minimized. And almost all of the light emitted from the light guide contributes to image formation. In this way, according to the present invention, it is possible to realize a projector that can use light from the light source with high efficiency and obtain a high-luminance image.

In the projector according to the aspect of the invention, when the horizontal / vertical dimension ratio of the pixels is 1, and the unit pixel pattern includes n (n: natural number) pixels, the horizontal / vertical dimension ratio A of the effective light modulation region is obtained. However, it is desirable that √ {n × (n−1)} <A ≦ √ {n × (n + 1)} is satisfied.
In the projector according to the present invention, the incident end face and the exit end face of the light guide are not the same size, the reflective side surface is in contact with the incident end face and the exit end face at an angle other than perpendicular, and the shape of the light guide is tapered. It is normal to make a shape. Therefore, since the horizontal / vertical dimension ratio A of the effective light modulation area of the light modulation element is a constant value unique to the apparatus, n, that is, the number of pixels included in the unit pixel pattern is optimized so as to satisfy the above inequality. This is preferable because the taper angle of the light guide is not increased as much as possible. This is because if the taper angle of the light guide becomes too large, the distortion of the light source image pattern from the plane increases, resulting in a loss of light quantity. The meaning of the inequality will be described later.

In the projector according to the aspect of the invention, the light from the light source may be incident on the center of the incident end face of the light guide.
According to this configuration, a unit pixel pattern including one pixel can be most accurately and easily formed, and loss of light amount can be minimized.

Alternatively, in the projector according to the aspect of the invention, the unit pixel pattern includes a pixel portion that is divided into four as a whole by dividing one pixel into two in the horizontal direction and the vertical direction, and the light from the light source is It can be set as the structure which injects into the corner | angular part of the said incident end surface of a light guide.
According to this configuration, for example, the same light source as that in the case where light from the light source is incident on the center of the incident end face can be divided into four parts, which is advantageous in terms of image uniformity and heat dissipation of the light source.

In that case, at least a part of the light incident on the corner may be a light of a different color from the other light.
According to this configuration, in some cases, a color image can be displayed with only one light modulation element. In this case, a light combining unit that combines light from a plurality of light modulation elements is not necessary, and a compact and low-cost projector can be realized.

In the projector according to the aspect of the invention, the light source may be arranged on the incident end face of the light guide.
According to this configuration, other optical members such as a light guide and a lens for guiding light from the light source to the light guide are not required, and a small and low-cost projector can be realized.

In the projector according to the aspect of the invention, the light emitted from the light source is incident, and a polarization conversion element that performs polarization conversion of the incident light is provided, and the light that has undergone polarization conversion by the polarization conversion element is incident on the light guide. It is good also as a structure.
According to this configuration, when the light modulation element uses one type of polarized light, such as a liquid crystal light valve, the light utilization efficiency can be further increased, and a projector with high efficiency and low power consumption can be realized.

In the projector according to the aspect of the invention, the light source may be a solid light source having a rectangular emission end surface.
This light source configuration is more suitable for the present invention than a lamp-type light source, and has a high light utilization efficiency and can realize a compact projector.

In the projector of the present invention, the pitch of the light source image on the incident end face of the light guide is P1, the horizontal / vertical pitch of the unit pixel pattern in the light modulation element is P2, the lens pitch of the lens array is PL, When the optical distance between the light source and the lens array is L1, and the optical distance between the lens array and the light modulation element is L2, both the following expressions (1) and (2) are satisfied. It is desirable.
PL = (m × P1 × P2) / (P1 + P2) (1) (m: natural number)
L2 / L1 = P2 / P1 (2)
According to this configuration, the light directly irradiated on the light modulation element from the light source and the light reflected on the reflection side surface of the light guide and irradiated on the light modulation element pass through different lenses of the lens array, and the same pixel. It is possible to realize a configuration in which light is condensed on top of each other.

Further, when the numerical aperture on the condensing side of the lens array is NA, the horizontal and vertical dimensions of the pixel aperture are a, and the wavelength of light from the light source is λ, the following equation (3) is obtained. It is desirable to be satisfied.
a ≧ λ / NA (3)
According to this configuration, since the spread of the light source image focused and imaged by the lens array due to the diffracted light is smaller than the size of the pixel opening, the light use efficiency can be further increased.

In the projector according to the aspect of the invention, it is preferable that an image forming point of the lens array is located in the pixel opening of the light modulation element.
According to this configuration, the light loss is the least, and the light utilization efficiency can be further increased.

  The electro-optical device according to the aspect of the invention reflects a light source that emits light, a rectangular incident end surface on which light emitted from the light source is incident, a reflective surface that reflects incident light, and the reflective surface. A light guide having a rectangular emission end surface for emitting light, a plurality of lenses arranged in an array, a lens array into which light emitted from the light guide is incident, and the lens array A light modulation element that modulates light emitted from each of the plurality of lenses, wherein the light modulation element includes a plurality of pixels arranged in a matrix and a unit pixel pattern including at least one of the pixels And a plurality of pixel openings corresponding to the plurality of pixels, and a horizontal / vertical dimension ratio of the incident end surface of the light guide is determined by the light modulation element. Of the above And the horizontal / vertical dimension ratio of the exit end face of the light guide coincides with the horizontal / vertical dimension ratio of the effective light modulation area of the light modulation element. It is characterized by.

  According to the electro-optical device of the present invention, as in the projector of the present invention described above, most of the light from each light source image (real image, virtual image) contributes to image formation, and the effective light modulation region of the light modulation element. Leakage of light to the outside is minimal. Accordingly, it is possible to realize an electro-optical device that has high use efficiency of light from the light source and can obtain a high-luminance image.

