WO2008068900A1

WO2008068900A1 - Spatial phase modulation element and projector

Info

Publication number: WO2008068900A1
Application number: PCT/JP2007/001345
Authority: WO
Inventors: Yoshiaki Horikawa
Original assignee: Olympus Corporation
Priority date: 2006-12-07
Filing date: 2007-12-04
Publication date: 2008-06-12
Also published as: JP2008145613A; JP5148868B2

Abstract

A spatial phase modulation element (12) performing projection display of a video image by passing light from a light source and exiting phase modulated diffraction light. A plurality of sectional parts for performing phase modulation are arranged two-dimensionally, and the number of sections in each sectional part is equal to or larger than that of the pixels.

Description

Specification

Spatial phase modulation element and projection apparatus

Technical field

The present invention relates to a novel spatial phase modulation element that can be used in a projection apparatus. Also

A projection device using the spatial phase modulation element is provided.

Background art

[0002] For general projectors, transmissive liquid crystals (Liquid Grysta to LG), reflective liquid crystals (Liquid Crystal On Si I icon COS), or DMD (Digtal Micro-mirror Device) are used. There is something.

[0003] In a projector using a conventional LG or LG0S, the image to be projected on the LG or LG0S liquid crystal is displayed, the liquid crystal is illuminated with the irradiating light, and the transmitted or reflected light from the liquid crystal is transmitted through the projection lens. The image was displayed by magnifying it onto the screen. On the other hand, in a projection device using DMD, binary control of 0N / 0FF is applied to the voltage applied to the electrode corresponding to the micromirror that constitutes the mirror element of DMD according to the image to be projected. Then, the state of the micromirror was switched, and the incident light was reflected on the projection optical path and the image was projected onto the screen via the projection lens.

[0004] A projector using a liquid crystal or a DMD as described above has a light source, an illumination optical system, and a projection lens. The illumination light from the light source is temporarily displayed on a liquid crystal or the like and transmitted or transmitted. A method of enlarging the reflected image light with a projection lens was used. In addition, in such a projector, when a color sequential method is used to display the color of an image, a color filter that switches the color of the light source is used. On the other hand, if a multi-plate method using multiple elements for each color is adopted, a color separation / synthesis optical system is required.

[0005] In addition, conventional projectors generally use an incoherent light source such as a high-pressure mercury lamp as a light source. In this case, a complex illumination optical system is required to illuminate the light from the light source efficiently and uniformly on the image display element such as a liquid crystal. As a result, if the illumination optical system becomes complicated and large The technical problem to say there were. In addition, when projecting high-definition images, a more accurate projection lens is required, and there has been a technical problem that the projection lens becomes larger and the projection apparatus itself becomes larger. In addition, with the color display of high-quality images, there are technical problems that a color filter is provided and a complicated color synthesis / separation optical system is required, which further increases the size of the projection apparatus. Therefore, there has been a problem that the production cost increases as the optical configuration of these projection apparatuses becomes larger and more complicated.

[0006] As one solution to these technical problems, for example, a simple illumination optical system using a spatial phase modulator (SPM) as shown in FIG. A small projection device that can be completed with a simple projection lens is disclosed.

[0007] In the following, as a conventional example of a projection apparatus that projects an image with diffracted light, the principle of the projection apparatus 200 of FIG.

[0008] In FIG. 20, linearly polarized light emitted from the light source (laser) 201 is incident on a PBS (polarized beam splitter) 203, reflected in the PBS203, and incident on an L COS202 as a spatial phase modulation element. Let A λ / 4 plate (not shown) is provided between the PBS 203 and the L COS 202. Here, the diffracted light 204 phase-modulated by the LCOS 202 according to the image information to be projected passes through the λ / 4 plate again, further passes through the PBS 203, and passes through the projection lens 205 to the screen 206. Project an image and display it. In FIG. 20, binary modulation with a phase difference of π can be obtained by the presence or absence of phase modulation of L COS202.

However, in the projection apparatus 200 as shown in FIG. 20, since the L COS202 is used, the amount of light is reduced when the light reciprocates in the liquid crystal, and the light use efficiency is low. There is a technical problem that the light source becomes darker or that the light source needs to be enlarged to ensure the brightness of the displayed image. In addition, there was no mention of the focus on the resolution of the displayed image or the improvement. In addition, since the removal of the 0th-order diffracted light 207 is insufficient, the 0th-order diffracted light 207 is mixed in the image on the screen 206 and the influence remains, so that the image is not clear. There was also a problem.

[0010] As described above, the conventional projection apparatus using the spatial phase modulation element has some technical problems.

In view of the above problems, an object of the present invention is to provide a spatial phase modulation element capable of ensuring a sufficient resolution of an image to be projected and displayed while the configuration of the apparatus is simple. It is another object of the present invention to provide a novel projection apparatus that can skillfully avoid the influence of 0th-order diffracted light.

Patent Document 1: International Publication No. WO / 2005/059881 Pamphlet

Disclosure of the invention

[0012] In order to solve the above-described problem, the first spatial phase modulation element of the present invention performs projection display of an image by emitting diffracted light that has undergone phase modulation via light from a light source. Spatial phase modulation element for fastening, and an image in which a plurality of partition parts for performing phase modulation in this spatial phase modulation element are arranged two-dimensionally and the number of sections in each partition part is projected and displayed A spatial phase modulation element equal to or greater than the number of pixels is provided.

[0013] Further, as a first form of the first spatial phase modulation element of the present invention, the number of vertical columns and the number of horizontal columns of the partition portion are set so that the number of vertical columns and the horizontal number of pixels of the displayed image are Desirably equal to or greater than the number of columns.

[0014] Furthermore, the first spatial phase modulation element of the present invention or the spatial phase modulation element of the first form is the second form, wherein the number of vertical columns and the number of horizontal columns of the partition portion are two. A power is preferable.

[0015] Moreover, the first spatial phase modulation element of the present invention or the spatial phase modulation element in the first mode or the second mode is, as the third mode, all of the partition portions for performing phase modulation. It is further desirable that the contour shape in the phase modulation section formed by the above is a square having the same aspect ratio and does not depend on the aspect ratio of the displayed image.

[0016] Then, the first spatial phase modulation element of the present invention or any one of the first to third modes—the spatial phase modulation element in one of the forms is the light from the light source as the fourth mode. A mirror surface for performing phase modulation when reflecting light, and an elastic member disposed on the mirror surface corresponding to each partition portion for performing phase modulation and a corresponding elastic member It is also possible to provide an electrode for moving or deforming the mirror surface against the restoring force of the elastic member by applying a voltage, and a substrate on which the electrode is arranged.

[0017] Further, in the spatial phase modulation element according to the fourth aspect of the present invention, as a first aspect, the mirror surface moves in response to the application of voltage to the electrode, and the amount of movement or deformation is The phase modulation amount may be determined accordingly.

[0018] Further, in the spatial phase modulation element according to the first aspect of the spatial phase modulation element of the fourth aspect of the present invention, as the second aspect, the movement control or deformation control of the one surface of the mirror is performed as described above. It may be determined only by whether or not voltage is applied to the electrodes.

In the spatial phase modulation element according to the second aspect of the spatial phase modulation element of the fourth aspect of the present invention, as the first control, the amount of movement or deformation of the mirror surface is the light of the incident light source The phase difference corresponding to ½ wavelength may be formed in the emitted diffracted light.

[0020] In the spatial phase modulation element of the first aspect of the spatial phase modulation element of the fourth aspect of the present invention, as a third aspect, the control of the movement amount or deformation amount of the mirror surface is applied to the electrode. And the amount of change in the applied voltage may be controlled to increase or decrease continuously and sequentially.

In the spatial phase modulation element according to the third aspect of the spatial phase modulation element of the fourth aspect of the present invention, as the second control, the maximum amount of movement or deformation of the mirror surface is the light of the incident light source It is preferable that the phase difference formed in the emitted diffracted light is within one wavelength.

[0022] In the spatial phase modulation element according to the fourth aspect of the present invention, the spatial phase modulation element according to any one of the first aspect to the third aspect, or the spatial phase modulation element capable of the first or second control, One side of the mirror is formed from an integral mirror. The elastic member and the electrode may be arranged corresponding to each partition portion for performing phase modulation of the mirror surface in the body-shaped mirror.

[0023] In the spatial phase modulation element of the fourth aspect of the present invention, the spatial phase modulation element of any one of the first aspect to the third aspect or the spatial phase modulation element capable of the first or second control, The mirror surface may be formed as an individual mirror in each partition for performing phase modulation, and an elastic member and an electrode may be arranged for each mirror.

[0024] In the spatial phase modulation element according to the fourth aspect of the present invention, the surface accuracy of the mirror surface is preferably 50 nm or less.

[0025] In the spatial phase modulation element according to the fourth aspect of the present invention, the surface roughness of the mirror surface is preferably 5 nm or less.

[0026] Furthermore, the first projection device of the present invention includes a light source, a condensing optical system that collects light emitted from the light source, and a light that is emitted from the light source collects via the condensing optical system. Is the number of sections of each section for phase modulation arranged in two dimensions arranged in the middle of the light condensing position equal to the number of pixels of the projected image displayed? There is also provided a projection device comprising: a large number of spatial phase modulation elements; and a shielding member that shields 0th-order diffracted light that is emitted without being diffracted from the spatial phase modulation elements and collected at the light collection position.

[0027] In the first projection device of the present invention, as a first embodiment, each partition portion of the spatial phase modulation element is based on spatial phase information generated corresponding to image information that is projected and displayed. The phase to be modulated is controlled, and each pixel of the projected and displayed image is preferably formed by diffracted light emitted from all the partition portions of the spatial phase modulation element.

In the first projection device of the present invention, as a second embodiment, the light source is disposed at a position separated from the optical axis of the condensing optical system, and the shielding member is emitted from the spatial phase modulation element Therefore, it is desirable to dispose the light beam outside the diffracted light beam that forms the projected image.

[0029] The first projection device of the present invention or the projection in the first embodiment or the second embodiment. In the shadow device, as a first aspect, the number of vertical columns and the number of horizontal columns of the partition portion in the spatial phase modulation element are equal to the number of vertical columns and horizontal columns of pixels of the image displayed by projection. Or more.

