JP2014157183A - Reflection type optical spatial modulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type optical spatial modulation device that can facilitate a configuration of a pixel section including a pixel drive circuit having the same dimension in a longitudinal direction and in a lateral direction and a reflection pixel electrode different in dimension in the longitudinal direction and in the lateral direction.SOLUTION: A pixel section 11 is given to a reflection pixel electrode 12a or 12b and a common electrode 30, and optically modulates read light in accordance with a difference in voltages to be applied to both ends of a liquid crystal 29. The pixel section 11 includes a pixel drive circuit 13 that supplies a pixel drive voltage in accordance with a pixel signal to the reflection pixel electrode 12a or 12b. The pixel drive circuit 13 is arranged in a matrix in a longitudinal direction and in a lateral direction. The number of arrangement rows in the longitudinal direction of the pixel drive circuit 13 or the number of arrangement columns in the lateral direction thereof is different from the number of arrangement rows in the longitudinal direction of the reflection pixel electrodes 12a and 12b corresponding to each of pixel drive circuit 13 or the number of arrangement columns in the lateral direction thereof.

Description

  The present invention relates to a reflective spatial light modulation device that modulates light by transmitting readout light through a liquid crystal.

  The reflective spatial light modulator may be used as a display device. As a conventional reflective liquid crystal display device, for example, the one described in Patent Document 1 shown below is known. In this liquid crystal display device, the readout light incident on the liquid crystal is transmitted and reflected by the pixel electrode, and then the liquid crystal is transmitted again and read out, whereby the readout light is modulated on a pixel unit basis to display an image.

  In a conventional liquid crystal display device, the resolution of an image is increased as square pixel portions are arranged in a matrix at regular intervals and narrow intervals, which is advantageous in improving image quality. Accordingly, the reflective pixel electrode and the pixel driving circuit for controlling the supply of the driving voltage to the reflective pixel electrode are preferably formed in a square shape and arranged in a matrix like the pixel portion.

  In addition, the reflective spatial light modulation device may be used in the field of optical communication, for example, utilizing the function of light modulation by liquid crystal. For example, a wavelength selective switch (WSS: Wavelength Selectable Switch) having a function of receiving an optical signal wavelength-multiplexed and passing / branching an arbitrary wavelength to an arbitrary path is a typical example.

  In the case of use in optical communication, the reflective pixel electrodes constituting the pixel portion do not necessarily have the same vertical and horizontal dimensions and are not necessarily arranged in a matrix like a liquid crystal display device. For example, in the wavelength selective switch, the resolution of wavelength selection can be improved as the vertical dimension of the reflective pixel electrode is narrower than the horizontal dimension. Therefore, the pixel drive circuit of the wavelength selective switch is formed corresponding to the size and arrangement of the reflective pixel electrodes.

  As described above, the liquid crystal display device and the wavelength selective switch use liquid crystals in the same manner, but the required specifications differ in the vertical and horizontal dimensions and arrangement of the reflective pixel electrodes. Along with this, the required specifications differ in the vertical and horizontal dimensions and arrangement of the reflective pixel electrode and the pixel driving circuit.

JP 2007-334113 A

  As described above, when the reflective spatial light modulation device is used as a liquid crystal display device or a wavelength selection switch, the vertical and horizontal dimensions and arrangement of the reflective pixel electrode and the pixel driving circuit of the pixel portion are different. It is common to design. Therefore, the exposure mask required in the semiconductor manufacturing process is separately designed and manufactured.

  That is, in order to manufacture the reflection type spatial light modulation device for the liquid crystal display device and the wavelength selective switch, a large number of man-hours and an increase in cost are caused.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a reflective spatial light modulation device capable of easily configuring a pixel unit including pixel drive circuits having the same vertical and horizontal dimensions and reflective pixel electrodes having different vertical and horizontal dimensions. is there.

  In the present invention, the incident readout light (L) is transmitted through the liquid crystal (29) disposed between the reflective pixel electrodes (12a, 12b) and the common electrode (30) and reflected by the reflective pixel electrode. The pixel unit includes a pixel unit (11) that transmits the liquid crystal again to read out light, and modulates the readout light in accordance with a difference in voltage applied to the reflection pixel electrode and the common electrode and applied to both ends of the liquid crystal. Comprises a pixel drive circuit (13) for supplying a pixel drive voltage corresponding to the pixel signal to the reflective pixel electrode, and the pixel drive circuits are arranged in a matrix form in the vertical direction and the horizontal direction, and are arranged in the vertical direction of the pixel drive circuit. Reflective spatial light modulation characterized in that the number of arranged rows or the number of arranged columns in the horizontal direction differs from the number of arranged rows in the vertical direction or the number of arranged columns in the horizontal direction of the reflective pixel electrode corresponding to each pixel driving circuit. Providing the device.

  According to the reflective spatial light modulation device of the present invention, it is possible to easily configure a pixel unit including pixel drive circuits having the same vertical and horizontal dimensions and reflective pixel electrodes having different vertical and horizontal dimensions.

It is a figure which shows the structure of the reflection type spatial light modulator which concerns on 1st Embodiment of this invention. It is a figure which shows the cross section of the A1-A1 part in FIG. It is a figure which shows arrangement | positioning of the reflective pixel electrode and wiring layer in the plane direction in the pixel part shown in FIG. It is a figure which shows the cross section of the B1-B1 part in FIG. 3, and the cross section of the C1-C1 part. It is a figure which shows another structure of a reflection type spatial light modulator. It is a figure which shows the cross section of the A2-A2 part in FIG. It is a figure which shows arrangement | positioning of the reflective pixel electrode and wiring layer in the plane direction in the pixel part shown in FIG. It is a figure which shows the cross section of the B2-B2 part in FIG. 7, and the cross section of the C2-C2 part. It is a figure which shows an example of the gradation display in the apparatus shown in FIG.1 and FIG.5.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
With reference to FIG. 1, the configuration of a reflective spatial light modulator according to the first embodiment of the present invention will be described.

  FIG. 1 is a diagram showing a configuration of a reflective spatial light modulator, FIG. 1A is a diagram showing a circuit configuration of the device, and FIG. 1B is a diagram showing an arrangement of reflective pixel electrodes in a planar direction. It is.

  In FIG. 1, the reflective spatial light modulator includes a pixel unit 11. The pixel unit 11 includes a reflective pixel electrode 12a (12a-1 to 12a-9) that reflects incident readout light, and a pixel drive circuit 13 (13−) that supplies a pixel drive voltage corresponding to the pixel signal to the reflective pixel electrode 12a. 1-13-9). The pixel unit 11 reads the incident readout light through the liquid crystal disposed between the common electrode and the reflective pixel electrode 12a and reflected by the reflective pixel electrode 12a, and then transmits the liquid crystal again. The pixel unit 11 optically modulates the readout light in accordance with the difference in voltage applied to both ends of the liquid crystal provided to the common electrode and the reflective pixel electrode 12a.

  The pixel driving circuit 13 includes row scanning lines G arranged in the vertical direction (Y-axis direction in FIG. 1A) and column pixel signal lines D arranged in the horizontal direction (X-axis direction in FIG. 1A). Are arranged in a matrix (matrix) at each intersection. In FIG. 1, the horizontal direction of the paper surface is the X-axis direction, and the vertical direction of the paper surface is the Y-axis direction, but the X-axis direction and the Y-axis direction may be reversed. Note that FIG. 1 shows a configuration in which nine pixel units 11 are arranged in a matrix as an example. However, the pixel unit 11 includes the number of rows in the vertical direction and the number of columns in the horizontal direction. Each can be set independently and independently.

