JP2006038944A - Spatial light modulator, and drive circuit used for the same, and driving method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spatial light modulator having high-density pixels and low power consumption, by reducing the number and resistance of electrode wires, further to provide a drive circuit used for the spatial light modulator, and a driving method of the spatial light modulator using the drive circuit. <P>SOLUTION: In the spatial light modulator 50, equipped with a plurality of photomagnetic effect elements 1 arranged in a matrix, lower side electrode wires 2 and upper side electrode wires 3 arranged between the adjacent photomagnetic effect elements 1, and the driving circuit to set respective directions of currents flowing through the lower side electrode wires 2 and the upper side electrode wires 3, the lower side electrode wires 2 and the upper side electrode wires 3 are arranged so as to be a single wire on respective intervals between the adjacent photomagnetic effect elements. Also respective one ends of the lower side electrode wires 2 and the upper side electrode wires 3 are connected to a common wire 4 and further the other ends of them are connected to the driving circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spatial light modulator that spatially modulates incident light, a driving circuit used in the spatial light modulator, and a driving method of the driving circuit.

  Spatial light modulators that spatially modulate incident light are used in fields such as optical information processing and computer-generated holograms.

  As a conventional spatial light modulator, one using liquid crystal or one using a micromirror device is known. In fields such as the above-described optical information processing and computer-generated holograms, it is necessary to process a large amount of information at high speed. Therefore, it can be said that it is preferable that the spatial light modulator applied thereto has a high operating speed.

  However, spatial light modulators using liquid crystals have the disadvantage of a low operating speed, and even when a ferroelectric liquid crystal with a relatively high operating speed among liquid crystals is used for the spatial light modulator, the response Time is on the order of microseconds.

  On the other hand, a spatial light modulator using a micromirror device can operate at a relatively high speed. However, this spatial light modulator is a micromachine with a complicated structure manufactured by an advanced semiconductor manufacturing process, so that the manufacturing cost is high and the reliability is low because it has a mechanical drive part. There's a problem.

  In view of the above problems, a spatial light modulator using the magneto-optic effect has been developed. A spatial light modulator using such a magneto-optical effect is made of a magneto-optical material, and has a plurality of pixels that can independently select the direction of magnetization. In a spatial light modulator using the magneto-optic effect, the polarization direction of light passing through each pixel is rotated by a predetermined angle in opposite directions according to the direction of magnetization in each pixel due to the Faraday effect. Therefore, spatially modulated light can be generated by arbitrarily selecting the direction of magnetization in each pixel.

  The spatial light modulator using the magneto-optic effect is similar to the liquid crystal display in that optical rotation is used, but is superior to the liquid crystal display in the following points.

  (1) The response speed is several ns, 1000 times faster than the high-speed liquid crystal of about 10 μs.

  (2) The image resolution can be easily increased to 1000 dpi or more.

  (3) Even if other means such as a touch panel are not used additionally, it is possible to easily add an image to the image with a magnetic pen.

  (4) A bag function (a glass plate, a plastic plate and liquid sealing) for preventing liquid leakage is unnecessary.

  (5) Part of the pixel is not lost due to a transistor or the like for switching the pixel state.

As the spatial light modulator using the magneto-optical effect, for example, those disclosed in Patent Documents 1 to 3 are known.
JP 2002-277842 (release date: September 25, 2002) JP 2001-343619 (Publication date: December 14, 2001) Japanese Patent No. 279736 (Registration Date: January 23, 1998 (1998), Publication: JP 2-79017, Publication Date: March 19, 1990)

  In the conventional spatial light modulator (conventional spatial light modulator 100) using the magneto-optical effect as described above, in order to set (invert) the magnetization direction in an arbitrary pixel, it is shown in FIGS. Such a loop-shaped electrode wiring (hereinafter referred to as a loop-shaped electrode wiring, in particular, the loop-shaped electrode wiring close to the viewer side of the spatial light modulator is the upper loop-shaped electrode wiring 32, and on the contrary, the loop-shaped electrode far from the viewer side. The wiring is referred to as a lower loop electrode wiring 31) corresponding to each pixel (magneto-optic effect element 1) in a lattice shape, and two lines intersecting at the position where the pixel (magneto-resistance effect element 1) is arranged. By energizing the lower loop electrode wiring 31 and the upper loop electrode wiring 32, a magnetic field for reversing the magnetization direction in the pixel (the magneto-optical effect element 1) is generated.

  Further, in the conventional spatial light modulator using the magneto-optical effect (conventional spatial light modulator 100), as shown in FIG. 9, by turning on / off the switches 6a and 6b, lower loop electrode wiring Each terminal 7 of 31 can be short-circuited (connected) to plus or minus. In such a structure, since each magnetic head (lower loop electrode wiring 31) can be energized simultaneously, it is possible to change (set) the magnetization directions of many magneto-optical effect elements 1 at the same time. Become.

  However, the conventional spatial light modulator using the magneto-optical effect (conventional spatial light modulator 100) uses the lower loop electrode wiring 31 in FIG. 9, and each pixel (magneto-optical) as shown in FIG. Since two lower loop electrode wirings 31 are arranged between the effect elements 1), it is difficult to arrange the pixels (magneto-optical effect element 1) at a small interval and to arrange them at high density.