[0030] The first projection device of the present invention, the projection device of the first embodiment or the second embodiment, or the projection device according to the first aspect, as a second aspect, is the longitudinal of the partition portion in the spatial phase modulation element. It is preferable that the number of columns and the number of horizontal columns are powers of 2.

[0031] The first projection device of the present invention, the projection device of the first embodiment or the second embodiment, or the projection device according to the first embodiment or the second embodiment is a spatial phase modulation element of the third embodiment. The contour shape in the phase modulation section formed by all of the partition portions for performing the phase modulation is a square having the same aspect ratio, and may not depend on the aspect ratio of the displayed image.

[0032] The first projection device of the present invention, the projection device of the first mode or the second mode, or any one of the projection devices according to the first mode to the third mode may be a space. The phase modulation element has a mirror surface for performing phase modulation when reflecting light from the light source, and is arranged corresponding to each partition portion for performing phase modulation provided on the mirror surface. A member, an electrode arranged corresponding to each elastic member, and piled on the restoring force of the elastic member by applying a voltage to move or deform the mirror surface; and a substrate on which the electrode is arranged It may be composed of,.

[0033] In the projection device of the fourth aspect of the present invention, as a first aspect, the mirror surface of the spatial phase modulation element moves in response to the application of voltage to the electrode, and the amount of movement or deformation It is preferable that the phase modulation amount is determined according to the above.

[0034] In the first aspect of the projection apparatus of the fourth aspect of the present invention, as the second aspect, the movement control or deformation control of the mirror surface in the spatial phase modulation element is performed only in the presence or absence of voltage application to the electrode. It may be determined by.

[0035] In the second aspect of the projection device of the fourth aspect of the present invention, as the first control, the amount of movement or deformation of the mirror surface in the spatial phase modulation element is incident light. It may be equivalent to a quarter wavelength of the source light, and a phase difference corresponding to a half wavelength may be formed in the emitted diffracted light.

[0036] As a third aspect of the projection apparatus of the fourth aspect of the present invention, the control of the movement amount or deformation amount of the mirror surface in the spatial phase modulation element depends on the voltage value applied to the electrode. The amount of change in the applied voltage may be controlled to be continuously increased or decreased.

[0037] As the second control in the third aspect of the projection device of the fourth aspect of the present invention, the maximum movement amount or deformation amount of the mirror surface in the spatial phase modulation element is 1 of the light of the incident light source. It is preferable that the phase difference formed within the diffracted light to be output is within one wavelength.

[0038] In the projection device according to the fourth aspect of the present invention, the projection device according to any one of the first to third aspects, or the projection device capable of the first or second control, the mirror in the spatial phase modulation element It is desirable that one surface is formed from an integrated mirror, and an elastic member and an electrode are arranged corresponding to each partition portion for performing phase modulation of the mirror surface in the integrated mirror.

[0039] In the projection device according to the fourth aspect of the present invention, the projection device according to any one of the first to third aspects, or the projection device capable of the first or second control, the mirror in the spatial phase modulation element The surface is preferably formed as an individual mirror in each partition portion for performing phase modulation, and an elastic member and an electrode are preferably arranged for each mirror.

[0040] In the projection device according to the fourth aspect of the present invention, it is desirable that the surface accuracy of the mirror surface in the spatial phase modulation element is 50 nm or less.

[0041] In the projection device according to the fourth aspect of the present invention, it is desirable that the surface roughness of the mirror surface of the spatial phase modulation element be 5 nm or less.

Brief Description of Drawings

[0042] The present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

FIG. 1 shows an embodiment of a projection apparatus using a transmissive spatial phase modulation element. FIG. 2 is a flowchart of signal processing for a signal input to a spatial phase modulation element in one embodiment of the present invention.

FIG. 3 is a schematic diagram of a switch circuit provided on a substrate of a spatial phase modulation element as one embodiment of the present invention.

[Fig. 4] As an example of displaying images in color by color sequential light source control, the relationship between the operation of the spatial phase modulator and the light emission operations of the red, green, and blue light sources is the same time axis. It is the figure which showed the timing chart expressed as

FIG. 5 is a schematic diagram showing how the readout light is diffracted by the spatial phase information displayed by the spatial phase modulation element, and the diffracted light is projected onto the screen.

One embodiment of FIG. 6 present invention, theta angle of incidence of the illumination light of the reading light incident on the diffraction grating of the grating pitch d which is displayed in the transmission type spatial phase modulator of FIG. 5 _R = FIG. 5 is a diagram showing the correspondence between the diffraction angle 0 s of diffracted light and the distance d of the diffraction grating when the wavelength of illumination light is λ = 0.5 m.

FIG. 7 is a plan view of a projection apparatus including a condensing optical system, a transmissive spatial phase modulation element, and a shielding member in one embodiment of the present invention.

FIG. 8 is a schematic diagram of a real domain corresponding to an image to be projected.

[Fig. 9A] The real domain in Fig. 8 is equal in length and width in the spatial phase modulator.

<It is the schematic diagram of the Fourier domain which carried out Fourier transform.

FIG. 9B is a schematic diagram of the Fourier domain of FIG. 9A in which the number of columns in the vertical partition portion is the same as the number of columns in the horizontal partition portion.

FIG. 9G is a schematic diagram of the Fourier domain of FIG. 9A in which the number of columns in the horizontal partition portion is the same as the number of columns in the vertical partition portion.

[FIG. 10A] A diagram showing a graph in which g (χ) is an image to be projected.

[FIG. 10 0] is a diagram showing a graph obtained by performing a one-dimensional Fourier transform of g (χ) on the image to be projected and converting the coordinates to G (v).

[FIG. 1 1] In another embodiment of the present invention, a condensing optical system and a reflective spatial phase modulation It is a top view of the projection apparatus provided with the element and the shielding member.

FIG. 12 is a plan view of a projection apparatus configured differently from FIG. 11 as still another embodiment of the present invention.

FIG. 13A is a plan view of a projection apparatus that includes a reflective spatial phase modulation element and a shielding member and performs full-color display of an image in one embodiment of the present invention.

CO

FIG. 13B is a side view of the projection device of FIG.

[FIG. 14A] As an embodiment of the present invention, a mirror composed of one surface of an integrated mirror.

FIG. 3 is a perspective view of an M M D element in which — is arranged on a substrate.

FIG. 14B is a perspective view of an MMD element in which a plurality of substantially square mirrors are two-dimensionally arranged on a substrate in another embodiment of the present invention.

FIG. 15A is a cross-sectional view taken along line XV-A of the MMD element shown in FIG. 14A as one embodiment of the present invention.

FIG. 15B is a cross-sectional view of the MMD element in FIG. 15A during phase modulation of light.

FIG. 16A is a cross-sectional view taken along line X V I — A of the MMD element shown in FIG. 14B as another embodiment of the present invention.

FIG. 16B is a cross-sectional view of the MMD element in FIG. 16A during phase modulation of light.

FIG. 17A is a diagram in which the electrodes of the MMD elements shown in FIG. 15A and FIG. 15B are arranged differently in one embodiment of the present invention.

FIG. 17B is a diagram in which the electrodes of the MMD elements shown in FIG. 16A and FIG. 16B are arranged differently in one embodiment of the present invention.

[FIG. 18] As an example, FIG. 18 is a schematic diagram showing the overall arrangement of the support and elastic members of the MMD element of the present invention on a substrate.

FIG. 19A is a diagram showing the shape of a column used in the MMD element of the present invention in one embodiment.

[FIG. 19B] As another embodiment, it is used for the MMD element of the present invention different from FIG. 19A. It is a figure which shows the shape of the support | pillar used.

FIG. 20 is a schematic diagram of a conventional projection apparatus using L C O S as a spatial phase modulation element, and the best mode for carrying out the invention

[0043] According to the present invention, it is possible to provide a spatial phase modulation element capable of simplifying the configuration of the apparatus and ensuring sufficient resolution for an image that is projected and displayed. Provided is a projection device including a spatial phase modulation element that can avoid the influence of 0th-order diffracted light on a projected image. In addition, as one of the novel spatial phase modulation elements used in the projection apparatus of the present invention, a reflection type capable of obtaining the optimum diffraction pattern by improving the light utilization efficiency and diffraction efficiency with a simple configuration. An MMD (Magnetic Micro Device) element which is a spatial phase modulation element (SPM) is provided.

[0044] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[Embodiment 1]

In the first embodiment, details of the projection apparatus of the present invention and a novel spatial phase modulation element used in the projection apparatus will be clarified. The condensing optical system that condenses the light emitted from the light source, and the light converging light that is emitted from the light source through the condensing optical system

A spatial phase modulation element; and a shielding member that shields the 0th-order diffracted light that is emitted from the spatial phase modulation element without being diffracted and collected at the light collection position.

In the present specification, a plurality of partition portions are provided on the spatial phase modulation element. This partition part is obtained by dividing the area on the spatial phase modulation element into a large number of fine sections, and each of the partition parts controls the desired phase by independently controlling the physical state of each partition part. The diffracted light can be emitted. This section is a concept that corresponds to a pixel in terms of a photoelectric conversion element such as a CCD or an image display element such as a liquid crystal, but the pixel of the CCD or liquid crystal itself becomes a part of the visible image. While the pixels of the projected image are one-to-one as they are, the relationship between each section and the actually displayed image is completely different from that of a CCD or liquid crystal display. That is, in the present application, the projected image is displayed. The image is converted to a visible image on the screen. At this time, when attention is paid to the pixels of the display image reproduced on the screen, each of these pixels is all on the spatial phase modulation element. It is formed by the sum of the diffracted light emitted from this section. That is, diffracted light from all sections is required to form one pixel to be displayed. Similarly, all displayed individual pixels are each formed by the sum of diffracted light emitted from all sections. Further, the phase modulation section referred to in the present application means the entire contour in which this section is provided.

In the first embodiment, it is assumed that a condensing lens is used as a condensing optical system for condensing light emitted from a light source, and a transmissive spatial phase modulation element is used as a spatial phase modulation element.

FIG. 1 shows one embodiment of the projection apparatus of the present invention that includes a condensing lens, a transmissive spatial phase modulation element, and a shielding member.