1 is a schematic configuration diagram of a projector according to a first embodiment of the invention. It is a figure for demonstrating the effect | action of a light guide rod and a micro lens array. It is a top view which shows the pixel pattern of a liquid crystal light valve. It is a perspective view which shows the part of a light source and a light guide rod. It is a figure which shows a light source image pattern. It is a perspective view which shows the part of the light source and light guide rod in the projector of 2nd Embodiment of this invention. It is a figure which shows a light source image pattern. It is a perspective view which shows the part of the light source and light guide rod in the projector of 3rd Embodiment of this invention. It is a figure for demonstrating the effect | action of a polarization beam splitter. It is a perspective view which shows the part of the light source and light guide rod in the projector of 4th Embodiment of this invention. It is a figure which shows a light source image pattern. It is a perspective view which shows the part of the light source and light guide rod in the projector of 5th Embodiment of this invention. It is a figure which shows a light source image pattern. It is a schematic block diagram of the projector of 6th Embodiment of this invention. It is a perspective view which shows the part of a light source and a light guide rod. It is a figure which shows a light source image pattern. It is a figure for demonstrating the effect | action of a micro lens array.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
This embodiment is an example of a projector using three sets of liquid crystal light valves, that is, a so-called three-plate projector.
FIG. 1 is a schematic configuration diagram of a projector according to the present embodiment. FIG. 2 is a diagram for explaining the operation of the light guide rod and the microlens array in the projector. FIG. 3 is a plan view showing a pixel pattern of a liquid crystal light valve in the projector. FIG. 4 is a perspective view showing portions of the light source and the light guide rod in the projector. FIG. 5 is a diagram showing a light source image pattern.
In the following drawings, in order to make each component easy to see, the ratio of dimensions and the scale may be appropriately changed depending on the component.

  As shown in FIG. 1, the projector 1 according to this embodiment includes three sets of illumination optical systems 2R, 2G, and 2B, and three sets of liquid crystal light valves 3R, 3G, and 2B corresponding to the illumination optical systems 2R, 2G, and 2B. 3B (light modulation element), a microlens array 4 (lens array) provided corresponding to each of the liquid crystal light valves 3R, 3G, and 3B, a cross prism 5, and a projection optical system 6. The three sets of illumination optical systems 2R, 2G, and 2B emit red (R) light, green (G) light, and blue (B) light, respectively.

  Each illumination optical system 2R, 2G, 2B directs the color light from each of the LED light sources 7R, 7G, 7B (light source, solid light source) that emits each color light, and the LED light sources 7R, 7G, 7B to the subsequent optical system. A light guide rod 8 (light guide) for guiding light. Each liquid crystal light valve 3R, 3G, 3B modulates each color light incident through the microlens array 4 from each illumination optical system 2R, 2G, 2B. The microlens array 4 collects light from the illumination optical systems 2R, 2G, and 2B at the pixel openings of the liquid crystal light valves 3R, 3G, and 3B. The cross prism 5 combines the three color lights modulated by the liquid crystal light valves 3R, 3G, and 3B. The projection optical system 6 projects the light combined by the cross prism 5 onto the screen 9 (projected surface).

  In the liquid crystal light valves 3R, 3G, and 3B of this embodiment, polarizing plates (not shown) are arranged on the light incident side and the light emission side of a liquid crystal panel (not shown) in which liquid crystal is sandwiched between a pair of substrates, respectively. It has been done. As shown in FIG. 3, the liquid crystal light valves 3R, 3G, and 3B have an effective light modulation region 13 in which a plurality of pixels 12 are arranged in a matrix except for the peripheral region 11 serving as a frame portion. The effective light modulation area 13 is an area that substantially contributes to display. In addition, the liquid crystal light valves 3R, 3G, and 3B include a lattice-shaped light shielding film 15 (black matrix) having a pixel opening 14 corresponding to each pixel 12.

  The shape of each pixel 12 is a square, and the horizontal dimension and the vertical dimension (pitch) are both 12 μm. The pixel opening 14 is provided at the center of each pixel 12. The shape of the pixel opening 14 is a square, and the horizontal and vertical dimensions are both 9 μm. Therefore, the pixel aperture ratio is (9 × 9) / (12 × 12) ≈0.56, which is about 56%. The liquid crystal light valves 3R, 3G, and 3B have 1024 horizontal pixels and 768 vertical pixels, and have a so-called XGA resolution. The effective light modulation region 13 has a horizontal dimension of about 12.3 mm, a vertical dimension of about 9.2 mm, and a horizontal / vertical dimension ratio (aspect ratio) of 4: 3.

  The light guide rod 8 is a solid rod-like member made of transparent glass having a refractive index of 1.5. As shown in FIG. 4, the incident end face 8 a of the light guide rod 8 is a square having a horizontal dimension of 9.4 mm and a vertical dimension of 9.4 mm. The exit end face 8b of the light guide rod 8 is a rectangle having a horizontal dimension of 12.5 mm and a vertical dimension of 9.4 mm. Therefore, the light guide rod 8 has a tapered shape that is widened only in the horizontal direction from the incident end face 8a side to the exit end face 8b side, and is not tapered in the vertical direction. The shape of the incident end face 8a of the light guide rod 8 is similar to the shape of the pixels 12 of the liquid crystal light valves 3R, 3G, 3B, and the shape of the exit end face 8b of the light guide rod 8 is the liquid crystal light valves 3R, 3G, 3B. The shape of the effective light modulation region 13 is substantially similar. Here, the exit end face 8b of the light guide rod 8 is slightly larger than the effective light modulation area 13 of the liquid crystal light valves 3R, 3G, and 3B. This is to give some margin to prevent non-uniformity. The four side surfaces in contact with the incident end surface 8a and the exit end surface 8b serve as reflective side surfaces 8c that reflect light passing through the inside.