  In order to solve the above problem, a pixel (magneto-optical effect element 1) is formed on the lower loop electrode wiring 31 as in the conventional spatial light modulator 101 disclosed in Patent Document 2 and FIG. Although there is a configuration, the material used for the lower loop electrode wiring 31 must be transparent to at least the light to be used, and it is necessary to use a transparent conductive film.

Typical examples of the transparent conductive film include a tin oxide film (SnO ₂ ) and an indium oxide (In ₂ O ₃ ) film having high visible light transmittance and conductivity. However, the transparent conductive film has an electrical resistivity about two orders of magnitude higher than that of the metal electrode (for example, ITO (Indium Tin Oxide) film = 1.5 × 10 ⁻⁴ Ωcm, Al film = 2.6 × 10 ⁻⁶ Ωcm). Therefore, there is a problem that power consumption becomes very large. In such a case, there are measures such as increasing the cross-sectional area of the conductive wire made of a transparent conductive film to lower the electrical resistance and reducing the power consumption, but the power consumption cannot be reduced as much as the metal electrode.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce the number of electrode wires and the electrical resistance of the electrode wires so that the spatial light modulator has a high density of pixels and low power consumption. Is to realize and provide. Furthermore, a driving circuit used for the spatial light modulator and a driving method of the spatial light modulator using the driving circuit are provided.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

  That is, the spatial light modulator according to the present invention is arranged between a plurality of magneto-optical effect elements arranged in a matrix and the adjacent magneto-optical effect elements, and is arranged in either a row or a column of the matrix. A spatial light modulator comprising: a plurality of electrode wirings extending in a direction along the drive circuit; and a drive circuit that sets a direction of a current flowing through each of the plurality of electrode wirings. One end of the plurality of electrode wirings extending in the same direction is connected to the common wiring, and the other end of the plurality of electrode wirings is connected to the drive circuit. It is characterized by having.

  According to such a configuration, since there is one electrode wiring disposed between the magneto-optical effect elements arranged in a matrix, it is possible to arrange the magneto-optical effect elements, that is, the pixels at a higher density. Become. Therefore, it is possible to provide a spatial light modulator with higher resolution.

  In the spatial light modulator according to the present invention, the spatial light modulator is preferably a transmission type.

  According to such a configuration, since there is one electrode wiring disposed between the magneto-optical effect elements arranged in a matrix, even a transmissive spatial light modulator has an electrical resistance as a material for the electrode wiring. Low metal electrode wiring can be used. Therefore, it is not necessary to increase the cross-sectional area of the electrode wiring, and the magneto-optical effect elements (pixels) can be arranged with higher density. In addition, power consumption can be reduced. Furthermore, the metal electrode wiring is not light-transmitting, and the electrode wiring itself disposed between the magneto-optical effect elements (pixels) becomes a black matrix, thereby improving the contrast and obtaining a clearer image. Play.

  The spatial light modulator according to the present invention is disposed between a plurality of magneto-optical effect elements arranged in a matrix and the adjacent magneto-optical effect elements, and is arranged in any one of rows or columns of the matrix. A reflective spatial light modulator comprising: a plurality of electrode wirings extending in a direction along; a drive circuit for setting a direction of a current flowing through each of the plurality of electrode wirings; and a reflective film. Assuming that the electrode wiring disposed at a position closer to the spatial light modulator from the viewer than the reflective film is a transmissive electrode wiring, one transmissive electrode wiring is provided between the magneto-optical effect elements. And one end of each of the transmissive part electrode wirings extending in the same direction is connected to the common wiring, and the other end of the transmissive part electrode wiring is connected to the drive circuit. It is characterized by.

  The reflective spatial light modulator includes a reflective film as described above on the surface opposite to the viewer side of the spatial light modulator, in other words, on the surface opposite to the light incident surface of the spatial light modulator. Yes. Since the light incident on the spatial light modulator is reflected by the reflective film and reaches the viewer's eyes, electrode wiring or the like disposed at a position far from the viewer is not necessarily light. It is not necessary to have the transparency. Therefore, in the process of increasing the density of the magneto-optical effect element (pixel), it is possible to use a metal electrode wiring that does not have optical transparency. Since such a metal electrode wiring has a low electrical resistance value, the cross-sectional area can be reduced. Therefore, even when a conventional loop electrode wiring is used, it does not become a relatively hindrance to increasing the density of the magneto-optical effect element (pixel).

  On the other hand, the electrode wiring (transmission electrode wiring) disposed at a position closer to the viewer than the reflective film is formed on the magneto-optical effect element in the process of increasing the density of the magneto-optical effect element (pixel). A situation occurs in which the electrode wiring is covered. In such a case, a transparent electrode having light permeability must be used for the electrode wiring, and problems such as an increase in power consumption occur as described above.

  Therefore, in the reflection type spatial light modulation, as described above, at least the transmission part electrode wiring is disposed so as to be one between the magneto-optical effect elements, and extends in the same direction. It can be said that it is necessary that one end of each transmissive electrode wiring is connected to the common wiring and the other ends of the plurality of electrode wirings are connected to the drive circuit.

