JP4492067B2 - projector - Google Patents

Description

  The present invention relates to a spatial light modulation device and a projector, and more particularly to a liquid crystal type spatial light modulation device.

  As an image display device, a dot matrix image display device such as a liquid crystal panel (liquid crystal display device), a CRT display device, or a plasma display device is often used. The dot matrix image display device expresses an image by a large number of pixels arranged two-dimensionally and periodically. At this time, a so-called sampling noise is generated due to the periodic arrangement structure, and a phenomenon in which the image quality is deteriorated (the image looks rough) is observed. And the method of reducing the phenomenon in which an image quality deteriorates is proposed (for example, refer patent document 1).

JP-A-8-122709

  In the dot matrix image display device, a light blocking portion called a black matrix is provided in a region between pixels in order to reduce unnecessary light. In recent years, as a usage mode of an image display device, a large screen is often observed from a relatively short distance. For this reason, the observer may recognize the black matrix image. As described above, the conventional dot matrix image display device has a problem that the image quality is deteriorated due to the black matrix image, such as an image with less smoothness or an image having roughness. In the above-mentioned Patent Document 1, it is difficult to reduce image quality degradation caused by a black matrix image.

  The present invention has been made to solve the above-described problems, and is a space that allows an observer to easily manufacture and obtain smooth image quality without recognizing an image of a light-shielding portion such as a black matrix. An object is to provide a light modulation device and a projector.

  In order to solve the above-described problems and achieve the object, the first invention is a spatial light modulation device having a modulation unit that modulates incident light according to an image signal and emits the light, and the modulation unit is a matrix. A strip having a plurality of pixel portions arranged in a shape and a light shielding portion provided between the plurality of pixel portions, provided on the emission side of the modulation portion, and refracting light from the modulation portion And a flat surface that transmits or reflects light from the modulation unit, the refraction unit has an inclined surface that is inclined along the longitudinal direction of the strip, and the refraction surface is from the refraction unit. A space characterized by having an orientation of a refracting surface that guides a projection image of a pixel portion onto a projection image of a light shielding portion and an angle formed by the refracting surface and a flat surface on a projection surface that is separated by a predetermined distance. An optical modulation device can be provided.

  Thereby, the light from one pixel part enters the refracting part. The light incident on the refracting portion is refracted by the refracting surface of the refracting portion and the optical path is bent in a predetermined direction. At this time, the direction in which the optical path is bent and its size (refraction angle) can be controlled according to the direction of the refracting surface and the angle between the flat surface and the refracting surface (hereinafter referred to as “tilt angle”). . In the present invention, the projection image of the pixel portion formed by the refracted light is guided onto the projection image of the light shielding portion on the projection surface that is separated from the refracting portion by a predetermined distance. As a result, a projection image of the pixel portion is formed in a superimposed manner on the projection image region of the light shielding portion on the projection plane that is separated from the refracting portion by a predetermined distance. Therefore, on the projection surface, it is possible to observe a smooth image with a reduced feeling of roughness without the observer recognizing the light shielding portion. The refracting surface is inclined along the longitudinal direction of the strip. For this reason, even when the inclination angle of the refracting surface is small, the height (depth) of the refracting portion can be sufficiently obtained at the end of the refracting portion. As a result, the refracting part can be easily manufactured.

  Further, according to a preferred aspect of the present invention, the refracting portion is in a first inclined surface that is inclined in the first direction along the strip-shaped longitudinal direction, and in a second direction opposite to the first direction. It is desirable to have an inclined second inclined surface. Thereby, the projected image of the pixel portion can be formed in two directions, the first direction and the second direction.

  Moreover, according to a preferable aspect of the present invention, it is desirable to provide two refracting portions each having a first inclined surface and a second inclined surface in a substantially orthogonal direction. Thereby, the projection image of a pixel part can be formed along two directions substantially orthogonal.

  According to a preferred aspect of the present invention, the unit area determined by the numerical aperture of the illumination optical system that supplies incident light to the modulation unit and the numerical aperture of the projection optical system that receives the modulated emission light from the modulation unit The ratio of the area of the flat surface to the area of the refracting surface is preferably proportional to the light intensity of the projected image of the pixel portion. Thereby, all the light emitted from the area within the unit area of the spatial light modulator is projected by the projection optical system. Then, by controlling the ratio of the area of the flat surface and the area of the refracting surface within the unit area, the amount of light transmitted or reflected through the flat surface and the amount of light refracted by the refracting surface is set to a desired value. Can do. Thereby, a projection image with uniform brightness can be obtained without recognizing an image of a light shielding part such as a black matrix on the projection surface.

  According to a second aspect of the invention, the projector includes: a light source that supplies light; the spatial light modulation device described above; and a projection optical system that projects light from the spatial light modulation device. Can provide. Thereby, in the image projected on the screen, the projection image of the pixel portion is formed so as to be superimposed on the region of the projection image of the light shielding portion. Therefore, on the screen, it is possible to observe a smooth image with a reduced feeling of roughness without the observer recognizing the image of the light shielding portion.

  Embodiments of a spatial light modulation device and a projector according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this Example.