  In the center of the incident end face 8a of the light guide rod 8, one square LED light source 7R, 7G, 7B having a horizontal dimension of 7 mm and a vertical dimension of 7 mm is disposed. As described above, the LED light sources 7R, 7G, and 7B emit one of R light, G light, and B light. The LED light sources 7R, 7G, and 7B are fixed to the light guide rod 8 with an optical adhesive or the like in a posture in which the light emission side surface is opposed to the incident end surface 8a of the light guide rod 8. The light emitted from the LED light sources 7R, 7G, and 7B is incident on the inside of the light guide rod 8 from the incident end face 8a, then is reflected a plurality of times by the reflective side face 8c, and is reflected from the exit end face 8b to the outside of the light guide rod 8. It is injected.

  At this time, when light from the LED light sources 7R, 7G, and 7B undergoes multiple reflections on the reflective side surface 8c of the light guide rod 8, as shown in FIG. 2, the LED light sources 7R, 7G, and 7B are placed outside the reflective side surface 8c. A virtual image is formed. In FIG. 2, only a virtual image resulting from one reflection is illustrated, but actually, a virtual image resulting from various times of reflection repeatedly appears outside the virtual image resulting from one reflection. FIG. 4 shows this as viewed from the exit end face 8b side of the light guide rod 8, and a plurality of virtual images 18 of the LED light sources 7R, 7G, 7B are arranged in a matrix around the real image 17 of the LED light sources 7R, 7G, 7B. The formed pattern (hereinafter, this pattern is referred to as the light source image pattern 19) is formed.

  At this time, since the light guide rod 8 is tapered only in the horizontal direction, the light source image pattern 19 shown in FIG. 5 is not actually formed in a planar shape, but a part thereof is shown in FIG. As shown, it is distorted into a curved surface (bent shape). However, the dimension of the light guide rod 8 in the light guide direction is, for example, several tens of millimeters, which is actually longer than the image shown in FIG. 2, and the taper angle (90 degrees from the angle formed by the incident end face 8a and the reflective side face 8c). Subtracted value) is small enough. Therefore, even if the light source image pattern 19 is distorted into a curved surface, the curvature is small, and the positional deviation of the light source images 17 and 18 due to the light source image pattern 19 being distorted into a curved surface does not cause much problem. However, it is desirable that the taper angle is as small as possible so that the curvature of the light source image pattern 19 does not increase. Therefore, in this embodiment, the vertical direction is not tapered, and only the horizontal direction is tapered. However, the degree to which the taper shape in the vertical direction and the horizontal direction is set is not limited as long as optimum values are used in consideration of various design factors. As an example, without changing the area of the exit end face 8b, the area of the entrance end face may be made slightly larger, for example, 10 mm × 10 mm, and the vertical direction may be a tapered reverse taper shape.

  In the present embodiment, one pixel 12 is considered as a unit pixel pattern, and it is considered that the effective light modulation region 13 is configured by repeating this unit pixel pattern. Then, the horizontal / vertical dimension ratio (9.4: 9.4 = 1: 1) of the incident end face 8a of the light guide rod 8 is the horizontal / vertical dimension ratio (12: 12 = 1: 1) of the unit pixel pattern. Match. Furthermore, the ratio (7: 9.4) of the dimension of one side of the LED light sources 7R, 7G, and 7B to the dimension of one side of the incident end face 8a of the light guide rod 8 is the pixel with respect to the dimension of one side of the unit pixel pattern (pixel 12). This substantially coincides with the ratio of the dimensions of one side of the opening 14 (9:12). Further, the horizontal / vertical dimension ratio (12.5: 9.4) of the exit end face 8b of the light guide rod 8 is equal to the horizontal / vertical dimension ratio (12.9.4) of the effective light modulation region 13 of the liquid crystal light valves 3R, 3G, 3B. 3: 9.2).

  As shown in FIGS. 1 and 2, the microlens array 4 is manufactured by forming a large number of recesses on the surface of a glass substrate by wet etching and filling the recesses with a resin having a high refractive index. Yes, it is affixed to the substrate on the light incident side of the liquid crystal light valves 3R, 3G, 3B. Further, the microlens array 4 is disposed so as to be in contact with the exit end face 8 b of the light guide rod 8. Any one microlens constituting the microlens array 4 reduces the light source images 17 and 18 constituting the light source image pattern 19 into the respective pixel openings 14 to form the light source images 17 and 18 and the pixels. The focal length and the position are set so that the opening 14 just overlaps. Then, as shown in FIG. 2, the adjacent microlenses are imaged so that the light source image pattern 19 is shifted on the effective light modulation area 13 by n pixels (in this embodiment, n = 1). The pitch between microlenses is set. As a result, the light from each light source image (real image 17, virtual image 18) is superimposed and condensed on each pixel opening 14. If the influence of the distortion of the light source image pattern 19, the aberration of the microlens, the diffraction limit, etc. is minute, almost all of the light from the LED light sources 7R, 7G, and 7B passes through the pixel opening 14 and is projected as an effective light beam. Contributes to image formation.

  Here, the pitch of the light source images 17 and 18 on the incident end face 8a of the light guide rod 8 is P1, the horizontal / vertical pitch of the unit pixel pattern in the liquid crystal light valves 3R, 3G, and 3B is P2, and the lenses of the microlens array 4 When the pitch is PL, the optical distance between the LED light sources 7R, 7G, and 7B and the microlens array 4 is L1, and the optical distance between the microlens array 4 and the liquid crystal light valves 3R, 3G, and 3B is L2, the light source Since the pitch of the images 17 and 18 is equal to one side of the incident end face 8a, P1 = 9.4 mm, and since the horizontal / vertical pitch of the unit pixel pattern is equal to the pixel pitch, P2 = 12 μm. The lens pitch PL of the microlens array 4 is 11.98 μm in both the horizontal and vertical directions, the optical distance L1 between the LED light source and the microlens array is 40 mm, and the microlens array-liquid crystal light valve (pixel opening of the light shielding film) When the optical distance L2 between them is set to 51 μm, both the conditions of the following expressions (1) and (2) are satisfied.