  The pixel drive circuit 13 supplies a pixel drive voltage corresponding to the pixel signal to the reflective pixel electrode 12a. The pixel drive circuit 13 includes a switching element 14 and a capacitor unit 15. The switching element 14 is configured by a transistor such as a MOSFET, for example. When the switching element 14 is formed of a MOSFET, the gate terminal is connected to the row scanning line G, the source terminal is connected to the column pixel signal line D, and the drain terminal is connected to the capacitor unit 15.

  The capacitor unit 15 includes a pixel drive circuit capacitor unit 15-1 and a liquid crystal capacitor unit 15-2 which will be described later. The pixel drive circuit capacitor unit 15-1 and the liquid crystal capacitor unit 15-2 are connected in parallel, one parallel connection point is connected to the reflective pixel electrode 12a, and the other parallel connection point is connected to the common electrode.

  The reflective spatial light modulator includes a vertical address circuit 16 and a pixel signal supply circuit 17.

  The vertical address circuit 16 is connected to the row scanning line G, and collectively selects the pixel driving circuits 13 for one row arranged in the horizontal direction based on a row scanning signal applied to the row scanning line G. The vertical address circuit 16 selectively performs the operation of selecting the pixel driving circuits 13 for one row at a time in the vertical direction.

  The pixel signal supply circuit 17 is connected to the column pixel signal line D and sequentially controls the pixel signals corresponding to the pixel drive circuits 13 selected at once by the vertical address circuit 16 to the pixel drive circuit 13. The pixel signal supply circuit 17 includes a horizontal address circuit 17-1 and a write switch 17-2.

  The horizontal address circuit 17-1 sequentially supplies a write control signal for controlling the conduction of the write switch 17-2 to the write switch 17-2. The horizontal address circuit 17-1 sequentially turns on the write switch 17-2 based on the write control signal.

  The write switch 17-2 is provided corresponding to the column pixel signal line D, and is configured by a transistor such as a MOSFET. When the write switch 17-2 is formed of, for example, a MOSFET, the gate terminal is connected to the horizontal address circuit 17-1 to receive a write control signal. The writing switch 17-2 is inserted between the pixel signal supply line S to which the pixel signal is supplied and the column pixel signal line D, and applies the pixel signal to the column pixel signal line D when it is turned on by the writing control signal.

  The nine pixel drive circuits 13 (13-1 to 13-9) corresponding to the nine pixel units 11 are arranged in a matrix of 3 rows × 3 columns as shown in FIG. . The pixel drive circuits 13-1 to 13-9 are formed in regions 13-1R to 13-9R surrounded by a broken line in FIG. The regions 13-1R to 13-9R are regions that are substantially equal in vertical dimension and horizontal dimension and are arranged at equal intervals.

  That is, the pixel drive circuit 13-1 is formed in the region 13-1R, the pixel drive circuit 13-2 is formed in the region 13-2R, and the pixel drive circuit 13-3 is formed in the region 13-3R. Yes. The pixel drive circuit 13-4 is formed in the region 13-4R, the pixel drive circuit 13-5 is formed in the region 13-5R, and the pixel drive circuit 13-6 is formed in the region 13-6R. The pixel drive circuit 13-7 is formed in the region 13-7R, the pixel drive circuit 13-8 is formed in the region 13-8R, and the pixel drive circuit 13-9 is formed in the region 13-9R.

  The pixel driving circuits 13-1 to 13-9 are formed in the square regions 13-1R to 13-9R, so that the pixel driving circuits 13-1 to 13-9 are arranged in the vertical direction and the horizontal direction. Are arranged at equal intervals set in advance.

  On the other hand, the nine reflective pixel electrodes 12a (12a-1 to 12a-9) corresponding to the nine pixel driving circuits 13 (13-1 to 13-9) are represented by 9 as shown in FIG. It is arranged in rows x 1 column. That is, the reflective pixel electrode 12a-1 corresponds to the pixel drive circuit 13-1, the reflective pixel electrode 12a-2 corresponds to the pixel drive circuit 13-2, and the reflective pixel electrode 12a-3 corresponds to the pixel drive circuit 13. -3. The reflective pixel electrode 12a-4 corresponds to the pixel drive circuit 13-4, the reflective pixel electrode 12a-5 corresponds to the pixel drive circuit 13-5, and the reflective pixel electrode 12a-6 corresponds to the pixel drive circuit 13-6. It corresponds to. The reflective pixel electrode 12a-7 corresponds to the pixel drive circuit 13-7, the reflective pixel electrode 12a-8 corresponds to the pixel drive circuit 13-8, and the reflective pixel electrode 12a-9 corresponds to the pixel drive circuit 13-9. It corresponds to.

  As shown in FIG. 1B, the reflective pixel electrodes 12a-1 to 12a-3 are formed in a region combining the regions 13-1R to 13-3R where the pixel driving circuits 13-1 to 13-3 are formed. Has been. Similarly, the reflective pixel electrodes 12a-4 to 12a-6 are combined with regions 13-4R to 13-6R where the pixel driving circuits 13-4 to 13-6 are formed, as shown in FIG. Formed in the region. As shown in FIG. 1B, the reflective pixel electrodes 12a-7 to 12a-9 are formed in a region combining the regions 13-7R to 13-9R where the pixel driving circuits 13-7 to 13-9 are formed. Has been.

  Therefore, the pixel driving circuit 13 is formed in a square region having substantially the same vertical and horizontal dimensions, whereas the reflective pixel electrode 12a has a rectangular shape whose vertical dimension is shorter than the horizontal dimension. Is formed. In the arrangement example shown in FIG. 1B, the vertical dimension of the reflective pixel electrode 12a is approximately 1/3 or less of the vertical dimension in the region where the pixel driving circuit 13 is formed. Further, the horizontal dimension of the reflective pixel electrode 12a is formed to be approximately three times the horizontal dimension in the region where the pixel driving circuit 13 is formed.

  As described above, in the first embodiment, the number of rows arranged in the vertical direction or the number of rows arranged in the horizontal direction of the pixel drive circuit 13 and the number of rows arranged in the vertical direction of the reflective pixel electrode 12a corresponding to each pixel drive circuit 13 are described. Alternatively, a configuration different from the number of arrangement columns in the horizontal direction is adopted. In other words, the pixel driving circuit 13 is arranged in 3 rows and 3 columns in the vertical direction and arranged in 3 rows × 3 columns, whereas the reflective pixel electrode 12a has 9 rows in the vertical direction and a horizontal row. Arranged in one column in the direction and arranged in 9 rows × 1 column.

  The pixel unit 11 including the reflective pixel electrode 12a and the pixel driving circuit 13 arranged in this way is configured as shown in the cross-sectional view of FIG. FIG. 2 is a diagram illustrating a cross section of the pixel unit 11 including the reflective pixel electrode 12a-5 and the pixel drive circuit 13-5, for example, as a representative of the pixel unit 11. That is, FIG. 2 is a view showing a cross section of the A1-A1 portion in FIG. The other pixel portions 11 are formed in the same manner as in FIG.

  In FIG. 2, the pixel drive circuit 13-5 constituting the pixel unit 11 is formed on, for example, a silicon substrate 21 of a semiconductor substrate. In the silicon substrate 21, a gate electrode 22, a source region 23, and a drain region 24 are formed. The gate electrode 22, the source region 23, and the drain region 24 constitute a transistor of the switching element 14. The gate electrode 22 is connected to the row scanning line G, the source region 23 is connected to the column pixel signal line D via the wiring layer L1, and the drain region 24 is connected to the reflective pixel electrode 12a-5.