In FIG. 1, an illumination light beam 15 of illumination light emitted from a light source (not shown) is collected by a condenser lens 11 and then incident on a transmissive spatial phase modulation element 12. 1 shows a projection apparatus 10 that projects diffracted light 17 that is phase-modulated and diffracted by a transmissive spatial phase modulation element 12 onto a screen 14. 0 in Fig. 1 represents the diffraction angle.

In the projection apparatus of the present invention, an image is formed by projecting and displaying the diffracted light emitted from the spatial phase modulation element on the screen. In each section of the spatial phase modulation element, the phase is controlled based on the spatial phase information generated corresponding to the image information projected and displayed. Further, the light source in the projection device of the present invention is disposed at a position separated from the optical axis of the condensing optical system, and forms a projected image by emitting the shielding member from the spatial phase modulation element. Yes It is configured to be placed outside the diffracted light beam.

With this configuration, in the projection apparatus in FIG. 1, the illumination light beam 15 is focused by the collecting lens 11 1, so that the 0th-order diffracted light 16 can be supplemented by the shielding member 13, and the screen By preventing the 0th-order diffracted light from being projected onto 14 It is possible to prevent the trust from being lowered. In FIG. 1, the screen 14 is drawn in the vicinity of the transmissive spatial phase modulation element 12, but actually, it is sufficiently far away from the transmissive spatial phase modulation element 12.

[0051] When the projection apparatus is configured as shown in Fig. 1, basically no projection lens is required, but when adjusting the distance from the screen 14 or changing the spread angle of the diffracted light 17. In some cases, a projection lens may be provided. Even when a projection lens is provided, unlike a conventional projection device that projects an image drawn on the display element, it is configured to project phase-modulated diffracted light, so a simple projection lens can be used. .

FIG. 2 shows a flowchart of signal processing of signals input to the spatial phase modulation element in the projection apparatus of the present invention.

[0053] Hereinafter, the type of signal and the flow of processing until the signal is input to the spatial phase modulation element will be described in detail.

[0054] First, image data 21 of an image to be projected is acquired. The image data (image) 21 is subjected to Fourier transform to become spatial phase distribution information. However, since the intensity distribution is generated together with the spatial phase distribution in this state, random phase information 22 in advance in the image data 21 is obtained. Is superimposed. Then, after the random phase information is superimposed on the image data, Fourier transform 23 is performed. This method of superimposing random phase information is a technique known as kinoform, such as W. H. Lee:

Computer-generated holograms: techniques and applications, in Pro gress in Optics, E. Wolf, ed., (North-Hol land, Amsterdam, 1978), Vol.1 6, pp.119-232 Yes. Thus, by superimposing the random phase information on the image data 21, the intensity on the spatial phase distribution is averaged, and a spatial distribution satisfying the image information can be obtained only by the phase information. Thus, the random phase is superimposed and the Fourier transformed image data becomes spatial phase information of only the phase. Then, the spatial phase information of only this phase is subjected to the correction process 24 based on the optical arrangement, and then input to the SPM driver 25. The image information at this time is two-dimensional matrix data, just like normal image information. S The PM driver 25 creates a drive signal for driving the spatial phase modulation element (SPM). Next, by applying this drive signal to the spatial phase modulation element, spatial phase information corresponding to an image to be projected onto the spatial phase modulation element (SPM) can appear as a phase distribution.

Here, as an example of signal processing, a mirror for performing phase modulation when reflecting light from a light source, and an elastic member disposed corresponding to each partition portion for performing phase modulation on the mirror surface of the mirror And an electrode for moving the mirror surface by applying a voltage to pile up the restoring force of the elastic member by applying a voltage, and a substrate on which the electrode is arranged, which will be described later Assuming that the section of the reflective spatial phase modulation element of the present invention is 3 × 3, the operation of the spatial phase modulation element by signal input will be briefly described. In FIG. 3, only 2 X 2 transistor circuits, which are the switch circuits 30 provided on the substrate corresponding to the spatial phase modulation elements in the 3 X 3 section, are shown. In FIG. 3, the drive circuit of the spatial phase modulation element sequentially sends drive signals from Y 1 to Y 3 of the signal lines 31 of each section, while sequentially from X 1 to X 3 of the scan lines 32 of each section. Suppose that normal X_Y scanning that sends a scanning signal is performed. Here, when a drive signal is sent from the signal line Y 1 and an ON scan signal is sent from the scan line X 1, the transistor 33 in the section (X 1, Y 1) is turned on, and the electrode 34 is applied to the electrode 34 according to the signal on the signal line Y 1. A voltage is applied. At this time, electric charge is accumulated between the elastic member 36 of the spatial phase modulation element and the electrode 34 by being a capacitor 35, and Coulomb force is generated according to the electric charge. This charge is maintained until the next signal comes. Next, when a driving signal is sent from the signal line Y 2 and an ON scanning signal is sent from the scanning line X 1, a voltage is applied to the electrode 34 in the section (X 1, Y 2). Similarly, after the drive signal is sent from the signal line Y3 to the section (X1, Y3) and scanned by the scanning line X1, the drive signal is sent from the signal line Y1 to the section (X2, Y1). Then, an ON scanning signal is sent from the scanning line X2, and the information of the driving signal is reflected on the spatial phase modulation element one after another. In this way, the phase modulation of light can be performed by expressing the spatial phase information in the entire spatial phase modulation element as needed. The spatial phase modulation element (S PM) It is possible to express the spatial phase distribution information of an image to be projected onto. Here, the elastic member 36 returns the mirror to the original when the voltage is applied to the electrode 34 connected to the switch circuit and the Coulomb force generated by the charge being accumulated in the capacitor 35 is released. It is provided to return to the state.

Further, the correction processing 24 based on the optical arrangement here is, for example, in the case of the optical arrangement shown in FIG. 1, irradiated on the transmissive spatial phase modulation element 12 by the condenser lens 11. This means that the spatial phase information appearing on the spatial phase modulation element is corrected so that the incident light is diffracted toward the screen 14 at a diffraction angle 0.

Note that this series of data processing is executed at high speed on a circuit provided in the projection apparatus so that an image can be displayed in real time. For example, F P

G A and A S I C are used.

[0058] Next, a procedure for performing power sequential display of an image by color-sequential light source control in the projection apparatus of the present invention including a condensing optical system, a spatial phase modulation element, and a shielding member will be described. The

FIG. 4 shows the operation of the spatial phase modulation element and the light emission operations of the red light source, the green light source, and the blue light source when performing color-sequential light source control and displaying an image with a power error in the projector of the present invention. This is a timing chart showing the relationship as the same time axis t. Hereinafter, referring to FIG. 4 as one embodiment, operations of a red light source, a green light source, a blue light source, and a spatial phase modulation element based on the progress of time t are shown.

[0060] First, time t. From t to t, the red light source is turned on and is incident on the spatial phase modulator. At this time, the spatial phase modulation element diffracts the red light source based on the spatial phase information reproduced on the element, and generates red diffracted light corresponding to the red light source for obtaining an appropriate image. In this way, the red part of the image to be projected can be displayed.

[0061] Next, at t ₂ from time t, the spatial phase modulator rewrites from the spatial phase information corresponding to the red light source to the spatial phase information corresponding to the green light source. At this time, as in the present embodiment, a color sequential method using one spatial phase modulation element is used. When projecting an image, the spatial phase information is different for each color light source. Therefore, in the rewrite time width 41 of the spatial phase information of the spatial phase modulation element, a diffraction pattern completely different from the image information to be projected is obtained. When light is incident on the diffraction pattern being rewritten, unlike the general magnified projection, all displayed display screens become color noise screens, and the displayed image quality is significantly reduced. Therefore, it is necessary to avoid the incidence of light at this timing. Therefore, in the time width 41 during which the spatial phase modulation element is rewriting the spatial phase information, it is necessary to turn off all the light sources. By doing this, there is no moment to display the noise screen, and if the displayed image is a moving image, an image with high contrast can be displayed.

[0062] Then, the spatial phase modulating element is completely after completing rewriting of the spatial phase information corresponding to the green light source is turned ON the green light source from the time t ₂ to t _3. In this way, green diffracted light can be generated and the green portion of the image to be projected can be displayed.

[0063] Similarly, in the t ₄ from the time t _3, the spatial light modulating element, rewriting from the spatial phase information corresponding to the green light source to the spatial phase information corresponding to the blue light source. As in the case of rewriting from the spatial phase information corresponding to the red light source to the spatial phase information corresponding to the green light source, all the light sources are turned off during this time width. Then, after the spatial phase modulation element has completely rewritten the spatial phase information corresponding to the blue light source, the blue light source is turned on from time t ₄ to t ₅ . In this way, blue diffracted light can be generated and the blue portion of the image to be projected can be displayed.

[0064] By performing the above operations sequentially and repeatedly in a short time, color display of an image to be projected using one spatial phase modulation element can be performed with high quality.

Note that a laser diode (L D) is preferable as the light source in the present embodiment.

[0066] In FIG. 4, the ON period is shown for each color light source. In the laser diode (LD), if light is pulsed during this ON period, light is emitted. You may do it.

Next, as one embodiment, diffracted light is generated by making readout light incident on the spatial phase information displayed on the transmission type spatial phase modulation element shown in FIG. 5, and an image is displayed on the screen. The method of projecting is described.

FIG. 5 shows how the readout light is diffracted by the transmissive spatial phase modulation element.

In FIG. 5, for the sake of simplicity, consider the case where the diffraction grating 51 is displayed on the spatial phase modulation element. The spatial phase modulation element here displays spatial phase information of an image to be projected, for example, Fourier transform information. When reading light (reference light), that is, illumination light beam 52 is incident on the diffraction grating 51 displayed on the spatial phase modulation element, signal light, that is, diffracted light (diffraction light) 53 is emitted. An image can be obtained by projecting the diffracted light 53 onto a screen 54 arranged at an appropriate distance.

[0070] In the following, in order to briefly explain the mathematical principle for projecting this diffracted light onto a screen, as an example, a simple diffraction grating having a constant grating spacing d in a transmissive spatial phase modulation element 51 is used. If is displayed, refer to Fig. 5.

