JP2006205491A - Method for producing fine structure element, fine structure element, space light modulation device, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fine structure element which can exactly produce a desired fine shape. <P>SOLUTION: The method comprises: a plane part forming process for forming a plane part in a substrate by an R bite 800 which is a circular cutting part; and an inflection surface forming process for forming an inflection surface having a prescribed angle to the plane part by a plane bite 800 which is an approximately plane cutting part. In the plane part forming process, the substrate is cut while the R bite 800 is moved in a prescribed direction in relation to the substrate. When the feed pitch of the R bite 800 in the direction approximately rectangular to the prescribed direction is P (meter), and the radius of the circular shape of the R bite 800 is r (meter), they satisfy the formula: 1.0×10<SP>-8</SP>>P<SP>2</SP>/8r. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a fine structure element, a fine structure element manufactured by this method, a spatial light modulator, and a projector, and more particularly to a method for manufacturing a fine structure element such as a microprism.

  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 a dot matrix image display device, a region between pixels is provided with a light shielding portion called a black matrix 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 improve the original image by reducing the deterioration of the image quality caused by the black matrix image due to the influence of higher-order diffraction.

  For this reason, it is conceivable that the light from the image display device is incident on the prism group so that the observer does not recognize the light blocking portion such as the black matrix. The flat part of the prism group transmits the light from the image display device as it is. The refractive surface of the prism group refracts and transmits light from the image display device. Such light transmitted through the prism group generates light whose optical path is deflected by the refractive surface of the prism, in addition to light that travels straight after exiting the flat portion. A pixel image is formed on the black matrix by the light deflected in the optical path. This can reduce the recognition of the black matrix.

  The shape of each prism element constituting the above-described prism group is a fine shape of nanometer to micron order. In the prior art, a prism element having a fine shape is manufactured by cutting, for example, using a cutting tool in a predetermined region. It is conceivable that the flat portion of the prism group is formed by using a flat tool formed substantially flat. The flat cutting tool cuts the substrate while moving in a predetermined direction with respect to the substrate to be processed. Further, when the flat cutting tool completes cutting in a predetermined direction, the flat cutting tool is moved in a direction substantially orthogonal to the predetermined direction, and cutting is performed again. When a small flat bite is used, pressure may be concentrated on the contact portion between the flat bite and the substrate, so that a machining streak may be formed between cutting traces by the flat bite. Since the machining streaks are formed at a substantially constant interval, diffraction of light due to the periodic structure may occur. When the light from the image display device is affected by diffraction, the contrast of the image is lowered.

  Further, as the flat bite becomes smaller, it becomes difficult to form the cutting edge flat. For example, the cutting edge of a flat bite becomes closer to a circular shape as it becomes smaller. If the flat bite cannot be formed in an accurate shape as described above, it is difficult to form a prism group having an accurate shape. Furthermore, in order to reduce the influence of environmental changes, it is desirable to perform the cutting process in as short a time as possible. In order to perform cutting in a short time, it is conceivable to increase the feed pitch of the flat cutting tool in a direction substantially orthogonal to the predetermined direction for cutting the substrate as much as possible by using a flat cutting tool having a large cutting surface. . When a flat cutting tool having a large cutting surface is used, the pressure applied to the contact portion between the flat cutting tool and the substrate is widely dispersed, and so-called chattering that makes the cutting surface unstable on the substrate is likely to occur. When chatter occurs, irregularities are formed on the flat portion. Furthermore, when processing micro-structured elements by machining such as cutting, in addition to processing conditions, changes in the processing accuracy of the processing machine itself due to changes in the surrounding environment such as atmospheric pressure and temperature, and shapes due to thermal expansion of the processing material A decrease in accuracy is a problem. Therefore, it has been confirmed that machining in a short time is essential in order to ensure machining accuracy. As described above, the conventional cutting process is problematic because it is difficult to accurately manufacture a prism group having a desired shape. The present invention has been made in view of the above problems, and a method for manufacturing a fine structure element capable of accurately manufacturing a desired fine shape, a fine structure element manufactured by this method, a spatial light modulation device, and the like An object is to provide a projector.

  In order to solve the above-described problems and achieve the object, according to the present invention, by using a circular cutting part having a circular shape, a flat part forming step for forming a flat part on a substrate and a substantially flat part are formed. By using the flat cutting portion, it is possible to provide a method of manufacturing a fine structure element including a refracting surface forming step of forming a refracting surface having a predetermined angle with respect to the flat portion.

  By using the circular cutting portion for forming the flat portion, the pressure applied to the contact portion between the circular cutting portion and the substrate is kept substantially constant, and the circular cutting portion is stabilized on the substrate. By stabilizing the circular cutting portion on the substrate, the occurrence of chatter is reduced, and a substantially flat flat portion with few irregularities can be formed on the substrate. By reducing the unevenness of the flat portion, the microstructure element can obtain optical characteristics that allow light to pass through the flat portion effectively. Further, since the flat portion serves as a reference surface for the refracting surface forming step, it is possible to form the refracting surface substantially flat by forming the flat portion with less unevenness. By reducing the unevenness of the refracting surface, the microstructure element can obtain optical characteristics that efficiently refract light in a desired direction on the refracting surface. Furthermore, since the formation of processing streaks on the flat portion and the refracting surface can be reduced, light diffraction caused by the periodic structure can be reduced.

  In the refracting surface forming step, the refracting surface having a desired angle with respect to the flat portion can be formed by inclining and fixing the flat cutting portion so as to match the inclination of the refracting surface. Since the amount of inclination of the flat cutting portion can be controlled with a mechanical accuracy of about 1 / 100,000 by a normal control method, a refracting surface with a minute inclination angle controlled with high accuracy can be formed. Thereby, a desired micro-shaped element can be manufactured accurately.