PL = (n × P1 × P2) / (P1 + P2) (1) (n: natural number)
L2 / L1 = P2 / P1 (2)
However, “n” here is the number of pixels when the light source image pattern 19 is imaged at a position shifted by the adjacent microlens, and as described above, n = 1 in this embodiment.

The formulas (1) and (2) are the liquid crystal light valves that are reflected directly on the liquid crystal light valves 3R, 3G, and 3B from the LED light sources 7R, 7G, and 7B and reflected on the reflective side surface 8c of the light guide rod 8. This is a condition for the light irradiated to 3R, 3G, and 3B to be condensed on the same pixel through different microlenses.
In the above, the optical distance L1 between the LED light source and the microlens array is expressed as 40 mm. This is a value converted into an optical distance in the air, and the refractive index of the light guide rod 8 is 1.5. Therefore, the actual length of the light guide rod 8 is 60 mm. Similarly, the optical distance L2 = 51 μm between the microlens array and the liquid crystal light valve is also a value converted into an optical distance in the air, and the actual length therebetween is 76.5 mm. Further, the optical distance L2 between the microlens array and the liquid crystal light valve coincides with the focal length of the microlens.

Further, the numerical aperture NA on the light condensing side of the microlens array 4 is 0.117, the horizontal and vertical dimensions a of the pixel openings 14 are 9 μm, and the wavelength λ of light from the LED light sources 7R, 7G, 7B is set. For example, in the case of G light and 0.632 μm, the following expression (3) is satisfied.
a ≧ λ / NA (3)
Λ / NA in the expression (3) indicates the spread of the light source image focused and imaged by the microlens array 4 due to the diffracted light. When the expression (3) is satisfied, since the spread of the light source image is smaller than the size of the pixel opening 14, the light use efficiency can be further increased.

  In general, since the LED light source has insufficient in-plane uniformity and has a radiance distribution, if it is used as it is, the luminance distribution and brightness unevenness occur on the liquid crystal light valve. In that respect, in the projector 1 of the present embodiment, the light reflected from the LED light sources 7R, 7G, and 7B is transmitted through the light guide rod 8 so that the multiple reflected light is superimposed, so that the luminance distribution is made uniform. . Since the exit end face 8b of the light guide rod 8 and the effective light modulation regions 13 of the liquid crystal light valves 3R, 3G, 3B have substantially the same shape and substantially the same size, light leaks outside the effective light modulation region 13. Therefore, almost all of the light emitted from the light guide rod 8 contributes to the formation of an image. Further, the light source image pattern 19 and the pixel pattern are similar to each other, and light from each light source image (real image 17, virtual image 18) enters the pixel openings 14 of the liquid crystal light valves 3 R, 3 G, and 3 B by the microlens array 4. It is condensed and superimposed. Thereby, most of the light can pass through the pixel opening 14 and contribute to the formation of an image as an effective light beam. In this way, according to the present embodiment, it is possible to realize a projector that has high utilization efficiency of light from the LED light source and can obtain a high-luminance image.

[Second Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
This embodiment is also an example of a three-plate projector. The basic configuration of the projector is the same as that of the first embodiment, and the shape of the light guide rod and the arrangement of the LED light sources are different from those of the first embodiment. Therefore, in the present embodiment, description of the basic configuration of the projector is omitted, and only differences from the first embodiment will be described.
FIG. 6 is a perspective view showing portions of the light source and the light guide rod in the projector according to the present embodiment. FIG. 7 is a diagram showing a light source image pattern.

  In the first embodiment, one unit pixel pattern is composed of one pixel, whereas in this embodiment, one unit pixel pattern is composed of two pixels. In this embodiment, the pixels of the liquid crystal light valve are square, and the horizontal and vertical dimensions (pitch) are both 10 μm. The pixel opening is square, and the horizontal and vertical dimensions are both 8 μm. Therefore, the pixel aperture ratio is about 64%. The liquid crystal light valve has a horizontal pixel number of 1920 and a vertical pixel number of 1080, and has a so-called full high-definition resolution. The effective light modulation area has a horizontal dimension of about 19.2 mm, a vertical dimension of about 10.8 mm, and a horizontal / vertical dimension ratio (aspect ratio) of 16: 9.

  As shown in FIG. 6, the incident end face 21a of the light guide rod 21 is a rectangle having a horizontal dimension of 20 mm and a vertical dimension of 10 mm. The exit end face 21b of the light guide rod 21 is a rectangle having a horizontal dimension of 20 mm and a vertical dimension of 11.6 mm. Therefore, the light guide rod 21 has a taper shape in which only the vertical direction widens from the incident end surface side to the exit end surface side, and is not tapered in the horizontal direction. The shape of the incident end face 21a of the light guide rod 21 is a rectangular shape in which two squares of 10 mm × 10 mm are arranged in the horizontal direction, and the horizontal dimension is 8 mm in the portion corresponding to the center of each square, and the vertical direction Two square LED light sources 22R, 22G, and 22B having a size of 8 mm are arranged.

  In the present embodiment, two pixels are considered as a unit pixel pattern, and it is considered that an effective light modulation region is configured by repeating this unit pixel pattern. Here, the horizontal / vertical dimension ratio (20: 10 = 2: 1) of the incident end face 21a of the light guide rod 21 matches the horizontal / vertical dimension ratio (20: 10 = 2: 1) of the unit pixel pattern. Yes. Furthermore, the ratio (8:10) of the vertical dimension of the LED light sources 22R, 22G, and 22B to the vertical dimension of the incident end face 21a of the light guide rod 21 is the pixel with respect to the vertical dimension of the unit pixel pattern (pixel). This corresponds to the ratio of the vertical dimension of the opening (8:10). Further, the horizontal / vertical dimension ratio (20: 11.6) of the exit end face 21b of the light guide rod 21 is substantially the same as the horizontal / vertical dimension ratio (19.2: 10.8) of the effective light modulation area of the liquid crystal light valve. Match.

