JP2008299279A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector for fully radiating heat generated from light sources while reducing cost. <P>SOLUTION: The projector comprises light sources 10R, 10G, 10B, an optical path changing means 20, a light modulating means 40, a microlens array 30 transmitting light emitted from the optical path changing means 20, to the light modulating means 40, and a projecting device 50 projecting light modulated by the light modulating means 40, on a projection plane 60. A plurality of light sources 10R, 10G, 10B are formed by forming a plurality of light emitting parts 11R, 11G, 11B emitting the same color light, on a substrate 12, and the microlens array 30 condenses the same color light emitted from the plurality of light emitting parts 11R, 11G, 11B, into apertures formed in pixels of the light modulating means 40 and condenses different color light emitted from the plurality of light sources 10R, 10G, 10B, to the different pixels of the light modulating means 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector.

  Conventionally, white light is color-separated by a color wheel, and R (red), G (green), and B (blue) light is incident on a single plate-like spatial light modulator, and each color light is time-divisionally divided. A so-called single-plate projector that projects a color image by projecting the image onto a screen has been proposed. In this single plate method, filter segments that transmit light of three colors or four colors are arranged on the color wheel, and are rotated in synchronization with the modulation period of the spatial light modulation means. However, for example, when white light is incident on a red color filter, blue light and green light other than red light are absorbed by the color filter, and only the red light is transmitted through the color filter. The same applies to light passing through the green color filter, and light other than green light is absorbed by the color filter. The same applies to blue light. Therefore, the amount of light substantially used for color image projection is about one-third or less of white light. Therefore, an electro-optical device that does not require a color filter has been proposed (see, for example, Patent Document 1).

The electro-optical device described in Patent Document 1 includes a point light source array in which RGB point light sources are sequentially arranged, a microlens array, and a liquid crystal light valve. Then, the light emitted from the point light sources of the respective colors of the liquid crystal light valve is condensed and superimposed on the pixels of the respective colors by the microlens array.
JP 2002-287142 A

  The following problems remain in the conventional technology. That is, since it is difficult to produce a point light source array arranged in the order of RGB, the cost increases. In addition, when the point light source is a laser or LED, it is difficult to integrally produce light sources arranged in the order of RGB, so even if separate chips are arranged on a substrate for each color, Since the pitch between the point light sources is not constant, it is complicated and expensive. Also, problems such as difficulty in designing the drive wiring for driving each point light source result in a complicated and expensive product. Further, when the point light sources arranged in the order of RGB are arranged on one substrate, there is a problem that the adjacent point light sources are not sufficiently spaced and the heat dissipation is poor.

  SUMMARY An advantage of some aspects of the invention is that it provides a projector that can sufficiently dissipate heat generated from a light source while reducing costs.

In order to achieve the above object, the present invention provides the following means.
The projector of the present invention has a plurality of light sources that respectively emit light of different colors, an optical path conversion unit that converts an optical path of light emitted from the plurality of light sources, and has different wavelength selectivity, A light modulation unit having an array of a plurality of types of pixels capable of independently modulating light of different colors whose light paths have been converted by the conversion unit, and transmitting light emitted from the light path conversion unit to the light modulation unit A microlens array including a plurality of microlenses; and a projection device that projects light modulated by the light modulation unit onto a projection surface, wherein each of the plurality of light sources emits light of the same color. Are formed on the substrate, and light of the same color emitted from the plurality of light emitting units by the microlens array is collected in an opening formed in a pixel of the light modulation unit, and Different colors of light emitted from the light source, characterized in that it is incident on different pixels of the light modulation means.