  That is, the drain region 24 is connected to the wiring layer L2, and the wiring layer L2 is connected to the wiring layer L3-5. The wiring layer L3-5 is connected to the wiring layer L4a-5, the wiring layer L4a-5 is connected to the wiring layer L5a-5, and the wiring layer L5a-5 is connected to the reflective pixel electrode 12a-5.

  On the silicon substrate 21, a first capacitor electrode 25 made of, for example, polysilicon and a second capacitor electrode 26 made of, for example, a diffusion layer are formed adjacent to the switching element 14. The first capacitor electrode 25 and the second capacitor electrode 26 are formed to face each other with an insulating layer 27 interposed therebetween. The first capacitor electrode 25, the second capacitor electrode 26, and the insulating layer 27 constitute a pixel drive circuit capacitor unit 15-1.

  The first capacitor electrode 25 is connected to the wiring layer L2, and is connected to the drain region 24 of the switching element 14 via the wiring layer L2. The second capacitor electrode 26 is connected to the wiring layer L6, and the wiring layer L6 is connected to the wiring layer L7a.

  The wiring layer L1, the wiring layers L2, L3-5, L4a-5, L5a-5, and the wiring layers L6, L7a are insulated by the insulating layer 27. The wiring layer L4a-5 and the wiring layer L7a function as a light shielding layer that suppresses the reading light L incident on the pixel unit 11 from entering the pixel driving circuit 13-5, and are formed of, for example, aluminum or an aluminum alloy. Is done.

  The switching element 14 and the pixel drive circuit capacitor unit 15-1 are electrically isolated by a field insulating film 28 that functions as an element isolation region. In FIG. 2, the pixel driving circuit 13-5 indicates a lower layer than the wiring layer L 4 a-5 and the wiring layer L 7 a.

  A reflective pixel electrode 12a-5 is disposed and formed above the pixel driving circuit 13-5. On the reflective pixel electrode 12a-5, a liquid crystal 29, a common electrode 30, and a glass substrate 31 constituting the pixel unit 11 are arranged and formed. A liquid crystal 29 is formed on the reflective pixel electrode 12a-5, and a transparent common electrode 30 is formed on the liquid crystal 29 so as to face the reflective pixel electrode 12a-5.

  The liquid crystal 29 is interposed and sealed between the reflective pixel electrode 12 a-5 and the common electrode 30 that are arranged to face each other. The liquid crystal 29 is driven by the pixel driving circuit 13-5 according to the voltage difference applied to the reflective pixel electrode 12a-5 and the common electrode 30, and optically modulates the readout light L.

  The reflective pixel electrode 12a-5 and the common electrode 30 and the liquid crystal 29 sandwiched between the reflective pixel electrode 12a-5 and the common electrode 30 constitute a liquid crystal capacitance unit 15-2.

  The common electrode 30 is configured as an electrode common to the liquid crystal 29 of each pixel unit 11. The common electrode 30 is covered with the glass substrate 31 so as to face the reflective pixel electrode 12a-5. The common electrode 30 is connected to the wiring layer L7a via a wiring layer (not shown), and the wiring layer L7a is connected to the second capacitor electrode 26 of the pixel drive circuit capacitor unit 15-1 via the wiring layer L6. Yes. Accordingly, the pixel drive circuit capacitor unit 15-1 and the liquid crystal capacitor unit 15-2 are electrically connected in parallel.

  FIG. 3 is a diagram showing a planar arrangement of the reflective pixel electrode 12a having the cross-sectional structure shown in FIG. 2 and the wiring layers L3 to L5a with respect to each pixel unit 11 shown in FIG. FIG. 3A is a diagram showing an arrangement of the wiring layers L3 (L3-1 to L3-9) and L4a (L4a-1 to L4a-9). FIG. 3B is a diagram showing the arrangement of the wiring layers L5a (L5a-1 to L5a-9), and FIG. 3C is a diagram showing the arrangement of the reflective pixel electrodes 12a-1 to 12a-9. Note that FIG. 3C is the same as FIG.

  3, in the lower layer of the reflective pixel electrodes 12a-1 to 12a-9 shown in FIG. 3C, as shown in FIG. 2, the wiring layers L5a-1 to L5a- shown in FIG. 9 is arranged and formed. In the lower layer of the wiring layers L5a-1 to L5a-9, wiring layers L4a-1 to L4a-9 shown in FIG. In the lower layer of the wiring layers L4a-1 to L4a-9, wiring layers L3-1 to L3-9 shown in FIG.

  In FIG. 3A, the wiring layers L3-1 to L3-9 are formed in a substantially square shape, and the wiring layers L4a-1 to L4a-9 are formed in a rectangular shape whose longitudinal dimension is longer than the horizontal direction. Has been. In FIG. 3B, the wiring layers L5a-1 to L5a-9 are formed in a substantially square shape.

  In FIG. 3, wiring layers L3-1, L4a-1, and L5a-1 corresponding to the reflective pixel electrode 12a-1 of the pixel driving circuit 13-1 are arranged and formed with the pixel driving circuit 13-1. ) And is formed in the region 13-1R shown in FIG. The wiring layers L3-2, L4a-2, and L5a-2 corresponding to the reflective pixel electrode 12a-2 of the pixel driving circuit 13-2 are regions shown in FIG. 13-2R is arranged and formed. The wiring layers L3-3, L4a-3, and L5a-3 corresponding to the reflective pixel electrode 12a-3 of the pixel driving circuit 13-3 are regions shown in FIG. 1B in which the pixel driving circuit 13-3 is arranged and formed. 13-3R is arranged and formed.

  The wiring layers L3-4, L4a-4, and L5a-4 corresponding to the reflective pixel electrode 12a-4 of the pixel driving circuit 13-4 are regions shown in FIG. 1B where the pixel driving circuit 13-4 is arranged and formed. 13-4R is arranged and formed. The wiring layers L3-5, L4a-5, and L5a-5 corresponding to the reflective pixel electrode 12a-5 of the pixel drive circuit 13-5 are regions shown in FIG. 1B where the pixel drive circuit 13-5 is arranged and formed. 13-5R is arranged and formed. The wiring layers L3-6, L4a-6, and L5a-6 corresponding to the reflective pixel electrode 12a-6 of the pixel driving circuit 13-6 are regions shown in FIG. 1B where the pixel driving circuit 13-6 is arranged and formed. 13-6R is arranged and formed.

  The wiring layers L3-7, L4a-7, and L5a-7 corresponding to the reflective pixel electrode 12a-7 of the pixel driving circuit 13-7 are regions shown in FIG. 1B where the pixel driving circuit 13-7 is arranged and formed. 13-7R is arranged and formed. The wiring layers L3-8, L4a-8, and L5a-8 corresponding to the reflective pixel electrode 12a-8 of the pixel drive circuit 13-8 are regions shown in FIG. 1B where the pixel drive circuit 13-8 is arranged and formed. 13-8R is arranged and formed. The wiring layers L3-9, L4a-9, and L5a-9 corresponding to the reflective pixel electrode 12a-9 of the pixel driving circuit 13-9 are regions shown in FIG. 1B where the pixel driving circuit 13-9 is arranged and formed. 13-9R is arranged and formed.