  According to the above configuration, in the reflective spatial light modulator, since there is one electrode wiring disposed between the magneto-optical effect elements arranged in a matrix, the magneto-optical effect element, that is, the pixels are arranged with higher density. It becomes possible to arrange in. Therefore, it is possible to provide a reflective spatial light modulator with higher resolution.

  Even in the case of the transmissive electrode wiring, a metal electrode wiring having a low electrical resistance value can be used as the material of the electrode wiring. Therefore, it is not necessary to increase the cross-sectional area of the electrode wiring, and the magneto-optical effect elements (pixels) can be arranged with higher density. In addition, power consumption can be reduced. Furthermore, the metal electrode wiring is not light transmissive, and the electrode wiring itself disposed between the magneto-optical effect elements (pixels) becomes a black matrix, so that the contrast can be increased and a clearer image layer can be obtained. There is an effect.

  In the spatial light modulator according to the present invention, it is preferable that the plurality of electrode wirings are arranged so that directions of currents flowing through the electrode wirings are orthogonal to each other.

  According to the above configuration, the magnetization direction can be set in a quadrangular (square, rectangular) region formed by mutually orthogonal electrode wirings. Therefore, it is possible to independently set and control the direction of magnetization for each of the magneto-optical effect elements that are two-dimensionally arranged so as to correspond to the square. Furthermore, since the electrode wirings are orthogonal to each other, the area of the region in which the magnetization direction can be set can be further reduced, and the magneto-optical effect element (pixel) can be densified. There is an effect that can be done.

  In the spatial light modulator according to the present invention, the drive circuit includes means for switching whether the other end of the electrode wiring is connected to the positive potential of the power source, connected to the ground potential, or opened. It is preferable.

  By having means for switching between the positive potential of the power source, the ground potential, or the open state as in the above configuration, the direction of the current flowing through each electrode wiring connected to the drive circuit is arbitrary It becomes possible to set to. By arbitrarily setting the direction of the current, it is possible to arbitrarily set and control the direction of the generated magnetization for each region surrounded by the electrode wiring. Therefore, it is possible to drive each magneto-optical effect element (pixel) more precisely while increasing the density of the magneto-optical effect element (pixel).

  On the other hand, the drive circuit according to the present invention is arranged such that there is one electrode wiring between a plurality of magneto-optical effect elements arranged in a matrix, and the plurality of electrodes extending in the same direction. A driving circuit for driving the spatial light modulator, wherein one end of each wiring is connected to the common wiring, and is connected to an end opposite to one end of the electrode wiring connected to the common wiring; It is characterized by having means for switching between connecting to the positive potential of the power source, connecting to the ground potential, or opening.

  By having means for switching between the positive potential of the power source, the ground potential, or the open state as in the above configuration, the direction of the current flowing through each electrode wiring connected to the drive circuit is arbitrary It becomes possible to set to. By arbitrarily setting the direction of the current, it is possible to arbitrarily set and control the direction of the generated magnetization for each region surrounded by the electrode wiring. Therefore, it is possible to drive each magneto-optical effect element (pixel) precisely while increasing the density of the magneto-optical effect element (pixel).

  On the other hand, an image display apparatus according to the present invention includes any one of the spatial light modulators described above.

  According to the above configuration, it is possible to provide a high-quality image display apparatus in which magneto-optical effect elements (pixels) are arranged at high density. In addition, because of the characteristics such as the simple structure of the spatial light modulator and the response speed much faster than that of the liquid crystal method, it is easy to make the screen size freely. There is an effect that it is possible to provide a wide variety of image display devices from a small display element such as a telephone to a large screen display for advertisement.

  On the other hand, the driving method of the spatial light modulator according to the present invention is such that one electrode wiring is arranged between a plurality of magneto-optical effect elements arranged in a matrix and extends in the same direction. One of the plurality of electrode wirings is connected to a common wiring, and the other end of the plurality of electrode wirings is connected to the driving circuit. The other end of each electrode wiring is connected to the positive potential of the power supply, connected to the ground potential, or switched to open state, so that the direction of the current flowing through each of the plurality of electrode wirings is appropriately combined , An arbitrary magnetization direction is set with respect to the corresponding magneto-optical effect element.

  According to the above driving method, it is possible to arbitrarily set the direction of current flowing through each electrode wiring. By arbitrarily setting the direction of the current, it is possible to arbitrarily set and control the direction of the generated magnetization for each region surrounded by the electrode wiring. Therefore, it is possible to drive each magneto-optical effect element (pixel) more precisely while increasing the density of the magneto-optical effect element (pixel).

  According to the spatial light modulator according to the present invention, one electrode wiring can be provided between the magneto-optical effect elements. Therefore, the magneto-optical effect element, that is, the pixels can be arranged at a high density, and an effect that a high-density spatial light modulator can be provided is achieved.

  Further, according to the driving circuit and the driving method of the driving circuit according to the present invention, there is an effect that the magnetization direction can be set for each of the magneto-optical effect elements arranged at high density.

  The embodiment of the present invention will be described as follows. Note that the present invention is not limited to this. In the following description, for the sake of convenience, the spatial light modulator is placed so that the surface close to the viewer of the spatial light modulator (that is, the light incident surface) is the top surface and the opposite surface is the bottom surface. It is explained as having been done.

