JP3832093B2 - Display device and display method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device, and more particularly, to a display device configured to form an image by a spatial light modulator including a plurality of pixels.
[0002]
[Prior art]
Conventionally, an image projection technique for forming an image at a predetermined distance by an optical projector such as a liquid crystal projector has been used. In this image projection technique, generally, the amplitude (intensity) of light is modulated and projected, and a desired image is displayed on a screen disposed at a predetermined distance by a lens imaging system.
[0003]
On the other hand, techniques for forming various images using a spatial light modulator (SLM) have been proposed. In the past, the inventors focused on an electric addressing type liquid crystal spatial light modulator (LCSLM) and attempted to manufacture a kinoform. For the principle of kinoform, see optical vol. 2 (1973) p. 133-152 “Kinoform and its application” (Yuki Ichioka). According to kinoform, a desired image can be formed by spatially modulating the phase of light, or an optical system equivalent to an optical lens can be formed, thereby forming an image formed at a predetermined distance. Can be formed.
[0004]
[Problems to be solved by the invention]
By the way, the conventional spatial light modulator is basically configured to form a very simple still image (for example, an image composed of only lines). There is a problem that it cannot be switched.
[0005]
In addition, since the conventional optical projector is configured to form an image at a predetermined distance using a lens imaging system, when projecting a predetermined image on a screen or the like, the distance to the screen is set. Accordingly, it is necessary to adjust the focal length accordingly, and there is a problem that preparation work for image projection is required.
[0006]
Further, in recent years, a method of pointing a predetermined part such as an object located at a distant position using a laser pointer or an image projected on a screen has been used, and a point of interest can be easily pointed out even from a distance. It is like that. However, since this laser pointer only projects the laser beam as it is, there is a problem that only a limited pattern shape such as a round spot and a pointer image of a predetermined size can be obtained. On the other hand, it is conceivable to form a pointer image with various image patterns such as arrows and other symbols, icons, and the like, but in this case, it is necessary to form the pointer image at a predetermined distance by the same principle as that of the optical projector. For this reason, when the projection distance from the operator changes depending on the position indicated, the focus adjustment must be continuously adjusted, and there is a problem that it is difficult to construct a practical one.
[0007]
Therefore, the present invention solves the above-mentioned problems, and the problem is that the switching of moving images and screens can be freely performed, and the adjustment work of the focal length when forming an image can be reduced. It is an object of the present invention to provide a technique capable of maintaining an image formation state even when the projection distance of the lens changes.
[0008]
[Means for Solving the Problems]
Means taken by the present invention in order to solve the above problems is a display device that forms a predetermined image on a screen and displays the image. The display device includes a light source that generates coherent light, and a plurality of pixels. A spatial light phase modulator that modulates the phase of the light, and a signal generation means for sending a phase modulation signal for controlling the phase modulation degree of each pixel to the spatial light phase modulator, the signal generation means comprising: A phase modulation pattern for forming the predetermined image at a predetermined position so that the predetermined image is formed on the screen disposed within a predetermined distance from the spatial light phase modulator. And a plurality of lens functions having different focal lengths are multiplied for each pixel to generate a multiplexed phase modulation pattern of the predetermined image, and based on the multiplexed phase modulation pattern The phase It generates a tone signal, and outputting the said phase modulation signal to the spatial light phase modulator.
[0009]
According to this means, since the phase modulation pattern sent from the signal generating means is realized by a plurality of pixels, it is possible to freely switch between moving images and screens and to set a predetermined image at a plurality of image forming positions. Since it is possible to form an image, it is possible to form images at a plurality of positions at different distances along the light projection direction, so it is only necessary to select one of the plurality of positions. It becomes possible to form more easily. In addition, unlike conventional liquid crystal projectors using lens imaging systems and liquid crystal shutters, images can be formed without restricting or blocking light, thus increasing the efficiency of light source light utilization for images. Can do.
