Projector

Abstract

To prevent a reduction in the display quality of a projector due to a pinhole in a wire grid layer.SOLUTION: A projector P1 has: a first light source 1 that emits first light; a first light guide element 2 on which the first light emitted from the first light source 1 is incident; a first polarization optical system 4 on which the first light emitted from the first light guide element 2 is incident, and that transmits a first polarization component in the first light and blocks a second polarization component in the first light; a first light modulation element 5 that modulates the first polarization component emitted from the first polarization optical system 4 on the basis of image information; and a projection optical system 7 that projects the light emitted from the first light modulation element 5. The first polarization optical system 4 includes a first polarization element 41 on which the first light emitted from the first light guide element 2 is incident, and a second polarization element 42 on which light emitted from the first polarization element 41 is incident. The first polarization element 41 is an inorganic polarizing plate having a wire grid layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a projector.

Background Art

[0002] Patent Document 1 describes a projector that forms image light using a light modulation element and enlarges and projects it using a projection lens. A transparent block made of acrylic resin or the like and a condenser lens are arranged between the light source and the light modulation element. The light source is an LED and emits non-polarized light.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a projector, in order to make a specific polarization component of the non-polarized light emitted from the light source enter the light modulation element, a polarization element is arranged on the incident side of the light modulation element. As the polarization element, an inorganic polarizing plate such as a wire grid polarizer or an organic polarizing plate is used.

[0005] Organic polarizing plates are generally less expensive than inorganic polarizing plates, but have low light resistance and heat resistance. Therefore, when non-polarized light is incident, the amount of heat generated by absorbing the polarization components that do not pass through is large and it is likely to deteriorate, so the lifespan is short. Therefore, when non-polarized light emitted from the light source directly enters the polarizing plate, it is preferable to use an inorganic polarizing plate that has higher light resistance and heat resistance than an organic polarizing plate.

[0006] However, minute pinholes may be formed in the wire grid layer. If inorganic polarizing plates with pinholes are selected by inspection and excluded as defective products, the yield will decrease and the cost of the inorganic polarizing plates will increase. Since there is no polarization separation function in the portion with pinholes, when forming image light with a light modulation element, the pixels into which the light passing through the pinholes is incident will be displayed brightly even in black display. Therefore, in order to avoid an increase in cost, there is a problem that the display quality deteriorates when using an inorganic polarizing plate with pinholes without selection.

Means for Solving the Problems

[0007] In order to solve the above problems, the projector of the present invention includes a first light source that emits first light, a first incident end into which the first light emitted from the first light source is incident, and a first emission end that emits the first light. A first light guide element, a first polarization optical system into which the first light emitted from the first light guide element is incident, allowing a first polarization component of the first light to pass through and blocking a second polarization component of the first light, and a first polarization optical system. A first light modulation element that modulates the first polarization component emitted from the system based on image information, and a projection optical system that projects the light emitted from the first light modulation element. The first polarization optical system includes a first polarization element into which the first light emitted from the first light guide element is incident, and a second polarization element into which the light emitted from the first polarization element is incident. The first polarization element is an inorganic polarizing plate having a wire grid layer.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] With reference to the drawings below, a projector according to an embodiment of the present invention will be described.

[0010] (Embodiment 1) FIG. 1 is an explanatory diagram showing a main part of a projector P1 according to Embodiment 1. As shown in FIG. 1, the projector P1 projects image light onto a screen S. The projector P1 includes a first light source 1, a first light guide element 2, a first collimating element 3, a first polarization optical system 4, a first light modulation element 5, a first output-side polarization element 6, a projection optical system 7, and a control unit 8. In this embodiment, the first light source 1, the first light guide element 2, the first collimating element 3, the first polarization optical system 4, the first light modulation element 5, the first output-side polarization element 6, and the projection optical system 7 are arranged in this order along an axis L. Hereinafter, in this specification, the direction along the axis L is referred to as the axial direction.

[0011] The first light source 1 emits first light. The first light is unpolarized light. The first light source 1 is composed of, for example, an ultra-high pressure mercury lamp, an LED, a laser light source, etc. In this embodiment, the first light source 1 is an LED. As shown in FIG. 1, the first light source 1 includes an LED element 11 that emits first light and a substrate 12 on which the LED element 11 is arranged.

[0012] The first light guide element 2 equalizes the illuminance distribution of the first light incident from the first light source 1 and then emits it. The first light guide element 2 includes a first incident end 21 on which the first light emitted from the first light source 1 is incident and a first output end 22 that emits the first light. The first light guide element 2 reflects the first light incident from the first incident end 21 on the inner surface and emits it from the first output end 22.

[0013] The first light guide element 2 is, for example, a cylindrical reflector provided with openings at a first incident end 21 and a first emission end 22, respectively. The inner surface of the first light guide element 2 is a reflecting surface that reflects the first light. As shown in FIG. 1, the first emission end 22 of the first light guide element 2 has a larger opening area than the first incident end 21. The cross-sectional area when the first light guide element 2 is cut by a plane perpendicular to the axis L increases from the first incident end 21 toward the first emission end 22. The cross-sectional shape when the first light guide element 2 is cut by a plane perpendicular to the axis L is rectangular.

[0014] The first collimating element 3 collimates and emits the first light emitted from the first light guide element 2. As shown in FIG. 1, the first collimating element 3 is, for example, a convex lens. The first collimating element 3 collimates and emits a light beam that is emitted from the first light guide element 2 while expanding into a light beam parallel to the axis L. The first light emitted from the first light guide element 2 is collimated by the first collimating element 3 and enters the first polarization optical system 4. The first polarization optical system 4 emits the first polarization component of the first light emitted from the first light guide element 2 toward the first light modulation element 5 and blocks the second polarization component of the first light.