  In FIG. 3, among the reflective pixel electrodes 12a arranged in 9 rows × 1 columns shown in FIG. 3C, the reflective pixel electrode 12a-1 is connected to the wiring layer L5a-1 shown in FIG. ing. The wiring layer L5a-1 is connected to the wiring layer L4a-1, and the wiring layer L4a-1 is connected to the wiring layer L3-1. The reflective pixel electrode 12a-2 is connected to the wiring layer L5a-2 shown in FIG. 5B, the wiring layer L5a-2 is connected to the wiring layer L4a-2, and the wiring layer L4a-2 is connected to the wiring layer L3-. 2 is connected. The reflective pixel electrode 12a-3 is connected to the wiring layer L5a-3 shown in FIG. 5B, the wiring layer L5a-3 is connected to the wiring layer L4a-3, and the wiring layer L4a-3 is connected to the wiring layer L3-. 3 is connected.

  The reflective pixel electrode 12a-4 is connected to the wiring layer L5a-4 shown in FIG. 5B, the wiring layer L5a-4 is connected to the wiring layer L4a-4, and the wiring layer L4a-4 is connected to the wiring layer L3-. 4 is connected. The reflective pixel electrode 12a-5 is connected to the wiring layer L5a-5 shown in FIG. 5B, the wiring layer L5a-5 is connected to the wiring layer L4a-5, and the wiring layer L4a-5 is connected to the wiring layer L3-. 5 is connected. The reflective pixel electrode 12a-6 is connected to the wiring layer L5a-6 shown in FIG. 5B, the wiring layer L5a-6 is connected to the wiring layer L4a-6, and the wiring layer L4a-6 is connected to the wiring layer L3-. 6 is connected.

  The reflective pixel electrode 12a-7 is connected to the wiring layer L5a-7 shown in FIG. 5B, the wiring layer L5a-7 is connected to the wiring layer L4a-7, and the wiring layer L4a-7 is connected to the wiring layer L3-. 7 is connected. The reflective pixel electrode 12a-8 is connected to the wiring layer L5a-8 shown in FIG. 5B, the wiring layer L5a-8 is connected to the wiring layer L4a-8, and the wiring layer L4a-8 is connected to the wiring layer L3-. 8 is connected. The reflective pixel electrode 12a-9 is connected to the wiring layer L5a-9 shown in FIG. 5B, the wiring layer L5a-9 is connected to the wiring layer L4a-9, and the wiring layer L4a-9 is connected to the wiring layer L3-. 9 is connected.

  4 is a diagram showing a partial cross section of FIG. 3C, FIG. 4A is a diagram showing a cross section of B1-B1 in FIG. 3C, and FIG. 4B is FIG. It is a figure which shows the cross section of the C1-C1 part in (c).

  In FIG. 4A, cross sections of the reflective pixel electrode 12a-5, the wiring layers L3-4, L3-5, L3-6, the wiring layers L4a-4, L4a-5, L4a-6, and the wiring layer L5a-5. Is shown. In FIG. 4A, as shown in FIG. 2, the reflective pixel electrode 12a-5 is connected to the wiring layer L5a-5 at a substantially central portion in the horizontal direction. The wiring layer L5a-5 is connected to the wiring layer L4a-5, and the wiring layer L4a-5 is connected to the wiring layer L3-5.

  A wiring layer L3-4 and a wiring layer L4a-4 corresponding to the reflective pixel electrode 12a-4 are arranged and formed on the left side of the drawing with respect to a location where the reflective pixel electrode 12a-5 and the wiring layer L5a-5 are connected. Has been. On the other hand, the wiring layer L3-6 and the wiring layer L4a-6 corresponding to the reflective pixel electrode 12a-6 are located on the right side of the drawing with respect to the location where the reflective pixel electrode 12a-5 and the wiring layer L5a-5 are connected. Arrangement is formed.

  In FIG. 4B, the reflective pixel electrodes 12a-1 to 12a-9, the wiring layers L3-2, L3-5, L3-8, the wiring layers L4a-2, L4a-5, L4a-8, and the wiring layer L5a- 2, cross sections of L5a-5 and L5a-8 are shown. In FIG. 4B, the reflective pixel electrodes 12a-1 to 12a-9 are arranged at equal intervals in the left-right direction (the vertical direction in FIGS. 1C and 3C).

  The reflective pixel electrode 12a-2 is connected to the wiring layer L5a-2, the wiring layer L5a-2 is connected to the wiring layer L4a-2, and the wiring layer L4a-2 is connected to the wiring layer L3-2. The reflective pixel electrode 12a-5 is connected to the wiring layer L5a-5, the wiring layer L5a-5 is connected to the wiring layer L4a-5, and the wiring layer L4a-5 is connected to the wiring layer L3-5. The reflective pixel electrode 12a-8 is connected to the wiring layer L5a-8, the wiring layer L5a-8 is connected to the wiring layer L4a-8, and the wiring layer L4a-8 is connected to the wiring layer L3-8.

  Next, the operation of the apparatus configured as described above will be described with reference to FIG. 1 and FIG.

  First, the vertical address circuit 16 sequentially outputs scanning signals to the row scanning lines G in synchronization with the horizontal synchronizing signal. The switching element 14 whose gate terminal is connected to the row scanning line G from which the scanning signal has been output becomes conductive.

  In such a state, the horizontal address circuit 17-1 sequentially outputs a write control signal to the write switch 17-2 in synchronization with the time-series output timing of the pixel signal. As a result, the write switch 17-2 is sequentially switched from a non-conductive state to a conductive state to a non-conductive state. As a result, a voltage corresponding to the pixel signal is applied to the reflective pixel electrode 12a through the switching element 14 which is connected to the row scanning line G from which the scanning signal is output and is in a conductive state.

  On the other hand, a common electrode voltage preset in common to all the pixel units 11 is applied to the common electrode 30. As a result, charges corresponding to the voltage applied to the reflective pixel electrode 12a are accumulated in the pixel drive circuit capacitor unit 15-1 and the liquid crystal capacitor unit 15-2. This accumulated charge is held until a voltage corresponding to the next pixel signal is applied to the reflective pixel electrode 12a.

  When a voltage corresponding to the pixel signal is applied to the reflective pixel electrode 12 a, an electric field corresponding to the difference between the voltages applied to the reflective pixel electrode 12 a and the common electrode 30 is generated at both ends of the liquid crystal 29. Due to this electric field, the liquid crystal 29 sandwiched between the reflective pixel electrode 12a and the common electrode 30 changes the light transmittance. That is, the light transmittance of the liquid crystal 29 changes in accordance with the voltage applied to the reflective pixel electrode 12a.

  The readout light L that is incident on the liquid crystal 29 through the glass substrate 31 and the common electrode 30 and is transmitted through the liquid crystal 29, reflected by the reflective pixel electrode 12 a, and then transmitted through the liquid crystal 29 again is emitted from the liquid crystal 29. Is modulated according to. Thereby, the readout light L modulated according to the pixel signal given to each pixel unit 11 is obtained for each pixel unit 11.

  Next, referring to FIG. 5 to FIG. 8, the reflective pixel electrode 12 a shown in FIG. 1 to FIG. A description will be given in comparison with the apparatus. 5 corresponds to FIG. 1, FIG. 6 corresponds to FIG. 2, FIG. 7 corresponds to FIG. 3, and FIG. 8 corresponds to FIG.

  FIG. 5 is a diagram showing the configuration of a reflective spatial light modulator in which the reflective pixel electrodes 12b are formed in a substantially square shape. FIG. 5 (a) is a diagram showing the circuit configuration of the device, and FIG. These are figures which show the arrangement | sequence of the plane of the reflective pixel electrode 12b.