(Explanation of the entire projector)
First, a schematic configuration of a projector according to Embodiment 1 of the present invention will be described with reference to FIG. Next, a characteristic configuration of the present embodiment will be described with reference to FIG. First, in FIG. 1, an ultra-high pressure mercury lamp 101 as a light source unit includes red light (hereinafter referred to as “R light”) as first color light and green light (hereinafter referred to as “G light”) as second color light. And blue light (hereinafter referred to as “B light”) which is the third color light. The integrator 104 uniformizes the illuminance distribution of the light from the ultrahigh pressure mercury lamp 101. The light whose illuminance distribution is made uniform is converted into polarized light having a specific vibration direction, for example, s-polarized light by the polarization conversion element 105. The light converted into the s-polarized light is incident on the R light transmitting dichroic mirror 106R constituting the color separation optical system. Hereinafter, the R light will be described. The R light transmitting dichroic mirror 106R transmits R light and reflects G light and B light. The R light transmitted through the R light transmitting dichroic mirror 106R is incident on the reflection mirror 107. The reflection mirror 107 bends the optical path of the R light by 90 degrees. The R light whose optical path is bent enters the spatial light modulator for first color light 110R that modulates the R light as the first color light according to the image signal. The spatial light modulator for first color light 110R is a transmissive liquid crystal display device that modulates R light according to an image signal. Since the polarization direction of the light does not change even if it passes through the dichroic mirror, the R light incident on the first color light spatial light modulator 110R remains as s-polarized light.

  The first color light spatial light modulator 110R includes a λ / 2 phase difference plate 123R, a glass plate 124R, a first polarizing plate 121R, a liquid crystal panel 120R, and a second polarizing plate 122R. The detailed configuration of the liquid crystal panel 120R will be described later. The λ / 2 phase difference plate 123R and the first polarizing plate 121R are arranged in contact with a light-transmitting glass plate 124R that does not change the polarization direction. Thereby, the problem that the first polarizing plate 121R and the λ / 2 phase difference plate 123R are distorted by heat generation can be avoided. In FIG. 1, the second polarizing plate 122R is provided independently. However, the second polarizing plate 122R may be disposed in contact with the exit surface of the liquid crystal panel 120R or the entrance surface of the cross dichroic prism 112.

  The s-polarized light incident on the first color light spatial light modulator 110R is converted into p-polarized light by the λ / 2 phase difference plate 123R. The R light converted into p-polarized light passes through the glass plate 124R and the first polarizing plate 121R as it is and enters the liquid crystal panel 120R. The p-polarized light incident on the liquid crystal panel 120R is converted into s-polarized light by modulation according to the image signal. The R light converted into s-polarized light by the modulation of the liquid crystal panel 120R is emitted from the second polarizing plate 122R. In this way, the R light modulated by the first color light spatial light modulator 110R is incident on the cross dichroic prism 112 which is a color synthesis optical system.

  Next, the G light will be described. The light paths of the G light and the B light reflected by the R light transmitting dichroic mirror 106R are bent by 90 degrees. The G light and the B light whose optical paths are bent enter the B light transmitting dichroic mirror 106G. The B light transmitting dichroic mirror 106G reflects the G light and transmits the B light. The G light reflected by the B light transmitting dichroic mirror 106G is incident on the second color light spatial light modulator 110G that modulates the G light, which is the second color light, according to the image signal. The spatial light modulator for second color light 110G is a transmissive liquid crystal display device that modulates G light according to an image signal. The second color light spatial light modulator 110G includes a liquid crystal panel 120G, a first polarizing plate 121G, and a second polarizing plate 122G. Details of the liquid crystal panel 120G will be described later.

  The G light incident on the second color light spatial light modulator 110G is converted into s-polarized light. The s-polarized light incident on the second color light spatial light modulator 110G passes through the first polarizing plate 121G as it is and enters the liquid crystal panel 120G. The s-polarized light incident on the liquid crystal panel 120G is converted into p-polarized light by modulation according to the image signal. The G light converted into p-polarized light by the modulation of the liquid crystal panel 120G is emitted from the second polarizing plate 122G. Thus, the G light modulated by the second color light spatial light modulator 110G enters the cross dichroic prism 112, which is a color synthesis optical system.

  Next, the B light will be described. The B light transmitted through the B light transmitting dichroic mirror 106G passes through the two relay lenses 108 and the two reflection mirrors 107, and the third light that modulates the B light as the third color light in accordance with the image signal. The light enters the color light spatial light modulator 110B. The spatial light modulator for third color light 110B is a transmissive liquid crystal display device that modulates B light according to an image signal.

  The reason why the B light passes through the relay lens 108 is that the optical path length of the B light is longer than the optical path lengths of the R light and the G light. By using the relay lens 108, it is possible to guide the B light transmitted through the B light transmitting dichroic mirror 106G directly to the third color light spatial light modulator 110B. The spatial light modulator for third color light 110B includes a λ / 2 phase difference plate 123B, a glass plate 124B, a first polarizing plate 121B, a liquid crystal panel 120B, and a second polarizing plate 122B. Note that the configuration of the spatial light modulation device 110B for the third color light is the same as the configuration of the spatial light modulation device 110R for the first color light described above, and thus detailed description thereof is omitted.