[0010]
Another embodiment of the present invention is a display device that forms a predetermined image on a screen and displays the image, and includes a light source that generates coherent light and a plurality of pixels, and modulates the phase of light from the light source. A spatial light phase modulator; and a signal generating means for sending a phase modulation signal for controlling a phase modulation degree of each pixel to the spatial light phase modulator, wherein the signal generating means The phase based on a plurality of phase modulation patterns for forming the predetermined image at different imaging positions so as to form an image on the screen arranged within a predetermined distance from the spatial light phase modulator The modulated signal is output to the spatial light phase modulator in a time division manner.
[0011]
In the present invention, it is desirable that the spatial light phase modulator constitutes a kinoform.
[0012]
In each of the above means, the spatial light phase modulator is preferably a liquid crystal panel capable of controlling the phase modulation state of light by a voltage applied to the liquid crystal layer. According to this means, the image to be formed can be a moving image, or the image can be switched and displayed.
[0013]
In this case, the liquid crystal panel is preferably an electric field controlled birefringence mode liquid crystal panel. The liquid crystal panel of the electric field control birefringence mode can easily obtain a continuous phase change of 2π or more, and the relationship between the phase change and the applied voltage can be made linear, and light transmission accompanying the phase change can be achieved. The variation in the amount can be reduced, and the electro-optical characteristics in the display area can be easily made uniform.
[0014]
In each of the above means, it is preferable that the spatial light phase modulator is configured to be able to form an image that changes with time due to a change in the phase modulation signal.
[0015]
In each of the above means, the image is preferably a pointer display for pointing to an object or a predetermined part of the display image. In the pointer display, the distance to the target object or target image changes because the light projection position changes by the user, so that a predetermined image projected by a conventional lens imaging system cannot be used. Even if the light projection position changes, a good pointer display can be formed without any problem.
[0016]
Another aspect of the present invention includes a light source that generates coherent light, a spatial light phase modulator that includes a plurality of pixels and modulates the phase of light from the light source, and a phase of each pixel to the spatial light phase modulator. A signal generation means for sending a phase modulation signal for controlling the degree of modulation, and a display method for forming a predetermined image on a screen and displaying the image, wherein the signal recording the image is converted into a phase modulation pattern and a phase modulation Converting to a signal, multiplying the phase modulation pattern by a plurality of lens functions to convert the phase modulation pattern to a multiplexed phase modulation pattern of the image, and multiplexing the image Converting the phase modulation signal based on a phase modulation pattern, and forming the predetermined image on the screen disposed within a predetermined distance from the spatial light phase modulator. And wherein the Rukoto.
[0017]
According to the above display method, it is possible to form a predetermined image at a plurality of imaging positions, and thus images can be formed at a plurality of positions at different distances. This makes it easier to form an image. In addition, unlike conventional liquid crystal projectors using lens imaging systems and liquid crystal shutters, images can be formed without restricting or blocking light, thus increasing the efficiency of light source light utilization for images. Can do.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of an embodiment of a display device according to the present invention. A laser oscillator 10 is used as a light source used in the present embodiment. This laser oscillator 10 is a semiconductor laser, and rectifies and shapes power obtained from an AC power supply 12 by a drive circuit 11 and oscillates it. As the light source, a solid-state laser such as a YAG laser or a gas laser such as a He—Ne laser can be used instead of the semiconductor laser as described above.
[0019]
The beam of laser light emitted from the laser oscillator 10 is expanded by the beam expander 13. The expanded light beam is projected onto the spatial light phase modulator 200. The phase of the light beam expanded by the beam expander 13 is modulated by a predetermined phase modulation pattern formed by the spatial light phase modulator 200 and projected forward. As will be described later, this phase modulation pattern is configured to display a predetermined image in advance, and the image is displayed on the screens 15 and 16 disposed in front. Note that the condensing lens 14 may be arranged according to the convergence characteristics of the light beam caused by the optical characteristics of the beam expander 13.