In the projector according to the present invention, the optical paths of the lights emitted from the plurality of light sources are converted in the same direction by the optical path conversion means. Then, each light converted in the same direction is collected by the microlens array and enters the pixel opening of the light modulation means. The light incident on the opening is modulated and projected onto the projection surface by the projection device. In this way, each color is projected onto the projection surface using the light modulation means.
Here, in the present invention, since the plurality of light emitting portions that emit light of the same color are formed on the substrate, it is easy to design and manufacture the plurality of light emitting portions on the same substrate. Thereby, it becomes easy to form a plurality of light emitting parts integrally at low cost, and furthermore, the pitch between the light sources can be formed constant.
Further, conventionally, since a plurality of light emitting portions having different color wavelengths are formed on one substrate, the number of light emitting portions formed on one substrate is large. Thereby, the space | interval of a some light emission part is narrow, and the arrangement | positioning density of a light emission part is large. However, in the light source used for the projector of the present invention, a plurality of light emitting portions that emit light of the same color are formed on the substrate. That is, since only the light emitting portions that emit light of one color are formed on the substrate, the number of light emitting portions on the substrate can be small. That is, since the interval between the plurality of light emitting units can be widened, the arrangement density of the light emitting units can be reduced, and a projector having a light source with good heat dissipation can be provided.

  In the projector according to the aspect of the invention, it is preferable that the pitches of the central axes of adjacent lights of different colors emitted from the optical path changing unit are substantially equal.

  In the projector according to the present invention, since the intervals between the central axes of the light emitted adjacently from the optical path changing means are substantially equal, the microlens array may be formed in accordance with the pitches of the central axes of the plurality of lights. Therefore, the design of the microlens array becomes easy.

  In the projector according to the aspect of the invention, it is preferable that the pitches of the light emitting units of the plurality of light sources are substantially equal and the number of the light emitting units for the plurality of light sources is the same.

  In the projector according to the present invention, since the intervals between the light emitting portions of the plurality of light sources are substantially equal and the number of the light emitting portions emitting the same color light is the same, for example, the microlenses are made the same size and arranged at equal intervals. By doing so, each light can be condensed on the opening. Therefore, the design of the microlens array becomes easy.

  In the projector according to the aspect of the invention, the ratio between the pitch of the light emitting units of each of the plurality of light sources and the pitch of the central axes of adjacent light beams of different colors emitted from the optical path changing unit may be It is preferable that the ratio between the pitch of pixels on which light of the same wavelength is incident and the pitch of adjacent pixels is substantially equal.

  In the projector according to the present invention, the ratio between the pitch of the light emitting unit that emits light of the same color and the interval between the central axes of adjacent light of different colors emitted from the optical path changing unit is the same wavelength of the light modulating unit. Since the ratio between the pitch of the incident pixels and the pitch of the adjacent pixels is substantially equal, each light emitted from the light source can be efficiently condensed on the pixels by the microlens array.

  In the projector according to the aspect of the invention, it is preferable that an optical distance between each of the plurality of light sources and the microlens array is different according to wavelengths of different colors of light emitted from the light sources.

  In the projector according to the present invention, since the microlens array generally has chromatic aberration, the focal position changes depending on the wavelength of the incident light. Therefore, the light source is arranged according to the wavelength of the light emitted from the light source. That is, in the present invention, since a plurality of light emitting portions that emit light of the same color are formed on the substrate, the optical distance (optical path length) between the light source and the microlens array can be adjusted to an optimum state. .

In the projector according to the aspect of the invention, it is preferable that optical distances between the plurality of light sources and the microlens array are substantially equal.
In the projector according to the present invention, when the chromatic aberration due to the microlens array does not affect the image displayed on the projection surface, the optical distance (optical path length) between each light source and the microlens array becomes substantially equal. By arranging in this way, it becomes easy to arrange a plurality of light sources.

  In the projector of the present invention, the pitch of the plurality of light emitting units is P1, the pitch of the plurality of pixels is P2, the pitch of microlenses of the microlens array is PL, each of the plurality of light sources and the microlens array PL = n {P1 · P2 / (P1 + P2)} where L1 is the optical distance and L2 is the optical distance between the microlens array and the light modulator. , N is a natural number) and L2 / L1 = P2 / P1 are preferably satisfied.