  The apparatus shown in FIG. 5 is the same as the apparatus shown in FIG. 1 except for the circuit configuration and the like, unlike the apparatus shown in FIG. 1 in that the reflective pixel electrode 12b is formed in a square shape. Accordingly, FIG. 5A is the same as FIG. 1A, and the same reference numerals as those in FIG.

  FIG. 5B is a diagram corresponding to FIG. In FIG. 5B, the reflection pixel electrodes 12b (12b-1 to 12b-9) are formed in a square shape having substantially the same vertical and horizontal dimensions as described above.

  As shown in FIG. 5B, the nine reflective pixel electrodes 12b (12b-1 to 12b-9) corresponding to the previous nine pixel drive circuits 13 (13-1 to 13-9) are arranged vertically and horizontally. Both are arranged in a matrix of 3 rows × 3 columns at approximately equal intervals.

  In other words, the reflective pixel electrode 12b-1 corresponds to the pixel drive circuit 13-1, the reflective pixel electrode 12b-2 corresponds to the pixel drive circuit 13-2, and the reflective pixel electrode 12b-3 corresponds to the pixel drive circuit 13. -3. The reflective pixel electrode 12b-4 corresponds to the pixel drive circuit 13-4, the reflective pixel electrode 12b-5 corresponds to the pixel drive circuit 13-5, and the reflective pixel electrode 12b-6 corresponds to the pixel drive circuit 13b-6. It corresponds to. The reflective pixel electrode 12b-7 corresponds to the pixel drive circuit 13-7, the reflective pixel electrode 12b-8 corresponds to the pixel drive circuit 13-8, and the reflective pixel electrode 12b-9 corresponds to the pixel drive circuit 13-9. It corresponds to.

  As shown in FIG. 5B, the reflective pixel electrode 12b-1 is formed in a region 13-1R where the pixel driving circuit 13-1 is formed. Similarly, the reflective pixel electrode 12b-2 is formed in the region 13-2R where the pixel driving circuit 13-2 is formed. The reflective pixel electrode 12b-3 is formed in the region 13-3R where the pixel driving circuit 13-3 is formed.

  The reflective pixel electrode 12b-4 is formed in the region 13-4R where the pixel driving circuit 13-4 is formed. The reflective pixel electrode 12b-5 is formed in the region 13-5R where the pixel driving circuit 13-5 is formed. The reflective pixel electrode 12b-6 is formed in the region 13-6R where the pixel driving circuit 13-6 is formed.

  The reflective pixel electrode 12b-7 is formed in the region 13-7R where the pixel driving circuit 13-7 is formed. The reflective pixel electrode 12b-8 is formed in the region 13-8R where the pixel driving circuit 13-8 is formed. The reflective pixel electrode 12b-9 is formed in the region 13-9R where the pixel driving circuit 13-9 is formed.

  As a result, the reflective pixel electrodes 12b-1 to 12b-9 are formed in a square shape having substantially the same dimensions as the regions 13-1R to 13-9R in which the pixel driving circuits 13-1 to 13-9 are formed. Yes. Therefore, the reflective pixel electrode 12b and the pixel drive circuit 13 have the same number of rows arranged in the vertical direction and the same number of columns arranged in the horizontal direction. That is, in the arrangement example of the first embodiment, the reflection pixel electrode 12b and the pixel driving circuit 13 are both arranged in a matrix of 3 rows × 3 columns arranged in 3 rows in the vertical direction and 3 columns in the horizontal direction. Has been.

  The pixel unit 11 including the reflective pixel electrode 12b and the pixel driving circuit 13 arranged in this way is configured as shown in the cross-sectional view of FIG. FIG. 6 is a diagram illustrating a cross section of the pixel unit 11 including the reflective pixel electrode 12b-5 and the pixel driving circuit 13-5 as a representative of the pixel unit 11. That is, FIG. 6 is a diagram showing a cross section of the A2-A2 portion in FIG. The other pixel portions 11 are formed in the same manner as in FIG.

  In FIG. 6, the same reference numerals as those in FIG. 2 are the same as those in FIG.

  6 differs from FIG. 2 in that the wiring layer L4b-5 and the wiring layer L5b-5 are different because the shape of the reflective pixel electrode 12b-5 is different from the shape of the reflective pixel electrode 12a-5. . Another difference is that the wiring layer L7b is different because the shape of the wiring layer L4b-5 is different from the shape of the wiring layer L4a-5. On the other hand, the other pixel drive circuit 13, wiring layers L2 and L3, liquid crystal 29, common electrode 30, and the like are the same as those in FIG.

  In FIG. 6, the drain region 24 constituting the switching element 14 is connected to the reflective pixel electrode 12b-5. That is, the drain region 24 is connected to the wiring layer L2, and the wiring layer L2 is connected to the wiring layer L3-5. The wiring layer L3-5 is connected to the wiring layer L4b-5, and the wiring layer L4b-5 is connected to the wiring layer L5b-5. The wiring layer L5b-5 is connected to the reflective pixel electrode 12b-5.

  The wiring layer 7b is connected to the wiring layer L6, and is connected to the common electrode 30 via a wiring layer (not shown). The wiring layer L4b and the wiring layer L7b function as light shielding layers in the same manner as the previous wiring layer L4a and wiring layer L7a.

  FIG. 7 is a diagram showing the arrangement in the planar direction of the reflective pixel electrode 12b having the cross-sectional structure shown in FIG. 6 and the wiring layers L3, L4b, and L5b for each pixel unit 11 shown in FIG. It is a figure corresponding to. FIG. 7A is a diagram showing the arrangement of the wiring layers L3 (L3-1 to L3-9) and L4b (L4b-1 to L4b-9). FIG. 7B is a diagram showing the arrangement of the wiring layers L5b (L5b-1 to L5b-9), and FIG. 7C is a diagram showing the arrangement of the reflective pixel electrodes 12b-1 to 12b-9. FIG. 7C is the same as FIG. 5B.

  In FIG. 7, as shown in FIG. 6, the wiring layers L5b-1 to L5b-9 shown in FIG. 7B are provided below the reflective pixel electrodes 12b-1 to 12b-9 shown in FIG. Arrangement is formed. Also, wiring layers L4b-1 to L4b-9 shown in FIG. 7A are arranged and formed below the wiring layers L5b-1 to L5b-9, and the same figure ( Wiring layers L3-1 to L3-9 shown in a) are arranged and formed.

  In FIG. 7A, the wiring layers L3-1 to L3-9 are formed in the same manner as shown in FIG. The wiring layers L4b-1 to L4b-9 are formed in a slightly larger square shape than the wiring layers L3-1 to L3-9. In FIG. 7B, the wiring layers L5b-1 to L5b-9 are formed in a square shape with substantially the same dimensions as the wiring layers L3-1 to L3-9. Note that the wiring layer L5b-2 and the wiring layer L5a-2 shown in FIG. Further, the wiring layer L5b-5 and the wiring layer L5a-5 shown in FIG. 3 have the same dimensions and arrangement, although the reference numerals are different. The wiring layer L5b-8 and the wiring layer L5a-5 shown in FIG. Although the reference numeral is different from 8, the dimensions and arrangement are the same.

  In FIG. 7, wiring layers L3-1, L4b-1, and L5b-1 corresponding to the reflective pixel electrode 12b-1 of the pixel driving circuit 13-1 are arranged and formed in the pixel driving circuit 13-1. The region 13-1R shown in FIG. The wiring layer L3-1, the wiring layer L4b-1, and the wiring layer L5b-1 are arranged in the vertical direction so that the central portions thereof are substantially the same.