  When the light from the two LED light sources 22R, 22G, and 22B undergoes multiple reflections at the reflection side surface 21c of the light guide rod 21, the two LED light sources are arranged around the real image 23 of the two LED light sources as shown in FIG. A light source image pattern 25 in which virtual images 24 are repeatedly arranged in a matrix is formed. As described in the first embodiment, since the light guide rod 21 has a tapered shape, the light source image pattern 25 is actually formed in a curved surface shape. It has a similar shape.

  In the case of a wide screen such as the liquid crystal light valve having an aspect ratio of 16: 9 as in the present embodiment, the exit end face 21b of the light guide rod 21 has a rectangular shape that is long in the horizontal direction. When one pixel is used as one unit pixel pattern as in the embodiment, the horizontal taper angle of the light guide rod becomes too large, and the curvature of the light source image pattern becomes large. Then, the positional deviation of the light source image due to the distortion of the light source image pattern in a curved surface cannot be ignored, resulting in a loss of light quantity. Therefore, in order to prevent the loss of the light amount as much as possible, it is desirable that the two pixels be one unit pixel pattern.

The determination of whether one pixel should be one unit pixel pattern or two pixels should be one unit pixel pattern according to the aspect ratio of the liquid crystal light valve can be considered as follows, for example. .
That is, a boundary (threshold) for determining whether a rectangle having an arbitrary aspect ratio is close to a square having an aspect ratio of 1: 1 or a rectangle having an aspect ratio of 1: 2 may be obtained. At the boundary, since the aspect ratio 1: x and the aspect ratio x: 2 are equal, x = √2. Therefore, when the aspect ratio A of the liquid crystal light valve satisfies A ≦ √2, it is determined that the shape is close to a square, and one pixel is preferably used as one unit pixel pattern. On the other hand, when the aspect ratio A of the liquid crystal light valve satisfies √2 <A ≦ √6, it is determined that the shape is close to a rectangle having an aspect ratio of 1: 2, and two pixels are regarded as one unit pixel pattern. It is desirable to do. When the aspect ratio A of the liquid crystal light valve exceeds √6, the shape is close to a rectangle with an aspect ratio of 1: 3, and it is desirable that the three pixels be one unit pixel pattern. Generalizing this, when the aspect ratio A of the liquid crystal light valve satisfies √ {n × (n−1)} <A ≦ √ {n × (n + 1)} (n: natural number), n pixels are It is desirable to use one unit pixel pattern.

  In the case of this embodiment, the pitch P1 of the light source image on the incident end face 21a of the light guide rod 21 is 10 mm, the horizontal / vertical pitch P2 of the unit pixel pattern is 10 μm, and the lens pitch PL of the microlens array is horizontal and vertical. In both cases, the optical distance L1 (in the air) between the LED light source and the microlens array is 50 mm (the actual length of the light guide rod is 75 mm), and the optical distance L2 between the microlens array and the liquid crystal light valve (air) The focal point of the middle lens and the microlens is 50 μm (actual length is 75 mm), which satisfies both the expressions (1) and (2) described in the first embodiment.

  Also in the present embodiment, the same effect as that of the first embodiment can be obtained, in which a projector that can use a light emitted from an LED light source and that can obtain a high-luminance image can be realized.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the projector of this embodiment is the same as that of the first embodiment. Moreover, the point which makes two pixels one unit pixel pattern is the same as that of 2nd Embodiment, and arrangement | positioning of the LED light source with respect to a light guide rod differs from 2nd Embodiment.
Therefore, in the present embodiment, only a part related to the arrangement of the LED light sources different from the second embodiment will be described.
FIG. 8 is a perspective view showing portions of the LED light source and the light guide rod in the projector according to the present embodiment. FIG. 7 is a diagram for explaining the operation of the polarization beam splitter.

  In this embodiment, as shown in FIGS. 8 and 9, a polarization beam splitter 28 (hereinafter abbreviated as PBS) (polarization conversion element) is provided on the incident end surface 27 a of the light guide rod 27. Yes. The PBS 28 includes a light guide 29, a polarization separation surface 30 provided inside the light guide 29, a wave plate 31, and a reflection surface 32. The polarization separation surface 30 reflects, for example, the S wave of the light from the LED light source 7G and transmits the P wave, and is installed at an angle of approximately 45 degrees with respect to the light guide direction of the light guide 29. ing. The LED light source 7G is fixed to the incident end surface of the light guide 29, and the end of the light guide 29 opposite to the side where the LED light source 7G is provided is approximately 45 with respect to the light guide direction. A reflective surface 32 is provided at an angle of degrees.

  In this configuration, when the light emitted from the LED light source 7G passes through the inside of the light guide 29, the S wave of the light from the LED light source 7G is reflected by the polarization separation surface 30 and is incident on the light guide rod 27. The light source image 33 is formed on the incident end surface 27a and is incident on the inside, facing the end surface 27a, as in the second embodiment. On the other hand, the P wave passes through the polarization separation surface 30 and is then converted into an S wave by passing through the wave plate 31, reflected by the reflection surface 32, directed to the incident end surface 27 a of the light guide rod 27, and the incident end surface 27 a. A light source image 33 is formed on the top and is incident on the inside.

  Also in this embodiment, the same effects as those in the first and second embodiments can be obtained, in which a projector capable of obtaining a high-luminance image with high use efficiency of light emitted from the LED light source can be obtained. In the case of the present embodiment, the light emitted from the LED light source 7G is polarized and converted by the PBS 28, and is aligned with one linearly polarized light (S wave in the present embodiment) through the light guide rod 27 to the liquid crystal light valve 3G. Incident. Therefore, this configuration is suitable for a liquid crystal light valve that uses one type of polarized light for display, and the light utilization efficiency can be further improved, and a projector with higher efficiency and lower power consumption can be realized.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. 10 and 11.
The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and the shape of the light guide rod and the arrangement of the LED light sources are different from those of the first embodiment. Therefore, in the present embodiment, description of the basic configuration of the projector is omitted, and only differences from the first embodiment will be described.
FIG. 10 is a perspective view showing portions of the light source and the light guide rod in the projector according to the present embodiment. FIG. 11 is a diagram showing a light source image pattern.