[0071] When the interval of the displayed diffraction grating is d, between the incident angle 0 _R of the illumination light beam 52 of the readout light and the exit angle 0 _S of the diffracted light 53 in FIG.

[0072] [Equation 1]

, λ

d two (1)

There is a relationship sm0 _R + sin ^ _s . For example, for the sake of simplicity, if 0 _R = O degrees,

[0073] [Equation 2]

(2)

It can be expressed as. In this case, the exit angle 0 _S is synonymous with the diffraction angle because the incident angle is 0 _R = O °. Here, when the wavelength λ of the readout light 52 is 0.5 m, the correspondence shown in FIG. 6 is obtained between the distance d of the diffraction grating 51 and the exit angle of the diffraction light 53, that is, the diffraction angle 0 _S. .

[0074] FIG. 6 shows the case where the incident angle 0 _R = O ° and the wavelength λ = 0.5 m of the readout light 52 to the diffraction grating 51 having the grating interval d displayed on the transmissive spatial phase modulator. FIG. 6 is a diagram showing a correspondence relationship between the exit angle of the diffracted light 53, that is, the diffraction angle S _s, and the interval d of the diffraction grating 51.

As apparent from FIG. 6, when the grating interval d of the diffraction grating 51 is reduced, the exit angle of the diffracted light 53, that is, the diffraction angle 0 _S can be increased. By suitably using this relationship, it is possible to separate the diffracted light 53 for projecting an image from the 0th-order diffracted light that is not diffracted by the spatial phase modulation element unnecessary for image display.

Next, consider a case where image data, that is, an image is actually projected and displayed on the screen 54. If the width of the phase modulation part formed by the phase information reproduction surface of the spatial phase modulation element, that is, the partition part for performing phase modulation of the spatial phase modulation element, is D, the illumination light beam 52 of wavelength; When the diffraction grating 51 of the phase modulation element is irradiated, the divergence angle 0 s by the diffracted light 53 is

[0077] [Equation 3]

It is represented by This represents the definition of the image that can be projected onto the screen 53 by the spatial phase modulation element whose phase modulation section width is D. As an example, consider a spatial phase modulator with a phase modulator width D = 0. 6 inch and an aspect ratio of each section of 4/5. At this time, the width D of the phase modulation section in the spatial phase modulation element is 0.6 X 4/5 X 25.4 = 1.2.2 mm, and the diffraction wavelength is λ when the readout light wavelength λ is 0.5 m. The divergence angle due to 0 s is 2.35 X 10-3 degrees. That is, a transmission type spatial phase modulation element having a width D = 0. 6 inch of the phase modulation section Resolution display can image in is the angular resolution, 2. which means that it is a 35 X 1 0_ ³ degrees.

Next, the conditions imposed on the spatial phase modulation element necessary for expressing the number of pixels of the image to be projected are examined. Here, if the image to be projected is NTS C (National Television Standard Committee), that is, if the number of pixels in the horizontal direction of the image to be projected is 720, the change in the diffraction angle of the diffracted light is at least 2. 35 X 1 0- 3 x 720 = 1. 7 degrees required. In the case of HDTV (High Definition Television), that is, if the number of pixels in the horizontal direction of the image to be projected is 1,920, a change in diffraction angle of at least 4.5 degrees is required. For Super Hi-Vision, the number of pixels in the horizontal direction of the image you want to project is 7680, and the required change in diffraction angle reaches 18 degrees. In order to project these images, it is necessary to display diffraction gratings with spacings d = 17, 6.4, and 1.6 m, respectively, in the spatial phase modulator from Eq. (2). Therefore, the spatial phase modulation element needs to have the ability to display spatial phase information with such a fine lattice spacing d.

[0079] Here, in order to display the spatial phase information of the diffraction grating with the grating interval d, P is the pitch between the partition portions constituting the spatial phase modulation element,

[0080] A spatial phase modulation element satisfying [Equation 4] d = 2P (4) is required. Here, the width of one section of the spatial phase modulation element corresponding to each of NTSC, HDTV, and Super Hi-Vision is preferably about 8.5 m, 3.2 m, and 0.8 m.

[0081] A spatial phase modulation element with a pitch P between each section cannot display a diffraction grating with a grating spacing d smaller than that in Eq. (4), so the diffraction angular force expressed by Eq. (2) This is the largest diffraction angle at which an image can be projected. For simplicity, assuming that the diffraction angle of the diffracted light is not so large, Equation (2) is

[0082] [Equation 5]

And can be approximated. Furthermore, in order to display the image by avoiding the 0th order diffracted light, where N is the number of pixels in the horizontal direction of the pixel of the image to be projected and displayed here, the number of horizontal columns N of the pixel of the image to be projected is displayed. It is necessary that the diffracted light spreading angle N 1 _δ required for the diffraction is smaller than the diffraction angle 0 _S. Therefore, to project and display an image while avoiding 0th order diffracted light,

[0083] [Equation 6]

It is necessary to satisfy the condition of Νθ _δ <θ ₈ (6). Substituting equations (3) to (5) into this conditional expression,

[0084] [Equation 7]

D, _r

-> 2N (7) is obtained. Here, D / P is the number M of horizontal columns of the partition portion of the spatial phase modulation element corresponding to the image to be projected and displayed, and the horizontal portion of the partition portion of the spatial phase modulation element corresponding to the image to be projected and displayed. If the number of columns in the direction is M = D / P,

[0085] [Equation 8]

M> 2N (8) This is the number of columns M required in the horizontal direction of the partition portion of the spatial phase modulation element corresponding to the number of horizontal columns N of the pixels of the image to be projected and displayed, and the spatial phase information is displayed on the spatial phase modulation element. This is a necessary condition.

[0086] Further, the pitch P between the partition portions constituting the spatial phase modulation element is expressed by (7) R

[0087] [Equation 9]

Can also be expressed.

From the above, the number of horizontal columns M of the partition portion of the spatial phase modulation element is set to the number of horizontal columns N of the pixels of the image to be projected and displayed.

[0089] [Equation 1 0]

M> 2N

By doing so, it is possible to provide an excellent projection device with high definition and high image quality.

[0090] Further, as the width D of the phase modulation section of the spatial phase modulation element and the number N of horizontal columns of pixels of the image to be projected and displayed, the pitch P between the respective partition portions constituting the spatial phase modulation element is

[0091] [Number 1 1]

P

By using a 2N spatial phase modulator, high-definition and high-quality image display can be optimally performed.

Next, a projection apparatus including a condensing optical system, a spatial phase modulation element that satisfies the necessary conditions for realizing the above-described spatial phase information, and a shielding member will be described.

[0093] FIG. 7 shows a condensing optical system that condenses illumination light from a light source and makes it incident on a spatial phase modulation element, and satisfies the necessary conditions for realizing the above-described spatial phase information as a phase distribution. And a shielding member that shields the 0th-order diffracted light that is emitted and collected without being diffracted from the spatial phase modulation element. A plan view is shown.

[0094] A projection apparatus 70 having a transmission type spatial phase modulation element in FIG. 7 includes a light source 71, a spatial filter 72 for removing noise of illumination light, a collimator 73, a condensing lens 74, and a transmission type The spatial phase modulation element 75 and the shielding member 76 are included. In such a configuration, a configuration without a λ plate or PBS can be performed, so that a simple optical configuration is required, and a projection lens is not required.

In FIG. 7, illumination light from a light source 71, for example, a laser beam, passes through a spatial filter 72 and a collimator 73, becomes an illumination light beam, and is collected by a condenser lens 74 and then transmitted through a spatial phase. The light enters the modulation element 75. The illumination light incident on the transmissive spatial phase modulation element 75 is phase-modulated and emits diffracted light 79. The spatial phase modulation element 75 embodies the spatial phase information generated based on the image data as a phase distribution on the element to perform phase modulation. The diffracted light 79 from the transmissive spatial phase modulation element 75 is projected onto the screen 77, and a desired image can be displayed on the screen 77. In this projection apparatus, the light is condensed and emitted from the spatial phase modulation element 75 without being diffracted through the condenser lens 74, and the 0th-order diffracted light is condensed and shielded by the shielding member 76 at the condensing position. The device is designed so as not to adversely affect the image being displayed. In FIG. 7, the shielding member 76 is arranged in the light beam of the diffracted light 79 emitted from the spatial phase modulation element 75. In practice, however, the screen 77 is sufficiently far from the position of the shielding member 76. As such, it has little adverse effect on the image displayed on the screen.

On the screen 77, diffracted light 79 emitted from the spatial phase modulation element 75 is projected. The correction processing 94 shown in FIG. 2 performed during this series of operation processing is performed corresponding to the arrangement position of each optical element, and the spatial phase distribution embodied on the spatial phase modulation element. This means that the spatial phase distribution obtained by the Fourier transform is corrected so as to be diffracted toward the screen 77.

Next, the conditions imposed on the transmissive spatial phase modulation element 75 for obtaining a desired image in the configuration of FIG. 7 will be examined below.

In the configuration shown in FIG. 7, the diffracted light 79 is generated with the 0th-order diffracted light sandwiched therebetween. Therefore, it is necessary to consider not only the positive first order but also the negative first order diffracted light.

[0099] In the embodiment of Fig. 1 in Embodiment 1, it is imposed on the transmissive spatial phase modulation element 12 for obtaining a desired image based on the diffracted light of only one of the plus 1st order or the minus 1st order. The condition was derived. In the case of the configuration shown in FIG. 7, it can be considered that the diffraction angle 0 _s in FIG. 1 is doubled.

[0100] [Equation 12]

It can be expressed as Νθ _δ <2G _S (io), and the conditions imposed on the transmissive spatial phase modulator 75 in FIG.

[0101] [Equation 13]

M≥N (1 1). Here, for example, when displaying an HDTV image signal, the number M of columns in the horizontal direction of the partition portion of the transmissive spatial phase modulation element 75 is preferably 1,920 or more. At this time, when the width D of the phase modulation part of the spatial phase modulation element is 0.6 inch and the aspect ratio of each division part is 4/5, one division part of the transmission type spatial phase modulation element 75 The size of the minute is 6.4 m. In other words, the size of the partition portion in FIG. 7 may be twice the size of one partition portion of the spatial phase modulation element shown in FIG. Similarly, in the case of NTSC, the size of one partition portion in the transmission type spatial phase modulation element 75 is 17 m, and in the case of Super Hi-Vision, the size of the transmission type spatial phase modulation element 75 The size of one section is 1.6 m.