According to a preferred aspect of the present invention, in the flat portion forming step, the substrate is cut while moving the circular cutting portion in a predetermined direction with respect to the substrate, and the circular cutting portion in a direction substantially orthogonal to the predetermined direction. If the feed pitch of P is m (meter) and the radius of the circular shape of the circular cutting part is r (meter), it is desirable to satisfy the equation (1).
1.0 × 10 ⁻⁸ > P ² / 8r (1)

  By forming the flat portion under the condition satisfying the expression (1), it is possible to form a substantially flat flat portion with less unevenness. Further, by appropriately setting the feed pitch P that satisfies the expression (1), it is possible to prevent the machining time from being unnecessarily prolonged. If the processing time can be shortened, the influence of surrounding environmental changes can be reduced, and the cutting can be performed stably. Thereby, a substantially flat flat part can be formed and cutting can be performed stably.

Moreover, according to the preferable aspect of this invention, it is further desirable to satisfy Formula (2).
2.0 × 10 ⁻³ ≦ r ≦ 6.0 × 10 ⁻³ (2)

  When the radius r is set to a value smaller than the range of the expression (2), the bite shape is transferred to the cutting surface, and thus the surface roughness increases. Further, when the feed pitch P of the circular cutting portion is reduced, the surface roughness can be reduced, but the processing time for forming the flat portion becomes longer. If the processing time is long, it becomes difficult to stably perform the cutting due to the influence of the surrounding environment. If the radius r is set to a value larger than the range of the expression (2), the processing state becomes unstable due to an increase in the load applied to the circular cutting part on the substrate, and chatter may occur. By using a circular cutting part that satisfies the formula (2), it is possible to shorten the processing time of the flat part. By shortening the machining time, it is possible to reduce the influence of surrounding environmental changes and perform the cutting process stably. Further, by using a circular cutting portion having a circular shape that satisfies the formula (2), chatter is reduced, and a substantially flat flat portion with few irregularities can be formed. Thereby, it can cut stably and can form a substantially flat flat part.

Moreover, as a preferable aspect of the present invention, it is further desirable to satisfy the formula (3).
5.0 × 10 ⁻⁶ ≦ P ≦ 20 × 10 ⁻⁶ (3)

  When the feed pitch P of the circular cutting part is set to a value smaller than the range of the expression (3), the processing time for forming the flat part becomes long. If the processing time is long, it becomes difficult to stably perform the cutting due to the influence of the surrounding environment. When the feed pitch P is set to a value larger than the range of the expression (3), a circular cutting part having a cutting surface with a large radius r is used. When the radius r of the circular cutting portion is increased, the processing state becomes unstable due to an increase in the load applied to the circular cutting portion on the substrate, which may cause chatter. By forming the flat portion with the feed pitch P that satisfies Expression (3), the processing time of the flat portion can be shortened. By shortening the machining time, it is possible to reduce the influence of surrounding environmental changes and perform the cutting process stably. Moreover, chattering is reduced by satisfying the expression (3), and a substantially flat flat portion with less unevenness can be formed. Thereby, it can cut stably and can form a substantially flat flat part.

  Moreover, as a preferable aspect of the present invention, it is desirable to form the refracting surface by performing the cutting by the flat cutting portion in a plurality of times in the refracting surface forming step. For the flat cutting part forming the refracting surface, for example, a flat cutting tool, a V-shaped cutting tool or a trapezoidal cutting tool can be used. When the refractive surface is formed by only one cutting, the substantially flat surface is processed so that the depth of cut by the flat cutting portion is several hundred nanometers to several hundred micrometers. When the load applied to the flat cutting portion increases in this manner, the load fluctuation is likely to increase on the workpiece to be processed that is a rigid body. If the flat cut portion becomes unstable due to a load change and chatter occurs on the processed surface, irregularities are formed on the refractive surface. In addition, sagging may occur in the edge shape between the refracting surface and the flat portion. Therefore, it is possible to reduce the load change of the flat cutting portion by forming the refracting surface by dividing the cutting by the flat cutting portion into a plurality of times. By keeping the load change of the flat cut portion small, the occurrence of chatter can be reduced and a refracting surface with less unevenness can be formed. Also, by cutting in multiple times, when forming a groove with a depth of several hundred nanometers to several hundred micrometers, the occurrence of sagging at the inflection point can be suppressed and the refractive surface can be accurately formed. be able to.

  Moreover, as a preferable aspect of the present invention, the flat cutting portion has a first flat cutting portion and a second flat cutting portion, and in the refractive surface forming step, the first flat cutting portion is used, and a predetermined cutting portion is used. It is desirable to form a first refracting surface oriented in the direction and to form a second refracting surface oriented in a direction different from the first refracting surface using the second flat cutting portion. By associating the first refracting surface with the first flat cutting portion and the second refracting surface with the second flat cutting portion, the deterioration of the flat cutting portion can be made uniform. By making the deterioration of the flat cutting portion uniform, the deterioration of the flat cutting portion as a whole can be suppressed, and the refractive surface can be accurately formed over a long period of time.

  Moreover, as a preferable aspect of the present invention, in the trial machining area, based on the machining data, a trial machining process for forming a predetermined shape by a circular cutting part and a flat cutting part, and a predetermined shape formed in the trial machining process are measured. A shape measuring process, a feedback process for correcting the machining data by feeding back a difference between the measurement data obtained in the shape measuring process and the machining data by the machining data, and a flat part forming process based on the corrected machining data It is desirable to perform the refractive surface forming step.

  The microstructure element is formed based on the processing data. A phenomenon in which a desired machining accuracy cannot be obtained due to the fact that the shape is not formed according to the machining data due to the influence of disturbance, a setting failure of the relative position between the machining tool and the workpiece, or the like occurs. In this aspect, the predetermined shape processed in advance is actually measured in the trial processing region. For example, it is desirable to fix the circular cutting part and the flat cutting part to a holder or the like so that they can move in conjunction with each other. Then, the measurement data of the measured micro-shaped element is compared with the original processing data, and the difference between the two data is calculated. The calculated difference is fed back to the machining data. Next, a flat portion forming step, a refracting surface forming step, and the like are performed based on the processing data corrected by the difference amount. In particular, when cutting with a flat bite, a V-shaped bite, or a trapezoidal bite is performed in a plurality of times in the refractive surface forming step, the refractive surface can be accurately formed by controlling the cutting amount. Thereby, the shape process in which the influence of disturbance etc. was reduced can be performed.