  In the projector according to the present invention, when the chromatic aberration due to the microlens array does not affect the image displayed on the projection surface, the light source, the light modulation unit, and the microlens array are formed so as to satisfy the above formula, Deploy. Thereby, the number of rays incident on each pixel can be adjusted by changing the value of n. Therefore, for example, when n is 1, the pitch PL of the microlenses is the smallest, so that light enters the pixel from the plurality of directions. In this way, the intensity of light projected on the projection surface can be made uniform.

  In the projector according to the aspect of the invention, the plurality of light sources may include a light source having a light emitting unit that emits red light, a light source having a light emitting unit that emits green light, and a light source having a light emitting unit that emits blue light. Preferably there is.

  In the projector according to the present invention, since the light source is a light source having a light emitting unit that emits red light, green light, and blue light, a full-color image can be displayed on the projection surface.

  In the projector according to the aspect of the invention, the optical path conversion unit may include a red light reflecting unit that transmits green light and reflects red light, and a blue light reflecting unit that transmits green light and reflects blue light. Is preferred.

In the projector according to the present invention, since the optical path changing unit includes the red light reflecting portion that reflects the red light and the blue light reflecting portion that reflects the blue light, the red light and the blue light emitted in different directions are reflected by the red light. And the blue reflecting portion are reflected in the same direction. The green light passes through the red and blue reflecting portions and travels in the same direction as the red light and blue light. In this way, by providing the reflecting portion that reflects the red light and blue light that are separated from each other in the band, the three colors are emitted from the optical path conversion unit in a well-balanced manner, so that a clear image can be projected onto the projection surface. It becomes possible.
Further, when a cross dichroic prism is used as the optical path conversion means, a red light source, a green light source, and a blue light source can be arranged on three sides of the cross dichroic prism, so that the entire apparatus can be reduced in size.

  Embodiments of a projector according to the present invention will be described below 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]
FIG. 1 is a schematic configuration diagram of an overall configuration of a projector according to the present invention, FIG. 2 is a perspective view illustrating a configuration of a light source, and FIG. 3 is a diagram illustrating light of each color emitted from a cross dichroic prism. FIG. 4 is a diagram showing an optical path of light emitted from the red light source unit and incident on the liquid crystal light valve, and FIG. 5 is an explanation in which each light source unit, microlens array, and liquid crystal light valve are arranged linearly. FIG. 6 is a schematic diagram showing each pixel of the liquid crystal light valve. 4 and 5 are diagrams in which the cross dichroic prism is omitted for easy understanding of the positional relationship between the liquid crystal light valve and each light source unit. Although the light is condensed by the microlens, only the main optical axis of the light passing through the center of the microlens is shown in order to avoid making the figure complicated. Further, FIG. 5 shows only the main optical axis of the light emitted from the light emitting unit disposed in the center of the light source unit.

  As shown in FIG. 1, the projector 1 according to the present embodiment includes a plurality of light source units 10, a cross dichroic prism (light path conversion unit) 20, a microlens array 30, a liquid crystal light valve (light modulation unit) 40, and the like. And a projection lens (projection device) 50. The projection lens 50 is a lens that enlarges and projects the light emitted from the liquid crystal light valve 40 onto a screen (projected surface) 60.

As shown in FIG. 1, the light source unit 10 includes a red light source unit (light source) 10R having a plurality of light emitting units 11R that emits red light and a green light source unit (light source) 10G having a plurality of light emitting units 11G that emit green light. And a blue light source unit (light source) 10B having a plurality of light emitting units 11B that emit blue light.
In addition, as shown in FIG. 2, the red, green, and blue light source units 10R, 10G, and 10B have a plurality of light emitting units 11R, 11G, and 11B that emit light of the same wavelength (light of the same color) formed on the substrate 12. ing. The red, green, and blue light source units 10R, 10G, and 10B are a two-dimensional array of 9 rows and 5 columns, and both the vertical pitch P1a (P1) and the horizontal pitch P1b (P1) are 0.9 mm.