[0020]
FIG. 2 is a schematic diagram showing an enlarged schematic structure of the liquid crystal panel 210 used in the spatial light phase modulator 200. The liquid crystal panel 210 is configured by sealing a liquid crystal layer 230 with a sealing material (not shown) between transparent substrates 211 and 214 made of alkali-free glass or the like. The liquid crystal panel has a large number of pixel regions arranged in a matrix. The number of pixel regions is, for example, 640 × 480.
[0021]
A transparent electrode 212 made of ITO (Indium Tin Oxide) or the like is formed on the inner surface of the transparent substrate 211, and a light shielding layer 213 made of black ink, a metal pattern, or the like is further provided on a part of the transparent electrode 212. Yes. Further, if necessary, an alignment film (not shown) made of polyimide, polyvinyl alcohol or the like is further formed on these structures and subjected to a rubbing treatment.
[0022]
On the other hand, on the inner surface of the transparent substrate 214, a semiconductor layer 215 made of polycrystalline silicon, a gate insulating film 216 formed on the semiconductor layer 215, and a gate electrode deposited on the gate insulating film 216. 217 and a TFT (thin film transistor) using a part of the semiconductor layer 215 as a source and a drain is formed for each pixel region. An X line 219 made of Al or the like extending in the X direction is formed on the TFT via an insulating film 218 made of silicon oxide or the like, and the X line 219 is connected to the source of the TFT. Further, a PSG (Phospho-Sillicate Glass) film 220 is deposited on these. A transparent electrode 221 made of ITO or the like independent for each pixel region is formed on the surface of the PSG film 220. The transparent electrode 221 is connected to the drain of the TFT. An alignment film similar to the above is formed on the inner surface structure of the transparent substrate 214 as necessary. FIG. 2 shows a cross section along the Y direction. Therefore, the Y line extending in the Y direction orthogonal to the X direction is not shown. This Y line is connected to the gate electrode 217.
[0023]
The transparent substrates 211 and 214 formed as described above are bonded to each other with a predetermined interval through a sealing material, and liquid crystal is injected into the interval. As the liquid crystal, a smectic liquid crystal is used in order to obtain high-speed switching characteristics. In this embodiment, a nematic liquid crystal is used from the viewpoint of stability and reliability. An ECB (electric field control birefringence) mode liquid crystal layer 230 was formed using this liquid crystal. In order to obtain sufficient phase modulation performance with a low driving voltage, different types of liquid crystals were appropriately mixed so that the liquid crystal layer 230 had a relatively high birefringence (Δn = 0.166). The rubbing direction of the alignment film formed on the inner surfaces of the transparent substrates 211 and 214 is the left-right direction (Y direction) in FIG. 2 so that a uniform alignment state can be obtained in the liquid crystal layer 230.
[0024]
In order to record the kinoform in the spatial light phase modulator 200, the following is generally required.
[0025]
1) A continuous phase change of 2π or more can be obtained.
[0026]
2) The relationship between the phase change and the applied voltage is linear.
[0027]
3) The fluctuation of the light amplitude (the square root of the transmitted light amount) accompanying the phase change is small.
[0028]
4) The electro-optical characteristics in the display area are uniform.
[0029]
Deviations from these requirements give unnecessary aberrations to the reproduction wavefront of the kinoform. For example, when applied to image reproduction, an intensity error with respect to the original image is generated.
[0030]
In this embodiment, the ECB mode is selected as the alignment state of the liquid crystal and is driven by the TFT panel. In order to increase the refractive index change perceived by light, linearly polarized light was used in which the initial alignment of the liquid crystal molecules was made substantially parallel to the transparent substrates 211 and 214 and aligned with the molecular axis direction. Further, in order to speed up the element response, a liquid crystal material having a large birefringence Δn is used to reduce the thickness d of the liquid crystal layer. In the present embodiment, the pixel pitch is 42 μm × 42 μm, the number of pixels is 640 × 480, the aperture ratio is 64%, and the cell gap d = 4.5 μm.