[0015] The first light modulation element 5 modulates the first polarization component emitted from the first polarization optical system 4 to generate image light. The first light modulation element 5 is, for example, a liquid crystal panel. The control unit 8 operates the first light modulation element 5 based on an image signal supplied from the outside, such as a video signal. The first light modulation element 5 has a rectangular arrangement area of effective pixels that form image light. The first light modulation element 5 is a small liquid crystal panel with the size of the arrangement area of the effective pixels being 24.95 mm × 44.35 mm or less.

[0016] As shown in FIG. 1, the projector P1 of this embodiment is a single-plate projector that generates image light using a single liquid crystal panel. The first light is light in a first wavelength band. For example, the first light is white light including red light, green light, and blue light. The first light modulation element 5 It includes pixels corresponding to the light. Thus, the first light modulation element 5 modulates the color light corresponding to each pixel to form full-color image light. Note that the first light may be light in a wavelength band different from white light.

[0017] The first output-side polarizing element 6 disposed on the output side of the first light modulation element 5 transmits the second polarization component included in the image light emitted from the first light modulation element 5. The first output-side polarizing element 6 is an organic polarizing plate. The projection optical system 7 enlarges the image light and projects it onto the screen S.

[0018] (First Polarization Optical System) The first polarization optical system 4 includes a first polarizing element 41 into which the first light emitted from the first light guide element 2 is incident, and a second polarizing element 42 into which the light emitted from the first polarizing element 41 is incident. The first polarizing element 41 and the second polarizing element 42 overlap when viewed from the direction in which the first light is incident. As shown in FIG. 1, the first light is incident on the first polarizing element 41 in the axial direction. The first polarizing element 41 and the second polarizing element 42 overlap when viewed from the axial direction.

[0019] Both the first polarizing element 41 and the second polarizing element 42 are rectangular. The first polarizing element 41 and the second polarizing element 42 have the same shape. Therefore, the dimension in the long side direction of the first polarizing element 41 is the same as the dimension in the long side direction of the second polarizing element 42. Also, the dimension in the short side direction of the first polarizing element 41 is equal to the dimension in the short side direction of the second polarizing element 42. The first polarizing element 41 and the second polarizing element 42 entirely overlap when viewed from the direction in which the first light is incident, that is, the axial direction.

[0020] The first polarizing element 41 allows the first polarization component of the first light emitted from the first light guide element 2 to pass through, and blocks the second polarization component of the first light. The first polarizing element 41 is an inorganic polarizing plate including a wire grid layer. For example, the first polarizing element 41 includes a light-transmissive base material such as glass and a wire grid layer made of a light-reflective metal formed on the surface of the base material. The wire grid layer is composed of metal wires arranged at equal intervals. The metal wires are formed by patterning using, for example, a photolithography method. In this embodiment, the metal forming the wire grid layer is aluminum. In this specification, "pass through" includes reflective and transmissive polarizing elements. Also, "block light" includes a polarizing element that separates light by reflecting some of the light and a polarizing element that separates light by absorbing some of the light. That is, what is described below is the first polarizing element 41 that passes through by transmitting the first polarization component and blocks light by reflecting the second polarization component. However, the first polarizing element 41 may be a polarization separation element that passes through by reflecting the first polarization component (in other words, makes the first polarization component incident on the second polarizing element by reflecting it). Alternatively, the first polarizing element 41 may be a polarization separation element that blocks light by absorbing the second polarization component.

[0021] In the first polarizing element 41, the extending direction of the slit provided in the wire grid layer is orthogonal to the vibration direction of the first polarization component. Thereby, the first polarizing element 41 passes through by transmitting the first polarization component. Also, in the first polarizing element 41, the extending direction of the slit provided in the wire grid layer coincides with the vibration direction of the second polarization component. Thereby, the first polarizing element 41 blocks light by reflecting the second polarization component. For example, one of the first polarization component and the second polarization component is p-polarized light, and the other is s-polarized light. Note that the first polarization component and the second polarization component may be polarization components different from p-polarized light and s-polarized light.

[0022] Of the first light incident on the first polarizing element 41, the second polarization component reflected by the first polarizing element 41 passes through the first collimating element 3 and is incident on the first emission end 22 of the first light guiding element 2. The first light guiding element 2 functions as a polarization conversion element that converts the second polarization component incident from the first emission end 22 into a first polarization component. In this embodiment, the first light guiding element 2 reflects the second polarization component incident from the first emission end 22 on the inner surface. The light reflected on the inner surface becomes light including the first polarization component and is emitted again from the first emission end 22. The first polarization component included in the light reflected on the inner surface is , passes through the first polarizing element 41 and is incident on the second polarizing element 42. The second polarization component included in the light reflected on the inner surface is reflected again by the first polarizing element 41, returns into the first light guiding element 2, and is reflected again on the inner surface. Thus, at least a part of the second polarization component of the first light incident on the first polarizing element 41 is converted into the first polarization component while repeating reflections between the first polarizing element 41 and the inner surface of the first light guiding element 2, and passes through the first polarizing element 41.