  The B light incident on the spatial light modulator for third color light 110B is converted into s-polarized light. The s-polarized light incident on the third color light spatial light modulator 110B is converted into p-polarized light by the λ / 2 phase difference plate 123B. The B light converted into p-polarized light passes through the glass plate 124B and the first polarizing plate 121B as it is, and enters the liquid crystal panel 120B. The p-polarized light incident on the liquid crystal panel 120B is converted into s-polarized light by modulation according to the image signal. The B light converted into the s-polarized light by the modulation of the liquid crystal panel 120B is emitted from the second polarizing plate 122B. The B light modulated by the third color light spatial light modulator 110B is incident on the cross dichroic prism 112 which is a color synthesis optical system. As described above, the R light transmissive dichroic mirror 106R and the B light transmissive dichroic mirror 106G constituting the color separation optical system convert the light supplied from the ultrahigh pressure mercury lamp 101 to the R light that is the first color light and the second light. The light is separated into G light, which is colored light, and B light, which is third color light.

  The cross dichroic prism 112, which is a color synthesis optical system, is configured by arranging two dichroic films 112a and 112b perpendicularly to an X shape. The dichroic film 112a reflects B light and transmits R light and G light. The dichroic film 112b reflects R light and transmits B light and G light. As described above, the cross dichroic prism 112 has the R light and G light modulated by the first color light spatial light modulation device 110R, the second color light spatial light modulation device 110G, and the third color light spatial light modulation device 110B, respectively. And B light. The projection lens 114 projects the light combined by the cross dichroic prism 112 onto the screen 116. Thereby, a full color image can be obtained on the screen 116.

  As described above, the light incident on the cross dichroic prism 112 from the first color light spatial light modulator 110R and the third color light spatial light modulator 110B is set to be s-polarized light. The light incident on the cross dichroic prism 112 from the second color light spatial light modulator 110G is set to be p-polarized light. In this way, by changing the polarization direction of the light incident on the cross dichroic prism 112, the light emitted from the spatial light modulators for the respective color lights in the cross dichroic prism 112 can be effectively combined. The dichroic films 112a and 112b are usually excellent in the reflection characteristics of s-polarized light. For this reason, R light and B light reflected by the dichroic films 112a and 112b are s-polarized light, and G light transmitted through the dichroic films 112a and 112b is p-polarized light.

(Configuration of LCD panel)
Next, details of the liquid crystal panel will be described with reference to FIG. The projector 100 described with reference to FIG. 1 includes three liquid crystal panels 120R, 120G, and 120B. These three liquid crystal panels 120R, 120G, and 120B differ only in the wavelength region of light to be modulated, and have the same basic configuration. Therefore, the following description will be made with the liquid crystal panel 120R as a representative example.

  FIG. 2 is a perspective sectional view of the liquid crystal panel 120R. The R light from the ultrahigh pressure mercury lamp 101 is incident on the liquid crystal panel 120R from the lower side of FIG. A counter substrate 202 having a transparent electrode and the like is formed inside the incident side dust-proof transparent plate 201. Further, a first refractive optical element 210a and a second refractive optical element 210b, which will be described later, are bonded to the exit side by an optical adhesive. A TFT substrate 205 having a TFT (thin film transistor), a transparent electrode, and the like is formed inside the second refractive optical element 210b. The first refractive optical element 210a and the second refractive optical element 210b also serve as the exit-side dustproof transparent plate. Then, the opposite substrate 202 and the TFT substrate 205 are opposed to each other, and the incident side dust-proof transparent plate 201 and the refractive optical elements 210a and 210b are bonded together. A liquid crystal layer 204 for image display is sealed between the counter substrate 202 and the TFT substrate 205. In addition, a black matrix forming layer 203 is provided on the incident light side of the liquid crystal layer 204 for shielding light.

  In the configuration shown in FIG. 1, the first polarizing plate 121R and the second polarizing plate 122R are provided separately from the liquid crystal panel 120R. However, instead of this, a polarizing plate may be provided between the incident-side dust-proof transparent plate 201 and the counter substrate 202, between the refractive optical elements 210a and 210b, and the TFT substrate 205, or the like. Further, the first and second refractive optical elements 210a and 210b may be formed on the second polarizing plate 122R or formed on the R light incident surface of the cross dichroic prism 112. In addition, the first refractive optical element 210a and the second refractive optical element 210b are preferably provided substantially perpendicular to the optical axis.

(Refractive optical element)
FIGS. 3A and 3B show perspective configurations of the first refractive optical element 210a and the second refractive optical element 210b, respectively. As shown in FIG. 3A, the first refractive optical element 210a includes a first inclined surface 211, which is a strip-shaped refracting portion, and a flat surface 212 (with diagonal lines) on one surface of a parallel plate of glass. And the second inclined surface 213 which is a strip-shaped refracting portion are repeatedly formed alternately. The flat surface 212 is substantially parallel to the other surface 214 of the parallel plate.

  The first inclined surface 211 is inclined so as to decrease in the − (minus) x direction, which is the first direction, along the longitudinal direction of the strip. On the other hand, the second inclined surface 213 is inclined so as to be lowered in the + (plus) x direction opposite to the −x direction which is the first direction. A flat surface 212 is formed between the first inclined surface 211 and the second inclined surface 213. FIG. 3A shows an enlarged part of a refractive optical element that is repeatedly formed. The second refractive optical element 210b has the same configuration as the first refractive optical element 210a. As shown in FIG. 3-2, the second refractive optical element 210b is provided in a direction substantially orthogonal to the first refractive optical element 210a.