  Moreover, as a preferable aspect of the present invention, it is desirable to include a mold transfer process in which the shape formed on the substrate is used as a mold and transferred to another member. Thereby, a replica can be manufactured easily and in large quantities.

  Furthermore, according to the present invention, it is possible to provide a microstructure element manufactured by the above-described method for manufacturing a microstructure element. Thereby, a fine structure element having a flat portion and a refracting surface that forms a minute angle with the flat portion can be manufactured.

  Furthermore, according to the present invention, it is possible to provide a spatial light modulation device having the above-described microstructure element. For example, it is possible to obtain a transmissive liquid crystal spatial light modulator having a prism group composed of microprism elements. By transmitting light through the prism group in which a desired shape is formed, the direction of the emitted light can be accurately refracted and deflected in a predetermined direction. For this reason, the light from the pixels can be refracted and guided onto the projected image of the black matrix portion between the pixels of the spatial light modulator. As a result, a high-quality image can be obtained without recognizing the black matrix portion.

  Furthermore, according to the present invention, a light source that supplies illumination light, the spatial light modulation device that modulates illumination light according to an image signal, a projection lens that projects light modulated by the spatial light modulation device, It is possible to provide a projector characterized by having In the present invention, since the spatial light modulation device described above is provided, a high-quality projected image can be obtained.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a projector 100 according to Embodiment 1 of the present invention. The ultra-high pressure mercury lamp 101 serving as the light source unit includes red light (hereinafter referred to as “R light”) as the first color light, green light (hereinafter referred to as “G light”) as the second color light, and third light. Light including blue light (hereinafter referred to as “B light”) that is colored light is supplied. 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.

  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.

  The G light and B light reflected by the R light transmitting dichroic mirror 106R have their optical paths bent 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.

  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 transmitting dichroic mirror 106R and the B light transmitting dichroic mirror 106G constituting the color separation optical system convert the light supplied from the ultrahigh pressure mercury lamp 101 into the R light that is the first color light, the second 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.

  FIG. 2 is a perspective view showing a main part of the liquid crystal panel 120R. The three liquid crystal panels 120R, 120G, and 120B of the projector 100 differ only in the wavelength region of light to be modulated, and have the same basic configuration. 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. A TFT substrate 205 having TFTs (thin film transistors), transparent electrodes, and the like is formed inside the emission-side dust-proof transparent plate 206. Then, the incident side dustproof transparent plate 201 and the emission side dustproof transparent plate 206 are bonded together with the counter substrate 202 and the TFT substrate 205 facing each other.

  A liquid crystal layer 204 for image display is sealed between the counter substrate 202 and the TFT substrate 205. Further, a black matrix forming layer 203 for light shielding is provided on the incident light side of the liquid crystal layer 204, for example, on the counter substrate 202. The prism group 210 which is a fine structure element is fixed to the TFT substrate 205 on the incident side via an adhesive layer 211. Further, the exit side of the prism group 210 is fixed to the cover glass 213 via an adhesive layer 212.

  FIG. 3 shows a perspective configuration of a main part of the prism group 210. The prism group 210 is made of a transparent member such as a transparent resin. The prism group 210 includes two prism elements 210a and 210b. The prism element 210a provided facing the exit side has a substantially triangular shape in the xz cross section. The prism element 210a has a longitudinal direction in the y-axis direction. The plurality of prism elements 210a are provided in parallel in the x-axis direction on the xy plane. The prism element 210b provided facing the incident side has a substantially triangular shape in the yz section. The prism element 210b has a longitudinal direction in the x-axis direction. The plurality of prism elements 210b are provided in parallel in the y-axis direction on the xy plane. The prism element 210a and the prism element 210b are disposed so that their longitudinal directions are substantially orthogonal to each other.

  The plurality of prism elements 210a are formed so that the size of the triangle shape and the interval in the x-axis direction are both random. By forming the prism elements 210a so that the sizes and intervals are random, the generation of diffracted light due to the periodic structure can be reduced. Similarly to the plurality of prism elements 210a, the plurality of prism elements 210b are also formed such that both the size of the triangle shape and the interval in the x-axis direction are random.

  FIG. 4 shows an xz cross-sectional configuration of the prism element 210a. The prism element 210 a is formed on the substrate 400. The triangular shape of the prism element 210a is composed of a slope 401 that is a first refractive surface oriented in a predetermined direction and a slope 402 that is a second refractive surface oriented in a direction different from the first refractive surface. It is configured. The flat portion 403 between the prism elements 210a is formed substantially parallel to the xy plane and substantially flat. The yz cross-sectional configuration of the prism element 210b is the same as the xz cross-sectional configuration of the prism element 210a.

  By transmitting light through the prism elements 210a and 210b having a desired shape, the direction of the emitted light can be accurately refracted and deflected in a predetermined direction. Therefore, the light from the pixels can be refracted and guided onto the projected image of the black matrix portion between the pixels of the spatial light modulators 110R, 110G, and 110B for each color light. As a result, a high-quality image can be obtained without recognizing the black matrix portion. In addition, according to the projector 100 including the spatial light modulators 110R, 110G, and 110B for each color light, a high-quality projected image can be obtained.

  In the projector 100, the projection light is affected by diffraction, which causes a decrease in image contrast and a decrease in image quality. In the design of the spatial light modulator 110R, as described above, the prism elements 210a and 210b are formed in a random shape, so that light diffraction caused by the periodic structure can be reduced. Further, as will be described in the next embodiment, light diffraction caused by the periodic structure can also be reduced by reducing the formation of machining streaks on the flat portion 403 and the slopes 401 and 402 during the machining process. .