[0023] The first polarizing element 41 does not exclude those with pinholes in the wire grid layer by inspection during manufacturing. The pinhole portions do not have a polarization separation function. Therefore, when there are pinholes in the wire grid layer of the first polarizing element 41, the light incident on the second polarizing element 42 from the first polarizing element 41 includes the second polarization component that has passed through the pinholes. If the light shielding rate of the first polarizing element 41 with respect to the second polarization component is S, then 50% ≤ S ≤ 100%. Replacing this numerical range of the light shielding rate S with the numerical range of the transmittance Tc of the first polarizing element 41 with respect to the second polarization component means that 0% < Tc < 50%.

[0024] The second polarizing element 42 allows the first polarization component of the light incident from the first polarizing element 41 to pass through and shields the second polarization component of the light incident from the first polarizing element 41. Therefore, even when there are pinholes in the wire grid layer of the first polarizing element 41, the second polarization component of the first light incident on the pinholes is shielded by the second polarizing element 42. The first polarization optical system 4 emits the first polarization component that has passed through the second polarizing element 42 toward the first light modulation element 5.

[0025] In this embodiment, the second polarizing element 42 is an organic polarizing plate. The second polarizing element 42 transmits the first polarization component of the light incident from the first polarizing element 41 and absorbs the second polarization component of the light incident from the first polarizing element 41. The second polarizing element 42 is manufactured, for example, by adsorbing and aligning an iodine compound or an organic dye on a base material such as polyvinyl alcohol (PVA).

[0026] (Operation and effect of Embodiment 1) The projector P1 of Embodiment 1 includes a first light source 1 that emits first light, a first light guide element 2 that includes a first incident end 21 into which the first light emitted from the first light source 1 is incident and a first emission end 22 that emits the first light, a first polarization optical system 4 into which the first light emitted from the first light guide element 2 is incident, passes the first polarization component of the first light, and blocks the second polarization component of the first light, a first light modulation element 5 that modulates the first polarization component emitted from the first polarization optical system 4 based on image information, and a projection optical system 7 that projects the light emitted from the first light modulation element 5. The first polarization optical system 4 includes a first polarizing element 41 into which the first light emitted from the first light guide element 2 is incident and a second polarizing element 42 into which the light emitted from the first polarizing element 41 is incident. The first polarizing element 41 is an inorganic polarizing plate having a wire grid layer.

[0027] In Embodiment 1, on the incident side of the first light modulation element 5, an inorganic polarizing plate having a wire grid layer is used as the first polarizing element 41 into which the first light is incident. Since the inorganic polarizing plate has high light resistance and heat resistance, it is less likely to deteriorate even if the incident first light is unpolarized light. Further, since the second polarizing element 42 into which the light that has passed through the first polarizing element 41 is incident is provided, even if there is a pinhole in the wire grid layer of the first polarizing element 41, the first light incident on the pinhole is not directly emitted as it is, but is polarization-separated by the second polarizing element 42. Therefore, the first polarization optical system 4 can suppress a decrease in display quality due to the pinhole in the wire grid layer. In addition, since the first light does not directly enter the second polarizing element 42, it is less likely to deteriorate. Therefore, since both the first polarizing element 41 and the second polarizing element 42 are less likely to deteriorate, the lifespan can be improved.

[0028] In Embodiment 1, the first polarizing element 41 blocks the second polarization component by reflecting the second polarization component of the first light. The second polarization component reflected by the first polarizing element 41 enters the first emission end 22 of the first light guide element 2. The first light guide element 2 reflects the first light on the inner surface and emits it from the first emission end 22, and converts the second polarization component incident from the first emission end 22 into the first polarization component and emits it from the first emission end 22. In this way, since the first polarizing element 41 reflects without absorbing the second polarization component, heat generation of the first polarizing element 41 can be suppressed. Therefore, deterioration due to high temperature can be suppressed, and the lifespan can be improved. Furthermore, since the second polarization component of the first light is converted into the first polarization component and used for forming image light, the utilization efficiency of the light emitted from the first light source 1 can be increased.

[0029] In Embodiment 1, the second polarizing element 42 is an organic polarizing plate. Since the organic polarizing plate is generally inexpensive, the cost can be reduced as compared with the case of using an inorganic polarizing plate. In addition, by providing an absorption layer that absorbs the polarization component to be blocked, stray light can be suppressed. Furthermore, as described above, since the structure is such that the light polarized and separated by the inorganic polarizing plate is incident on the organic polarizing plate, deterioration of the organic polarizing plate can be suppressed, and the lifespan can be improved.

[0030] In Embodiment 1, assuming that the light shielding rate of the first polarizing element 41 with respect to the second polarization component is S, 50% ≤ S ≤ 100%. In this way, in the first polarization optical system 4, by not blocking a part of the second polarization component in the first polarizing element 41 and blocking it in the second polarizing element 42, the heat load can be dispersed. Thereby, deterioration of the first polarizing element 41 can be suppressed, and the lifespan can be improved.

[0031] The first optical modulation element 5 of Embodiment 1 is a liquid crystal panel with the size of the arrangement area of effective pixels being 24.95 mm × 44.35 mm or less. When the panel size of the liquid crystal panel is small, the projection magnification (projection size / panel size) becomes large, so the pinhole is enlarged and displayed. In Embodiment 1, a decrease in display quality due to the pinhole can be suppressed. Therefore, although the projector P1 has a small panel size, there is little adverse effect on the display quality due to the enlarged display of the pinhole. Also, when the panel size of the liquid crystal panel is small, the sizes of the polarizing plates arranged on the incident side and the exit side can be reduced. Therefore, costs can be reduced.