  FIG. 4A shows a configuration of the first refractive optical element 210a as viewed from above. A first inclined surface 211 (with a right-down oblique line), a flat surface 212, a second inclined surface 213 (with a left-down oblique line), and a flat surface 212 are repeatedly formed in this order. Yes. FIGS. 4-2, 4-3, and 4-4 show cross-sectional configurations of the first inclined surface 211, the second inclined surface 213, and the flat surface 212, respectively. As is clear from FIGS. 4-2 and 4-3, the first direction (−x direction) in which the first inclined surface 211 is inclined and the second direction (+ x direction) in which the second inclined surface 213 is inclined. ) Is the opposite direction. The cross-sectional configuration of the first refractive optical element 210a is a combination of the first inclined surface 211, the second inclined surface 213, and the flat surface 212, as shown in FIG. 4-5. Further, it is desirable that the length in the longitudinal direction of the first inclined surface 211 and the length in the longitudinal direction of the second inclined surface 213 are substantially equal to the length of one side of the liquid crystal panel 120R.

(Configuration of the opening corresponding to the pixel portion)
FIG. 5 is a plan view of the black matrix forming layer 203. The black matrix portion 220 which is a light shielding portion shields the R light incident from the ultrahigh pressure mercury lamp 101 so as not to be emitted to the screen 116 side. The black matrix portion 220 has predetermined widths W1 and W2, and is formed in a lattice shape in the orthogonal direction. A rectangular region surrounded by the black matrix portion 220 forms an opening 230. The opening 230 allows the R light from the extra-high pressure mercury lamp 101 to pass through. The R light transmitted through the opening 230 passes through the counter substrate 202, the liquid crystal layer 204, and the TFT substrate 205 as shown in FIG. The polarization component of the R light is modulated in the liquid crystal layer 204 in accordance with the image signal. In this way, the pixel portion in the projected image is formed by the light that has been modulated by being transmitted through the opening 230, the liquid crystal layer 204, and the TFT substrate 205. Since this light is light transmitted through the opening 230, the position and size of the opening 230 correspond to the position and size of the pixel portion, respectively. Further, the center line CL of the belt-like black matrix portion 220 is indicated by a one-dot chain line. Hereinafter, for convenience of description, a region indicated by a thick line surrounded by the center line CL is referred to as a periodic region 240. As is apparent from the figure, the adjacent periodic regions 240 are periodically and repeatedly arranged without gaps.

(Projected image of aperture)
FIG. 6 is an enlarged view of an image projected on the screen 116 by a projector according to the prior art. An aperture image 230P is projected by being surrounded by a belt-like black matrix image 220P. Further, corresponding to the periodic region 240, a periodic region image 240P surrounded by a thick line in FIG. 6 is projected. Further, a position where the center line images CLP intersect is defined as an intersection CP. In the following description of all embodiments including the present embodiment, description will be made using an image projected on the screen 116 by the projection lens 114. Here, when the first spatial light modulator for light 110R itself is taken out and considered, the projection lens 114 is not interposed. In this case, it can be handled as a projection image projected on a virtual projection plane that is a predetermined distance away from the first inclined surface 211 that is a refraction part. The projected image by the projector 100 and the projected image by the first spatial light modulator for the first color light 110R are substantially the same with only the image magnification being different. For this reason, hereinafter, a description will be given by taking a projected image projected on the screen 116 as an example.

(Positional relationship between inclined surface and opening)
FIG. 7 is a cross-sectional view showing the relationship between the black matrix forming layer 203 and the first inclined surface 211 that is a refracting portion. Here, in order to facilitate understanding, the illustration of the other components excluding the black matrix forming layer 203 and the first inclined surface 211 is omitted. The R light transmitted through the opening 230 corresponding to one pixel portion travels as a conical divergent light. The R light is incident on at least a part of the first inclined surface 211 in a region where the first inclined surface 211, the flat surface 212, and the second inclined surface 213 are repeatedly formed.

(Inclination angle and amount of refraction)
Next, the amount of angle by which the light transmitted through the liquid crystal layer 204 is refracted with the above configuration will be described with reference to FIG. FIG. 8 is an enlarged view showing the vicinity of the first inclined surface 211 in the first refractive optical element 210a. Consider a case where a medium (for example, air) between the first refractive optical element 210a and the screen 116 has a refractive index n1, and a member constituting the refractive optical element 210a, for example, a glass has a refractive index n2. The first inclined surface 211 is formed so as to have an angle θ with respect to a surface 212 a parallel to the flat surface 212. Hereinafter, the angle θ is referred to as an inclination angle. In FIG. 8, only the first inclined surface 211 and the screen 116 are shown, and the illustration of the cross dichroic prism 112 and the projection lens 114 is omitted.

For simplicity, parallel light out of the light from the liquid crystal layer 204 will be described. Light rays incident on the flat surface 212 are incident perpendicular to the flat surface 212. For this reason, without being refracted by the flat surface 212, it proceeds straight as it is to form a projected image on the screen 116. On the other hand, the light incident on the first inclined surface 211 is refracted so as to satisfy the following conditional expression.
n1 × sin β = n2 × sin α
Here, the angle α is an incident angle based on the normal line N of the first inclined surface 211, and the angle β is an emission angle.