  The wiring layers L3-2, L4b-2, and L5b-2 corresponding to the reflective pixel electrode 12b-2 of the pixel driving circuit 13-2 are regions shown in FIG. 5B in which the pixel driving circuit 13-2 is arranged and formed. 13-2R is arranged and formed. The wiring layer L3-2, the wiring layer L4b-2, and the wiring layer L5b-2 are arranged in the vertical direction so that the central portions thereof are substantially the same.

  The wiring layers L3-3, L4b-3, and L5b-3 corresponding to the reflective pixel electrode 12b-3 of the pixel drive circuit 13-3 are regions shown in FIG. 5B in which the pixel drive circuit 13-3 is arranged and formed. 13-3R is arranged and formed. The wiring layer L3-3, the wiring layer L4b-3, and the wiring layer L5b-3 are arranged in the vertical direction so that the central portions thereof are substantially the same.

  The wiring layers L3-4, L4b-4, and L5b-4 corresponding to the reflective pixel electrode 12b-4 of the pixel drive circuit 13-4 are regions shown in FIG. 5B where the pixel drive circuit 13-4 is arranged and formed. 13-4R is arranged and formed. The wiring layer L3-4, the wiring layer L4b-4, and the wiring layer L5b-4 are arranged in the vertical direction so that the center portions thereof are substantially the same.

  The wiring layers L3-5, L4b-5, and L5b-5 corresponding to the reflective pixel electrode 12b-5 of the pixel driving circuit 13-5 are regions shown in FIG. 5B where the pixel driving circuit 13-5 is arranged and formed. 13-5R is arranged and formed. The wiring layer L3-5, the wiring layer L4b-5, and the wiring layer L5b-5 are arranged in the vertical direction so that the center portions thereof are substantially the same.

  The wiring layers L3-6, L4b-6, and L5b-6 corresponding to the reflective pixel electrode 12b-6 of the pixel driving circuit 13-6 are regions shown in FIG. 5B where the pixel driving circuit 13-6 is arranged and formed. 13-6R is arranged and formed. The wiring layer L3-6, the wiring layer L4b-6, and the wiring layer L5b-6 are arranged in the vertical direction so that the center portions thereof are substantially the same.

  The wiring layers L3-7, L4b-7, and L5b-7 corresponding to the reflective pixel electrode 12b-7 of the pixel driving circuit 13-7 are regions shown in FIG. 5B where the pixel driving circuit 13-7 is arranged and formed. 13-7R is arranged and formed. The wiring layer L3-7, the wiring layer L4b-7, and the wiring layer L5b-7 are arranged in the vertical direction so that the center portions thereof are substantially the same.

  The wiring layers L3-8, L4b-8, and L5b-8 corresponding to the reflective pixel electrode 12b-8 of the pixel drive circuit 13-8 are regions shown in FIG. 5B where the pixel drive circuit 13-8 is arranged and formed. 13-8R is arranged and formed. The wiring layer L3-8, the wiring layer L4b-8, and the wiring layer L5b-8 are arranged in the vertical direction so that the center portions thereof are substantially the same.

  The wiring layers L3-9, L4b-9, and L5b-9 corresponding to the reflective pixel electrode 12b-9 of the pixel drive circuit 13-9 are regions shown in FIG. 5B where the pixel drive circuit 13-9 is arranged and formed. 13-9R is arranged and formed. The wiring layer L3-9, the wiring layer L4b-9, and the wiring layer L5b-9 are arranged in the vertical direction so that the central portions thereof are substantially the same.

  In FIG. 7, among the reflective pixel electrodes 12b-1 to 12b-9 arranged in 3 rows × 3 columns shown in FIG. 7C, the reflective pixel electrode 12b-1 is a wiring layer shown in FIG. It is connected to L5b-1. The wiring layer L5b-1 is connected to the wiring layer L4b-1 shown in FIG. 7A, and the wiring layer L4b-1 is connected to the wiring layer L3-1.

  The reflective pixel electrode 12b-2 is connected to the wiring layer L5b-2 shown in FIG. 7B, and the wiring layer L5b-2 is connected to the wiring layer L4b-2 shown in FIG. 7A, and the wiring layer L4b. -2 is connected to the wiring layer L3-2. The reflective pixel electrode 12b-3 is connected to the wiring layer L5b-3 shown in FIG. 7B, the wiring layer L5b-3 is connected to the wiring layer L4b-3 shown in FIG. 7A, and the wiring layer L4b. -3 is connected to the wiring layer L3-3.

  The reflective pixel electrode 12b-4 is connected to the wiring layer L5b-4 shown in FIG. 7B, the wiring layer L5b-4 is connected to the wiring layer L4b-4 shown in FIG. 7A, and the wiring layer L4b. -4 is connected to the wiring layer L3-4. The reflective pixel electrode 12b-5 is connected to the wiring layer L5b-5 shown in FIG. 7B, the wiring layer L5b-5 is connected to the wiring layer L4b-5 shown in FIG. 7A, and the wiring layer L4b. −5 is connected to the wiring layer L3-5. The reflective pixel electrode 12b-6 is connected to the wiring layer L5b-6 shown in FIG. 7B, the wiring layer L5b-6 is connected to the wiring layer L4b-6 shown in FIG. 7A, and the wiring layer L4b. −6 is connected to the wiring layer L3-6.

  The reflective pixel electrode 12b-7 is connected to the wiring layer L5b-7 shown in FIG. 7B, the wiring layer L5b-7 is connected to the wiring layer L4b-7 shown in FIG. 7A, and the wiring layer L4b. −7 is connected to the wiring layer L3-7. The reflective pixel electrode 12b-8 is connected to the wiring layer L5b-8 shown in FIG. 7B, the wiring layer L5b-8 is connected to the wiring layer L4b-8 shown in FIG. 7A, and the wiring layer L4b. −8 is connected to the wiring layer L3-8. The reflective pixel electrode 12b-9 is connected to the wiring layer L5b-9 shown in FIG. 7B, the wiring layer L5b-9 is connected to the wiring layer L4b-9 shown in FIG. 7A, and the wiring layer L4b. −9 is connected to the wiring layer L3-9.

  8 is a diagram showing a partial cross section of FIG. 7C, FIG. 8A is a diagram showing a cross section of B2-B2 portion in FIG. 7C, and FIG. 8B is FIG. It is a figure which shows the cross section of the C2-C2 part in (c).

  In FIG. 8A, cross sections of the reflective pixel electrodes 12b-4 to 12b-6, the wiring layers L3-4 to LL3-6, the wiring layers L4b-4 to L4b-6, and the wiring layers L5b-4 to L5b-6. Is shown. The same applies to the other reflective pixel electrodes 12b-1 to 12b-3, 12b-7 to 12b-9, and the cross-sections of the wiring layers connected to these reflective pixel electrodes.

  In FIG. 8A, as shown in FIG. 6, the reflective pixel electrode 12b-4 is connected to the wiring layer L5b-4 at a substantially central portion. The wiring layer L5b-4 is connected to the wiring layer L4b-4, and the wiring layer L4b-4 is connected to the wiring layer L3-4. The reflective pixel electrode 12b-5 is connected to the wiring layer L5b-5 at a substantially central portion, the wiring layer L5b-5 is connected to the wiring layer L4b-5, and the wiring layer L4b-5 is connected to the wiring layer L3-5. ing. The reflective pixel electrode 12b-6 is connected to the wiring layer L5b-6 at a substantially central portion, the wiring layer L5b-6 is connected to the wiring layer L4b-6, and the wiring layer L4b-6 is connected to the wiring layer L3-6. ing.