[0031]
6 to 8 show the electro-optical characteristics, specifically the voltage-phase characteristics, of the liquid crystal layer 230 when the birefringence Δn of the liquid crystal material of the liquid crystal panel of the present embodiment is changed. 6 is the same as the above, Δn = 0.166 (when the wavelength is 589 nm), FIG. 7 is the case where Δn = 0.139 (wavelength 589 nm), FIG. 8 is the wavelength 450 nm when Δn = 0.126 (wavelength 589 nm), The phase of transmitted light at 550 nm and 633 nm is shown with respect to the applied voltage. In either case, a phase change of approximately 2π is obtained with the drive voltage 5v. In particular, by increasing the birefringence index Δn as in this embodiment, a phase fluctuation range of 2π or more can be secured even for light having a wavelength of 550 nm, and a phase fluctuation range close to 2π can be obtained even at a wavelength of 633 nm. Can do.
[0032]
FIG. 9 is a graph showing a relationship between an applied voltage, a phase modulation amount, and a transmittance in a liquid crystal layer of the same type of ECB mode. This graph is a result of measurement using a helium neon laser (wavelength 632.8 nm) as a light source. Further, the birefringence was increased to reduce the cell thickness, thereby improving the response characteristics. Δn = 0.209, d = 6.0 μm, the number of effective pixels is 320 × 220, the pixel interval is 80 μm in the horizontal direction, 90 μm in the vertical direction, and the pixel opening is 56 μm × 64 μm. Other configurations of the liquid crystal layer are the same as those in the above embodiment. In this liquid crystal panel, the phase changes almost linearly from 0 to 2π in the range of 1.7 v to 4.5 v. On the other hand, the amplitude variation is considered to be caused by the change in the orientation of the liquid crystal molecules and the direction of travel of the light beam being inclined, and the amount of light transmitted through the pixel aperture varies. By making Δnd larger and setting the pretilt angle higher, fluctuations in the amount of transmitted light can be suppressed. In addition, since an aberration mainly caused by the thickness unevenness occurs in the display area of the liquid crystal panel, it can be compensated by measuring this aberration in advance and subtracting it from the kinoform phase data for correction. .
[0033]
FIG. 3 is a schematic block diagram showing a schematic configuration of the spatial light phase modulator 200 and a control drive device 300 that performs control drive of the spatial light phase modulator 200. The spatial light phase modulator 200 is configured so that it can be easily connected to a control drive device 300 constituted by, for example, a personal computer. The overall circuit configuration of the spatial light phase modulator 200 is the same as that of a normal active matrix liquid crystal display device.
[0034]
In order to form a predetermined image at a position separated by a predetermined distance by the spatial light phase modulator 200, an image signal (a video signal in the case of a moving image) is converted into a predetermined phase modulation pattern, and this phase modulation pattern is converted into a space. It is necessary to form a kinoform by forming a plurality of pixels of the liquid crystal panel 210 of the optical phase modulator 200. The following equation is established between the phase modulation pattern Φ on the kinoform formed in the spatial light phase modulator 200 and the transmittance T of the kinoform surface separated by a predetermined distance z0.
[0035]
T (x, y, z0) = C · exp [−iΦ (x, y, z0)] (1)
Here, (x, y) is a coordinate in a plane orthogonal to the optical axis, and C is a constant. For the calculation of the phase modulation pattern, a simulated annealing method (Science 220, p.671-680,1983, hereinafter simply referred to as “SA method”) was used. The construction of the rules necessary for the operation of the SA method requires experience, and the success or failure of this rule greatly affects whether or not a “good solution” can be obtained. A “good solution” is a solution that satisfies the optical characteristics required for the phase modulation pattern, and the optical characteristics are determined by the intended use of the phase modulation pattern. In order to design a phase modulation pattern using the SA method, at least (1) definition of evaluation function and setting of weight, (2) temperature scheduling, and (3) determination of equilibrium state must be defined respectively. Don't be. The evaluation function is an amount corresponding to the difference between the estimated value regarding the performance of the phase modulation pattern and the target value, and the solution when the function value is the smallest is the optimal solution.