[0032] In Embodiment 1, when the first light guide element 2 is cut along a plane perpendicular to the direction in which the first light is incident, the cross-sectional shape is rectangular, and the first polarizing element 41, the second polarizing element 42, and the optical modulation element are rectangular. By making the cross-sectional shape of the first light guide element 2 rectangular in this way, the light incident from the first light source 1 can be emitted as rectangular light with a uniform illuminance distribution. Therefore, light can be emitted in accordance with the shapes of the optical elements after the first light guide element 2, so the light utilization efficiency can be increased. Also, by making the shapes of the respective optical elements rectangular, an increase in the size of each optical element can be suppressed.

[0033] In the first polarizing element 41 of Embodiment 1, the material of the wire grid layer is aluminum. By using aluminum, even when the wire grid layer is irradiated with the first light and becomes high in temperature, the heat dissipation property is high, so the temperature rise can be suppressed. Therefore, deterioration due to high temperature can be suppressed.

[0034] In the first polarization optical system 4 of Embodiment 1, both the first polarizing element 41 and the second polarizing element 42 are rectangular and have the same shape. When viewed from the direction in which the first light is incident on the first polarizing element 41, the first polarizing element 41 overlaps the second polarizing element 42. Since the shapes of the first polarizing element 41 and the second polarizing element 42 are such that neither one protrudes outside the other, the formation of dead space due to the protruding portion on the outside can be suppressed.

[0035] As a modification example of the first polarization optical system 4 in Embodiment 1, the following forms can be adopted.

[0036] (Modification Example 1) FIG. 2 is an explanatory diagram of the first polarization optical system 4A and the first optical modulation element 5 of Modification Example 1. In the first polarization optical system 4A, the light emitting surface of the second polarization element 42 is joined to the light incident surface of the first optical modulation element 5. Thereby, even if the light incident surface of the first optical modulation element 5 is not covered with an antireflection film, light equivalent to the light incident on the first optical modulation element 5 in the configuration of Embodiment 1 can be made incident on the first optical modulation element 5. Therefore, the antireflection film can be reduced without degrading the characteristics. Also, since there is no gap between the second polarization element 42 and the first optical modulation element 5, miniaturization can be achieved.

[0037] (Modification Example 2) FIG. 3 is an explanatory diagram of the first polarization optical system 4C of Modification Example 2. In the first polarization optical system 4C, the first polarization element 41 is fixed to one surface of the light transmissive substrate 43, and the second polarization element 42 is fixed to the other surface of the light transmissive substrate 43. By fixing the first polarization element 41 and the second polarization element 42 to the same substrate in this way, a plurality of polarization elements can be unitized. Therefore, miniaturization can be achieved. Also, the installation of the first polarization optical system 4C is easy.

[0038] (Modification Example 3) In the first polarization optical system 4, a configuration can be adopted in which a sealing layer that seals the wire grid layer is provided on the first polarization element 41, and the surface of the sealing layer is joined to the light incident surface of the second polarization element 42. By doing so, as in Modification Example 2, a plurality of polarization elements can be unitized. Therefore, miniaturization can be achieved. Also, the installation of the first polarization optical system 4 is easy.

[0039] (Modification Example 4) In the first polarization optical system 4, an inorganic polarizing plate can be used as the second polarizing element 42 instead of an organic polarizing plate. The inorganic polarizing plate may be an inorganic polarizing plate including a wire grid layer, or may be one including a dielectric multilayer film formed by laminating thin films of an inorganic dielectric. Note that the first emission-side polarizing element 6 may also be an inorganic polarizing plate. By disposing the second polarizing element 42 on the emission side of the first polarizing element 41, it is possible to suppress a decrease in display quality due to pinholes in the wire grid layer.

[0040] (Modification 5) The first light guide element 2 is not limited to a cylindrical reflector. For example, the first light guide element 2 may be a block made of a material that transmits light, and may be configured to reflect light incident from the first incident end 21 on the inner surface by providing a reflective layer that reflects light inward on the outer peripheral surface of the block.

[0041] (Embodiment 2) FIG. 4 is an explanatory diagram showing a main part of the projector P2 of Embodiment 2. As shown in FIG. 4, Embodiment 2 is a three-panel projector P2. The projector P2 collimates light from three light sources, separates specific polarization components, and causes the separated light to enter three light modulation elements, and then synthesizes and projects the three image lights. The projector P2 includes a first light source 1G, a first light guide element 2G, a first collimating element 3G, a first polarization optical system 4G, a first light modulation element 5G, and a first emission-side polarizing element 6G; a second light source 1R, a second light guide element 2R, a second collimating element 3R, a second polarization optical system 4R, a second light modulation element 5R, and a second emission-side polarizing element 6R; a third light source 1B, a third light guide element 2B, a third collimating element 3B, a third polarization optical system 4B, a third light modulation element 5B, and a third emission-side polarizing element 6B; a light synthesizing element 10; a projection optical system 7; and a control unit (not shown).

[0042] The first light source 1G emits first light. The second light source 1R emits second light different from the first light. The third light source 1B emits third light different from the first light and the second light. The first light, the second The first light, the second light, and the third light are unpolarized light. The first light is light in a first wavelength band. The second light is light in a second wavelength band. The third light is light in a third wavelength band. For example, the first light is green light. The wavelength band of green light is, for example, 500 nm to 600 nm. The second light is red light. The wavelength band of red light is, for example, 600 nm to 680 nm. The third light is blue light. The wavelength band of blue light is, for example, 420 nm to 500 nm.