  In the first embodiment, one unit pixel pattern is composed of one pixel, and in the second embodiment, one unit pixel pattern is composed of two pixels, whereas in the present embodiment, two horizontal pixels × One unit pixel pattern is composed of a total of four pixels in two vertical directions. The same liquid crystal light valve as that in the first embodiment is used. In other words, the pixels of the liquid crystal light valve are square, the horizontal and vertical dimensions (pitch) are both 12 μm, the pixel openings are square, and the horizontal and vertical dimensions are both 9 μm. The liquid crystal light valve has a horizontal pixel count of 1024, a vertical pixel count of 768, an effective light modulation area with a horizontal dimension of about 12.3 mm, a vertical dimension of about 9.2 mm, and a horizontal / vertical dimension ratio ( Aspect ratio) is 4: 3.

  As shown in FIG. 10, the light guide rod 35 is a square whose horizontal and vertical dimensions of the incident end face 35a are 9.4 mm, the horizontal dimension of the emission end face 35b is 12.5 mm, and the vertical dimension is 9 .4 mm rectangle, which is the same as in the first embodiment, but the optical length in the light guiding direction is about half that of the first embodiment. Therefore, the light guide rod 35 has a tapered shape that is widened only in the horizontal direction from the incident end surface 35a side to the exit end surface 35b side, and is not tapered in the horizontal direction. The incident end surface 35a of the light guide rod 35 is a square in a form in which four squares of 4.7 mm × 4.7 mm are arranged in two in the horizontal direction and in the vertical direction, and a first portion is formed in a portion corresponding to the center of each square. Four LED light sources 36 in which the same LED light source of the embodiment is divided into four, that is, both the horizontal and vertical dimensions are 3.5 mm are arranged.

  In the present embodiment, a unit pixel pattern including four pixels is considered, and it is assumed that an effective light modulation region is configured by repeating this unit pixel pattern. When the light from the four LED light sources 36 causes multiple reflection on the reflection side surface 35c of the light guide rod 35, the virtual images of the four LED light sources around the real images 37 of the four LED light sources as shown in FIG. A light source image pattern 39 in which 38 is repeatedly arranged in a matrix is formed. Also in this case, the light source image pattern 39 and the pixel pattern are similar, and light from each of the light source images 37 and 38 can be condensed on each pixel opening by the microlens array.

  In the present embodiment, the horizontal / vertical pitch P1 of the light source image on the incident end face 35a of the light guide rod 35 is 4.7 mm, the horizontal / vertical pitch P2 of the unit pixel pattern is 12 μm, and the lens pitch PL of the microlens array is 11.97 μm in both the horizontal and vertical directions, the optical distance L1 (in the air) between the LED light source and the microlens array is 20 mm (the actual length of the light guide rod is 30 mm), and the optical distance between the microlens array and the liquid crystal light valve Since the focal lengths of L2 (in air) and the microlens are 51 μm (actual length is 76.5 mm), both the expressions (1) and (2) described in the first embodiment are satisfied.

  Also in the present embodiment, the same effects as those of the first to third embodiments can be obtained, in which a projector capable of obtaining a high-luminance image with high utilization efficiency of light emitted from the LED light source can be obtained. In this embodiment, the same liquid crystal light valve as that in the first embodiment is used. However, this configuration is advantageous when a bright projector is configured using a relatively large liquid crystal light valve. According to this configuration, even if a plurality of LED light sources 36 are used, the light utilization efficiency does not decrease, and the LED light sources are arranged apart from each other, which is advantageous in terms of light source mounting and heat dissipation.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and the shape of the light guide rod and the arrangement of the LED light sources are different from those of the first embodiment. Therefore, in the present embodiment, description of the basic configuration of the projector is omitted, and only differences from the first embodiment will be described.
FIG. 12 is a perspective view showing portions of the light source and the light guide rod in the projector according to the present embodiment. FIG. 13 is a diagram showing a light source image pattern.

  In the first to fourth embodiments, one unit pixel pattern is configured so as to include at least one pixel as it is. On the other hand, in the present embodiment, one unit pixel pattern is configured by four pixel portions obtained by dividing one pixel into four (two in the horizontal direction and two in the vertical direction). The same liquid crystal light valve as that in the first embodiment is used. In other words, the pixels of the liquid crystal light valve are square, the horizontal and vertical dimensions (pitch) are both 12 μm, the pixel openings are square, and the horizontal and vertical dimensions are both 9 μm. The liquid crystal light valve has a horizontal pixel count of 1024, a vertical pixel count of 768, an effective light modulation area with a horizontal dimension of about 12.3 mm, a vertical dimension of about 9.2 mm, and a horizontal / vertical dimension ratio ( Aspect ratio) is 4: 3.

  As shown in FIG. 12, the light guide rod 8 is a square whose horizontal and vertical dimensions of the incident end face 8a are 9.4 mm, the horizontal dimension of the exit end face 8b is 12.5 mm, and the vertical dimension is 9 A rectangular shape of 4 mm, which is the same as that of the first embodiment. At the four corners of the incident end face 8a of the light guide rod 8, the same LED light source of the first embodiment is divided into four parts, that is, a square LED having both horizontal and vertical dimensions of 3.5 mm. Each light source 36 is arranged.

  In the case of this embodiment, as shown in FIG. 13, one light source image in the light source image pattern 41 is formed by four different mirror images (one real image 42 and three virtual images 43, or four virtual images 43). Yes. In this configuration, the dimension of each side of the incident end face 8a of the light guide rod 8 is the pitch of the light source image. Also in this case, the light source image pattern 41 and the pixel pattern are similar, and light from each light source image can be condensed on each pixel opening by the microlens array.