[Embodiment 1]
Hereinafter, the present embodiment will be described in detail with reference to the drawings. FIG. 1 is a schematic view of an element part of a transmissive spatial light modulator 50 according to the present embodiment. FIG. 2 is a plan view of an element part of the transmissive spatial light modulator 50 according to the present embodiment. FIG. 3 is a cross-sectional view taken along the line AA ′ in FIG.

  As shown in FIGS. 1 to 3, the transmissive spatial light modulator 50 according to this embodiment includes a magneto-optical effect element 1, a lower electrode wiring 2, an upper electrode wiring 3, and a common wiring 4. The plurality of magneto-optical effect elements 1 are arranged in a matrix on the same plane of the substrate 5.

  Between the magneto-optical effect elements 1 (pixels) arranged in such a matrix, an insulating layer 8 is formed as shown in FIG.

  On the other hand, the electrode wiring (lower electrode wiring 2 and upper electrode wiring 3) is disposed between the adjacent magneto-optical effect elements 1, and the matrix row (in the x-axis direction in FIG. 2) or column (in FIG. 2). Is extended in a direction along any one of the y-axis directions). More specifically, the lower electrode wiring 2 extends in the column direction of the matrix (in the y-axis direction in FIG. 2), and the upper electrode wiring 3 extends in the row direction of the matrix (in the x-axis direction in FIG. 2). is doing. That is, the lower electrode wiring 2 and the upper electrode wiring 3 are extended in the orthogonal direction. The extending direction of the lower electrode wiring 2 and the upper electrode wiring 3 is not limited to the above, and may be a reverse pattern. That is, the lower electrode wiring 2 extends in the matrix row direction (x-axis direction in FIG. 2), and the upper electrode wiring 3 extends in the matrix column direction (y-axis direction in FIG. 2). It may be.

  Here, among the plurality of electrode wirings, the electrode wiring close to the viewer side (that is, the electrode wiring positioned on the upper side in FIGS. 1 to 3) is referred to as the upper electrode wiring 3, and the electrode wiring farther from the viewer (that is, the diagram) 1 to 3 is referred to as a lower electrode wiring 2. The lower electrode wiring 2 and the upper electrode wiring 3 are arranged one by one between the adjacent magneto-optical effect elements 1. Referring to FIG. 2, one magneto-optic effect element 1 is formed in a region surrounded by the lower electrode wiring 2 and the upper electrode wiring 3 to form one pixel region.

  The lower electrode wiring 2 composed of a plurality of electrode wirings extending in the same direction is connected to the common wiring 4 at one end thereof. Similarly, the upper electrode wiring 3 composed of a plurality of electrode wirings extending in the same direction is connected to the common wiring 4 at one end thereof. The common wiring 4 and the lower electrode wiring 2 (or the upper electrode wiring 3) may be configured as separate bodies, or the common wiring 4 and the lower electrode wiring 2 (or the upper electrode wiring 3) are integrated. It may be configured as a wiring. By setting the direction of the current flowing through the electrode wiring connected to the lower electrode wiring 2 and the common wiring 4 and the electrode wiring connected to the upper electrode wiring 3 and the common wiring 4 to a desired direction, A desired magnetization direction can be set in a region surrounded by the electric wiring 2 and the upper electrode wiring 3. The setting operation of the direction of current flowing through the electrode wiring and the direction of magnetization will be described later.

  Here, the material of the lower electrode wiring 2 and the upper electrode wiring 3 is not particularly limited, and may be selected as appropriate according to the configuration of the spatial light modulator and the like. For example, a metal electrode wiring that does not have optical transparency such as copper, aluminum, nickel, or platinum may be used, or a transparent conductive electrode wiring such as ITO may be used. However, it can be said that a metal electrode wiring having no light transmittance is preferable because the electrical resistance value is low and the cross-sectional area can be reduced and the power consumption can be reduced. The lower electrode 2 and the upper electrode 3 in the present embodiment are made of a metal thin film material that does not transmit visible light and does not exhibit ferromagnetism.

  On the other hand, the material constituting the magneto-optical effect element 1 may be any magneto-optical material having a magneto-optical effect (Faraday effect) that is transmissive to incident light, and in particular, a magnetic garnet thin film or a one-dimensional photo. It is preferable to use a nick crystal. A typical example of the magnetic garnet thin film is a rare earth iron garnet thin film. As a method for producing a magnetic garnet thin film, for example, there is a method of forming a single crystal magnetic garnet thin film on a gadolinium gallium garnet substrate by a liquid phase epitaxial growth method (LPE method) or a sputtering method.

A typical one-dimensional photonic crystal has a structure in which a dielectric multilayer film is formed on both sides of a magnetic layer. As the magnetic material, rare earth garnet, bismuth-substituted rare earth garnet, or the like is used. The dielectric multilayer film is configured by alternately laminating SiO ₂ films and Ta ₂ O ₅ films, for example. The period of the layer structure in the one-dimensional magnetic photonic crystal is about ¼ of the wavelength of light used. With this one-dimensional magnetic photonic crystal, a large Faraday effect can be obtained.