[0043] The first light source 1G, the second light source 1R, and the third light source 1B are composed of an ultra-high pressure mercury lamp, an LED, a laser light source, etc., in the same manner as in Embodiment 1. In this embodiment, the first light source 1G, the second light source 1R, and the third light source 1B are all LEDs. Therefore, the first light source 1G, the second light source 1R, and the third light source 1B all emit unpolarized light.

[0044] The first light guide element 2G includes a first incident end 21G into which the first light emitted from the first light source 1G is incident, and a first emission end 22G that emits the first light. The second light guide element 2R includes a second incident end 21R into which the second light emitted from the second light source 1R is incident, and a second emission end 22R that emits the second light. The third light guide element 2B includes a third incident end 21B into which the third light emitted from the third light source 1B is incident, and a third emission end 22B that emits the third light.

[0045] The first polarization optical system 4G emits the first polarization component of the first light emitted from the first light guide element 2G toward the first light modulation element 5G, and emits the second polarization component of the first light. The second polarization optical system 4R emits the third polarization component of the second light emitted from the second light guide element 2R toward the second light modulation element 5R, and emits the fourth polarization component of the second light. The third polarization optical system 4B emits the fifth polarization component of the third light emitted from the third light guide element 2B toward the third light modulation element 5B, and emits the sixth polarization component of the third light.

[0046] The control unit (not shown) operates the first optical modulation element 5G, the second optical modulation element 5R, and the third optical modulation element 5B based on an external image signal such as a video signal. The first optical modulation element 5G modulates the first polarization component of the first light that has been polarization-separated by the first polarization optical system 4G to generate first image light in a first wavelength band. The second optical modulation element 5R modulates the third polarization component of the second light that has been polarization-separated by the second light guide element 2R to generate second image light in a second wavelength band. The third optical modulation element 5B modulates the fifth polarization component of the third light that has been polarization-separated by the third light guide element 2B to generate third image light in a third wavelength band.

[0047] The first image light, the second image light, and the third image light with different wavelength bands are such that the second polarization component of the first image light passes through the first output-side polarization element 6G, the fourth polarization component of the second image light passes through the second output-side polarization element 6R, and the sixth polarization component of the third image light passes through the third output-side polarization element 6B, and they enter the light combining element 10 from different directions. The light combining element 10 combines the image light incident from three directions and emits it toward the projection optical system 7. The projection optical system 7 enlarges the image light incident from the light combining element 10 and projects it onto the screen S.

[0048] (Polarization optical system) In Embodiment 2, each of the first polarization optical system 4G, the second polarization optical system 4R, and the third polarization optical system 4B includes an inorganic polarizing plate having a wire grid layer and an organic polarizing plate disposed on the output side of the inorganic polarizing plate, similar to the first polarization optical system 4 of Embodiment 1. Hereinafter, the configuration of each polarization optical system will be described.

[0049] The first polarization optical system 4G includes a first polarization element 41G into which the first light emitted from the first light guide element 2G is incident, and a second polarization element 42G into which the light emitted from the first polarization element 41G is incident. The first polarization element 41G allows the first polarization component of the first light emitted from the first light guide element 2G to pass through and blocks the second polarization component of the first light. The second polarization element 42G allows the first polarization component of the light incident from the first polarization element 41G to pass through and the light incident from the first polarization element 41G The second polarization component of the emitted light is blocked. The first polarization element 41G is an inorganic polarizing plate including a wire grid layer. The second polarization element 42G is an organic polarizing plate.

[0050] The second polarization optical system 4R includes a third polarization element 41R into which the second light emitted from the second light guide element 2R is incident, and a fourth polarization element 42R into which the light emitted from the third polarization element 41R is incident. The third polarization element 41R allows the third polarization component of the second light emitted from the second light guide element 2R to pass through, and blocks the fourth polarization component of the second light. The fourth polarization element 42R allows the third polarization component of the light incident from the third polarization element 41R to pass through, and blocks the fourth polarization component of the light incident from the third polarization element 41R. The third polarization element 41R is an inorganic polarizing plate including a wire grid layer. The fourth polarization element 42R is an organic polarizing plate.

[0051] The third polarization optical system 4B includes a fifth polarization element 41B into which the third light emitted from the third light guide element 2B is incident, and a sixth polarization element 42B into which the light emitted from the fifth polarization element 41B is incident. The fifth polarization element 41B allows the fifth polarization component of the third light emitted from the third light guide element 2B to pass through, and blocks the sixth polarization component of the third light. The sixth polarization element 42B allows the fifth polarization component of the light incident from the fifth polarization element 41B to pass through, and blocks the sixth polarization component of the light incident from the fifth polarization element 41B. The fifth polarization element 41B is an inorganic polarizing plate including a wire grid layer. The sixth polarization element 42B is, for example, an organic polarizing plate.

[0052] In this embodiment, the first polarization component, the third polarization component, and the fifth polarization component are polarization components having the same vibration direction, and the second polarization component, the fourth polarization component, and the sixth polarization component are polarization components having the same vibration direction. For example, each of the first polarization optical system 4G, the second polarization optical system 4R, and the third polarization optical system 4B allows one of p-polarized light and s-polarized light to pass through and blocks the other. The first polarization component, the third polarization component, and the fifth polarization component are one of p-polarized light and s-polarized light. The second polarization component, the fourth polarization component, and the sixth polarization component are the other of p-polarized light and s-polarized light.

[0053] Note that the first polarization component, the third polarization component, and the fifth polarization component are not limited to those that transmit one of p-polarization and s-polarization and block the other. Also, the first polarization component, the third polarization component, and the fifth polarization component may be different polarization components respectively. Similarly, the second polarization component, the fourth polarization component, and the sixth polarization component may be different polarization components respectively.