  In the present embodiment, the horizontal / vertical pitch P1 of the light source image on the incident end face 8a of the light guide rod 8 is 9.4 mm, the horizontal / vertical pitch P2 of the unit pixel pattern is 12 μm, and the lens pitch PL of the microlens array is 11.98 μm in both the horizontal and vertical directions, the optical distance L1 (in the air) between the LED light source and the microlens array is 40 mm (the actual length of the light guide rod is 60 mm), and the optical distance between the microlens array and the liquid crystal light valve The focal lengths of L2 (in the air) and the microlens are 51 μm (actual length is 76.5 mm), and both the conditions of the expressions (1) and (2) described in the first embodiment are satisfied.

  Also in this embodiment, the same effects as those in the first to fourth embodiments can be obtained, in which a projector capable of obtaining a high-luminance image with high use efficiency of light emitted from the LED light source can be obtained. In this embodiment, the dimensions and optical parameters of each component are substantially the same as those in the first embodiment. However, since the LED light source is divided into four parts, the uniformity of the screen and the surface of heat dissipation are obtained. Is advantageous.

[Sixth Embodiment]
Hereinafter, a sixth embodiment of the present invention will be described with reference to FIGS.
In the first to fifth embodiments, an example of a three-plate projector is shown. In the present embodiment, a projector that realizes color display using only one set of liquid crystal light valves, an example of a so-called single-plate projector. Show.
FIG. 14 is a schematic configuration diagram of the projector according to the present embodiment. FIG. 15 is a perspective view showing portions of a light source and a light guide rod. FIG. 16 is a diagram showing a light source image pattern. FIG. 17 is a diagram for explaining the operation of the microlens array.
In FIG. 14, the same components as those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 14, the projector 45 of the present embodiment includes LED light sources 46R, 46G, 46B, 46W, a light guide rod 47, a microlens array 4, a liquid crystal light valve 48, a projection optical system 6, It has. In the first to fifth embodiments, three sets of independent illumination optical systems are provided for different color lights. In the present embodiment, as described later, one light guide rod 47 has different colors. A plurality of LED light sources 46R, 46G, 46B, and 46W for emitting colored light are arranged, and a plurality of colored lights of different colors are emitted from a set of illumination optical systems 49.

  The pixels of the liquid crystal light valve 48 of the present embodiment include sub-pixels that modulate red (R) light, sub-pixels that modulate green (G) light, sub-pixels that modulate blue (B) light, and white (W) light. Are composed of four sub-pixels. The sub-pixel array pattern 51 includes, for example, R sub-pixels 52R such as R, B, R, B,... In an odd-numbered sub-pixel column in the horizontal direction, as shown on the right side of FIG. The B sub-pixels 52B are alternately arranged, and in the even-numbered sub-pixel columns, the G sub-pixels 52G and the W sub-pixels 52W are alternately arranged as G, W, G, W,. ing.

  Corresponding to the sub-pixel array pattern 51, red light is emitted from the four corners of the incident end face 47a of the light guide rod 47 to the upper left corner as viewed from the light incident side, as shown in FIG. A red LED light source 46R that emits light is disposed, a green LED light source 46G that emits green light is disposed in the lower left corner, and a blue LED light source 46B that emits blue light is disposed in the upper right corner. A white LED light source 46 </ b> W that emits white light is disposed at the corners of FIG.

  In this embodiment, four color lights of red, green, blue, and white are used. However, three colors of red, green, and blue are used for color expression, and white improves the brightness and contrast of the image. It is used for. However, the color to be used is not limited to this. For example, when the intensity of the green LED light source is relatively weak, two green pixels may be used as R, G1, G2, and B. For example, another color such as yellow may be introduced to expand the color gamut that can be expressed.

  In the case of this embodiment, as shown in FIG. 16, one light source image in the light source image pattern 53 is formed by four mirror images (one real image 54 and three virtual images 55, or four virtual images 55) of the same color. Is done. When attention is paid to one row in the horizontal direction and one column in the vertical direction, the light source images of two different colors are repeated in any row and column. In the case of the present embodiment, as shown in FIG. 17, the light source image pattern 53 and the pixel pattern (sub-pixel array pattern 51) have similar shapes in which the patterns are reversed in both the horizontal direction and the vertical direction. Light from each light source image can be condensed on each pixel opening by the microlens array 56.

  In the case of this embodiment, a VGA (640 × 480 pixels) panel having a subpixel pitch of 10 μm is used for the liquid crystal light valve. The horizontal / vertical pitch P1 of the light source image on the incident end face 47a of the light guide rod 47 is 20 mm, the horizontal / vertical pitch P2 of the unit pixel pattern is 20 μm, and the lens pitch PL of the microlens array is 19. 98 μm, optical distance L1 between LED light source and microlens array (in air) is 80 mm (actual length of light guide rod is 120 mm), optical distance L2 between microlens array and liquid crystal light valve (in air) and microlens Has a focal length of 80 μm (actual length is 120 mm), which satisfies both the conditions of the expressions (1) and (2) described in the first embodiment.

  Also in the present embodiment, the same effects as those in the first to fifth embodiments can be obtained, in which a projector capable of obtaining a high-luminance image with high use efficiency of light emitted from the LED light source can be obtained. Further, in the present embodiment, color expression is possible with one set of liquid crystal light valves 48, and it is not necessary to perform color synthesis with a cross prism, and therefore the projection optical system 6 is disposed directly after the liquid crystal light valve 48. Can do. Thereby, the miniaturization and cost reduction of the entire projector can be realized.

  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, in the above embodiment, a solid light guide rod is used, but instead of this configuration, a hollow (tubular) light guide rod having an inner surface as a reflection surface may be used. Also, instead of a configuration in which the LED light source is directly fixed to the incident end face of the light guide rod, light from the light source arranged at a position away from the light guide rod is imaged by the lens, and a light source image is formed on the incident end face of the light guide rod. May be formed. Alternatively, another light guide rod may be used to form a light source image on the incident end face of the light guide rod.