[0102] Here, in the case of FIG. 7, in the pitch P between the partition portions of the transmission type spatial phase modulation element 75,

[0103] [Equation 14]

The condition P≤— (1 2) N is imposed.

[0104] From the above, the number of horizontal columns M of the partition portion of the transmissive spatial phase modulation element is set to the number of horizontal columns N of the pixels of the image to be projected.

[0105] [Equation 15]

By setting M≥N, high-definition and high-quality display can be performed.

[0106] Further, the phase information display surface of the spatial phase modulation element 75, that is, the horizontal width D of the phase modulation unit, the number N of pixel columns in the horizontal direction of the image to be projected, the partition partial pitch P of the transmission type spatial phase modulation element 75 The

[0107] [Equation 1 6]

By doing so, a high-definition and high-quality image can be projected in a relatively large section, and the burden on the spatial phase modulation element 75 can be reduced. Preferably, an optimum spatial phase modulation element for a projection apparatus can be provided by setting the pitch P between the partition portions of the spatial phase modulation element 75 to 6.4 m to 3.2 m.

[Embodiment 2]

8 and 9A, FIG. 9B, and FIG. 9C exemplify the correspondence between the real domain in the image to be projected and displayed and the Fourier domain in the spatial phase information of the spatial phase modulation element used in the projection apparatus of the present invention. ing. [0108] Here, the real domain is, for example, image data to be displayed or an image on the screen that is displayed. For example, in FIG. 8, the real domain 80 is shown as pixels of horizontal N x vertical Q = 1 6 X 9. Here, the portion represented as one pixel 81 to be projected is indicated by the shaded portion of the real domain. In the case of the HDTV format, the real domain 80 requires a number of horizontal columns N x vertical columns Q = 1 9 2 0 X 1 0 8 0 pixels. The Fourier transform of this real domain 80 creates basic data of spatial phase information. Since the maximum spatial frequency of the image to be projected is the same in the vertical and horizontal directions, it is efficient to make the vertical length K and the horizontal length J of the phase modulation part in the spatial phase modulation element in the Fourier domain equal. Whatever aspect ratio of the projected image is displayed, it does not depend on that ratio.

FIG. 9A shows a case where the vertical length K and the horizontal length J of the phase modulation part of the spatial phase modulation element are equal in the Fourier domain 90 obtained by Fourier transforming the real domain 80 of FIG. . Also in this case, as described in the first embodiment, the number of horizontal columns M or the number of vertical columns L of the partition portion of the spatial phase modulation element is the number of horizontal columns N of the pixels of the image to be projected or the vertical direction. It is desirable to be equal to or greater than the number of columns of Q. Here, for example, the number of horizontal columns M or the number of vertical columns L of the partition portion of the spatial phase modulation element is equal to the number of horizontal columns N or the number of vertical columns Q of the pixels of the image to be projected. Then, as shown in FIG. 9A, the interval in the horizontal section of the spatial phase modulation element is smaller than the interval in the vertical section. The number of columns of the spatial portion 93 of the spatial phase modulation element at this time in FIG. 9A is the number of partitions of the number of horizontal columns MX the number of vertical columns L = 16 × 9. 9B shows that the number of vertical columns in the section of the spatial phase modulation element is the same as the number of horizontal columns, that is, the number of horizontal columns MX the number of vertical columns L = 1 6 X 16 FIG. 9 shows a Fourier domain 91 smaller than A. In FIG. 9G, contrary to FIG. 9B, the number of horizontal columns in the section of the spatial phase modulation element is the same as the number of vertical columns, that is, the number of horizontal columns MX the number of vertical columns L = 9 X 9 shows the Fourier domain 92 larger than Fig. 9A. However, in the case of Figure 9C, The reproducibility of the low-frequency image in the horizontal direction is slightly degraded in theory, with the advantage that the number of spatial phase modulation elements can be reduced. Therefore, a plurality of partition parts for performing phase modulation in the spatial phase modulation element are two-dimensionally arranged, and the number of sections in each partition part is equal to or greater than the number of pixels of the projected image. It is desirable.

[0110] The Fourier transform from Fig. 8 to Fig. 9A, Fig. 9B, and Fig. 9C will be described below.

[0111] If the image to be displayed in Fig. 8 is g (x, y), its Fourier transform

G (u, V) is

[0112] [Equation 17]

G (w, V) = jjg (x, y) e- ^{j27r ux + vy} dxdy (13) In an actual projector, the Fourier transform is performed at high speed by digital calculation. Instead of the continuous Fourier transform expressed by Eq. (1 3), the discrete Fourier transform expressed by Eq. (14) below is used.

[0113] [Equation 18]

G _mn = ∑∑g ^-； (14)

/ = 0 * = 0 where

[0114] is the image you want to display, and k and I are understood to be pixel addresses in the image. In addition, the number of pixels in Equation (14) is NXP.

[0115]

Ski

[0116] Fourier transform,

[0117] [Equation 19] w = 0,1,2, ....., Ν-\

"= 0,1,2, ......, -1, the fast Fourier transform (FFT) can be used for the discrete Fourier transform of Equation (1 4). This fast Fourier transform By using, the image you want to project

[0118] can be Fourier-transformed in real time in a short time, and can correspond to the speed of the moving image. Therefore, the number of horizontal columns of the pixels of the image to be projected and displayed X the number of vertical columns = NXP and the number of horizontal columns of the phase modulation section of the spatial phase modulator X and the number of vertical columns = Mx L In other words, it is convenient to make N and M, and P and L equal. In this way, the necessary and sufficient condition that the amount of information can be maintained even by Fourier transform can be satisfied, so that a sufficient amount of information is secured to form the displayed image, and the resolution is secured. Displayed high-quality images. Of course, the amount of information can be further increased if the number of columns in the partition portion is larger than the number of pixels to be projected and displayed. In addition, in N and P, there is an advantage that the calculation of the powers of 2 is shaky. Therefore, the number of vertical columns and horizontal columns of the partition portion in the spatial phase modulation element is , By making it a power of 2, it is possible to speed up the arithmetic processing.

As described above, according to the second embodiment, in the present invention, in the spatial phase modulation element, the number of vertical columns and the number of horizontal columns of the partition portion for performing phase modulation in the spatial phase modulation element are on the screen. Optimal for projecting images that are equal to or greater than the number of vertical and horizontal columns of pixels of the projected image displayed on the screen, and sufficiently satisfy the number of images displayed on the screen. It can be a spatial phase modulation element. By making the vertical and horizontal lengths of the spatial phase modulation elements equal, the vertical and horizontal spatial frequencies (resolutions) in the image can be displayed equally. Even when the vertical and horizontal lengths of images to be displayed are different, the minimum necessary spatial frequency can be output while the vertical and horizontal lengths of the spatial phase modulation elements remain the same. In addition, an image can be projected by diffracting light with a projection apparatus equipped with spatial phase modulation elements with equal length and width. Therefore, the contour shape in the phase modulation part formed by all the partition parts for performing the phase modulation of the spatial phase modulation element is a square having the same aspect ratio, and does not depend on the aspect ratio of the projected image. The image can be projected on the screen. Furthermore, light is diffracted by a projection device having a spatial phase modulation element in which the number of vertical and horizontal columns of pixels of the image displayed on the screen is equal to the number of vertical and horizontal columns of the phase modulation section of the spatial phase modulation element. Can project high quality images

[0120] In Fig. 1 OA and Fig. 1 OB, to help further understanding, an image g (x) to be projected is shown as a graph G (u) by one-dimensional Fourier transform as an example.

[0121] When the number of pixels of the image g (χ) to be projected is Ν, the number of numerical values of G (u) is N as a result of the discrete Fourier transform. Here, in Fig. 1 OA, the image to be projected is shown as g (X), and in Fig. 10B, the image g (x) to be projected in Fig. 10A is Fourier transformed and coordinate-converted to the image frequency. G

(u) is shown. In Fig. 10 B, G. Indicates the frequency 0, and indicates the maximum frequency at which the image frequency can be displayed.

[Embodiment 3] Figure 11 shows the converging optical system that collects the illumination light from the light source and makes it incident on the spatial phase modulation element, the reflective spatial phase modulation element, and the light emitted from the spatial phase modulation element without being diffracted. 1 shows a projection device provided with a shielding member that shields the diffracted 0-order diffracted light at its condensing position.

The projection apparatus 1 10 in FIG. 11 includes a light source 1 1 1, a reflective spatial phase modulation element 1 13, a shielding member 1 14, and a condensing lens 1 12 as a condensing optical system. . In the optical configuration shown in FIG. 11, the spatial filter is omitted. This optical configuration is an illumination optical system that does not require the use of a λ plate, is very simple, can be reduced in cost, and can be downsized.

Unlike the transmissive spatial phase modulation element used in FIG. 1, this projection apparatus 110 emits diffracted light 118 that has been phase-modulated by a reflective spatial phase modulation element 113. The diffracted light is projected onto the screen 1 15 through the condenser lens 1 12. In the reflection type spatial phase modulation element 1 13 in FIG. 1, the 0th-order diffracted light 1 1 7 is also reflected, but the reflected 0th-order diffracted light 1 1 7 is shielded by the shielding member 1 14 However, the image projected on the screen 115 is not adversely affected. Since the 0th-order diffracted light 1 1 7 has a diffraction angle of 0 degrees and travels straight, the light source 1 1 1 is placed outside the optical path of the diffracted light as shown in FIG. Unlike the projection device shown in FIG. 7, the light beam of the diffracted light beam can be placed outside the diffracted light beam projected to the screen by placing the shielding member 1 1 4 at an oblique direction. The shielding member can be excluded from the inside, and the shadow of the diffracted light generated by the shielding member can be made zero.