[0036]
A plurality of lens functions Ln having different focal lengths (n is an arbitrary natural number) are added to the phase modulation pattern obtained as described above.
Ln = exp [iPn (x2 + y2)] (Pn is a lens constant)... (2) is multiplied to multiplex a plurality of image patterns formed at different positions according to the focal length of the lens function. can do. This lens function Ln is a phase modulation pattern that performs the same function as the lens, and changes the imaging position z0 of the phase modulation pattern Φ (x, y, z0) corresponding to the image according to the lens constant Pn.
[0037]
As shown in FIG. 3, a video signal a for recording a still image or a moving image is input from an external recording device, a CCD camera, or the like, and input to the phase pattern conversion circuit 301 of the control drive device 300. The phase pattern conversion circuit 301 converts the image information of the video signal a into the phase modulation pattern Φ based on the video signal a, and outputs a phase modulation signal φ corresponding to the phase modulation pattern Φ. Further, based on the video signal a, the sync separation circuit 302 forms a horizontal sync signal h and a vertical sync signal v. The phase modulation pattern Φ is input to the lens conversion circuit 303 and multiplied by the plurality of lens functions Ln (n = 1, 2,...), And phase modulation for realizing a multiplexed phase modulation pattern Ψ. The signal ψ is output.
[0038]
The multiplexed phase modulation pattern Ψ is multiplexed by a number of lens functions Ln so as to form an image included in the video signal a almost continuously within a range from a predetermined distance z1 to z2. Yes.
[0039]
The horizontal synchronization signal h, the vertical synchronization signal v, and the phase modulation signal ψ are input to the control circuit 240 of the spatial light phase modulator 200, and the X line data signal DX, the X line clock signal CLX, and the Y line scan are input from the control circuit 240. The signal DY and the Y line clock signal CLY are input to the X driver circuit 210X and the Y driver circuit 210Y built in the liquid crystal panel 210. These X driver circuit 210X and Y driver circuit 210Y supply predetermined data signals and scanning signals respectively to a plurality of X lines and Y lines formed in the liquid crystal panel.
[0040]
FIG. 4 is an explanatory diagram showing a state at the time of image projection in the projection display using the present embodiment having the above-described configuration. The light emitted from the light source passes through the liquid crystal pixel area of the spatial light phase modulator 200 provided with the liquid crystal panel and is projected onto the screen 401 disposed in front. The screen 401 has the distances z1 to z2 described above. Therefore, a desired image 401 a is formed on the screen 401. Similarly, since the screen 402 is also disposed within the range from the distance z1 to z2, a desired image 402a is formed in the same manner. Here, the images 401a and 402a are the same image for the reason described above.
[0041]
As described above, according to the present invention, the image projected from the spatial light phase modulator 200 is formed anywhere within the range from the predetermined distance z1 to z2. If you place the screen in any position, you can see the same image. Therefore, it is not necessary to accurately determine the position of the screen or to adjust the focus of the light projector, and the image can be projected very easily. Note that even if the screen surface is inclined from the orthogonal posture with respect to the light projection direction, an image formed in the same manner can be seen as long as it is within the range from z1 to z2. Such characteristics are particularly effective when the surface of a moving object is used as the screen, or when the surface of an object having an uneven surface is used.
[0042]
In this embodiment, the light amount of the light source is not formed by limiting or blocking the amplitude of the light emitted from the light source as in a normal liquid crystal display device or projector. Since all the light is used as it is to form an image, there is an advantage that the light use efficiency can be improved. Note that the projected images 401a and 402a shown in FIG. 4 may be still images or moving images.