  In the above embodiment, an LED light source is used as a light source. However, a laser light source may be used, or a lamp light source may be condensed and formed into a rectangular shape. In particular, when a laser light source is used, since the beam shape is circular, strictly speaking, a light source image does not have a similar shape with respect to a rectangular pixel opening. However, since a sufficiently thin light beam can be obtained from the laser light source and the light beam can be incident on the pixel opening without waste, a bright projector with high light utilization efficiency can be obtained. In addition, specific configurations such as shapes, dimensions, and arrangements of the respective parts exemplified in the above embodiment can be appropriately changed.

  Further, in the above embodiment, an example in which the present invention is applied to a projector has been described. However, if a configuration in which a user directly views a liquid crystal light valve except for a projection optical system from the above embodiment, a direct view type liquid crystal display is provided. It becomes a device. In this way, the present invention can also be applied to an electro-optical device such as a liquid crystal display device.

  DESCRIPTION OF SYMBOLS 1,45 ... Projector, 3R, 3G, 3B, 48 ... Liquid crystal light valve (light modulation element), 4, 56 ... Micro lens array (lens array), 6 ... Projection optical system, 7R, 7G, 7B, 22R, 22G , 22B, 36, 46R, 46G, 46B, 46W ... LED light source (light source, solid light source), 8, 21, 27, 35, 47 ... Light guide rod (light guide), 8a, 21a, 27a, 35a, 47a ... incident end face, 8b, 21b, 27b, 35b, 47b ... exit end face, 8c, 21c, 27c, 35c, 47c ... reflective side face, 9 ... screen (projected face), 12 ... pixel, 13 ... effective light modulation area, 14: Pixel opening.

Claims (12)

A light source that emits light;
A light guide having a rectangular incident end surface on which light emitted from the light source is incident, a reflective side surface that reflects the incident light, and a rectangular emission end surface that emits the light reflected on the reflective side surface. Body,
A lens array in which a plurality of lenses are arranged in an array and light emitted from the light guide is incident;
A light modulation element that modulates light emitted from each of the plurality of lenses constituting the lens array;
A projection optical system that projects the light modulated by the light modulation element onto the projection surface;
Is provided,
The light modulation element includes an effective light modulation region in which a plurality of pixels are arranged in a matrix and is configured by repeating a unit pixel pattern including at least one of the pixels, and a plurality of pixels corresponding to the plurality of pixels. An opening is provided,
The horizontal / vertical dimension ratio of the incident end face of the light guide coincides with the horizontal / vertical dimension ratio of the unit pixel pattern of the light modulation element, and the horizontal / vertical dimension of the exit end face of the light guide The projector is characterized in that the ratio matches the horizontal / vertical dimension ratio of the effective light modulation area of the light modulation element.   When the horizontal / vertical dimension ratio of the pixel is 1 and the unit pixel pattern includes n (n: natural number) pixels, the horizontal / vertical dimension ratio A of the effective light modulation area is √ {n × The projector according to claim 1, wherein (n−1)} <A ≦ √ {n × (n + 1)} is satisfied.   The projector according to claim 1, wherein light from the light source is incident on a center of the incident end face of the light guide. The unit pixel pattern includes a pixel portion that is divided into four as a whole by dividing one pixel into two in the horizontal direction and the vertical direction,
The projector according to claim 1, wherein light from the light source is incident on a corner portion of the incident end face of the light guide.   The projector according to claim 4, wherein at least a part of the light incident on the corner portion is light having a color different from that of the other light.   The projector according to claim 1, wherein the light source is disposed on the incident end face of the light guide.   The light emitted from the light source is incident, and a polarization conversion element for converting the incident light is provided. The light converted by the polarization conversion element is incident on the light guide. The projector according to claim 1.   The projector according to claim 1, wherein the light source is a solid light source having a rectangular emission end face. The pitch of the light source image on the incident end face of the light guide is P1, the horizontal / vertical pitch of the unit pixel pattern in the light modulation element is P2, the lens pitch of the lens array is PL, the light source and the lens array The following equation (1) and equation (2) are both satisfied, where L1 is the optical distance between the lens array and L2 is the optical distance between the lens array and the light modulation element. Item 9. The projector according to any one of Items 1 to 8.
PL = (m × P1 × P2) / (P1 + P2) (1) (m: natural number)
L2 / L1 = P2 / P1 (2) When the numerical aperture on the condensing side of the lens array is NA, the horizontal and vertical dimensions of the pixel aperture are a, and the wavelength of light from the light source is λ, the following expression (3) is satisfied. The projector according to claim 9.
a ≧ λ / NA (3)   11. The projector according to claim 1, wherein an imaging point of the lens array is located in the pixel opening of the light modulation element. A light source that emits light;
A light guide having a rectangular incident end surface on which light emitted from the light source is incident, a reflective side surface that reflects the incident light, and a rectangular emission end surface that emits the light reflected on the reflective side surface. Body,
A lens array in which a plurality of lenses are arranged in an array and light emitted from the light guide is incident;
A light modulation element that modulates light emitted from each of the plurality of lenses constituting the lens array;
Is provided,
The light modulation element includes an effective light modulation region in which a plurality of pixels are arranged in a matrix and is configured by repeating a unit pixel pattern including at least one of the pixels, and a plurality of pixels corresponding to the plurality of pixels. An opening is provided,
The horizontal / vertical dimension ratio of the incident end face of the light guide coincides with the horizontal / vertical dimension ratio of the unit pixel pattern of the light modulation element, and the horizontal / vertical dimension of the exit end face of the light guide An electro-optical device characterized in that the ratio matches a horizontal / vertical dimension ratio of the effective light modulation region of the light modulation element.

Images