Further, on the screen 116 that is separated from the first inclined surface 211 by a distance L, the position of the light that travels straight, the position of the refracted light, and the distance S are expressed as follows.
S = L × Δβ
Δβ = β-α
In this way, by controlling the inclination angle θ of the first inclined surface 211, the distance S, which is the amount of movement of the aperture image transmitted through the liquid crystal layer 204 on the screen 116, can be arbitrarily set. Further, as apparent from FIG. 8, the direction in which the light beam LL2 is refracted depends on the direction in which the first inclined surface 211 is inclined. In other words, by controlling the direction of the first inclined surface 211 with respect to the opening of the liquid crystal layer 204, the direction in which the opening image is formed on the screen 116 can be arbitrarily set.

(Contents of the projected image)
A projected image by the R light projected onto the screen 116 by the first inclined surface 211 will be described with reference to FIG. FIG. 9 shows one periodic region image 240 </ b> P on the screen 116. The light that is substantially perpendicularly incident on the flat surface 212 of the refractive optical element 210a travels straight without being refracted by the flat surface 212. The straightly traveling light forms an opening image (direct transmission image) 230P at the center of the periodic region image 240P on the screen 116.

  Next, consider the light incident on the first inclined surface 211 of the refractive optical element 210a. The light incident on the first inclined surface 211 is refracted by the refraction direction, the amount of refraction, and the amount of refracted light corresponding to the direction of the first inclined surface 211, the inclination angle θ, and the area. A direction along the length of the first inclined surface 211 (x-axis direction) and the direction of the center line CL of the black matrix forming layer 203 are configured to be substantially parallel. Therefore, for example, the light refracted by the first inclined surface 211 or the second inclined surface 213 is only the distance SA described above in the direction of the arrow from the opening image (direct transmission image) 230P as shown in FIG. An opening image 230Pa is formed at a distant position. In the following description, for the sake of simplicity, it is assumed that there is no up / down / left / right reversal of the image due to the image forming action of the projection lens 114. Further, it is assumed that the observer always observes from the direction of viewing the ultrahigh pressure mercury lamp 101 that is the light source unit. For example, it is assumed that the image projected on the screen 116 is also observed from the back side of the screen 116 from the direction of viewing the ultra high pressure mercury lamp 101 (the direction of viewing the incoming light).

  Similarly, consider light refracted by the second refractive optical element 210b shown in FIG. 10-1 so as to be substantially orthogonal to the first refractive optical element 210a. The light refracted by the second refractive optical element 210b forms an opening image 230Pb at a position away from the opening image 230P in the y-axis direction by a distance SB as shown in FIG. 10-2. When the first refractive optical element 210a and the second refractive optical element 210b are provided so as to be substantially orthogonal to each other, as shown in FIG. 11, the opening portion image (direct transmission image) 230P becomes the first refractive light. The light is refracted in the x-axis direction by the optical element 210a, and further refracted in the y-axis direction by the second refractive optical element 210b. Thereby, the projection image of a pixel part can be formed along two directions substantially orthogonal.

(Area ratio of inclined surface in unit area)
Next, the area ratio of the inclined surface in the unit area will be described. First, the unit area will be described. FIG. 12 shows an optical path from the ultrahigh pressure mercury lamp 101 to the screen 116 for explaining the unit area aφ. In FIG. 12, for the sake of simplicity of explanation, only the ultrahigh pressure mercury lamp 101 and the integrator 104 that constitute the illumination system ILL and the projection lens 114 that constitutes the projection system PL are shown as optical systems, and other color separations are shown. Illustration of the optical system and the like is omitted. For convenience, the projection lens 114 is shown as a biconvex single lens. For this reason, in FIG. 12, the projection lens 114 and the projection system PL coincide.

Illumination light from the ultra-high pressure mercury lamp 101 as a light source enters the integrator 104. The integrator 104 illuminates the liquid crystal panel 120R by superimposing illumination light from the ultrahigh pressure mercury lamp 101. The illumination light from the integrator 104 enters the liquid crystal panel 120R with a predetermined angular distribution. The position OBJ on the liquid crystal panel 120R is illuminated in a superimposed manner with light of various incident angles. The light from the position OBJ is incident on the first refractive optical element 210a while spatially spreading at the F number of the illumination system ILL. The light emitted from the liquid crystal panel 120R passes through the first refractive optical element 210a and enters the projection lens 114. The modulation surface of the liquid crystal panel 120R and the screen 116 are in a conjugate relationship. Therefore, the position OBJ on the liquid crystal panel 120R forms an image at the position IMG on the screen 116. At this time, the light from the position OBJ on the liquid crystal panel 120R is projected onto the screen 116 by the projection lens 114 as light having the same or smaller F number as the F number of the projection lens 114. The following three relationships (A), (B), and (C) can be considered between the F number of the illumination system ILL and the F number of the projection system PL.
(A) F number of illumination system ILL> F number of projection system PL,
(B) F number of illumination system ILL = F number of projection system PL,
(C) F number of illumination system ILL <F number of projection system PL.