  The red, green, and blue light source units 10R, 10G, and 10B are substantially point light source arrays because they use semiconductor surface emitting laser arrays. Each of the light source units 10R, 10G, and 10B has an InGaAs active layer and an external resonator structure, the red light source unit 10R is 1260 nm, the green light source unit 10G is 1060 nm, and the blue light source unit 10B is oscillated near 920 nm. The light is output as visible light having a half wavelength, that is, center wavelengths of 630 nm, 530 nm, and 460 nm, using SHG (second harmonic generation element, SHG: Second Harmonic Generation, not shown) such as PPLN.

  As shown in FIG. 1, the cross dichroic prism 20 is formed by bonding four right-angle prisms, and has a dielectric multilayer film (red light reflecting portion) 20a that reflects red light and a dielectric that reflects blue light on its inner surface. The body multilayer film (blue light reflecting portion) 20b is arranged in a cross shape. Further, a red light source unit 10R, a green light source unit 10G, and a blue light source unit 10B are disposed on three sides of the cross dichroic prism 20. Specifically, the blue light source unit 10B is disposed on the upper end surface 20d side of the cross dichroic prism 20, the green light source unit 10G is disposed on the left end surface 20e side, and the red light source unit 10R is disposed on the lower end surface 20f side. Has been placed. The dielectric multilayer film 20a uses a low-pass filter having a cutoff of about 570 nm, and the dielectric multilayer film 20b uses a low-pass filter having a cutoff of about 500 nm. As a result, the optical path of the red light is bent 90 degrees by the dielectric multilayer film 20a, and the blue light is emitted from the exit end face 20c of the cross dichroic prism 20 with the optical path bent 90 degrees by the dielectric multilayer film 20b. Further, the green light is transmitted without being reflected by either of the dielectric multilayer films 20a and 20b of the cross dichroic prism 20, and is emitted from the emission end face 20c. That is, the cross dichroic prism 20 converts the optical paths so that the optical paths of the red light, the green light, and the blue light emitted from the red, green, and blue light source units 10R, 10G, and 10B are in the same direction. As described above, the light paths of the red light, the green light, and the blue light emitted from the three light source units 10R, 10G, and 10B can be efficiently converted into the same direction by the simple design of the dielectric multilayer films 20a and 20b. it can.

The liquid crystal light valve 40 is a transmission type liquid crystal panel using a high-temperature polysilicon TFT, has different wavelength selectivity, and can independently modulate each color light emitted from the emission end face 20a of the cross dichroic prism 20. A plurality of types of pixels are arranged in an array. Specifically, as shown in FIG. 5, the liquid crystal light valve 40 includes a plurality of red light pixels 40R on which red light emitted from the red light source unit 10R is incident and a green light emitted from the green light source unit 10G. A plurality of pixels 40G for green light on which light is incident and a plurality of pixels 40B for blue light on which blue light emitted from the blue light source unit 10B is incident. Each of the pixels 40R, 40G, and 40B is formed with an opening 40a of a black matrix (BM), and light condensed by the microlens array 30 enters from the opening 40a.
Further, the microlens array 30 is formed and disposed so as to be focused on the incident end face 40b of the opening 40a of the liquid crystal light valve 40.

As shown in FIG. 4, the micro lens array 30 includes a plurality of micro Fresnel lenses (micro lenses: diffractive lenses) 30a. Here, the light emitted from the red light source unit 10R will be described. As shown in FIG. 4, the red light emitted from the red light source unit 10 </ b> R is condensed toward the pixel 40 </ b> R of the liquid crystal light valve 40 by the microlens array 30. Similarly, the light emitted from the green light source unit 10G and the blue light source unit 10B is condensed by the microlens 30 onto the pixels 40G and 40B, respectively.
Further, since the micro Fresnel lens 30a has low aberration, high efficiency, and high NA (numerical aperture) performance, it can be suitably used in this embodiment. Furthermore, the chromatic aberration of the microlens array 30 is such that it does not significantly affect the image.