  Note that the transmissive spatial light modulator 50 according to the present embodiment may be manufactured by monolithically forming all the constituent elements, or may be formed by dividing into a plurality of parts and then combining the plurality of parts. It may be manufactured. When the transmissive spatial light modulator 50 is formed by being divided into a plurality of parts, for example, the part from the substrate 5 to the magneto-optical effect element 1 may be divided into other parts. Further, all the components of the transmissive spatial light modulator 50 according to the present embodiment can be manufactured by using a semiconductor process.

  Next, the driving method and operation of the spatial light modulator 50 according to the present embodiment will be described with reference to FIG. FIG. 4 is a diagram showing a drive circuit in the spatial light modulator 50 according to the present embodiment. For convenience of explanation, FIG. 4 omits the drive circuit for the upper electrode wiring 3 and shows only the drive circuit for the lower electrode wiring 2.

  As shown in FIG. 4, the terminals (7a to 7c,...) On the opposite side of the terminals (70a to 70c,...) That are terminals of the lower electrode wiring 2 and are connected to the common wiring 4. Each is connected to a terminal of the drive circuit 9. In the drive circuit 9, switches 6a to 6f,... Are arranged, and the switches 6a, 6c, 6e,... Are electrically connected in parallel with the positive potential (terminal) of the power source. The switches 6b, 6d, 6f,... Are electrically connected to the ground potential. The switches 6a to 6f arranged on the drive circuit 9 are switches using field effect transistors (FETs). Further, the switches 6a to 6f,... Arranged in the driving circuit 9 are operated by a known control means, and the terminals 7a to 7c,. It is possible to switch between connection, connection to ground potential, or open state. In other words, when the switches 6a to 6f,... Operate, the terminals 7a to 7c,... Are short-circuited (connected) positively or short-circuited (connected) negatively. You can switch between them.

  More specifically, taking the terminal 7a as an example, when both the switches 6a and 6b are in the off state, the terminal 7a can be said to be in the “open state”, and the switch 6a is in the on state and the switch 6b is in the off state. In this case, it can be said that the terminal 7a is “connected to the positive potential of the power supply (positively shorted (connected))”. When the switch 6a is in the off state and the switch 6b is in the on state, the terminal 7a is “to the ground potential. It can be said that “connection (minus short circuit (connection))”.

  As described above, the drive circuit 9 can switch whether each of the terminals 7a to 7c... Is connected to the positive potential of the power source, connected to the ground potential, or opened, and the lower electrode according to the switching pattern. A current flows in each wiring 2 in a desired direction.

  For example, when the switches 6a and 6d are turned on and the switches 6b, 6c, 6e, and 6f are turned off, current flows in the order of terminal 7a → terminal 70a → terminal 70b → terminal 7b → ground. That is, a clockwise (rightward) current is generated around the magneto-optical effect element 1a.

  Conversely, when the switches 6b and 6c are turned on and the switches 6a, 6d, 6e and 6f are turned off, current flows in the order of terminal 7b → terminal 70b → terminal 70a → terminal 7a → ground. That is, a counterclockwise (counterclockwise) current is generated around the magneto-optical effect element 1a.

  On the other hand, when the switch 6c and the switch 6f are turned on and the switch 6a, the switch 6b, the switch 6d, and the switch 6e are turned off, the current flows from the terminal 7b → the terminal 70b → the terminal 70c → the terminal 7c → the ground. That is, a clockwise (clockwise) current is generated around the magneto-optical effect element 1b.

  Conversely, when the switch 6d and the switch 6e are turned on and the switch 6a, the switch 6b, the switch 6c and the switch 6f are turned off, the current flows from the terminal 7c → the terminal 70c → the terminal 70b → the terminal 7b → the ground. That is, a counterclockwise (counterclockwise) current is generated around the magneto-optical effect element 1b.

  If the switch connection pattern is changed in the same manner as described above, a current can flow in a desired direction in the lower electrode wiring 2. Furthermore, by driving the upper electrode wiring 3 omitted in FIG. 4 using the same drive circuit 9, a current can be passed in a desired direction.

  By combining the directions of the currents flowing through the lower electrode wiring 2 and the upper electrode wiring 3 as described above, a magnetic field having a desired magnetization direction can be generated in a region surrounded by the lower electrode 2 and the upper electrode wiring 3. This will be further described with reference to FIG.

  In the lower electrode wiring 2 in FIG. 2, current is set to flow in the direction of point A → point i and point c → point d, and in the upper electrode wiring 3 in the direction of point a → point c and point d → a. Assuming that current is set to flow, the area surrounded by the lower electrode wiring 2 and the upper electrode wiring 3, that is, a square centered at point A, point I, point C, and point D, is apparently clockwise. Current flows in the direction (clockwise). At this time, a magnetic field having magnetization in the direction from the front surface to the back surface in FIG. 2 is generated in a region surrounded by the lower electrode wiring 2 and the upper electrode wiring 3. Therefore, magnetization in the same direction as described above can be set in the magneto-optical effect element 1a disposed corresponding to such a region.

  Here, a direction from the front surface to the back surface in FIG. 2 is referred to as an off direction, and a magneto-optical effect element (pixel) in which magnetization in the off direction is set is referred to as an off pixel. On the other hand, the direction from the back surface to the front surface in FIG. 2 is referred to as the on direction, and the magneto-optical effect element (pixel) in which the magnetization in the on direction is set is referred to as the on pixel. Therefore, in the above state, the magneto-optic effect element 1a is set to the off-direction magnetization and is an off pixel.