[0043]
FIG. 5 shows another application example of the present embodiment. In this case, the present embodiment is configured as a small, graspable pointer device 500 having a pen type casing. The pointer device 500 emits light from its tip. When the pointer device 500 is held and the front end portion 500a is directed to the screens 501 and 502, pointer displays 501a and 502a are displayed on the screens 501 and 502. In this case as well, the pointer displays 501a and 502a are imaged on the screens 501 and 502 and are clearly visible as long as the screen is disposed within the range from z1 to z2 from the pointer device 500, as described above. Is done.
[0044]
In general, since the pointer device 500 is used by being held in hand, the position of the pointer device 500 varies depending on the will of the user. Accordingly, since the distance between the pointer device 500 and the screens 501 and 502 is constantly fluctuating, an image can be formed regardless of the distance between the pointer device 500 and the screens 501 and 502 as long as it is within a predetermined range. The embodiment is particularly effective.
[0045]
The image projected from the pointer device 500 may be a pointer display as a still image, but the pointer display may be a moving image. Further, as shown in the figure, it may be configured to be switched to another different pointer display 501b or 502b depending on the purpose of use as shown in the figure.
[0046]
In the above-described embodiment, an ECB mode liquid crystal panel that can modulate the phase largely without modulating the amplitude of light is used as the spatial light phase modulator 200. An image may be formed by modulating the amplitude (intensity). However, since it is necessary to remove at least a part of the light in order to modulate the amplitude of the light, the light use efficiency decreases.
[0047]
In the above embodiment, since the same image having different imaging positions is multiplexed by the phase modulation pattern (kinoform) configured in the spatial light phase modulator 200, the same image is displayed almost continuously within a predetermined range. Although it is possible to form an image, “substantially continuously” means that, for example, when a screen is used in a normal use mode, the image can be visually recognized even if the screen is placed at an arbitrary position. Say that is multiplexed.
[0048]
In the above usage mode, image reproduction by projection using a screen has been described as an example. However, the present invention is not limited to such usage mode. For example, the back surface of the phosphor screen is opposite to the viewer. By projecting from the side, it can be configured as a rear projection type display device. In this case, the display can be colored by using a color filter or a color phosphor.
[0049]
In the above embodiment, a plurality of images formed at different distances are multiplexed using a plurality of lens functions Ln having different focal lengths, but the present invention is not limited to such a multiplexing method. As a result, a plurality of images may be multiplexed. As another multiplexing method, for example, when a plurality of phase modulation patterns for forming images formed at different imaging positions with respect to the liquid crystal panel 200 are formed in a time-sharing manner, for example, the images are displayed on the screen Alternatively, only an image formed on the screen based on human visual characteristics can be selectively viewed. In this case, time-division driving of the liquid crystal panel can be performed by a known method.
[0050]
【The invention's effect】
As described above, according to the present invention, since the phase modulation pattern sent from the signal generating means is realized by a plurality of pixels, it is possible to freely switch between moving images and screens, and a plurality of predetermined images. Since an image can be formed at a plurality of positions along the light projection direction, it is only necessary to select one of the plurality of positions. An image can be formed more easily. In addition, unlike conventional liquid crystal projectors using lens imaging systems and liquid crystal shutters, images can be formed without restricting or blocking light, thus increasing the efficiency of light source light utilization for images. Can do.
[0051]
In particular, since the predetermined image is formed almost continuously over a predetermined range along the light projection direction, it is not necessary to adjust the focal length. An image can be formed at the position.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing the overall configuration of an embodiment of a display device according to the present invention.
FIG. 2 is an enlarged schematic view of a liquid crystal panel included in the spatial light phase modulator in the same embodiment.
FIG. 3 is a schematic block diagram showing a schematic configuration of a control drive device and a spatial light phase modulator in the same embodiment.
FIG. 4 is an explanatory diagram showing a usage mode when the embodiment is used as an image projector.
FIG. 5 is an explanatory diagram showing a usage mode when the embodiment is used as a pointer device;
6 is a graph showing electro-optical characteristics (phase of transmitted light with respect to applied voltage) of a liquid crystal layer of the liquid crystal panel of the embodiment. FIG.