[0054] (Operation and Effect of Embodiment 2) The projector P2 of Embodiment 2 includes a first light source 1G that emits first light, a first light guide element 2G that includes a first incident end 21G where the first light emitted from the first light source 1G is incident and a first emission end 22G that emits the first light, a first polarization optical system 4G where the first light emitted from the first light guide element 2G is incident, which passes the first polarization component of the first light and blocks the second polarization component of the first light, a first light modulation element 5G that modulates the first polarization component emitted from the first polarization optical system 4G based on image information, and a projection optical system 7 that projects the light emitted from the first light modulation element 5G. The first polarization optical system 4G includes a first polarizing element 41G where the first light emitted from the first light guide element 2G is incident, and a second polarizing element 42G where the light emitted from the first polarizing element 41G is incident. The first polarizing element 41G is an inorganic polarizing plate having a wire grid layer.

[0055] In addition to the above, the projector P2 of Embodiment 2 includes a second light source 1R that emits second light, a third light source 1B that emits third light, a second light guide element 2R that includes a second incident end 21R where the second light emitted from the second light source 1R is incident and a second emission end 22R that emits the second light, a third light guide element 2B that includes a third incident end 21B where the third light emitted from the third light source 1B is incident and a third emission end 22B that emits the third light, a second polarization optical system 4R where the second light emitted from the second light guide element 2R is incident, which passes the third polarization component of the second light and blocks the fourth polarization component of the second light, and the third light emitted from the third light guide element 2B is incident, and among the third light A third polarization optical system 4B that allows the fifth polarization component to pass through and blocks the sixth polarization component of the third light, a second light modulation element 5R that modulates the third polarization component emitted from the second polarization optical system 4R based on image information, a third light modulation element 5B that modulates the fifth polarization component emitted from the third polarization optical system 4B based on image information, and a light combining element 10 that combines the light emitted from the first light modulation element 5G, the light emitted from the second light modulation element 5R, and the light emitted from the third light modulation element 5B.

[0056] In Embodiment 2, the first polarization optical system 4G, the second polarization optical system 4R, and the second polarization optical system 4B are all configured in the same manner as the first polarization optical system 4 in Embodiment 1. Therefore, a three-panel projector P2 that suppresses a decrease in display quality due to pinholes in the wire grid layer can be realized. In addition, since the plurality of polarization elements provided in each polarization optical system are all less likely to deteriorate, the lifespan can be improved.

[0057] (Modification example) Among the first polarization optical system 4G, the second polarization optical system 4R, and the second polarization optical system 4B, at least the first polarization optical system 4G includes an inorganic polarizing plate having a wire grid layer and an organic polarizing plate disposed on the emission side of the inorganic polarizing plate, and the others can be composed of only the inorganic polarizing plate or only the organic polarizing plate.

[0058] In this case, it is preferable that the first light is green light as described above. Since green light has the highest relative visibility among the three color lights of red light, green light, and blue light, the decrease in display quality due to pinholes is the largest for green light. Therefore, by disposing an inorganic polarizing plate having a wire grid layer and an organic polarizing plate disposed on the emission side of the inorganic polarizing plate on the incident side of the light modulation element that forms the image light of green light, the decrease in display quality can be effectively suppressed.

[0059] Alternatively, a configuration may be adopted in which the first light is blue light, the second light is green light, and the third light is red light. Since blue light has the shortest wavelength among the three color lights of red light, green light, and blue light, it has a great impact on the lifespan of the polarizing element. Therefore, by disposing an inorganic polarizing plate having a wire grid layer on the incident side of the light modulation element that forms the image light of blue light, and an organic polarizing plate disposed on the emission side of the inorganic polarizing plate, it is possible to effectively suppress the decrease in lifespan.

[0060] (Summary of the present disclosure) The summary of the present disclosure is appended below.

[0061] (Appendix 1) A first light source that emits first light, A first light guide element including a first incident end where the first light emitted from the first light source is incident and a first emission end where the first light is emitted, A first polarization optical system where the first light emitted from the first light guide element is incident, allowing a first polarization component of the first light to pass through and blocking a second polarization component of the first light, A first light modulation element that modulates the first polarization component emitted from the first polarization optical system based on image information, A projection optical system that projects the light emitted from the first light modulation element, and having, The first polarization optical system is, A first polarizing element where the first light emitted from the first light guide element is incident, A second polarizing element where the light emitted from the first polarizing element is incident, and comprising, The first polarizing element is an inorganic polarizing plate having a wire grid layer, and a projector characterized thereby.

[0062] According to Appendix 1, while suppressing the deterioration of display quality due to pinholes in the wire grid layer Moreover, the lifespan of the polarization element can be extended. That is, since the first polarization element into which light from the light source is incident is an inorganic polarizing plate having a wire grid layer, it is less likely to deteriorate. Also, since a second polarization element is added on the emission side of the inorganic polarizing plate, even if there are pinholes in the wire grid layer of the first polarization element, a decrease in display quality can be suppressed. Furthermore, since the light incident on the second polarization element is the light that has passed through the inorganic polarizing plate, the second polarization element is less likely to deteriorate.