[0124] It should be noted that the optical arrangement of Fig. 11 also requires correction corresponding to the arrangement position of each optical element, and this correction is such that the irradiation light irradiated to the spatial phase modulation element is directed toward the screen 115. This means that the spatial phase distribution displayed on the spatial phase modulation element obtained by Fourier transformation is corrected so that it is diffracted and projected.

[0125] Next, FIG. 12 shows still another embodiment of a projection apparatus including a reflective spatial phase modulation element.

[0126] The projection device 120 in FIG. 12 includes a light source 121 and a condensing lens 1 as a condensing optical system. 22, a reflective spatial phase modulation element 123, a shielding member 124, and a screen 125 for projecting the diffracted light 128. In the configuration of Fig. 12, the spatial filter is omitted. Even in this optical configuration, the illumination optical system that does not require the use of the λ plate is very simple, can be reduced in cost, and can be downsized.

In the projection device of FIG. 12, illumination light from a light source 121, for example, a laser beam, is converted into an illumination light beam 126 by a condensing optical system condensing lens 122 and is incident on a reflective spatial phase modulation element 123. Like that. Then, the phase-modulated diffracted light 128 is emitted by the reflective spatial phase modulation element 123 and projected onto the screen 125, and an image is displayed on the screen. In this reflection type spatial phase modulation element 123, the 0th-order diffracted light 127 is also reflected and emitted into the light beam of the diffracted light 128, but the screen 125 is configured to be shielded by the shielding member 124. The image displayed above is not adversely affected by practical use.

[0128] Note that the optical arrangement shown in Fig. 12 also requires correction corresponding to the arrangement position of each optical element. In this correction, the irradiation light applied to the spatial phase modulation element is directed toward the screen 125. This means that the spatial phase distribution obtained by Fourier transform is corrected so as to be diffracted.

As described above, in FIGS. 11 and 12, one embodiment of the projection apparatus including the condensing optical system, the reflective spatial phase modulation element, and the shielding member has been described. A projection lens may be provided without providing the projection lens. That is, when the projection distance to the screen is long with respect to the size of the spatial phase modulation element, it is not necessary to adjust the focus, so that the projection lens can be eliminated. On the other hand, if the projection distance to the screen is close to the size of the spatial phase modulation element, a projection lens may be required for focus adjustment. In addition, if you want to add a zoom function as a projection device, you need a projection lens that carries the zoom function. However, even the projection lens added at this time can use a cheaper and smaller object than the projection lens used in the conventional projection apparatus.

[0130] Further, in any of the embodiments shown in FIGS. As described above, illumination light from red light source R, green light source G, and blue light source B, for example, light from red light source, green light source G, and laser from blue light source B, is used to illuminate each color in a time-sequential manner. Full color display is possible. Here, the normal one-color image display is 60 Hz, so when switching between the three colors, 180 Hz is the minimum required. In order to reduce the color break phenomenon, it is preferable to switch between three colors of 5 4 OHz or higher. Therefore, the switching speed of the spatial phase distribution corresponding to the image of the spatial phase modulation element in the case of performing full color display needs to be at least 1800 Hz, and preferably 5400 Hz or more.

[0131] Next, FIGS. 13A and 13B are each a projection device 130 that includes a plurality of reflective spatial phase modulation elements and a shielding member, has a multi-plate configuration, and performs full-color display of an image. Is shown.

[0132] FIG. 13A is a plan view of the projector 130, and FIG. 13B is a view of the portion including the spatial phase modulation element 133b corresponding to the blue light source of FIG. A side view of the hour is shown.

[0133] The projection device 130 in FIG. 1A includes a light source of each color of red light source R, green light source G, and blue light source B, collimators 131 r, 131 g, 131 b corresponding to the light sources of each color, Total reflection prisms 132r, 132g, 132b corresponding to the light sources, reflective spatial phase modulation elements 133r, 133g, 133b corresponding to the light sources of the respective colors, and shielding members 1 36r, 136g, 136b corresponding to the light sources of the respective colors A color synthesizing prism 137 for synthesizing the diffracted lights of the respective colors, and a projection lens 138.

Here, although the projection lens 138 shown in FIG. 13A is a concave lens, it may be a convex lens.

[0135] Here, as a principle for projecting a full color image with diffracted light in Fig. 13A, first, for the sake of simplicity, only the part corresponding to the blue spatial phase modulation element 133b in Fig. 13B The principle of emitting blue diffracted light is described.

[0136] In FIG. 13B, the blue illumination light emitted from the blue light source 134b, for example, a blue laser beam, is reflected by the total reflection prism 132b, passes through the collimator 131b, and corresponds to the blue light source 134b. The light enters the reflective spatial phase modulation element 133b. And The blue diffracted light modulated and emitted by the spatial phase information for the blue image corresponding to the reflective spatial phase modulation element 133b passes through the collimator 131b again, becomes a substantially parallel light beam, and becomes a color synthesis prism. Incident on 137. The blue zero-order diffracted light here is emitted from the spatial phase modulation element 133b, then again passes through the collimator 131b, is totally reflected by the total reflection prism 132b, and is blocked by reaching the shielding member 136b. .

Here, the portions corresponding to the spatial phase modulation elements 133g and 133r of the green light source and the red light source in FIG. 13A also have the same configuration as the portions corresponding to the spatial phase modulation element 133b of the blue light source 134b. Red and green diffracted light can be obtained, and diffracted light emitted from the spatial phase modulation element corresponding to each color is incident on the color synthesis prism 137. Here, the 0th-order diffracted light of the red light source and the green light source is removed by the shielding members 136g and 133r in the same manner as the 0th-order diffracted light of the blue light source. In Fig. 1 3 A, the blue, red, and green diffracted light generated from the spatial phase modulation element 133b corresponding to the blue light source, the spatial phase modulation element 133r corresponding to the red light source, and the spatial phase modulation element 133g corresponding to the green light source Is incident on the color combining prism 137, and the diffracted lights of the respective colors are combined to form a full-color diffracted light, which is projected onto the screen 139 via the projection lens 138, thereby displaying a full power error image.

[0138] In this multi-plate configuration, each illumination light is always illuminated, and there is no need to switch the light source of each color as in the color sequential method in Fig. 4, so there is no worry of a color break phenomenon.

[0139] With the configuration as described above, it is possible to provide a projection device that performs full-color display of an image that is small, inexpensive, and that can avoid the influence of 0th-order diffracted light.

[0140] Note that, in the projection apparatuses shown in Embodiments 1 to 3, L C and L C O S can be applied as a transmissive spatial phase modulation element. On the other hand, D M D cannot be used as a reflective spatial phase modulation element, but can be used as a spatial intensity modulation element that can realize the spatial phase as an amplitude diffraction element. However, in this case, the diffraction efficiency cannot be increased.

[Embodiment 4] In the present invention, MM D (Spatial Phase Modu later: S PM) is a reflection type spatial phase modulation element that can improve the light utilization efficiency and diffraction efficiency with a simpler structure and obtain an optimum diffraction pattern. Magic Mirror Device) element is provided. An image can be projected by using the MMD element of the present invention for the above-described projection apparatus.

FIGS. 14A and 14B are perspective views showing the MMD elements 150 and 160. FIG.

[0142] Mirrors 151 and 161 of an MM D (Magic Mirror Device) element include partition portions for phase-modulating light from a light source, and elastic members disposed corresponding to the partition portions, Each electrode is arranged corresponding to each elastic member, and has an electrode for moving the mirror by applying a voltage to the restoring force of the elastic member, and a substrate on which the electrode is arranged. In FIGS. 14 and 14B, the section 93 for performing phase modulation in the MMD elements 150 and 160 is shown shaded. The MMD element, which is a spatial phase modulation element that emits phase-modulated diffracted light from light from the light source of the present invention, has a plurality of partition portions 93 for performing phase modulation arranged in two dimensions, The number of sections of each section 93 is set equal to or greater than the number of pixels of the projected image. Furthermore, it is preferable that the number of vertical columns and the number of horizontal columns of the partition part 93 in the MMD element is equal to or larger than the number of vertical columns and horizontal columns of pixels of the projected image. Further, it is more preferable that the number of vertical columns and the number of horizontal columns of the partition portion 93 in the MMD element is a power of two. The contour shape in the phase modulation section formed by all of the partition sections 93 for performing phase modulation of the MMD element is a square having the same aspect ratio, and does not depend on the aspect ratio of the projected image.

[0143] As shown in Fig. 1 4 A and Fig. 1 4 B, the MM D elements 150 and 160 have electrodes (not shown), elastic members (not shown), pillars (not shown), and mirrors 151 and 161 arranged on the substrate 157. is doing. For example, the mirror used for the MMD element may be an integral type mirror surface, or may be a mirror surface obtained by dividing the integral type into a plurality of mirror surfaces. When controlling an integrated mirror with multiple electrodes, the mirror must be flexible. In Fig. 14 A, multiple electrodes are associated with one integrated mirror 151. It shows how it works. In FIG. 14A, one elastic member is made to correspond to each partition portion 93 for performing phase modulation in the integrated mirror 151. On the other hand, in FIG. 14B, one electrode is made to correspond to one substantially square mirror 161, and a plurality of mirrors 161 are arranged in the vertical and horizontal directions while maintaining a constant spacing between the mirrors, so-called pitch. A state in which the element 160 is configured is shown. In FIG. 14A and FIG. 14B, the partition part 93 for performing phase control in the MMD element 160 is shown shaded. In Fig. 14 B, the pitch of the mirror 161 does not have to be constant. It is desirable that the distance between the mirrors be as close as possible to the extent that the mirrors do not interfere with each other during operation. For example, the number of sections required to display a projected image having a number of pixels of 1 980 X 1 080 in the horizontal X vertical direction is the same as the number of pixels in order to secure a desired resolution as already described in the above embodiments. If the number is the same, the number of vertical columns X the number of horizontal columns = 1 920 X 1 080 = 2, 073, 600. In addition, since this MMD element only needs to have a function capable of phase modulation, a desired function can be exhibited by performing control capable of forming a height position difference of about a fraction of the wavelength of light. Therefore, the surface accuracy of the mirror surface of the MMD element needs to be about one-tenth of a wavelength. Also, considering the light use efficiency and image contrast, the surface roughness of the mirror of the MMD element is preferably about 1 / 100th of the wavelength. Therefore, when used with visible light, the surface accuracy of the mirror surface of the MMD element is preferably 5 Onm or less, and the surface roughness of the mirror surface is preferably 5 nm or less. The accuracy here may be achieved at rms or peak-to-peak. By setting the mirror surface accuracy to 5 Onm or less, images with high fidelity can be displayed. Also, by setting the mirror surface roughness to 5 nm or less, the scattered light can be reduced and an image with high contrast wrinkles can be displayed.