  The prism elements 210a and 210b may not have a random shape but may have a periodic structure. In this case, it is desirable that the prism group 210 is provided with the prism elements 210a and 210b with a period of 3 cycles or more and 15 cycles or less per unit area. Here, the period of the prism elements 210a and 210b is the number of edges at the boundary between the prism elements 210a and 210b, and the edges of the prism elements 210a and 210b that are substantially perpendicular to a straight line along the diameter of the circular area having a unit area. Is the number of The unit area is a predetermined circular region that is transmitted on the prism group 210 when light from one point on the spatial light modulator 110R forms an image on a certain point on the screen 116. The unit area is determined by the F number of the illumination system or the F number of the projection system.

  By providing the prism elements 210a and 210b with a period of 3 cycles or more and 15 cycles or less per unit area, generation of diffracted light due to the periodic structure of the prism group 210 can be reduced. In addition, by providing 3 to 15 prism elements 210a and 210b per unit area, the generation of diffracted light due to the periodic structure of the prism group 210 can be reduced. By reducing the generation of diffracted light, a high-definition image can be displayed.

  In addition, it is preferable that the prism group 210 includes 5 to 12 periods, or 5 to 12 prism elements 210a and 210b per unit area. More preferably, the prism group 210 is provided with 5 to 10 periods, or 5 to 10 prism elements 210a and 210b per unit area. Thereby, generation | occurrence | production of diffracted light can be reduced further and a higher-definition image can be displayed.

  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 dustproof transparent plate 201 and the counter substrate 202, between the emission-side dustproof transparent plate 206 and the TFT substrate 205, and the like. As in the projector 1100 illustrated in FIG. 5, the prism group 1110 may be disposed between the cross dichroic prism 112 and the projection lens 114. Further, the prism group 1110 may be disposed between the projection lens 114 and the screen 116.

  By adopting a configuration in which the respective color lights synthesized by the cross dichroic prism 112 are incident on the prism group 210, the prism group 210 can be integrated into one, and the projector 100 can be configured simply. Further, the prism group 210 may be formed on the second polarizing plate 122 </ b> R or on the R light incident surface of the cross dichroic prism 112. If the prism group 210 is provided for each color light, the refraction angle can be set corresponding to each wavelength.

  A method for manufacturing a microstructure element according to Example 2 of the present invention will be described with reference to FIGS. The prism group 210, which is a fine structure element, is manufactured by using a mold formed by an arc bit that is a circular cutting portion and a flat bit that is a flat cutting portion. As shown in the perspective configuration of FIG. 6, the round bite 600 has a rake face 601 and a flank face 602 provided to give the rake face 601 a thickness. The cutting tool 600 cuts the workpiece by moving it in the direction in which the rake face 601 faces on the workpiece. As shown in the plan configuration of FIG. 7, the cutting edge 703 of the rake face 601 forms an arc having a radius r centered on the point O in the rake face 601. Thus, the round tool 600 which is a circular cutting part has a circular shape. Returning to FIG. 6, the flank 602 is formed so as to be inclined near the cutting edge ridge 703 so that the angle formed with the rake face 601 is smaller than 90 degrees.

  FIG. 8 shows a planar configuration of the flat tool 800. The flat cutting tool 800 has a rake face 811 and a flank (not shown) as in the case of the cutting tool 600 shown in FIG. The flat cutting tool 800 has a first flat cutting part 801 and a second flat cutting part 802. Both the first flat cutting part 801 and the second flat cutting part 802 are formed substantially flat. The first flat cutting part 801 and the second flat cutting part 802 are formed so as to form an angle β with each other. The rake face 811 has a trapezoidal shape in which a triangular tip formed by the first flat cutting portion 801 and the second flat cutting portion 802 is removed. The flat cutting tool 800 may be a V-shaped cutting tool in which the first flat cutting part 801 and the second flat cutting part 802 form a triangular shape.

  FIG. 9 shows the round bite 600 and the flat bite 800 fixed to the bite holder 910. The round bite 600 and the flat bite 800 are installed in the cutting machine through the bite holder 910. The round bite 600 and the flat bite 800 are fixed so that the central axes shown by the alternate long and short dash line form a predetermined distance L. By disposing the round bite 600 and the flat bite 800 in the common bite holder 910, it is possible to prevent displacement due to replacement or the like. Further, by fixing the round bite 600 and the flat bite 800 at a predetermined interval L, the machining data can be set based on the relative positional relationship between the two.

  In the manufacturing method of this embodiment, a case where the shape formed by the round bite 600 and the flat bite 800 is transferred to another member as a die will be described. For this reason, in the cutting with the round bite 600 and the flat bite 800, the prism element 210a is inverted. As a pre-process of the process of forming the prism element 210a, first, trial processing is performed according to the procedure shown in FIG. In step a of FIG. 10, cutting is performed with respect to the flat plate-shaped substrate 1000 for trial processing by the R-bit tool 600. The substrate 1000 is a trial processing region that is different from the substrate for main processing. In step a, as shown in step b, a circular cutting mark 1001 is formed on the substrate 1000.

  Next, the tool holder 910 shown in FIG. 9 is moved to arrange the flat tool 800 on the substrate 1000. The flat cutting tool 800 is further inclined by the first flat cutting part 801 so as to form a first refracting part. As shown in step b of FIG. 10, the flat cutting tool 800 performs cutting at a position different from the cutting trace 1001 on the substrate 1000 by the first flat cutting unit 801. The cutting by the first flat cutting unit 801 is performed in a plurality of times. The point of performing the cutting in a plurality of times will be described in the main processing step described later. By the step b, as shown in the step c, a cutting mark 1002 that is flat and has an inclination with respect to the substrate 1000 is formed on the substrate 1000.