  In FIG. 8B, the reflective pixel electrodes 12b-2, 12b-5, 12b-8, the wiring layers L3-2, L3-5, L3-8, the wiring layers L4b-2, L4b-5, L4b-8, The cross section of wiring layer L5b-2, L5b-5, and L5b-8 is shown. The same applies to the other reflective pixel electrodes 12b-1, 12b-3 to 12b-4, 12b-6 to 12b-7, 12b-9, and the cross sections of the wiring layers connected to these reflective pixel electrodes.

  In FIG. 8B, as shown in FIG. 6, the reflective pixel electrode 12b-2 is connected to the wiring layer L5b-2 at a substantially central portion. The wiring layer L5b-2 is connected to the wiring layer L4b-2, and the wiring layer L4b-2 is connected to the wiring layer L3-2. The reflective pixel electrode 12b-5 is connected to the wiring layer L5b-5 at a substantially central portion, the wiring layer L5b-5 is connected to the wiring layer L4b-5, and the wiring layer L4b-5 is connected to the wiring layer L3-5. ing. The reflective pixel electrode 12b-8 is connected to the wiring layer L5b-8 at a substantially central portion, the wiring layer L5b-8 is connected to the wiring layer L4b-8, and the wiring layer L4b-8 is connected to the wiring layer L3-8. ing.

  That is, as can be seen from FIG. 8, the corresponding reflective pixel electrodes 12b-1 to 12b-9 and the wiring layers L3-1 to L3-9, L4b-1 to L4b-9, and L5b-1 to L5b-9, respectively. , Arranged in a similar manner.

  Next, with reference to FIG. 9, a gradation display in which the readout light is modulated based on the pixel signal and the display state of the liquid crystal 29 changes only in the vertical direction will be described. FIG. 9A is a diagram showing an example of a gradation display state in the vertical direction of the apparatus shown in FIGS. 1 to 4 in which the reflective pixel electrode 12a is formed in a rectangular shape. FIG. 9B is a diagram showing an example of a gradation display state in the vertical direction of the device shown in FIGS. 5 to 8 in which the reflective pixel electrode 12b is formed in a square shape.

  In FIG. 9, the numerical values described in the reflective pixel electrodes 12a and 12b are, for example, 256 gray scale display (“0” to “255” gray scale) by pixel signals that are 8-bit gray scale data. This shows the degree of gradation in the case where possible. Accordingly, white is displayed at the “0” gradation, black is displayed at the “255” gradation, and a gray color is displayed at the intermediate “128” gradation, for example.

  In the vertical gradation display example shown in FIG. 9A, for example, a pixel signal corresponding to the “0” gradation is written to the pixel driving circuit 13-1 corresponding to the reflective pixel electrode 12a-1. As a result, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-1, the readout light is modulated corresponding to the pixel signal of “0” gradation, and a gradation display state corresponding to “0” gradation is obtained.

  Similarly, for example, a pixel signal corresponding to the “32” gradation is written into the pixel driving circuit 13-2 corresponding to the reflective pixel electrode 12a-2. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-2, the readout light is modulated corresponding to the pixel signal of “32” gradation, and a gradation display state corresponding to “32” gradation is obtained.

  For example, the pixel signal corresponding to the “64” gradation is written into the pixel driving circuit 13-3 corresponding to the reflective pixel electrode 12a-3. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-3, the readout light is modulated corresponding to the pixel signal of “64” gradation, and a gradation display state corresponding to “64” gradation is obtained.

  For example, the pixel signal corresponding to the “96” gradation is written into the pixel driving circuit 13-4 corresponding to the reflective pixel electrode 12a-4. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-4, the readout light is modulated corresponding to the pixel signal of “96” gradation, and the gradation display state corresponding to “96” gradation is obtained.

  For example, the pixel signal corresponding to the “128” gradation is written into the pixel driving circuit 13-5 corresponding to the reflective pixel electrode 12a-5. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-5, the readout light is modulated corresponding to the pixel signal of “128” gradation, and a gradation display state corresponding to the “128” gradation is obtained.

  For example, the pixel signal corresponding to the “160” gradation is written into the pixel driving circuit 13-6 corresponding to the reflective pixel electrode 12a-6. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-6, the readout light is modulated corresponding to the pixel signal of “160” gradation, and a gradation display state corresponding to “160” gradation is obtained.

  For example, the pixel signal corresponding to the “192” gradation is written into the pixel driving circuit 13-7 corresponding to the reflective pixel electrode 12a-7. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-7, the readout light is modulated in accordance with the pixel signal of “192” gradation, and the gradation display state corresponding to the “192” gradation is obtained.

  For example, the pixel signal corresponding to the “224” gradation is written into the pixel driving circuit 13-8 corresponding to the reflective pixel electrode 12a-8. As a result, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-8, the readout light is modulated corresponding to the pixel signal of “224” gradation, and a gradation display state corresponding to “224” gradation is obtained.

  For example, the pixel signal corresponding to the “255” gradation is written into the pixel driving circuit 13-9 corresponding to the reflective pixel electrode 12a-9. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrode 12a-9, the readout light is modulated corresponding to the pixel signal of “255” gradation, and a gradation display state corresponding to the “255” gradation is obtained.

  On the other hand, in the gradation display example shown in FIG. 9B, for example, pixel drive circuits 13-1 to 13-13 corresponding to the reflection pixel electrodes 12b-1 to 12b-3 in the same row correspond to the pixel signal corresponding to the “0” gradation. -3. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrodes 12b-1 to 12b-3, the readout light is modulated corresponding to the pixel signal of “0” gradation, and the gradation display state corresponding to “0” gradation. It becomes.

  Similarly, for example, pixel signals corresponding to “128” gradation are written to the pixel drive circuits 13-4 to 13-6 corresponding to the reflective pixel electrodes 12b-4 to 12b-6 in the same row. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrodes 12b-4 to 12b-6, the readout light is modulated corresponding to the pixel signal of “128” gradation, and the gradation display state corresponding to “128” gradation It becomes.

  For example, the pixel signal corresponding to the “255” gradation is written to the pixel driving circuits 13-7 to 13-9 corresponding to the reflective pixel electrodes 12b-7 to 12b-9 in the same row. Thereby, in the liquid crystal 29 corresponding to the reflective pixel electrodes 12b-7 to 12b-9, the readout light is modulated corresponding to the pixel signal of “255” gradation, and the gradation display state corresponding to “255” gradation. It becomes.

  As described above, in the device in which the reflective pixel electrodes 12a are arranged in the vertical direction, as shown in FIG. 9A, the read light is supplied to each pixel unit 11 corresponding to each reflective pixel electrode 12a-1 to 12a-9. It is possible to change the degree of modulation. That is, the readout light can be modulated in nine stages, the number of which is the same as the number of arrangement, in the vertical direction, which is the arrangement direction of the reflective pixel electrodes 12a.

  In contrast, in an apparatus in which the reflective pixel electrodes 12b are arranged in the vertical direction and the horizontal direction, as shown in FIG. 9B, the readout light in the pixel unit 11 corresponding to the reflective pixel electrodes 12b arranged in the horizontal direction. The degree of modulation is the same. As a result, in the arrangement example in which the reflective pixel electrodes 12b are arranged in 3 rows × 3 columns shown in FIG. 9B, the readout light is modulated in three stages, which is the same as the number of arrangement in the vertical direction.