Each color light emitted from the exit end face 20c of the cross dichroic prism 20 has a central axis pitch Q1 of 0.3 mm as shown in FIG. That is, the red, green, and blue light source units 10R, 10G, and 10B are arranged so that the light emitting units 11R, 11G, and 11B are displaced in the in-plane direction. That is, as shown in FIG. 5, the light emitting units 11R, 11G, and 11B are arranged so that the pitch (corresponding to Q1) is a constant pattern of equal intervals of 0.3 mm. FIG. 5 is a diagram in which red, green, and blue light source units 10R, 10G, and 10B are arranged on the same optical axis.
It should be noted that the red, green, and blue light source units 10R, 10G, and 10B are not arranged to be shifted in the in-plane direction of the light emitting units 11R, 11G, and 11B, but the positions of the light emitting units 11R, 11G, and 11B are shifted on the substrate 12. The arrangement may be such that the end faces of the red, green, and blue light source portions 10R, 10G, and 10B are aligned.

As shown in FIG. 5, the optical distance (optical path length) L1 between the light source units 10R, 10G, and 10B and the microlens array 30 is 90 μm. The optical distance (optical path length) L2 between the microlens array 30 and the liquid crystal light valve 40 is 3 mm.
Furthermore, in this modification, when the pitch of the micro Fresnel lens 30a of the microlens array 30 is PL, PL = n {P1 · P2 / (P1 + P2)} (where n is a natural number) Equation 1 and L2 / L1 = P2 / P1 ... It is comprised so that the conditions of Formula 2 may be satisfied.

Here, if the value of n in Formula 1 is reduced and the pitch PL of the micro Fresnel lens 30a of the microlens array 30 is made too narrow, the diffracted light in the microlens array 30 increases too much, resulting in light loss and color mixing. Therefore, it is not preferable. Also, if the value of n is increased to make the pitch PL of the micro Fresnel lens 30a too wide, the number of times of diffracted light overlapping in the micro lens array 30 decreases, and the variation in the amount of light of each pixel 40R, 40G, 40B increases. This is not preferable. Therefore, in this modification, when n = 4, the pitch PL of the micro Fresnel lens 30a is about 116 μm according to Equation 1.
Further, since the pitch P1 of the light emitting portions 11R, 11G, and 11B is 0.9 mm and the pitch P2 of the pixels 40R, 40G, and 40B is 30 μm, Expression 2 is satisfied.

  Further, as shown in FIG. 6, each of the pixels 40R, 40G, and 40B has a rectangular shape and is arranged in a stripe shape, and the adjacent pixel pitch P2 for red light is 30 μm. A pitch between adjacent pixels (for example, a pitch between adjacent red pixel 40R and green pixel 40G) Q2 is 10 μm. That is, the ratio (30 μm / 10 μm) between the pixel pitch P2 for each color light and the pitch Q2 between adjacent pixels (30 μm / 10 μm) is the pitch between the horizontal pitch P1 of the light emitting units 11R, 11G, and 11B and the central axis of the adjacent color light (each light emission). It is substantially equal to the ratio (0.9 mm / 0.3 mm) to the pitch Q1 of the portions 11R, 11G, and 11B.

  In the projector 1 according to the present embodiment, a plurality of light emitting units 11R that emit red light are formed on the substrate 12, and similarly, a plurality of light emitting units 11G and 11B that emit green light and blue light are formed on the substrate 12. ing. That is, since the light emitting portions 11R, 11G, and 11B that emit light of the same wavelength are formed on one substrate 12, it is easy to form the plurality of light emitting portions 11R, 11G, and 11B on the same substrate 12. Thereby, a color image can be displayed by projecting each color light on the screen 60 using the liquid crystal light valve 40 at low cost. Furthermore, since the design of the light emitting units 11R, 11G, and 11B for each color light is the same, it is easy to form a constant pitch of the light emitting units 11R, 11G, and 11B that emit light of the same wavelength. Therefore, the design of the light emitting units 11R, 11G, and 11B is facilitated, so that the cost can be reduced.