  In step c, the flat cutting tool 800 is tilted by the second flat cutting part 802 so as to form a second refracting part. The flat cutting tool 800 is cut by the second flat cutting unit 802 at a position adjacent to the cutting trace 1002 on the substrate 1000. The cutting by the second flat cutting unit 802 is also performed in a plurality of times. By the process c, as shown in the process d, a cutting mark 1003 that is flat and inclined with respect to the substrate 1000 is formed on the substrate 1000. The cutting trace 1002 and the cutting trace 1003 are formed so as to form an angle α. In this embodiment, a flat bite 800 having an angle β of 90 degrees is used to form a slope having an angle α of 179.94 degrees. The angle β of the flat tool 800 may be smaller than the angle α of the slope to be formed, and is not limited to 90 °. Through the trial processing steps described above, as shown in the perspective configuration of FIG. 11, cutting traces 1001 forming circular grooves and flat cutting traces 1002 and 1003 forming V-shaped grooves are formed on the substrate 1000. .

  Next, in the shape measurement step, the depth, angle, etc. of the shape processed into the substrate 1000 are measured. Data for forming a flat portion can be obtained from the shape of the cutting trace 1001 by the R-Bite 600. Data for forming the first refracting surface and the second refracting surface can be obtained from the shapes of the cutting marks 1002 and 1003 by the flat cutting tool 800, respectively. Then, the difference between the machining data set in the cutting machine and the measurement data obtained in the shape measurement process is fed back to the machining data to correct the machining data. The corrected data is stored in the cutting machine. When a prism element described below is formed using this cutting machine, cutting is performed based on the corrected data.

  Here, in the trial processing step, the relative positional relationship between the cutting traces 1001, 1002, and 1003 corresponds to the positional relationship between the test processing substrate 1000 and the cutting machine. Therefore, the trial processing may be performed on a partial region of the substrate on which the mold of the prism element 210a is formed, or on a separate substrate different from the substrate on which the mold of the prism element 210a is formed. Either is fine.

  FIGS. 12-1 to 12-3 illustrate the procedure of the main processing subsequent to the trial processing. In step a of FIG. 12A, a substrate 1200 for main processing different from the substrate 1000 subjected to the above-described trial processing is used. In the process described below, cutting is performed based on the machining data corrected as described above. The substrate 1000 for trial processing that has undergone the trial processing step described above is removed from a processing machine (not shown). Next, the substrate 1200 for main processing is attached to a processing machine.

  In the flat part forming step, an round bite 600 which is a circular cutting part is used. The R-Bite 600 cuts the surface of the substrate 1200 while moving in a predetermined direction with respect to the substrate 1200. FIG. 12A shows a state in which the substrate 1200 is being cut while moving the cutting tool 600 in a direction perpendicular to the paper surface. When the cutting in the predetermined direction by the round tool 600 is completed once, the round tool 600 is moved away from the substrate 1200 and moved in a direction substantially orthogonal to the predetermined direction. FIG. 12A shows a state in which the cutting tool 600 is moved in a direction parallel to the paper surface, as illustrated by the broken line and the solid line. After the round bite 600 is moved in a direction substantially orthogonal to the predetermined direction, the round bite 600 cuts the substrate 1200 while moving again in the predetermined direction. By repeating this, a flat portion 1201 is formed on the substrate 1200 as shown in step b. The flat part 1201 forms the flat part 403 by a mold transfer process described later.

  Next, in the refracting surface forming step of step c to step h, a slope for forming a refracting surface having a predetermined angle with respect to the flat portion 1201 is formed. In step c, by moving the tool holder 910 (see FIG. 9), the flat tool 800 is placed on the substrate 1200 instead of the Ear tool 600. The flat cutting tool 800 is further tilted so as to form a slope 1203 by the first flat cutting part 801. In step c, cutting is performed by the first flat cutting portion 801 at a depth corresponding to, for example, one fifth of the cutting depth for forming a desired prism element. As a result, as shown in step d, a cutting trace 1202 having a depth corresponding to approximately one fifth of the cutting depth for forming a desired prism element is formed.

  From step c to step e shown in FIG. 12-2, cutting for forming a desired prism element is performed, for example, five times. By performing the cutting by the first flat cutting part 801 in five steps, a slope 1203 is formed as shown in step f. As described above, the slope 1203 is formed using the first flat cutting portion 801. The inclined surface 1203 forms an inclined surface 401 that is a first refracting surface by a mold transfer process described later.

  Next, the flat tool 800 is tilted by the second flat cutting part 802 so as to form a slope 1204. In step g, as in the case of the first flat cutting portion 801, the second flat cutting portion 802 has a depth corresponding to about one fifth of the cutting depth for forming a desired prism element. Cut 5 times. By performing the cutting by the second flat cutting portion 802 in five steps, a slope 1204 is formed as shown in step h. As described above, the inclined surface 1204 is formed by using the second flat cutting portion 802. For example, when forming a groove having a depth of 820 nanometers, by performing the cutting process in a plurality of times, an increase in the load applied to the flat cutting part is reduced, and the load fluctuation on the processing object that is a rigid body Can be reduced. Further, by performing the cutting process in a plurality of times, the sagging at the inflection point can be suppressed, and the highly accurate slope 402 can be formed. The inclined surface 1204 forms an inclined surface 402 that is a second refracting surface by a mold transfer process described later.

  After the inclined surfaces 1203 and 1204 are formed on the substrate 1200 by the refractive surface forming step, the shape formed on the substrate 1200 is transferred to the transparent member 1205 as another member by using the shape formed on the substrate 1200 by the mold transfer step shown in step i. . Replicas can be manufactured easily and in large quantities by the mold transfer process. Thus, the prism element 210a shown in step j is completed. The prism element 210b can be manufactured by the same manufacturing procedure as the prism element 210b. The prism group 210 can be manufactured by bonding the prism element 210a and the prism element 210b on the substrate 400 side so that the longitudinal directions thereof are substantially orthogonal to each other.

  By using the round bite 600 to form the flat portion 1201, the pressure applied to the contact portion between the round bite 600 and the substrate 1200 is kept substantially constant, and the round bite 600 is stabilized on the substrate 1200. By stabilizing the round bite 600 on the substrate 1200, the occurrence of chatter is reduced, and a substantially flat flat portion 1201 with less unevenness can be formed on the substrate 1200. By reducing the unevenness of the flat portion 1201, the prism group 210 can obtain optical characteristics that allow the flat portion 403 to transmit light effectively.