In any relationship, only the light in the angle range defined by the smaller F number of the illumination system ILL or the projection system PL is effectively projected on the screen 116 on the liquid crystal panel 120R. For example, in the case of the relationship (A) or (B), the following equation is established.
1 / (2FILL) = sin θa
Here, FILL is the F number of the projection system PL,
θa is an angle formed with the optical axis of the light emitted from the position OBJ.

  Light emitted from the liquid crystal panel 120R at a spatial expansion angle θa irradiates a unit area aφ that is a circular area on the first refractive optical element 210a. Thus, all the light from the unit area aφ on the first refractive optical element 210 a is projected onto the screen 116 by the projection lens 114. On the other hand, in the case of the relational expression (C), the unit area aφ on the first refractive optical element 210a that is effectively projected on the screen 116 by the F number of the illumination system ILL is defined.

  Accordingly, in any relationship (A), (B), or (C), the light from the unit area aφ on the first refractive optical element 210a is effectively projected onto the screen 116 by the projection lens 114. The total area of the first inclined surface 211 refracted in a predetermined direction per unit area aφ, the total area of the second inclined surface 213, and the total area of the flat surface 212 are the same in any unit area. It is the same value. The light amount of the image projected on the screen 116 is proportional to the area ratio of the unit area aφ. FIG. 13 shows a front configuration in which the first refractive optical element 210a and the second refractive optical element 210b in the unit area aφ are shown in the same drawing.

  For example, in FIG. 13, the area ratio of the flat surfaces 212, the first inclined surfaces 211, and the second inclined surfaces 213 of the first refractive optical element 210a and the second refractive optical element 210b within the unit area aφ. Is 1/2: 1/4: 1/4. In this case, the ratio of the amount of light of each projection image on the screen 116 is distributed as shown in FIG. The adjacent periodic region images 240P are formed such that the black matrix portion images 220P (FIG. 6) that are projection images of the black matrix portion 220 overlap each other. For this reason, the light quantity of the image finally projected on the screen 116 is all ¼ in the periodic area image 240P. In addition, the projection image by each refracting part is a sum of light from adjacent direct transmission images, so that a new pixel having a halftone between adjacent direct projection images is formed. Therefore, on the screen 116, an observer can observe an image with uniform brightness, smoothness, and reduced roughness, without the observer recognizing the black matrix portion 220. In the present embodiment, even when the inclination angle θ is small, the inclined surface can be easily formed because it is inclined along the longitudinal direction of the strip. The manufacturing method of the first refractive optical element 210a and the second refractive optical element 210b is, for example, a photolithography method such as gray school, a mold transfer method using an ultraviolet curable resin, a glass press method, or direct cutting by machining. The method etc. can be mentioned.

  Further, one refractive optical element of the first refractive optical element 210a and the second refractive optical element 210b may be formed on the exit-side dustproof transparent plate. Next, the other refractive optical element is manufactured separately from the exit side dustproof plate. Then, the other refractive optical element is fixed to the exit-side dust-proof transparent plate having one refractive optical element formed on the surface with an optical transparent adhesive. Also with this configuration, the same effect as in the present embodiment can be obtained.

Furthermore, in this embodiment, one surface 214 (planar side) of the first refractive optical element 210a and the surface on which the first inclined surface 211 and the like of the second refractive optical element 210b are formed face each other. It is stuck. However, the present invention is not limited to this, and any one of the following configurations (1) to (3) may be used.
(1) The surface on which the first inclined surface 211 or the like of the first refractive optical element 210a is formed faces the surface on which the first inclined surface 211 or the like of the second refractive optical element 210b is formed. A configuration that adheres together.
(2) Configuration in which the surface on which the first inclined surface 211 or the like of the first refractive optical element 210a is formed and one surface 214 (planar side) of the second refractive optical element 210b face each other and are fixed. .
(3) A configuration in which one surface 214 (planar side) of the first refractive optical element 210a and one surface 214 (planar side) of the second refractive optical element 210b are fixed facing each other.

  FIG. 15A illustrates a front configuration of the spatial light modulation device according to the second embodiment. Since the configuration other than the refractive optical element 1310 is the same as that of the spatial light modulation device described in the first embodiment, a duplicate description is omitted. In the present embodiment, a first inclined surface 1311 (with a slanting line on the lower left) is formed in one region from the vicinity of the center CT in one strip-shaped region. In addition, a second inclined surface 1313 (with a downward slanting diagonal line) is formed in the other region from the vicinity of the center CT. The first inclined surface 1311 and the second inclined surface 1313 are inclined in opposite directions along the strip-like longitudinal direction (x-axis direction). Further, a flat surface 1312 is formed adjacent to the first inclined surface 1311 and the second inclined surface 1313. These configurations are formed repeatedly. A cross-sectional configuration of the refractive optical element 1310 is shown in FIG. The first inclined surface 1311 and the second inclined surface 1313 form a valley shape that is recessed in the vicinity of the center CT with respect to the flat surface 1312. With such a configuration, since the length of the inclined surface in the inclined direction is sufficiently long, a depth dp sufficient for manufacturing can be obtained.