Further, as compared with the case where a plurality of light emitting portions having different wavelengths are formed on one substrate 12 as in the prior art, the light source units 10R, 10G, and 10B used in the projector 1 of the present invention are formed on one substrate 12. Since the light emitting portions 11R, 11G, and 11B having the same wavelength are formed, the arrangement density of the light emitting portions 11R, 11G, and 11B can be reduced. Therefore, since the space | interval of light emission part 11R, 11G, 11B can be widened, the projector 1 which has light source part 10R, 10G, 10B with favorable heat dissipation can be provided.
Furthermore, it is effective when the chromatic aberration caused by the microlens array 30 does not affect the image displayed on the screen 60. That is, the microlens array 30 and the light source units 10R, 10G, and 10B are arranged so that the optical distances are the same, and the light source units 10R, 10G, and 10B and the liquid crystal light valve are satisfied so as to satisfy the above formulas 1 and 2. 40. Microlens array 30 is formed and placed.
Thereby, in this modification, by setting n = 4, it is possible to suppress the generation of light amount loss and color mixing and to superimpose the diffracted light emitted from the microlens array 30 so that the variation in the light amount is reduced. It becomes possible. Therefore, an image with reduced luminance unevenness can be displayed on the screen 60.
That is, the projector 1 of the present embodiment has a constant pitch between the light emitting units 11R, 11G, and 11B, and can sufficiently dissipate heat from the light emitting units 11R, 11G, and 11B while reducing costs.

[Modification of First Embodiment]
In the first embodiment shown in FIG. 1, the optical distance between the microlens array 30 and the light source units 10R, 10G, and 10B is the same, but may be changed for each color. In other words, when the chromatic aberration of the microlens array 30 affects the image, the optical distance (optical path length) L1 between the light source units 10R, 10G, and 10b and the microlens array 30 shown in FIG.

Since the microlens array 30 is a diffractive lens, the focal position differs depending on the wavelength of incident light. That is, among the incident red light, green light, and blue light, the focal length fr of the red light having the longest wavelength is the shortest, and the focal length becomes longer in the order of the focal length fg of the green light and the focal length fb of the blue light ( fr <fg <fb). As a result, the optical distance (optical path length) between the microlens array 30 and the red light source unit 10R is the shortest, and the microlens array 30 and the green light source unit 10G, and the microlens array 30 and the blue light source unit 10B become longer in this order. That is, the red light source unit 10R, the green light source unit 10G, and the blue light source unit 10B are arranged in this order from the microlens array 30 side.
When a refractive lens is used as the microlens array 30, the focal length fb of blue light is the longest, and the focal length fg of green light and the focal length fr of red light are shortened in this order (fb <fg <fr). Therefore, in this case, the blue light source unit 10B, the green light source unit 10G, and the red light source unit 10R are arranged in this order from the micro lens array 30 side.

  Therefore, in this configuration, since the focal position of the microlens array 30 changes depending on the wavelength of incident light, the light emitting portions 11R, 11G, and 11B having the same wavelength are formed on one substrate 12 as in the present embodiment. The distance between the light emitting units 11R, 11G, and 11B and the microlens array 30 can be adjusted to an optimum state.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIGS. In the drawings of the respective embodiments described below, portions having the same configuration as those of the projector 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
In the projector according to the present embodiment, the arrangement of the light emitting units 11R, 11G, and 11B and the arrangement of the pixels 40R, 40G, and 40B are the same as those of the first embodiment in other configurations that are different from the first embodiment.