  Further, since the flat portion 1201 serves as a reference surface for the refracting surface forming step, the inclined surfaces 1203 and 1204 can be formed substantially flat by forming the flat portion 1201 with less unevenness. By reducing the unevenness of the inclined surfaces 1203 and 1204, the prism group 210 efficiently refracts light in a desired direction on the inclined surface 401 that is the first refractive surface and the inclined surface 402 that is the second refractive surface. Can be obtained. Furthermore, since the formation of machining streaks on the flat portion 403 and the slopes 401 and 402 can be reduced, light diffraction caused by the periodic structure can be reduced.

  In the refracting surface forming step, the inclined surfaces 1203, 1204 having a desired angle with respect to the flat portion 1201 are formed by fixing the flat cutting tool 800 so that the inclination of the flat cutting portions 801, 802 matches the inclination of the inclined surfaces 1203, 1204. Can be formed. Since the inclination amount of the flat tool 800 can be controlled with a mechanical accuracy of about 1 / 100,000 by a normal control method, the inclined surfaces 1203 and 1204 controlled with high accuracy can be formed. By controlling the inclination angles of the inclined surfaces 1203 and 1204 with high accuracy, the inclined surfaces 401 and 402 having minute inclination angles can be formed. Thereby, there exists an effect that a desired fine shape element can be manufactured correctly.

  In the refracting surface forming step, when the inclined surfaces 1203 and 1204 are formed by only one cutting, the depth of cut by the flat cutting tool 800 is large, so that the load change of the flat cutting tool 800 during cutting becomes large. When chatter occurs due to the flat cutting tool 800 becoming unstable due to a load change, irregularities are formed on the slopes 1203 and 1204.

  Therefore, by forming the inclined surfaces 1203 and 1204 by dividing the cutting with the flat cutting tool 800 a plurality of times, it is possible to reduce the load change of the flat cutting tool 800. By keeping the load change of the flat tool 800 small, it is possible to reduce the occurrence of chatter and to form the inclined surfaces 1203 and 1204 with less unevenness. Thereby, the slopes 1203 and 1204 can be formed accurately. In the refracting surface forming step, the cutting by the first flat cutting part 801 and the second flat cutting part 802 is not limited to being performed in five steps. The cutting by the first flat cutting part 801 and the second flat cutting part 802 may be divided into a plurality of times. For example, it is desirable that the processing object formed by nickel plating is processed in 5 to 17 times with one cutting depth of 50 to 200 nanometers.

  In the refracting surface forming step, the first flat cutting portion 801 is used to form the inclined surface 1203. The second flat cutting portion 802 is used for forming the slope 1204. By making the two cutting parts 801 and 802 of the flat cutting tool 800 correspond to the two inclined surfaces 1203 and 1204 formed on the substrate 1200, the deterioration of the cutting parts 801 and 802 of the flat cutting tool 800 can be made uniform. . By making the deterioration of the cutting part uniform, the deterioration of the flat cutting tool 800 as a whole can be suppressed, and the inclined surfaces 1203 and 1204 can be accurately formed over a long period of time.

FIG. 13 illustrates the relationship between the feed pitch P of the round bite 600 and the circular radius r of the round bite 600 in the flat portion forming step. The feed pitch P is a distance by which the round bite 600 is shifted in a direction substantially orthogonal to a predetermined direction in which the round bite 600 moves while cutting the substrate 1200. It is desirable that the feed pitch P and the radius r satisfy the formula (1).
1.0 × 10 ⁻⁸ > P ² / 8r (1)

In the formula (1), P ² / 8r is a height difference between the ridge line portion 1301 generated between the cutting traces by the round bite 600 and the substantially central portion 1302 of the cutting trace by the round bite 600, and is flat. The maximum value Rmax of the roughness of the flat part 1201 formed by the part forming process is shown. According to Expression (3), by setting the maximum roughness value Rmax to be less than 1.0 × 10 ⁻⁸ meters, it is possible to form a substantially flat flat portion 1203 with less unevenness.

  Cutting may be affected by environmental changes such as temperature, pressure, and humidity around the cutting machine. In particular, since the temperature directly affects the thermal expansion of the material and the processing apparatus, the cutting is performed in an environment in which the temperature is controlled to ± 0.025 degrees, for example. Regardless of such temperature control, the temperature around the cutting machine changes every several hours due to the influence of changes in the outside air temperature, temperature changes in the cutting machine, and the like. For this reason, it is desirable to complete the cutting process in as short a time as possible.

  When cutting a region of several tens of millimeters square in the flat portion forming step, the time required for the cutting greatly varies depending on the feed pitch P of the round bite 600. Therefore, by appropriately setting the feed pitch P that satisfies the expression (1), it is possible to prevent the machining time from being unnecessarily prolonged. If the processing time can be shortened, the influence of environmental changes in the surroundings can be reduced, and cutting can be performed stably. Thereby, the substantially flat flat part 1201 can be formed, and cutting can be performed stably.

It is desirable that the radius r further satisfies the formula (2).
2.0 × 10 ⁻³ ≦ r ≦ 6.0 × 10 ⁻³ (2)

If the radius r is set to a value smaller than the range of the expression (2), the radius r of the round bite 600 becomes smaller than the feed pitch P. As a result, the maximum roughness value Rmax on the processed surface is increased. Become. Or if it changes so that the feed pitch P may also be made into a small value according to the radius r of the round bite 600, the processing time for forming the flat part 1201 will become long. If the processing time is long, it becomes difficult to stably perform the cutting due to the influence of the surrounding environment. Further, when the radius r is set to a value larger than the range of the expression (2), the R-bite 600 may become unstable on the substrate 1200 and cause chatter. By using the round bite 600 having a radius r of 2.0 × 10 ⁻³ meters or more, the processing time of the flat portion 1201 can be shortened. By shortening the machining time, it is possible to reduce the influence of surrounding environmental changes and perform the cutting process stably. Further, by using the round tool 600 having a radius r of 6.0 × 10 ⁻³ meters or more, chatter is reduced, and a substantially flat flat portion 1201 with less unevenness can be formed. Thereby, it can cut stably and can form the substantially flat flat part 1201. FIG.