  When two devices having different shapes and arrangements of the reflection pixel electrodes 12a and 12b are compared, they are similar in terms of the number, shape and arrangement of the pixel drive circuit 13, and the number of reflection pixel electrodes 12a and 12b. Is adopted. On the other hand, the device in which the reflective pixel electrodes 12a are arranged in the vertical direction, as compared with the device in which the reflective pixel electrodes 12b are arranged in the vertical and horizontal directions, as described above, the resolution of gradation display in the vertical direction, that is, the resolution of modulation of the readout light. Can be significantly improved.

  As described above, in both the above devices, the configuration and arrangement of the pixel drive circuit are the same. As a result, the reflective spatial light modulator of the first embodiment can share the pixel drive circuit 13 when manufacturing the pixel units 11 having different dimensions and arrangements of the reflective pixel electrodes.

  Therefore, it is not necessary to redesign the pixel drive circuit 13 and the like when constructing the pixel portion 11 having different dimensions and arrangement of the reflective pixel electrodes 12a and 12b, and all the exposure masks in the semiconductor manufacturing process are recreated. There is no need. That is, the exposure mask used when forming the pixel drive circuit 13 and the wiring layers L1, L2, and L6 can be shared. As a result, in the reflection type spatial light modulation device, the pixel unit 11 having a common pixel drive circuit 13 and different reflection pixel electrode dimensions and arrangement can be easily configured.

  As described above in the section of the problem to be solved by the invention, in the wavelength selective switch used in the field of optical communication, the pixel portion has a wavelength selection that becomes narrower in the vertical direction than in the horizontal direction. Resolution can be improved. That is, it has been conventionally known that a wavelength selective switch preferably has a higher resolution of gradation display in the vertical direction than that in the horizontal direction, that is, a higher resolution of modulation of readout light in the vertical direction.

  Therefore, the reflective spatial light modulator shown in FIGS. 1 to 4 in which the reflective pixel electrodes 12a are arranged in the vertical direction is required to have high resolution for modulating the readout light in the vertical direction, as represented by a wavelength selective switch or the like. It is possible to provide a suitable configuration for the device.

  On the other hand, liquid crystal display devices that display video and the like have been conventionally known that the resolution of a display image is increased as square pixels are arranged at equal and narrower intervals, which is advantageous in improving image quality. ing. Therefore, the reflective spatial light modulator shown in FIGS. 5 to 8 in which the reflective pixel electrodes 12b are arranged at equal intervals in the vertical and horizontal directions can provide a configuration suitable as a liquid crystal display device.

  For example, in a reflective spatial light modulation device suitable as a liquid crystal display device in which the reflective pixel electrodes 12b are arranged in rows and columns in the vertical and horizontal directions, the reflective and suitable as a wavelength selective switch can be obtained by changing the shape and arrangement of the reflective pixel electrodes 12b. Type spatial light modulator can be provided. On the contrary, in a reflective spatial light modulator suitable as a wavelength selective switch in which the reflective pixel electrodes 12a are arranged in the vertical direction, it is suitable as a liquid crystal display device by changing the shape and arrangement of the reflective pixel electrodes 12a. A reflective spatial light modulator can be provided.

  Therefore, by using the pixel driving circuit 13 also, a device in which reflective pixel electrodes typified by wavelength selective switches are arranged in the vertical direction from a liquid crystal display device in which the reflective pixel electrodes 12b are arranged in a matrix in the vertical and horizontal directions can be easily obtained. Can be configured. Alternatively, the pixel drive circuit 13 is also used to facilitate a liquid crystal display device in which the reflective pixel electrodes 12b are arranged in a matrix in the vertical and horizontal directions from a device in which the reflective pixel electrodes typified by the wavelength selective switch are arranged in the vertical direction. Can be configured.

  As a result, in the reflective spatial light modulator of the first embodiment, the reflective spatial light modulator suitable as a liquid crystal display device, or a reflective pixel electrode suitable for a wavelength selective switch or the like is arranged in the vertical direction. Type spatial light modulator can be provided easily and inexpensively.

  In the first embodiment, as an example, the pixel drive circuits 13 are arranged in 3 rows × 3 columns, and in a device in which the reflective pixel electrodes 12b are formed in a square shape, the reflective pixel electrodes 12b are arranged in 3 rows × 3 columns. The arranged arrangement has been described. In the device in which the reflective pixel electrodes 12a are formed in a rectangular shape, the configuration in which the reflective pixel electrodes 12a are arranged in 9 rows × 1 column has been described.

The number and arrangement of the pixel driving circuit 13 and the reflection pixel electrodes 12a and 12b are not limited to this. That is, in an apparatus in which the reflective pixel electrode 12b is formed in a square shape,
The same effect can be obtained even if the pixel driving circuit 13 and the reflective pixel electrode 12b are m rows × n columns. In the device in which the reflective pixel electrode 12a is formed in a rectangular shape, the same effect can be obtained even if the pixel driving circuit 13 has m rows × n columns and the reflective pixel electrode 12b has mn rows × 1 column. Note that m is a positive integer, and n is a positive integer of 2 or more.

DESCRIPTION OF SYMBOLS 11 ... Pixel part 12a (12a-1 to 12a-9), 12b (12b-1 to 12b-9) ... Reflection pixel electrode 13 (13-1 to 13-9) ... Pixel drive circuit 13-1R to 13-9R ... Area 14 ... Switching element 15 ... Capacitor 15-1 ... Pixel drive circuit capacitor 15-2 ... Liquid crystal capacitor 16 ... Vertical address circuit 17 ... Pixel signal supply circuit 17-1 ... Horizontal address circuit 17-2 ... Write switch DESCRIPTION OF SYMBOLS 21 ... Silicon substrate 22 ... Gate electrode 23 ... Source region 24 ... Drain region 25 ... 1st capacity electrode 26 ... 2nd capacity electrode 27 ... Insulating layer 28 ... Field insulating film 29 ... Liquid crystal 30 ... Common electrode 31 ... Glass substrate L1, L2, L3 (L3-1 to L3-9), L4 (L4a-1 to L4a-9), L5 (L5a-1 to L5a-9), L6, L7 (L7a, L7b) ... Line layer D ... column pixel signal line G ... row scanning line S ... pixel signal supply line

Claims (2)

The incident readout light is transmitted through the liquid crystal disposed between the reflective pixel electrode and the common electrode, reflected by the reflective pixel electrode, and then read again through the liquid crystal, and shared with the reflective pixel electrode and the common pixel electrode. A pixel unit that optically modulates readout light according to a difference in voltage applied to both ends of the liquid crystal given to the electrode;
The pixel unit includes a pixel drive circuit that supplies a pixel drive voltage corresponding to a pixel signal to the reflective pixel electrode,
The pixel drive circuit is arranged in a matrix in the vertical direction and the horizontal direction, the number of rows arranged in the vertical direction or the number of columns arranged in the horizontal direction of the pixel drive circuit, and the reflective pixel electrode corresponding to each pixel drive circuit The reflection type spatial light modulation device is different from the number of arranged rows in the vertical direction or the number of arranged columns in the horizontal direction. The pixel driving circuits are arranged in m (m: positive integer) rows in the vertical direction and arranged in n (n: positive integers of 2 or more) in the horizontal direction, and m × n pixel driving circuits. 2. The reflection type spatial light modulator according to claim 1, wherein m × n reflective pixel electrodes corresponding to are arranged in mn rows × 1 columns in the vertical direction.