The arrangement of the light emitting units 11R, 11G, and 11B of the light source units 10R, 10G, and 10B is a delta arrangement, and the arrangement of each color light emitted from the cross dichroic prism 20 is also a delta arrangement as shown in FIG. Further, since the light emitting portions 11R, 11G, and 11B have a two-dimensional array structure for all three colors, the vertical pitch P1a is 0.6 mm, and the horizontal pitch P1b is 0.9 mm, the light is emitted from the cross dichroic prism 20. As shown in FIG. 7, the vertical pitch and horizontal pitch of each color light are 0.6 mm for P1a and 0.9 mm for P1b.
The red, green, and blue light source units 10R, 10G, and 10B emit light so that the pitch Q1a of the central axes of adjacent color lights in the vertical direction and the pitch Q1b of the central axes of adjacent color lights in the horizontal direction are 0.3 mm. The portions 11R, 11G, and 11B are arranged so as to be shifted in the arrangement in-plane direction so that the intervals of the central axes of the light emitted adjacently are equal, that is, a constant pattern with equal intervals.

The arrangement of the pixels 40R, 40G, and 40B of the liquid crystal light valve 40 is also a delta arrangement as shown in FIG. The vertical pitch P2a of the pixels 40R, 40G, and 40B is 20 μm, and the pitch Q2a between the columns is 10 μm.
Further, the horizontal pitch P2b of the pixels 40R, 40G, and 40B is 30 μm, and the inter-row pitch Q2b is 10 μm. That is, the ratio (20 μm / 10 μm) between the pixel pitch P2a for each color light in the vertical direction and the pitch Q2a between the adjacent pixels 40R, 40G, 40B is equal to the vertical pitch P1a of the light emitting units 11R, 11G, 11B in the vertical direction. It is substantially equal to the ratio (0.6 mm / 0.3 mm) with the pitch Q1a of the central axes of adjacent color lights (pitch of each light emitting part 11R, 11G, 11B). Further, the ratio (30 μm / 10 μm) between the pixel pitch P2b for each color light in the horizontal direction and the pitch Q2b between the adjacent pixels 40R, 40G, 40B is equal to the vertical pitch P1b of the light emitting units 11R, 11G, 11B in the horizontal direction. It is substantially equal to the ratio (0.9 mm / 0.3 mm) to the pitch (the pitch between the light emitting portions 11R, 11G, and 11B) Q1b of adjacent color lights.
Further, in the present embodiment, when n = 4 is used, the pitch PL of the micro-Fresnel lens 30a in the lateral direction is about 116 μm according to Equation 1. On the other hand, the pitch PL of the longitudinal micro Fresnel lens 30a is about 77.4 μm.

In the projector according to the present invention, since the arrangement of the light emitting units 11R, 11G, and 11B and the arrangement of the pixels 40R, 40G, and 40B are in a delta arrangement, the pixels 40R, 40G, and 40B are striped as shown in the first embodiment. The regularity between the pixels 40R, 40G, and 40B is weaker than when arranged in a shape. Therefore, display unevenness and the like due to light interference are less likely to occur, and an image with uniform brightness can be displayed on the screen 60.
Since the image is inverted by the microlens array 30, the arrangement pattern of the pixels 40R, 40G, and 40B and the arrangement pattern of the light emitting units 11R, 11G, and 11B are inverted.

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 cross dichroic prism is used as the optical path changing means, the present invention is not limited to this. As the optical path changing means, for example, a dichroic mirror having a cross arrangement to combine color lights, or a dichroic mirror arranged in parallel to combine color lights can be used.
In the projectors of the above embodiments (including modifications), a light source unit that emits red light, green light, and blue light is used. However, light sources of four or more colors may be used.
Further, the light emitted from the light emitting unit does not have to be a point light source, and may be a patterned light source array close to the point light source. The light source is not limited to a laser, and an LED light source, an organic EL array, or the like can be used.
Further, although a transmissive liquid crystal panel is used as the light modulation means, DMD or LCOS may be used.