It is desirable that the feed pitch P further satisfies the expression (3).
5.0 × 10 ⁻⁶ ≦ P ≦ 20 × 10 ⁻⁶ (3)

If the feed pitch P of the round bite 600 is set to a value smaller than the range of the expression (3), the processing time for forming the flat portion 1201 becomes long. If the processing time is long, it becomes difficult to stably perform the cutting due to the influence of the surrounding environment. Further, when the feed pitch P is set to a value larger than the range of the expression (3), the round bite 600 having a circular shape with a large radius r is used. When the radius r is increased, the R-bite 600 may become unstable on the substrate 1200 and cause chatter. By forming the flat portion 1201 with a feed pitch P of 5.0 × 10 ⁻⁶ meters or more, the processing time of the flat portion 1201 can be shortened. By shortening the machining time, it is possible to reduce the influence of surrounding environmental changes and perform the cutting process stably. Further, by forming the flat portion 1201 with a feed pitch P of 20 × 10 ⁻⁶ meters or more, chatter is reduced, and a substantially flat flat portion 1201 with few irregularities can be formed. Thereby, it can cut stably and can form the substantially flat flat part 1201. FIG.

  FIG. 14 illustrates a range of the radius r and the feed pitch P of the round bite 600 that is preferable for use in forming the flat portion 1201. In the graph of FIG. 14, the vertical axis represents the feed pitch P, and the horizontal axis represents the radius r of the round bite 600. A hatched portion and a blank portion in the drawing represent taking the maximum value Rmax of roughness as shown in FIG. The above formulas (1), (2), and (3) are all satisfied in the range surrounded by the thick line in the graph of FIG. Therefore, by setting the radius r and the feed pitch P within the range surrounded by the thick line in FIG. 14, it is possible to stably perform the cutting process and form the substantially flat flat portion 1201.

  Next, based on FIG. 16, a flow until the mold is manufactured in the manufacturing procedure of the prism elements 210 a and 210 b will be described. First, in step S601, an operator sets processing data such as a processing position, a processing angle, a processing depth, a tool rotation speed, a processing speed, and the number of times of cutting in a refractive surface forming process to form a desired fine shape. Input to the control unit. Then, the round tool 600 and the flat tool 800 are attached to the tool holder 910 (see FIG. 9) of the processing machine. In step S602, a substrate 1000, which is a work for trial processing, is set in a holder of a processing machine. In step S603, the trial processing as described above is performed on the substrate 1000.

  In step S604, the depth of the groove shape obtained by trial processing using a laser microscope, an atomic force microscope, or an interference optical measuring instrument without removing the substrate 1000 from the work holder. Measure slope angle, pitch, etc. The parameter of the measurement data is preferably at least one of pitch, angle, depth, and flat surface roughness. Even when the measurement is performed by removing the substrate 1000 as the measurement object from the work holder, it is possible to obtain information necessary for feedback by measuring the relative relationship between the processed shapes.

  In step S605, the difference between the measurement data and the machining data is fed back to the machining data. Moreover, the workpiece for trial processing is removed from the holder of a processing machine. Next, in step S606, the machining data is corrected based on the fed back difference value. Specifically, the cutting angle of the cutting tool, the cutting depth, the pitch, the parameters for flat surface processing, etc. are corrected. For example, the machining angle, cutting depth, groove pitch, and flat surface machining parameters are corrected by bite angle correction, bite depth correction, feed pitch correction, and feed pitch correction, respectively. In step S607, the work for main processing is set in the holder of the processing machine. At this time, in the workpiece for main machining, an upper layer surface or another area different from the area for main machining may be used as the area for trial machining. This is the end of the trial machining process.

  Next, based on the corrected data, in step S608, the flat portion 1201 (step a in FIG. 12-1) is cut by the round tool 600. In step S609, the flat cutting tool 800 is disposed on the substrate 1200 instead of the round cutting tool 600, and the inclined surface 1203 (steps cf of FIGS. 12-1 and 12-2) is formed by the first flat cutting portion 801. . Cutting by the first flat cutting unit 801 is performed by the number of cuttings input to the control unit. Next, the inclination of the flat cutting tool 800 is changed, and the inclined surface 1204 (steps g and h in FIG. 12-2) is formed by the second flat cutting portion 802. Cutting by the second flat cutting unit 802 is performed by the number of cuttings input to the control unit.

  In step S610, it is determined whether or not the predetermined shape of the groove has been finished. If the determination result is false, in step S611, the position of the machining head holding the flat cutting tool 800 is moved according to the procedure described above. And the process of step S609 is repeated. If the determination result in step S610 is true, the processing is terminated. Thereby, the shape process in which the influence of disturbance etc. was reduced can be performed. Further, as described above, the test processing substrate 1000 and the main processing substrate 1200 may be the same.

  According to the manufacturing method of the present embodiment, the applicant applied the flat portion 1201 to the 10-point average roughness Rz = 17.2 nm, the arithmetic average roughness Ra = 19.0 nm, and the slopes 1203 and 1204 to the 10-point average roughness Rz =. It was confirmed that the film can be formed at 5.6 nm and arithmetic average roughness Ra = 5.0 nm. In addition, periodic machining streaks were not observed in any of the flat portion 1201 and the slopes 1203 and 1204. As described above, since a substantially flat portion 1201 and inclined surfaces 1203 and 1204 can be formed, a desired fine shape can be accurately manufactured. The flat portion 1201 and the inclined surfaces 1203 and 1204 are represented by lines in the cross section of the substrate 1200. The ten-point average roughness Rz is the average of the absolute values of the elevations at the five highest points from the average line of the roughness curve and the depth at the five lowest points in the reference length of the roughness curve. Is the sum of the absolute values of The arithmetic average roughness Ra is a value obtained by adding and averaging the absolute values of deviations from the average line of the roughness curve to the roughness curve in the reference length of the roughness curve.