  On the other hand, when the current flows in the counterclockwise (counterclockwise) direction in the region where the magneto-optical effect element 1a is disposed, the on-direction magnetization can be set in the magneto-optical effect element 1a. It can be. In this way, by setting the desired magnetization direction for each magneto-optical effect element 1, it functions as a spatial light modulator.

  However, adjacent magneto-optical effect elements 1 (pixels) cannot be driven simultaneously. Considering the magneto-optical effect elements 1a and 1b as examples of the adjacent magneto-optical effect elements, when the magneto-optical effect element 1a is set to an off pixel, the point a → i, the point i → c, the point u → d, the point It is necessary to pass current in the direction of d. On the other hand, when the magneto-optical effect element 1b is an on pixel, it is necessary to pass a current in the direction of point d → f, point f → o, point o → c, and point u → d. However, it is physically impossible to simultaneously pass currents in different directions within a single wiring. That is, it is impossible to simultaneously realize the current flow in the direction of the electrode wiring point D → a and the current flow in the direction of the point D → F on the same upper electrode wiring 3. Therefore, it can be seen that the adjacent magneto-optical effect elements 1a and 1b cannot be driven simultaneously.

  Even when the adjacent magneto-optical effect elements 1a and 1b are to be driven simultaneously with other patterns, there is always a physical contradiction in the current flow as described above. Therefore, when actually driving the spatial light modulator according to the present embodiment, it is necessary to drive each magneto-optical effect element 1 by a time-division scanning method in which each magneto-optical effect element 1 is driven with a time difference.

  Next, the structure of one pixel (magnetooptic effect element 1) region in the transmissive spatial light modulator 50 according to the present embodiment will be described with reference to FIG. The magneto-optical effect element 1 includes a magneto-optical material 13 having a magneto-optical effect, a color filter 12 used for performing color display thereon, and a polarizer 11 serving as a modulated light filter. A protective film 10 for preventing damage or the like of the magneto-optical effect element 1 (pixel) is formed thereon. Further, according to FIG. 5, in the spatial light modulator according to the present embodiment, the polarizer 11 and the backlight 14 are formed in the lower layer of the substrate 5. The spatial light modulator according to the present invention may include a known configuration in addition to the above configuration.

  As shown in FIGS. 1 to 3, the transmissive spatial light modulator 50 according to the present embodiment includes the magneto-optical effect elements 1 arranged in a matrix on a substrate 5, and this magneto-optical device. As a magnetic field generating means that is provided so as to correspond to the effect element 1 and generates a magnetic field for independently setting the magnetization direction in each magneto-optical effect element 1 (pixel), the current directions intersect with each other at right angles ( The lower electrode wiring 2 and the upper electrode wiring 3 are arranged so as to be orthogonal to each other, but are not particularly required to be orthogonal and surround the magneto-optical effect element 1. Any positional relationship may be employed as long as it is arranged and the magneto-optical effect element 1 can set the direction of magnetization. However, in order to further increase the density of the magneto-optical effect element 1, it can be said that it is preferable that the magneto-resistance effect element 1 is disposed in a positional relationship in which the directions of currents flowing through the lower electrode wiring 2 and the upper electrode wiring 3 are orthogonal.

  In FIG. 2, the region surrounded by the lower electrode wiring 2 and the upper electrode wiring 3 is 25 μm square. At this time, the magnetic field strength at the center of the region was about 340 Oe when 200 mA was applied to each electrode wiring (lower electrode wiring 2, upper electrode wiring 3). This magnetic field strength can reverse the magnetization direction of the magneto-optical material contained in the magnetization setting element.

  In the spatial light modulator 50 according to the present embodiment, the upper electrode wiring 2 and the lower electrode wiring 3 are arranged so as to sandwich the magneto-optical effect element 1 as shown in FIG. If an insulating layer is provided between the electrode wirings so as not to be short-circuited, the same effect can be obtained even if the upper electrode wiring 2 and the lower electrode wiring 3 are provided in the upper layer or lower layer of the magneto-optical effect element 1.

  That is, when viewed from the viewer side of the spatial light modulator, even if the upper electrode wiring, the lower electrode wiring, and the magneto-optical effect element are configured in this order, the magneto-optical effect element, the upper electrode wiring, and the lower electrode wiring The effect of the present invention can be obtained even in an aspect configured in this order.

[Embodiment 2]
FIG. 6 is an explanatory diagram showing the structure of one pixel (magneto-optical effect element 1) region in the reflective spatial light modulator 60 according to the present embodiment. The structure of the magneto-optical effect element 1 is the same as that described in the first embodiment. However, since the spatial light modulator according to this embodiment is a reflection type, the back provided in the lower layer of the lower electrode wiring 2 is different from the configuration of the transmission type magneto-optical effect element 50 described in the first embodiment. The light 14 and the polarizer 11 are omitted. Instead of the above omission, a reflective film 15 for reflecting incident light is formed. Due to the difference in configuration, the reflective spatial light modulator 60 according to the present embodiment does not require power for driving the backlight when performing image display, and the transmissive spatial light modulation described in the first embodiment. The power consumption of the device 50 can be reduced to about 1/4.