[0144] The details of the MM D element of the present invention will be described below with reference to cross-sectional views of the MM D element shown by lines XV—A and XV I —A in FIGS. 14A and 14B. The

FIG. 15A shows a cross-sectional view along line XV—A of the MMD element 150 of FIG. 14A. An insulating layer 156 is overlaid on the substrate 157 of the MMD element 150, and a conductive elastic member 154 disposed corresponding to each partition portion 93 is provided on the insulating layer 156. ing. Below each elastic member 154, an electrode 155 is provided above the insulating layer so as to correspond to each section and connected to the switch circuit. On the other hand, a support column 153 is coupled to the upper portion of the elastic member 154, and the upper portion of the support column 153 is further coupled to the thin film 152, and a mirror 151 is disposed on the thin film 152. In FIG. 15A, the mirror 151 is integrally connected, and the support 153, the elastic member 154, and the electrode 155 are arranged corresponding to each partition portion of the single mirror 151. The mirror 151 here has flexibility and can be easily deformed so as to bend. Preferably, the mirror 151 is formed of a highly reflective metal or dielectric multilayer film. The thin film 152 can be formed using a material having high flexibility and durability. As the thin film 152, a flexible organic film, Si ₂ N ₃ or the like is preferably used. The thin film 152 may be omitted. Also, it struts 153 may be used as convenient in the manufacturing process, such as S i and S i 0 _2. For the elastic member 154, a flexible metal or a conductive organic film can be used. Further, a material obtained by coating this organic film with a conductive material may be used. For the electrode 155, AI, Cu, W, or the like can be used as a conductor. S i 0 _{2 or} 3 i C can be used for the insulating layer 156, and S i can be used for the substrate 157.

Therefore, the mirror surface in FIG. 15A is formed from an integral mirror, and the elastic member and the electrode correspond to each partition portion for phase modulation of the mirror surface in the integral mirror. By using a mirror, it is possible to provide a spatial phase modulation element with high light utilization efficiency that can use almost 100% of incident light by using a mirror.

FIG. 15 B shows a cross-sectional view of the MMD element of FIG. 15 A during phase modulation of light.

[0149] In FIG. 15B, by applying a voltage to the electrode 155 from the initial state of FIG. 15A, a Coulomb force acts between the elastic member 154 and the electrode 155 in the corresponding partition portion 93. The elastic member 154 approaches the electrode 155 and is bent so that the surface of the flexible integrated mirror 151 is depressed, and a movement amount Δ h of the mirror surface is generated. Here, the phase difference is caused by the difference in the optical path between the incident light reflected by the other non-curved mirror surface and the incident light reflected by the curved mirror surface, due to the difference in the movement amount Δh of the mirror surface. Modulation is possible. If the mirror surface is curved and recessed, that is, the amount of deformation of the mirror surface is Ah force 1/4 wavelength, the incident light reflected by the curved mirror is half a wavelength in the round trip. That is, it is possible to create a phase difference of π compared to the reflected light reflected by other non-curved mirror surfaces. In this way, in the MMD element of the present invention, the phase can be reversed by a binary operation of applying a voltage of 0N / 0FF to the electrode. Similarly, if the deformation amount Δh of the mirror surface is curved by a maximum of 1/2 wavelength, the reflected light reflected by the curved mirror surface is reflected by other uncurved mirror surfaces. Compared to the reflected light, it can create a phase difference of up to one wavelength by reciprocation.

[0150] In this way, the mirror surface is curved in response to the application of a voltage to the electrode, so that the phase difference that can be produced according to the amount of deformation is determined. In addition, the control of the curvature of the mirror surface, that is, the deformation, can be determined only by the presence or absence of voltage application to the electrodes, so the control is simple. Control is not limited to binary control. For example, the maximum deformation amount of the mirror surface should be within the half wavelength equivalent of the light of the incident light source, and the voltage value when this maximum deformation amount can be generated is the maximum value and a voltage within that range is applied. With, the amount of deformation of the mirror surface can be set to an arbitrary amount. The control may be analog control, or the voltage from zero to the maximum voltage value may be divided into several voltage steps in advance, and the control may be increased or decreased sequentially one by one. good. Of course, the maximum deformation may be 1/4 wavelength. Even if the maximum deformation of the mirror surface is within half the wavelength equivalent to the light from the incident light source, the phase difference formed in the emitted diffracted light is one wavelength, and all phase differences can be created. . Of course, more than one wavelength is acceptable.

[0151] Furthermore, by appropriately selecting the elastic constant of the elastic member 154, the depression of the elastic member 154 That is, it is possible to control the deformation amount Δ h of the mirror surface due to the curvature of the mirror surface. In addition, by controlling the amount of deformation Δh on the mirror surface to increase and decrease sequentially, and by changing the amount of deformation of the integrated mirror 151 continuously and slowly, binary one-phase modulation by binary operation is performed. It is possible to suppress unnecessary diffraction orders.

[0152] The elastic member 154 can return to the initial state by the restoring force of the elastic member 154 by setting the voltage to zero after the voltage is applied and the electrode is depressed.

[0153] As described above, phase modulation can be performed by applying a voltage to the specific electrode 155 and selectively bending the specific portion of the mirror 151 connected to the integral type. By continuously and gently changing the height of the mirror 151, generation of unnecessary diffraction orders can be suppressed, and higher diffraction efficiency than binary one modulation can be obtained.

[0154] Fig. 16A shows a cross-sectional view of the MMD element of Fig. 14B taken along line XVI-A.

[0155] In the MMD element 160 shown in Fig. 1 6 A, the integrated mirror as shown in Fig. 1 5-8 is divided into a plurality of mirrors 161, and each of the divided mirrors 16 1 The support 153, the elastic member 154, and the electrode 155 are arranged so as to have a one-to-one correspondence. Other than that, the configuration is the same as that of the MMD element 150 in FIGS. 15-8 and 15B. In this configuration, when the thin film 162 is used in the lower part of the mirror 161, a hard organic film or Si may be used for the thin film 162. In this figure, the mirror 161 and the thin film 162 are assumed to be substantially square, and the details will be described below. Even in this configuration, a mirror is used in the same manner as in FIGS. 15 and 15B, so that light can be used at approximately 100%, and a spatial phase modulation element with high light utilization efficiency is provided. I can do things. In FIG. 16A, each section 93 for performing phase modulation is one mirror.

FIG. 16B shows a cross-sectional view of the MMD element of FIG. 16 A during phase modulation of light.

In FIG. 16B, by applying a voltage to the electrode 155 from the state of FIG. 16A, a Coulomb force acts between each elastic member 154 and each electrode 155, and the elastic member 154 becomes the electrode 155. And near Follow. Here, as the elastic member 154 approaches the substrate 157, the mirror 161 on the elastic member 154 moves downward via the support column 153. By moving the mirror 161 downward, the light incident on the mirror 161 is mirrored by another mirror to which no voltage is applied and another mirror to which the voltage is applied. The amount of movement A h ₂ , that is, the optical path difference is generated, which enables the phase modulation of light. The mirror is the height change amount, or moving amount delta h ₂ mirrors are moving downward, if it is 1/4-wavelength of the phase of the incident light, reciprocal 1/2-wavelength, i.e. the voltage A phase difference of π can be created in a reciprocating manner in the incident light between the other mirror that is not applied and the mirror that is moving downward by applying a voltage. In this way, it is possible to invert the phase by performing binary control to the electrode with a voltage of 0N / 0FF. Note that the control is not limited to binary one control. For example, the maximum amount of movement on one side of the mirror is set to be within a half wavelength equivalent of the light from the incident light source, and the voltage within the range is applied with the maximum voltage value when this maximum amount of movement can be generated. Thus, the amount of movement of the mirror surface can be set to an arbitrary amount. The control may be analog control, or the voltage from zero to the maximum voltage value may be divided into several voltage steps in advance, and the control may be made to increase or decrease this step sequentially one by one. Even if the maximum amount of movement of the mirror surface is within 1/2 wavelength equivalent of the light from the incident light source, the phase difference formed in the emitted diffracted light is one wavelength, and all phase differences can be created. Of course, it may be more than one wavelength.

[0158] Furthermore, the depression of the elastic member 154 by selecting appropriately the elastic constant of the elastic member 154, i.e. it is possible to control the movement amount △ h ₂ of one surface mirror. Also, the amount of movement of the mirror surface Δ h ₂ is controlled so as to increase and decrease sequentially, and the amount of movement of the mirror 161 is changed continuously and gently, resulting in binary one-phase modulation by binary operation. Unnecessary diffraction orders can be suppressed.

[0159] The elastic member 154 can return to the initial state by the restoring force of the elastic member 154 by setting the voltage to zero after the voltage is applied and the electrode is depressed.

[0160] As described above, a voltage is applied to a specific electrode 155 to select a specific mirror 161. By selectively moving, phase modulation can be performed. By continuously and slowly changing the height of the mirror 161, generation of unnecessary diffraction orders can be suppressed, and furthermore, a diffraction efficiency higher than that of binary modulation can be obtained.

[0161] In the MMD element shown in FIGS. 15A and 15B and FIGS. 16A and 16B described above, the spatial phase modulation element in the color sequential light source control sequence of FIG. Spatial phase information rewrite time 41 corresponds to the time during the movement or deformation operation of the section of each MMD element.

[0162] Regarding the structure and binary control of the elastic member used in the present invention, US-patent 5, 835, 255 and US-patent 6, 040, 937 can be referred to. However, these documents describe a technique related to an element that performs color display using the principle of the Fabry-Perot etalon, which is different from the present invention.

[0163] FIG. 17A shows an example in which the arrangement of electrodes in the MMD elements of FIG. 15A and FIG. 15B is different.