  The applicant can realize the processing of the microstructure element with the above-mentioned surface roughness, and can reduce the deterioration of the characteristics of the microstructure element due to the generation of diffracted light due to the processing marks and the variation in the inclination of the refractive surface, etc. It was confirmed that In addition, it is good also as manufacturing the microstructure element of a shape different from said microstructure element by applying the manufacturing method of a present Example. Further, the manufacturing method of the present embodiment is not limited to the case including the mold transfer step, and the fine structure element may be manufactured by the same procedure as that for forming the mold of the present embodiment.

  As described above, the method for manufacturing a microstructure element according to the present invention is useful for accurately manufacturing a desired fine shape, and particularly for manufacturing a microstructure element used for a spatial light modulation device of a projector. Is suitable.

1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment of the invention. The figure which shows the principal part perspective cross section of a liquid crystal panel. The figure which shows the principal part perspective structure of a prism group. The figure which shows the cross-sectional structure of a prism group. The figure explaining the arrangement position of a prism group. The figure which shows the perspective structure of an R bite. The figure which shows the planar structure of an R byte. The figure which shows the plane structure of a flat bite. The figure which shows the round bite and the flat bite of the state fixed to the bite holder. The figure explaining the procedure of trial processing among the manufacturing methods concerning Example 2. FIG. The figure which shows the isometric view structure of the board | substrate with which the groove | channel was formed by trial processing. The figure explaining the procedure of this process among the manufacturing methods which concern on Example 2. FIG. The figure explaining the procedure of this process among the manufacturing methods which concern on Example 2. FIG. The figure explaining the procedure of this process among the manufacturing methods which concern on Example 2. FIG. The figure explaining the relationship between the radius of a round bite and a feed pitch. The figure explaining the range of the radius of a round bite, and a feed pitch. The figure which shows the maximum value of roughness. FIG. 6 is a diagram for explaining a manufacturing procedure of Example 2.

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, 106GB B light transmission dichroic mirror, 107 Reflection mirror, 108 Relay lens, 110R Spatial light modulation device for 1st color light, 110G Spatial light modulator for second color light, 110B Spatial light modulator for third color light, 112 Cross dichroic prism, 112a, 112b Dichroic film, 114 Projection lens, 116 Screen, 120R, 120G, 120B Liquid crystal panel, 121R, 121G, 121B First polarizing plate, 122R, 122G, 122B Second polarizing plate, 123R, 123B λ / 2 phase difference plate, 124R, 124B glass plate, 201 incident-side dustproof transparent plate, 202 counter substrate, 203 Black matrix forming layer, 204 Liquid crystal layer, 205 TFT substrate, 206 Ejection side dustproof transparent plate, 210 Prism group, 210a, 210b Prism element, 211, 212 Adhesive layer, 213 Cover glass, 400 substrate, 401 First refractive surface 402 Second refractive surface, 403 flat part, 1100 projector, 1110 prism group, 600 round bite, 601 rake face, 602 flank face, 703 cutting edge, 800 flat bite, 801 first flat cutting part, 802 first 2 flat cutting part, 811 rake face, 910 tool holder, 1000 substrate, 1001, 1002, 1003 cutting trace, 1200 substrate, 1201 flat part, 1202 cutting trace, 1203, 1204 slope, 1205 transparent member, 1301 ridge line part, 1302 During ~ Heart

Claims (11)

By using a circular cutting part having a circular shape, a flat part forming step for forming a flat part on the substrate;
And a refracting surface forming step of forming a refracting surface having a predetermined angle with respect to the flat portion by using a flat cutting portion formed substantially flat. In the flat portion forming step, the substrate is cut while moving the circular cutting portion in a predetermined direction with respect to the substrate,
When the feed pitch of the circular cutting part in a direction substantially orthogonal to the predetermined direction is P (meter), and the radius of the circular shape of the circular cutting part is r (meter), the following conditional expression is satisfied. The method for manufacturing a microstructure element according to claim 1, wherein the method is satisfied.
1.0 × 10 ⁻⁸ > P ² / 8r Furthermore, the following conditional expressions are satisfied, The manufacturing method of the microstructure element of Claim 2 characterized by the above-mentioned.
2.0 × 10 ⁻³ ≦ r ≦ 6.0 × 10 ⁻³ Furthermore, the following conditional expressions are satisfied, The manufacturing method of the microstructure element of Claim 2 or 3 characterized by the above-mentioned.
5.0 × 10 ⁻⁶ ≦ P ≦ 20 × 10 ⁻⁶   5. The microstructure element according to claim 1, wherein in the refractive surface forming step, the refractive surface is formed by performing the cutting by the flat cutting portion in a plurality of times. Manufacturing method. The flat cutting part has a first flat cutting part and a second flat cutting part,
In the refracting surface forming step, the first refracting surface oriented in a predetermined direction is formed using the first flat cutting portion, and the first refracting surface is formed using the second flat cutting portion. The method for manufacturing a microstructure element according to any one of claims 1 to 5, wherein a second refractive surface directed in a direction different from the surface is formed. In the trial machining area, based on machining data, a trial machining step of forming a predetermined shape by the circular cutting part and the flat cutting part,
A shape measuring step for measuring the predetermined shape formed in the trial processing step;
A feedback step of correcting the machining data by feeding back the difference between the measurement data obtained in the shape measurement step and the machining data with the machining data;
The method for manufacturing a microstructure element according to any one of claims 1 to 6, wherein the flat portion forming step and the refractive surface forming step are performed based on the corrected processing data.   The method for manufacturing a microstructure element according to any one of claims 1 to 7, further comprising a mold transfer step in which a shape formed on the substrate is used as a mold and transferred to another member.   A microstructure element manufactured by the method for manufacturing a microstructure element according to any one of claims 1 to 8.   A spatial light modulator comprising the microstructure element according to claim 9. A light source for supplying illumination light;
The spatial light modulation device according to claim 10, wherein the illumination light is modulated according to an image signal;
And a projection lens that projects the light modulated by the spatial light modulator.

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