  The spatial light modulator 60 according to the present embodiment includes a conventional lower part as shown in FIG. 7 as an electrode wiring disposed opposite to the upper electrode wiring 3 in the configuration of the first embodiment. A loop electrode wiring 31 is employed. By electrically short-circuiting (connecting) each terminal of the lower loop electrode wiring 31 independently to plus or minus, all the electrodes can be energized simultaneously.

  In general, a reflective spatial light modulator includes a reflective film on the surface opposite to the viewer side of the spatial light modulator, in other words, on the surface opposite to the light incident surface of the spatial light modulator as described above. ing. Since the light incident on the spatial light modulator is reflected by the reflective film and reaches the viewer's eyes, members such as electrode wiring disposed below the reflective film, that is, at a position far from the viewer Does not necessarily have to be light transmissive. Therefore, in the process of increasing the density of the magneto-optical effect element (pixel), it is possible to use a metal electrode wiring that does not have optical transparency. Since such a metal electrode wiring has a low electrical resistance value, the cross-sectional area can be reduced. Therefore, even when a conventional loop electrode wiring is used, it does not become a relatively hindrance to increasing the density of the magneto-optical effect element (pixel). Therefore, in the reflective spatial light modulator 60 according to the present embodiment, the lower loop electrode wiring 31 is employed.

  The lower loop electrode wiring 31 is changed to an electrode wiring having the same configuration as the lower electrode wiring 2 described in the first embodiment, thereby further increasing the density of the magneto-optical effect element 1 (pixel). This can be said to be a more preferable configuration.

  On the other hand, the upper layer of the reflection film, that is, the electrode wiring (transmission part electrode wiring) disposed closer to the viewer, the magneto-optical effect in the process of increasing the density of the magneto-optical effect element (pixel). A situation occurs in which the electrode wiring covers the element. Therefore, the transmissive part electrode wiring must use a transparent electrode having light transmittance as the electrode wiring, which causes problems such as an increase in power consumption as described above. Therefore, the spatial light modulator 60 according to the present embodiment uses the upper electrode wiring 3 described in the first embodiment.

  The reflective spatial light modulator 60 according to the present embodiment causes a current to flow through the upper electrode wiring 3 where the magneto-optical effect element 1 to which a magnetic field is to be applied is present by the switch operation of the electrode wiring described in the first embodiment. After selecting the row (x-axis direction) of the magneto-optical effect element 1 in FIG. 7, it is simultaneously applied to all arbitrary columns (y-axis direction) of the lower loop electrode wiring 31 where the magneto-optical effect element 1 to which a magnetic field is to be applied exists. By energizing, it becomes possible to change the direction of magnetization of a large number of magneto-optical effect elements 1 in one operation, and the driving speed can be increased.

  In addition, the structure shown below may be sufficient as the spatial light modulator concerning this invention.

  (1) A magneto-optical effect that has a plurality of magneto-optical effect elements made of a magneto-optical material and applies a rotation of a polarization direction corresponding to the magnetization direction of the magneto-optical effect element to incident light by a magneto-optical effect. Magnetic field generation that sets the direction of magnetization independently (individually) for each of the plurality of magneto-optical effect elements by generating a magnetic field by spreading in the direction in which the main surface of the layer and the magneto-optical effect layer expands The magneto-optical effect element is arranged in a matrix, and the magnetic field generating layer has an electrode wiring and a drive circuit provided corresponding to the magneto-optical element, and the electrode wiring Includes two groups of branch wiring groups composed of a plurality of branch wirings extending in a direction along one of the rows or columns of the matrix, and the driving circuit has a plurality of driving means sections for independently driving the branch wirings. And each of the above One end of 岐配 line is connected to the common wiring of each group, the spatial light modulator, characterized in that the other end is connected to the drive means unit independently.

  (2) The spatial light modulator according to (1), wherein the magnetic field generating element is formed of a metal thin film electrode that does not transmit visible light.

  (3) The spatial light modulator according to (1) or (2), wherein the electrode wiring is arranged such that the two systems of branch wiring groups have their current traveling directions orthogonal to each other. .

  (4) Each driving means section has two switches at both ends of a wiring portion branched from a connection section with each branch wiring, and one of the switches can be connected to each ground section, and the other is an integrated wiring. The state according to any one of (1) to (3) above, wherein both the state of being short-circuited positively and the state of being short-circuited negatively are opened by opening and closing the switch. Drive circuit for spatial light modulator.

  (5) Each switch of the drive circuit connected to each terminal of the magnetization generating layer has an arbitrary magnetization direction according to a combination of a state of short-circuiting to plus, a state of short-circuiting to minus, and a state of opening both. The method (method) for driving a spatial light modulator according to any one of the above (1) to (4), characterized in that the spatial light modulator can be set in the magnetization setting layer.

  (6) In the drive circuit connected to the magnetization generation layer, a drive method (system) is adopted in which one side is short-circuited to plus, the other is minus-circuited, and the other is opened between two adjacent outputs. The driving method of the spatial light modulator according to (5).