  FIG. 16A illustrates a front configuration of the spatial light modulation device according to the third embodiment. Since the configuration other than the refractive optical element 1410 is the same as that of the spatial light modulation device described in the first embodiment, a duplicate description is omitted. In this embodiment, a first inclined surface 1411 (with a slanting line on the lower left) is formed in one area from the vicinity of the center CT in one strip-shaped area. In addition, a second inclined surface 1413 (with a downward slanting diagonal line) is formed in the other region from the vicinity of the center CT. The first inclined surface 1411 and the second inclined surface 1413 are inclined in opposite directions along the strip-like longitudinal direction (x-axis direction). Further, a flat surface 1412 is formed adjacent to the first inclined surface 1411 and the second inclined surface 1413. These configurations are formed repeatedly. A cross-sectional configuration of the refractive optical element 1410 is shown in FIG. The first inclined surface 1411 and the second inclined surface 1413 form a mountain shape that is convex in the vicinity of the center CT with respect to the flat surface 1412. With such a configuration, since the length of the inclined surface in the direction of inclination is sufficiently long, a height ht sufficient for manufacturing processing can be obtained.

  FIG. 17A illustrates a part of the front configuration of the spatial light modulation device according to the fourth embodiment. In the present embodiment, a procedure for setting the area ratio in the unit area aφ to a desired value will be described. As illustrated in FIG. 17A, the strip-shaped first inclined surface 1511, the strip-shaped flat surface 1512, and the strip-shaped second inclined surface 1513 are equal to each other. The two flat surfaces 1512, the first inclined surface 1511, and the second inclined surface 1513 are combined to form a unit U1. When the area of the unit U1 is 1, the area ratio of the flat surface 1512, the first inclined surface 1511, and the second inclined surface 1513 is 1/2: 1/4: 1/4. For this reason, as shown in FIG. 17-2, if the refractive optical element 1510 is configured by repeatedly arranging the units U1, the total area of the flat surface 1512 and the total of the first inclined surface 1511 in the refractive optical element 1510. The ratio of the area and the total area of the second inclined surface 1513 is 1/2: 1/4: 1/4. Thus, the area ratio is set to a desired value by changing the quantity of the strip-like flat surfaces 1512 constituting the unit U1, the quantity of the first inclined surfaces 1511, and the quantity of the second inclined surfaces 1513. Can be set. As a result, the light quantity ratio on the screen 116 can be easily controlled.

  In this case, as in the first embodiment, the ratio of the amount of light of each projection image on the screen 116 is distributed as shown in FIG. The adjacent periodic region images 240P are formed such that the black matrix portion images 220P (FIG. 6) that are projection images of the black matrix portion 220 overlap each other. For this reason, the light quantity of the image finally projected on the screen 116 is all ¼ in the periodic area image 240P. Therefore, on the screen 116, an observer can observe an image with uniform brightness, smoothness, and reduced roughness, without the observer recognizing the black matrix portion 220.

  FIG. 18A illustrates a part of the front configuration of the spatial light modulation device according to the fifth embodiment. In this embodiment, another procedure for setting the area ratio in the unit area aφ to a desired value will be described. As shown in FIG. 18A, the area of one strip-shaped flat surface 1612 and one strip-shaped second inclined surface 1613 are equal. On the other hand, the area of one strip-shaped flat surface 1612 is twice the area of the first inclined surface 1611. One flat surface 1612, one first inclined surface 1611, and one second inclined surface 1613 are combined to form a unit U2. When the area of the unit U2 is 1, the area ratio of the flat surface 1612, the first inclined surface 1611, and the second inclined surface 1613 is 1/2: 1/4: 1/4. Therefore, as shown in FIG. 18B, when the refractive optical element 1610 is configured by repeatedly arranging the units U2, the total area of the flat surface 1612 and the total of the first inclined surface 1611 in the refractive optical element 1610. The ratio of the area and the total area of the second inclined surface 1613 is 1/2: 1/4: 1/4. Thus, the area ratio is changed to a desired value by changing the area of the strip-shaped flat surface 1512 constituting the unit U2, the area of the first inclined surface 1511, and the area of the second inclined surface 1513. Can be set. As a result, the light quantity ratio on the screen 116 can be easily controlled.

  In the case of the present embodiment, as in the fourth embodiment, the ratio of the amount of light of each projected image on the screen 116 is distributed as shown in FIG. The adjacent periodic region images 240P are formed such that the black matrix portion images 220P (FIG. 6) that are projection images of the black matrix portion 220 overlap each other. For this reason, the light quantity of the image finally projected on the screen 116 is all ¼ in the periodic area image 240P. In addition, the projection image by each refracting part is a sum of light from adjacent direct transmission images, so that a new pixel having a halftone between adjacent direct projection images is formed. Therefore, on the screen 116, an observer can observe an image with uniform brightness, smoothness, and reduced roughness, without the observer recognizing the black matrix portion 220.

  As described above, according to the present invention, it is possible to observe an image with uniform brightness, smoothness, and reduced roughness, without the observer recognizing the black matrix portion 220. In addition, since the inclined surface of the refractive optical element is inclined in the longitudinal direction of the strip shape, the height or depth of the inclined surface can be sufficiently secured even in the case of a minute inclination angle. As a result, an inclined surface with a small inclination angle can be easily manufactured.

  As described above, the spatial light modulation device according to the present invention is useful for a spatial light modulation device having a light blocking portion such as a black matrix, and is particularly suitable for a liquid crystal type spatial light modulation device.