1 is a plan view showing a projector according to a first embodiment of the invention. It is a perspective view which shows the light source part of the projector of FIG. It is a figure which shows arrangement | positioning of each light inject | emitted from the optical path conversion means. It is a schematic diagram which shows the positional relationship with a red light source part, a micro lens array, and a light modulation means. It is a schematic diagram which shows a positional relationship with a red, green, blue light source part, a micro lens array, and a light modulation means. It is a schematic diagram which shows each pixel of a light modulation means. It is a figure which shows arrangement | positioning of each light inject | emitted from the optical path conversion means. It is a schematic diagram which shows each pixel of a light modulation means.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,70 ... Projector, 10R ... Red light source part (light source), 10G ... Green light source part (light source), 10B ... Blue light source part (light source), 11R, 11G, 11B ... Light emission part, 12 ... Board | substrate, 20 ... Cross dichroic Prism (optical path changing means), 20a ... dielectric multilayer film (red reflection part), 20b ... dielectric multilayer film (blue reflection part), 30 ... micro lens array, 30a ... micro Fresnel lens (micro lens), 40 ... liquid crystal Light valve (light modulation means), 40R, 40G, 40B ... pixel, 40a ... opening, 50 ... projection lens (projection device), 60 ... screen (projected surface)

Claims (9)

A plurality of light sources that respectively emit light of different colors;
Optical path conversion means for converting the optical paths of light emitted from the plurality of light sources in the same direction;
A light modulator having an array of a plurality of types of pixels capable of independently modulating light of different colors whose optical paths have been converted by the optical path converter;
A microlens array including a plurality of microlenses that transmit light emitted from the optical path changing unit to the light modulating unit;
A projection device for projecting the light modulated by the light modulation means onto the projection surface;
Each of the plurality of light sources has a plurality of light emitting portions that emit light of the same color formed on a substrate,
The microlens array condenses light of the same color emitted from the plurality of light emitting units at openings formed in pixels of the light modulation unit, and light of different colors emitted from the plurality of light sources A projector characterized in that light is condensed on different pixels of the light modulation means.   2. The projector according to claim 1, wherein pitches of central axes of adjacent light beams of different colors emitted from the optical path changing unit are substantially equal.   3. The projector according to claim 1, wherein the pitch of the light emitting units of each of the plurality of light sources is substantially equal, and the number of the light emitting units for each of the plurality of light sources is the same.   Pixels on which light of the same wavelength of the light modulation means is incident, the ratio of the pitch of the light emitting portions of each of the plurality of light sources to the pitch of the central axis of adjacent light of different colors emitted from the optical path changing means 4. The projector according to claim 1, wherein the projector is substantially equal to a ratio of a pitch of the adjacent pixel to a pitch of adjacent pixels. 5.   5. The optical distance between each of the plurality of light sources and the microlens array is different according to wavelengths of different colors of light emitted from the light sources. The projector according to item.   5. The projector according to claim 1, wherein an optical distance between each of the plurality of light sources and the microlens array is substantially equal. 6.   When the pitch of the plurality of light emitting units is P1, the pitch of the plurality of pixels is P2, the pitch of the microlens of the microlens array is PL, and the optical distance between each of the plurality of light sources and the microlens array is equal Where L1 is the optical distance and L2 is the optical distance between the microlens array and the light modulation means, PL = n {P1 · P2 / (P1 + P2)} (where n is a natural number) and L2 / The projector according to claim 6, wherein the projector is configured to satisfy a condition of L1 = P2 / P1.   The plurality of light sources are a light source having a light emitting part for emitting red light, a light source having a light emitting part for emitting green light, and a light source having a light emitting part for emitting blue light. The projector according to any one of claims 1 to 7.   9. The optical path conversion unit according to claim 8, further comprising: a red light reflecting portion that transmits green light and reflects red light; and a blue light reflecting portion that transmits green light and reflects blue light. The projector described.

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