[0063] (Appendix 2) A second light source that emits second light, A third light source that emits third light, A second light guide element including a second incident end on which the second light emitted from the second light source is incident and a second emission end that emits the second light, A third light guide element including a third incident end on which the third light emitted from the third light source is incident and a third emission end that emits the third light, A second polarization optical system that receives the second light emitted from the second light guide element, allows a third polarization component of the second light to pass through, and blocks a fourth polarization component of the second light, A third polarization optical system that receives the third light emitted from the third light guide element, allows a fifth polarization component of the third light to pass through, and blocks a sixth polarization component of the third light, A second light modulation element that modulates the third polarization component emitted from the second polarization optical system based on image information, A third light modulation element that modulates the fifth polarization component emitted from the third polarization optical system based on image information, The projector according to Appendix 1, further comprising a light combining element that combines the light emitted from the first light modulation element, the light emitted from the second light modulation element, and the light emitted from the third light modulation element.

[0064] According to Appendix 2, it is possible to realize a three-panel projector that suppresses a decrease in display quality due to pinholes in the wire grid layer and extends the lifespan of the polarization element.

[0065] (Appendix 3) The first polarizing element blocks the second polarization component by reflecting the second polarization component among the first light. The second polarization component reflected by the first polarizing element enters the first emission end of the first light guide element. The first light guide element reflects the first light incident from the first incident end on the inner surface and emits it from the first emission end, and converts the second polarization component incident from the first emission end into the first polarization component and emits it from the first emission end. The projector according to Appendix 1 or 2, characterized in that.

[0066] According to Appendix 3, the second polarization component can be reflected to suppress heat generation by absorption. Therefore, deterioration of the first polarizing element can be suppressed, and the life can be improved. In addition, since the reflected second polarization component can be reused, the light utilization efficiency can be increased.

[0067] (Appendix 4) The projector according to any one of Appendices 1 to 3, characterized in that the second polarizing element is an organic polarizing plate.

[0068] According to Appendix 4, since the second polarization component can be absorbed by the organic polarizing plate, stray light due to reflection can be suppressed.

[0069] (Appendix 5) The projector according to any one of Appendices 1 to 3, characterized in that the second polarizing element is an inorganic polarizing plate.

[0070] According to Appendix 5, a structure in which inorganic polarizing plates are stacked is formed, and a decrease in display quality due to pinholes in the wire grid layer can be suppressed.

[0071] (Appendix 6) The projector according to Appendix 4, characterized in that the light emitting surface of the second polarizing element is joined to the light incident surface of the first light modulation element.

[0072] According to Supplementary Note 6, it is not necessary to provide an antireflection film on the light incident surface of the first optical modulation element 5. Therefore, the antireflection film can be reduced without degrading the characteristics.

[0073] (Supplementary Note 7) The projector according to any one of Supplementary Notes 1 to 6, wherein when the light shielding rate of the first polarizing element with respect to the second polarization component is S, 50% ≤ S ≤ 100%.

[0074] According to Supplementary Note 7, a part of the second polarization component is incident on the second polarizing element and shielded. Therefore, the heat load associated with the shielding of the second polarization component can be dispersed between the first polarizing element and the second polarizing element.

[0075] (Supplementary Note 8) The projector according to any one of Supplementary Notes 1 to 7, wherein the first optical modulation element is a liquid crystal panel having an effective pixel arrangement area with a size of 24.95 mm × 44.35 mm or less.

[0076] According to Supplementary Note 8, a projector can be realized in which even if the panel size is small, the adverse effect on the display quality due to the enlarged display of pinholes is small. In addition, the size of the polarizing elements arranged on the incident side and the exit side of the liquid crystal panel can be reduced. Therefore, the cost can be reduced.

[0077] (Supplementary Note 9) The projector according to any one of Supplementary Notes 1 to 8, wherein the first polarizing element is fixed to one surface of the light-transmissive substrate, and the second polarizing element is fixed to the other surface of the light-transmissive substrate.

[0078] According to Supplementary Note 9, a plurality of polarizing elements can be unitized. Therefore, miniaturization can be achieved. In addition, the installation of the first polarization optical system becomes easy due to the unitization.

[0079] (Supplementary Note 10) The projector according to Supplementary Note 2, wherein the first light is green light, the second light is red light, and the third light is blue light.

[0080] According to Supplementary Note 10, a first polarization optical system capable of suppressing a decrease in display quality due to pinholes in the wire grid layer can be applied to an optical system that forms image light using green light with high specific sensitivity. Therefore, a decrease in display quality can be effectively suppressed.

[0081] (Supplementary Note 11) The projector according to Supplementary Note 2, wherein the first light is blue light, the second light is green light, and the third light is red light.

[0082] According to Supplementary Note 11, a first polarization optical system in which an inorganic polarizing plate with high heat resistance and light resistance is arranged as the first one can be applied to an optical system that forms image light using blue light with a short wavelength. Therefore, a decrease in the life of the polarization element can be suppressed.

[0083] (Supplementary Note 12) When the first light guide element is cut along a plane perpendicular to the direction in which the first light is incident, the cross-sectional shape is rectangular. The projector according to any one of Supplementary Notes 1 to 11, wherein the first polarization element, the second polarization element, and the light modulation element are rectangular.

[0084] According to Supplementary Note 12, rectangular illumination light with a uniform illuminance distribution can be generated. In addition, since the shapes of the optical elements after the first light guide element are in shapes matching the shape of the illumination light, an increase in the size of the optical elements can be suppressed.

[0085] (Supplementary Note 13) The projector according to any one of Supplementary Notes 1 to 12, wherein the material of the wire grid layer is aluminum.

[0086] According to Supplementary Note 13, even when the wire grid layer is irradiated with the first light and becomes high in temperature, the heat dissipation effect is high. Therefore, deterioration of the first polarization element due to high temperature can be suppressed.