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  Since the spatial light modulator according to the present invention uses a ferromagnetic material, it can be stored for a long time without energy and can be freely rewritten. In addition, it is easy to colorize pixels, and it is also possible to manufacture a spatial light modulator that can read and transmit handwritten information as digital input. Furthermore, it can also be used as an image display device (element) instead of a liquid crystal display. Since the screen size can be made freely, various image displays are possible, from small image display devices (elements) such as IC cards and portable telephones to large screen image display devices (displays) for advertisement. It can be used as a device (element). Therefore, it can be said that the present invention can be suitably used in the entire electronic / electric equipment industry.

It is the schematic of the element part of the transmissive | pervious spatial light modulator concerning Embodiment 1 of this invention. It is a top view of the element part of the transmissive | pervious spatial light modulator concerning Embodiment 1 of this invention. It is A-A 'sectional drawing in the top view (FIG. 2) of the element part of the transmissive | pervious spatial light modulator concerning Embodiment 1 of this invention. It is a figure which shows the drive circuit of the transmissive | pervious spatial light modulator concerning Embodiment 1 of this invention. It is a figure explaining the structure of 1 pixel (magneto-optic effect element) area | region in the transmissive | pervious spatial light modulator concerning Embodiment 1 of this invention. It is a figure explaining the structure of 1 pixel (magneto-optic effect element) area | region in the reflection type spatial light modulator concerning Embodiment 2 of this invention. It is a top view of the element part of the reflection type spatial light modulator concerning Embodiment 2 of this invention. It is the schematic of the element part of a conventionally well-known spatial light modulator. It is a figure which shows the drive circuit of a conventionally well-known spatial light modulator. It is sectional drawing of the element part of a conventionally well-known spatial light modulator. It is sectional drawing of the element part of a conventionally well-known spatial light modulator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magneto-optical effect element 2 Lower electrode wiring 3 Upper electrode wiring 4 Common wiring 5 Board | substrate 6a-6f Switch 7a-7c Terminal 8 Insulating layer 9 Drive circuit 10 Protective film 11 Polarizer 12 Color filter 13 Magneto-optical material 14 Backlight 15 Reflection Film 31 Lower loop electrode wiring 32 Upper loop electrode wiring 50 Transmission type spatial light modulator 60 Reflection type spatial light modulator 70a-c Terminal 100 Spatial light modulator 101 Spatial light modulator

Claims (8)

A plurality of magneto-optical effect elements arranged in a matrix;
A plurality of electrode wirings disposed between adjacent magneto-optical effect elements and extending in a direction along one of the rows or columns of the matrix;
A spatial light modulator including a drive circuit that sets a direction of a current flowing through each of the plurality of electrode wirings;
The plurality of electrode wirings are arranged so as to be one between the magneto-optical effect elements,
A spatial light modulator, wherein one end of each of the plurality of electrode wires extending in the same direction is connected to a common wire, and the other end of the plurality of electrode wires is connected to the drive circuit.   The spatial light modulator according to claim 1, wherein the spatial light modulator is a transmissive type. A plurality of magneto-optical effect elements arranged in a matrix;
A plurality of electrode wirings disposed between the adjacent magneto-optical effect elements and extending in a direction along either a row or a column of the matrix;
A drive circuit for setting the direction of current flowing through each of the plurality of electrode wirings;
In a reflective spatial light modulator comprising a reflective film,
Among the plurality of electrode wirings, the distance from the viewer of the spatial light modulator is an electrode wiring disposed at a position closer to the reflective film as a transmission electrode wiring,
The transmission part electrode wiring is disposed so as to be one between the magneto-optical effect elements, and one end of the transmission part electrode wiring extending in the same direction is connected to a common wiring,
The spatial light modulator is characterized in that the other end of the transmissive part electrode wiring is connected to the drive circuit.   The spatial light modulator according to any one of claims 1 to 3, wherein the plurality of electrode wirings are arranged so that directions of currents flowing through the electrode wirings are orthogonal to each other.   5. The drive circuit according to claim 1, further comprising means for switching whether the other end of the electrode wiring is connected to a positive potential of a power source, connected to a ground potential, or opened. The spatial light modulator according to any one of claims. Between the plurality of magneto-optical elements arranged in a matrix, one electrode wiring is arranged,
One end of the plurality of electrode wirings extending in the same direction is a driving circuit for driving a spatial light modulator connected to each common wiring,
Connected to the end opposite to one end of the electrode wiring connected to the common wiring;
A drive circuit comprising means for switching whether the end is connected to a positive potential of a power source, connected to a ground potential, or opened.   An image display device comprising the spatial light modulator according to claim 1. Between the plurality of magneto-optical elements arranged in a matrix, one electrode wiring is arranged,
One end of each of the plurality of electrode wires extending in the same direction is connected to a common wire,
A method of driving a spatial light modulator in which the other ends of the plurality of electrode wirings are connected to the driving circuit,
By switching between the other end of the electrode wiring connected to the positive potential of the power supply, the ground potential, or the open state by the drive circuit, the current flowing in each of the plurality of electrode wirings The direction of
A method of driving a spatial light modulator, wherein an arbitrary magnetization direction is set for a corresponding magneto-optical effect element.

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