1 is a schematic configuration diagram of a projector according to Embodiment 1. FIG. FIG. 3 is a perspective view of the spatial light modulation device for the projector according to the first embodiment. The perspective view of a 1st refractive optical element. The perspective view of the 2nd refractive optical element. The top view of the 1st refractive optical element. Explanatory drawing of a 1st inclined surface. Explanatory drawing of a 2nd inclined surface. Explanatory drawing of a flat surface. Sectional drawing of a 1st refractive optical element. The top view of a black matrix formation layer. The figure of the projection image of the 1st refractive optical element. The figure which shows the positional relationship of an inclined surface and an opening part. Explanatory drawing of a refraction angle. The top view of a projection image. The top view of the 2nd refractive optical element. The figure of the projection image by the 2nd refractive optical element. The figure of the projection image of the 1st and 2nd refractive optical element. The figure explaining a unit area. The top view of the inclined surface in a unit area. The light quantity distribution figure of a projection image. FIG. 6 is a top view of the refractive optical element of Example 2. Sectional drawing of the refractive optical element of Example 2. FIG. FIG. 6 is a top view of a refractive optical element according to Example 3. Sectional drawing of the refractive optical element of Example 3. FIG. FIG. 6 is a top view of a refractive optical element according to Example 4. Sectional drawing of the refractive optical element of Example 4. FIG. FIG. 6 is a top view of a refractive optical element according to Example 5. Sectional drawing of the refractive optical element of Example 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Projector, 101 Super high pressure mercury lamp, 104 Integrator, 105 Polarization conversion element, 106R R light transmission dichroic mirror, 106G G light transmission dichroic mirror, 107 Reflection mirror, 108 Relay lens, 110R R light spatial light modulation device, 110G G Spatial light modulator for color light, 110B Spatial light modulator for B light, 112 cross dichroic prism, 112a dichroic film, 112b dichroic film, 114 projection lens, 116 screen, 120R liquid crystal panel, 120G liquid crystal panel, 120B liquid crystal panel, 121R 1 polarizing plate, 121G first polarizing plate, 121B first polarizing plate, 122R second polarizing plate, 122G second polarizing plate, 122B second polarizing plate, 123R λ / 2 phase difference plate, 123B λ / 2 phase difference plate, 124 Glass plate, 124B glass plate, 201 incident-side dustproof transparent plate, 202 counter substrate, 203 black matrix forming layer, 204 liquid crystal layer, 205 TFT substrate, 210a first refractive optical element, 210b second refractive optical element, 211 first 1 inclined surface, 212 flat surface, 212a surface, 213 second inclined surface, 214 other surface, 220 black matrix portion, 220P black matrix portion image, 230 opening portion, 230P opening portion image, 230Pa opening portion image, 230Pb Aperture image, 240 periodic region, 240P periodic region image, 1310 refractive optical element, 1311 first inclined surface, 1312 flat surface, 1313 second inclined surface, 1410 refractive optical element, 1411 first inclined surface, 1412 flat Surface, 1413 second inclined surface, 1510 refractive optical element, 1511 1st inclined surface, 1512 flat surface, 1513 2nd inclined surface, 1610 refractive optical element, 1611 1st inclined surface, 1612 flat surface, 1613 2nd inclined surface, aφ unit area, CL center line, CLP center Line image, CP intersection, CT center, ILL illumination system, PL projection system

Claims (5)

A projector that projects an image on a projection surface,
A modulation unit that has a plurality of pixel units arranged in a matrix and a light shielding unit provided between the plurality of pixel units , and modulates and emits incident light according to an image signal ;
Provided on the exit side of the modulating unit includes a strip-shaped bent portion for refracting the light from the modulating unit, and a refractive optical element having a flat surface that spend translucent light from the modulation unit,
The refracting portion has a refracting surface inclined along the longitudinal direction of the strip shape,
The refractive surface is corresponding to the distance from the refracting unit to the projection plane, and the direction of the refracting surface as the projected images guided onto a projection image of the light shielding portion of the pixel portion, the flat and the refractive surface projector, characterized in that it comprises the angle between the surface and. The refracting portion includes a first inclined surface that is inclined in a first direction along the strip-shaped longitudinal direction, and a second inclined surface that is inclined in a second direction opposite to the first direction. The projector according to claim 1, further comprising: 3. The projector according to claim 2, wherein two refracting portions each having the first inclined surface and the second inclined surface are provided in a substantially orthogonal direction. An illumination optical system for supplying incident light to the modulator;
A projection optical system on which the modulated emission light from the modulation unit enters, and
And the numerical aperture of the front KiTeru Meiko science-based, in the unit area on the refractive optical element before determined by the numerical aperture of the Kito shooting optical system, the ratio between the area and the area of the flat surface wherein the refractive surface are both Is the same in the unit area of
When the numerical aperture of the illumination optical system is different from the numerical aperture of the projection optical system, the unit area is the smaller numerical aperture, or the numerical aperture of the illumination optical system and the numerical aperture of the projection optical system are equal. If any numerical aperture is F,
1 / (2F) = sin θa
The area of a circular region on the refractive optical element irradiated with light emitted from a predetermined position of the modulation unit at a spatial expansion angle θa determined by The projector according to one item. The projector according to claim 1 , further comprising a light source that supplies light.

Images