FIG. 7 is a graph showing electro-optical characteristics (phase of transmitted light with respect to applied voltage) of a liquid crystal layer of the liquid crystal panel of the same embodiment.
FIG. 8 is a graph showing electro-optical characteristics (phase of transmitted light with respect to applied voltage) of a liquid crystal layer of the liquid crystal panel of the same embodiment.
FIG. 9 is a graph showing electro-optical characteristics (phase change and amplitude transmittance with respect to applied voltage) of a liquid crystal layer of a liquid crystal panel different from the embodiment.
[Explanation of symbols]
10 Laser oscillator
11 Drive circuit
12 AC power supply
13 Beam expander
14 Condensing lens
15,16 screen
200 Spatial optical phase modulator
210X X driver circuit
210Y Y driver circuit
210 LCD panel
211,214 Transparent substrate
212 Transparent electrode
213 Shading layer
215 Semiconductor layer
216 Gate insulation film
217 Gate electrode
218 Insulating film
219 electrode
221 Transparent electrode
230 Liquid crystal layer
240 Control circuit
300 Control drive
301 Phase pattern conversion circuit
302 Sync separation circuit
303 Lens conversion circuit
401, 402, 501, 502 Screen
401a, 402a images
500 pointer device
501a, 502a, 501b, 502b Pointer display
Φ, Ψ phase modulation pattern
φ, ψ Phase modulation signal

Claims (8)

A display device that forms and displays a predetermined image on a screen,
A light source that generates coherent light;
A spatial light phase modulator comprising a plurality of pixels and modulating the phase of light from the light source;
Signal generating means for sending a phase modulation signal for controlling the phase modulation degree of each pixel to the spatial light phase modulator;
The signal generating means forms the predetermined image at a predetermined position so that the predetermined image is formed on the screen disposed within a predetermined distance from the spatial light phase modulator. And a plurality of lens functions having different focal lengths are multiplied for each pixel to generate a multiplexed phase modulation pattern of the predetermined image, and the multiplexed phase A display device that generates the phase modulation signal based on a modulation pattern and outputs the phase modulation signal to the spatial light phase modulator. A display device that forms and displays a predetermined image on a screen,
A light source that generates coherent light;
A spatial light phase modulator comprising a plurality of pixels and modulating the phase of light from the light source;
Signal generating means for sending a phase modulation signal for controlling the phase modulation degree of each pixel to the spatial light phase modulator;
The signal generating means forms the predetermined image at a different imaging position so that the predetermined image is formed on the screen disposed within a predetermined distance from the spatial light phase modulator. The phase modulation signal based on a plurality of phase modulation patterns for output to the spatial light phase modulator in a time division manner.   The display device according to claim 1, wherein the spatial light phase modulator forms a kinoform.   The display device according to claim 1, wherein the spatial light phase modulator is a liquid crystal panel that controls a phase modulation state of light by an applied voltage.   The display device according to claim 4, wherein the liquid crystal panel is in an electric field control birefringence mode.   The display device according to claim 1, wherein the spatial light phase modulator forms an image that changes with time according to a change in the phase modulation signal.   The display device according to claim 1, wherein the image is a pointer display for pointing to an object or a predetermined part of a display image. A light source that generates coherent light;
A spatial light phase modulator comprising a plurality of pixels and modulating the phase of light from the light source;
A signal generation means for sending a phase modulation signal for controlling the degree of phase modulation of each pixel to the spatial light phase modulator, and a display method for forming a predetermined image on a screen and displaying it.
Converting the signal recording the image into a phase modulation pattern and a phase modulation signal;
Multiplying the phase modulation pattern by a plurality of lens functions to convert the phase modulation pattern into a multiplexed phase modulation pattern of the image;
Converting the phase modulation signal based on a multiplexed phase modulation pattern of the image,
The display method, wherein the predetermined image is formed on the screen disposed within a predetermined distance from the spatial light phase modulator.

Images