FIG. 17A shows a configuration in which the electrode 155 provided above the insulating layer 156 in FIGS. 15A and 15B is provided on the insulating layer 156. FIG. All are the same except that the arrangement of the upper electrode 155 in the insulating layer is changed to the arrangement of the electrode 171 on the insulating layer 156.

FIG. 17B shows an example in which the electrode arrangements in the MMD elements of FIGS. 16A and 16B are different.

FIG. 17B shows a configuration in which an electrode 155 provided above the insulating layer in FIGS. 16A and 16B is provided on the insulating layer 156. FIG. All are the same except that the arrangement of the upper electrode 155 in the insulating layer 156 is changed to the arrangement of the electrode 171 on the insulating layer.

FIG. 18 is a schematic view showing the overall arrangement of the support 153 and the elastic member 154 on the substrate 157 of the MMD element in the reflective spatial phase modulation element of the present invention.

[01 68] In this figure, the elastic member 154 and the support 153 in the MMD elements 150 and 160 shown in FIGS. 15A and 15B and FIGS. 16A and 16B are shown in FIG. A state in which the two-dimensional arrangement is vertically and horizontally is schematically shown.

[0169] Next, referring to Fig. 19A and Fig. 19B, the support in the MMD elements 150, 160 is used. A specific example of the shape of the pillar 153 will be described.

[01 70] In FIG. 19A, the cross section of the support 153 in the MMD element is circular.

[01 71] In FIG. 19B, the cross section of the support 153a in the MMD element is rectangular.

Of course, the cross-sectional shape of the column in the MMD element may be other shapes, and an arbitrary cross-section such as an oval or a rectangle may be appropriately selected.

[0173] The elastic member 154 has a target shape centered on the support column with respect to the substrate 157 as shown in FIG. 15A and the like. However, the elastic member 154 may have an asymmetric shape. In addition, the contact portion with the substrate 157 may be formed on only one side centered on the support column.

As described above, in each embodiment, the configuration of the apparatus is simplified, and the projection apparatus provided with the spatial phase modulation element that can avoid the influence of the 0th-order diffracted light, and the light use efficiency and the diffraction efficiency are improved. A reflective spatial phase modulation element that can simplify the optical system is described.

[0175] The embodiments and modifications of the present invention arbitrarily combined also belong to the present invention.

Furthermore, the present invention is not limited to the example as the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0177] As described above, the projection apparatus of the present invention can be configured with a simple optical system that can eliminate the λ plate, and can be projected and displayed while simplifying the configuration of the projection apparatus itself. It is possible to provide a spatial phase modulation element capable of ensuring a sufficient resolution. In addition, by using a condensing optical system such as a condensing lens, the 0th-order diffracted light is shielded by the shielding member, so that the 0th-order diffracted light is not mixed in the image projected on the screen, and the image contrast is reduced. Can be prevented. Further, the projection apparatus of the present invention can be made inexpensive by having a simpler configuration than the conventional projection apparatus.

On the other hand, the new reflective spatial phase modulation element of the present invention has a simple configuration, is inexpensive to produce, has a mirror, and has almost no light loss. Use efficiency is good. Furthermore, by using an elastic member and an electrode to continuously control the amount of movement or deformation of the mirror surface depending on the voltage applied to the electrode, unnecessary diffraction orders can be suppressed and diffraction efficiency can be improved. be able to.

Claims

The scope of the claims

[1] A spatial phase modulation element for projecting and displaying an image by emitting diffracted light subjected to phase modulation via light from a light source,

A plurality of partition portions for performing phase modulation in the spatial phase modulation element are two-dimensionally arranged, and the number of partitions in each partition portion is equal to the number of pixels of an image to be projected and displayed, or Spatial phase modulation element characterized by many.

[2] The space according to claim 1, wherein the number of vertical columns and horizontal columns of the partition portion is equal to or greater than the number of vertical columns and horizontal columns of pixels of an image to be displayed. Phase modulation element.

[3] The spatial phase modulation element according to [1] or [2], wherein the number of vertical columns and horizontal columns of the partition part is a power of two.

[4] The contour shape of the phase modulation section formed by all the sections for performing the phase modulation is a square having the same aspect ratio, and is independent of the aspect ratio of the displayed image. The spatial phase modulation element according to any one of claims 1 to 3.

[5] Having a mirror surface for phase modulation when reflecting light from the light source,

An elastic member disposed on the mirror surface and corresponding to each partition portion for performing phase modulation;

An electrode for moving or deforming the mirror surface against a restoring force of the elastic member by applying a voltage, a substrate on which the electrode is disposed,

The spatial phase modulation element according to any one of claims 1 to 4, further comprising:

6. The space according to claim 5, wherein the mirror surface moves in response to application of a voltage to the electrode, and a phase modulation amount is determined according to the movement amount or deformation amount. Phase modulation element.

7. The spatial phase modulation element according to claim 6, wherein the movement control or deformation control of the mirror surface is determined only by whether or not voltage is applied to the electrode.

[8] The amount of movement or deformation of the mirror surface is equivalent to a quarter wavelength of the light of the incident light source, and a phase difference corresponding to a half wavelength is formed in the emitted diffracted light. The spatial phase modulation element according to claim 7.

[9] The movement amount or deformation amount of the mirror surface is determined depending on the voltage value applied to the electrode, and the change amount of the applied voltage is continuously increased or decreased. 7. The spatial phase modulation element according to claim 6, wherein the spatial phase modulation element is controlled as needed.

[10] The maximum amount of movement or deformation of the mirror surface is within half of the wavelength of the incident light source, and the phase difference formed in the emitted diffracted light is within one wavelength. The spatial phase modulation element according to claim 9.

[11] The one mirror surface is formed of an integral mirror, and an elastic member and an electrode are arranged corresponding to each partition portion for performing phase modulation of the mirror surface of the integral mirror. The spatial phase modulation element according to any one of claims 5 to 10, characterized by:

[12] The mirror surface is formed as an individual mirror in each partition portion for performing phase modulation, and an elastic member and an electrode are arranged on each mirror, respectively. The spatial phase modulation element according to any one of claims 5 to 10.

13. The spatial phase modulation element according to claim 5, wherein the surface accuracy of the one surface of the mirror is 50 nm or less.

14. The spatial phase modulation element according to claim 5, wherein the mirror surface has a surface roughness of 5 nm or less.

[15] a light source;

A condensing optical system for condensing light emitted from the light source;

The light emitted from the light source is disposed in the middle of the light collecting position where the light is collected via the light collecting optical system, and a plurality of two-dimensionally arranged phase modulations are performed. Spatial phase modulation elements in which the number of sections in each section is equal to or more than the number of pixels in the projected image displayed;

A shielding member that shields the zero-order diffracted light that is emitted and collected without being diffracted from the spatial phase modulation element at the condensing position;

A projection apparatus comprising:

[16] Each partition portion of the spatial phase modulation element is controlled in phase to be modulated based on spatial phase information generated corresponding to image information to be projected and displayed. 16. The projection apparatus according to claim 15, wherein each pixel is formed by diffracted light emitted from all of the partition portions of the spatial phase modulation element.

[17] The light source is disposed at a position separated from the optical axis of the condensing optical system, and the shielding member emits diffracted light that is emitted from the spatial phase modulation element and forms a projected image. 16. The projection device according to claim 15, wherein the projection device is disposed outside the light beam.

[18] The number of vertical columns and horizontal columns of the partition portion in the spatial phase modulation element is equal to or greater than the number of vertical columns and horizontal columns of pixels of the image displayed by projection. The projection apparatus according to claim 15, wherein the projection apparatus is characterized in that:

[19] The number of vertical columns and the number of horizontal columns of the partition portion in the spatial phase modulation element is a power of 2 according to any one of claims 15 to 18. Projection device.

[20] The contour shape in the phase modulation section formed by all of the partition portions for performing phase modulation of the spatial phase modulation element is a square having the same aspect ratio, and does not depend on the aspect ratio of the displayed image. The projection device according to any one of claims 15 to 19, characterized by:

[21] The spatial phase modulation element,

A mirror surface for performing phase modulation when reflecting light from the light source, and corresponding to each of the partition portions for performing phase modulation provided on the mirror surface; An elastic member arranged

The projection apparatus according to any one of claims 15 to 20, further comprising:

[22] The mirror surface of the spatial phase modulation element moves in response to application of a voltage to the electrode, and the phase modulation amount is determined according to the movement amount or deformation amount. The projection device according to claim 21.

23. The projection device according to claim 22, wherein the movement control or deformation control of the mirror surface in the spatial phase modulation element is determined only by whether or not a voltage is applied to the electrode.

[24] The amount of movement or deformation of the mirror surface in the spatial phase modulator is equivalent to 1/4 wavelength of the light from the incident light source, and forms a phase difference of 1/2 wavelength in the emitted diffracted light The projection device according to claim 23, wherein:

[25] Control of the movement amount or deformation amount of the mirror surface in the spatial phase modulation element is determined depending on the voltage value applied to the electrode, and the change amount of the applied voltage is successively and sequentially. The projection apparatus according to claim 22, wherein the projection apparatus is controlled to be increased or decreased.

[26] The maximum movement amount or deformation amount of the mirror surface in the spatial phase modulation element is within a half wavelength equivalent of the light of the incident light source, and the phase difference formed in the emitted diffracted light is 1 The projection device according to claim 25, wherein the projection device is within a wavelength.

[27] The mirror surface of the spatial phase modulation element is formed of an integral mirror, and an elastic member and an electrode are arranged corresponding to each partition portion for performing phase modulation of the mirror surface of the integral mirror. The projection apparatus according to any one of claims 21 to 26, wherein:

[28] The mirror surface in the spatial phase modulation element is formed as an individual mirror in each partition portion for performing phase modulation, and an elastic member and an electrode are arranged for each mirror. The projection device according to any one of Claims 21 to 26.

29. The projection apparatus according to claim 21, wherein the surface accuracy of the mirror surface in the spatial phase modulation element is 50 nm or less.

30. The projection device according to claim 21, wherein the surface roughness of the mirror surface in the spatial phase modulation element is 5 nm or less.