[0087] (Supplementary Note 14) Both the first polarizing element and the second polarizing element are rectangular, the dimension in the long side direction of the first polarizing element is equal to the dimension in the long side direction of the second polarizing element, the dimension in the short side direction of the first polarizing element is equal to the dimension in the short side direction of the second polarizing element, The projector according to any one of Appendices 1 to 13, wherein when viewed from the direction in which the first light is incident on the first polarizing element, the first polarizing element overlaps the second polarizing element.

[0088] According to Appendix 14, neither the first polarizing element nor the second polarizing element protrudes outward beyond the other. Therefore, the formation of a dead space due to the protruding portion can be suppressed.

Explanation of Signs

[0089] 1, 1G... First light source, 1R... Second light source, 1B... Third light source, 2, 2G... First light guide element, 2R... Second light guide element, 2B... Third light guide element, 3, 3G... First collimating element, 3R... Second collimating element, 3B... Third collimating element, 4, 4A, 4C, 4G... First polarization optical system, 4R... Second polarization optical system, 4B... Third polarization optical system, 5, 5G... First light modulation element, 5R... Second light modulation element, 5B... Third light modulation element, 6, 6G... First output-side polarizing element, 6R... Second output-side polarizing element, 6B... Third output-side polarizing element, 7... Projection optical system, 8... Control unit, 10... Light combining element, 11... LED element, 12... Substrate, 21, 21G... First incident end, 21R... Second incident end, 21B... Third incident end, 22, 22G... First emission end, 22R... Second emission end, 22B... Third emission end, 41, 41G... First polarizing element, 41R... Third polarizing element, 41B... Fifth polarizing element, 42, 42G... Second polarizing element, 42R... Fourth polarizing element, 42B... Sixth polarizing element, 43... Translucent substrate, L... Axis, P1, P2... Projector, S... Screen.

Claims

1. a first light source that emits first light; a first light guide element including a first incident end on which the first light emitted from the first light source is incident and a first emission end that emits the first light; a first polarization optical system on which the first light emitted from the first light guide element is incident, that passes a first polarization component of the first light, and that blocks a second polarization component of the first light; a first light modulation element that modulates the first polarization component emitted from the first polarization optical system based on image information; a projection optical system that projects the light emitted from the first light modulation element, and having: wherein the first polarization optical system includes a first polarization element on which the first light emitted from the first light guide element is incident; and a second polarization element on which the light emitted from the first polarization element is incident, wherein the first polarization element is an inorganic polarizing plate having a wire grid layer, a projector characterized in that.

2. a second light source that emits second light; a third light source that emits third light; a second light guide element including a second incident end on which the second light emitted from the second light source is incident and a second emission end that emits the second light; a third light guide element including a third incident end on which the third light emitted from the third light source is incident and a third emission end that emits the third light; a second polarization optical system on which the second light emitted from the second light guide element is incident, that passes a third polarization component of the second light, and that blocks a fourth polarization component of the second light; a third polarization optical system on which the third light emitted from the third light guide element is incident, that passes a fifth polarization component of the third light, and that blocks a sixth polarization component of the third light; a second light modulation element that modulates the third polarization component emitted from the second polarization optical system based on image information; a third light modulation element that modulates the fifth polarization component emitted from the third polarization optical system based on image information; and a light combining element that combines the light emitted from the first light modulation element, the light emitted from the second light modulation element, and the light emitted from the third light modulation element, the projector according to claim 1, further comprising.

3. the first polarization element blocks the second polarization component by reflecting the second polarization component of the first light; the second polarization component reflected by the first polarization element is incident on the first emission end of the first light guide element, The first light guide element reflects the first light incident from the first incident end on its inner surface and emits it from the first emission end, and converts the second polarization component incident from the first emission end into the first polarization component and emits it from the first emission end. The projector according to claim 1, characterized in that.

4. The projector according to any one of claims 1 to 3, characterized in that the second polarization element is an organic polarizing plate.

5. The projector according to any one of claims 1 to 3, characterized in that the second polarization element is an inorganic polarizing plate.

6. The light emitting surface of the second polarization element is joined to the light incident surface of the first light modulation element The projector according to claim 4, characterized in that.

7. The projector according to claim 1, characterized in that when the light shielding rate of the first polarization element with respect to the second polarization component is S, 50% ≦ S ≦ 100%.

8. The projector according to claim 1, characterized in that the first light modulation element is a liquid crystal panel in which the size of the arrangement region of effective pixels is 24.95 mm × 44.35 mm or less.

9. The projector according to claim 1, characterized in that the first polarization element is fixed to one surface of the light transmissive substrate, and the second polarization element is fixed to the other surface of the light transmissive substrate.

10. The projector according to claim 2, characterized in that the first light is green light, the second light is red light, and the third light is blue light.

11. The projector according to claim 2, characterized in that the first light is blue light, the second light is green light, and the third light is red light.

12. When the first light guide element is cut along a plane perpendicular to the direction in which the first light is incident, the cross-sectional shape is a rectangle, The projector according to claim 1, characterized in that the first polarization element, the second polarization element, and the light modulation element are rectangular.

13. The projector according to claim 1, characterized in that the material of the wire grid layer is aluminum.

14. Both the first polarization element and the second polarization element are rectangular, The dimension in the long side direction of the first polarization element is equal to the dimension in the long side direction of the second polarization element, The dimension in the short side direction of the first polarization element is equal to the dimension in the short side direction of the second polarization element, The projector according to claim 1, wherein when viewed from the direction in which the first light is incident on the first polarizing element, the first polarizing element overlaps the second polarizing element.

Images