Driving method for radio wave reflection device

Abstract

Provided is a driving method for a radio wave reflection device that includes a reflector unit cell having a first electrode, a second electrode that faces the first electrode and is provided apart from the first electrode, and a liquid crystal layer provided between the first electrode and the second electrode, said radio wave reflection device being configured to be able to control the traveling direction of a reflected radio wave. This driving method includes applying a first potential to the first electrode and applying a second potential, which has a polarity different from that of the first potential, to the second electrode.

Description

Method for driving radio wave reflecting device

[0001] One embodiment of the present invention relates to a method for driving a radio wave reflecting device that can control the traveling direction of reflected radio waves.

[0002] In recent years, devices using high frequencies in the 10 GHz to 100 GHz range have become increasingly popular. For example, a high-frequency device may include a metasurface that includes multiple antenna elements arranged in a planar configuration. By applying a signal containing a potential corresponding to a predetermined phase to each of the multiple antenna elements, the metasurface can control the antenna direction while each of the multiple antenna elements remains fixed. As a result, a high-frequency device including a metasurface can change the transmission direction of radio waves, avoiding obstacles and expanding the communication area.

[0003] For example, Patent Documents 1 and 2 disclose a metasurface that adjusts the amplitude and phase of a signal applied to each of a plurality of antenna elements and utilizes the change in dielectric constant due to the orientation state of liquid crystals.

[0004] JP 11-103201 Publication Special Publication No. 2019-530387 Publication

[0005] For example, the potential applied to the antenna element of a radio wave reflecting device is higher than the potential applied to the liquid crystal display element of a liquid crystal display device. Therefore, driving a non-display device such as a radio wave reflecting device, typified by a metasurface, requires a higher potential than driving a display device such as a liquid crystal display device.

[0006] In view of such problems, one object of one embodiment of the present invention is to provide a method for driving a radio wave reflecting device that can control the traveling direction of reflected radio waves and can apply a high potential.

[0007] One embodiment of the present invention is a method for driving a radio wave reflection device that includes a reflector unit cell having a first electrode, a second electrode facing the first electrode and spaced apart from the first electrode, and a liquid crystal layer provided between the first electrode and the second electrode, and is configured to be able to control the direction of travel of reflected radio waves, the method including applying a first potential to the first electrode and applying a second potential having a polarity different from that of the first potential to the second electrode.

[0008] One embodiment of the present invention is a method for driving a radio wave reflecting device configured to be able to control the traveling direction of a reflected radio wave, the method including: applying a first potential to the first electrode of the reflector unit cell in the (m-1)th row and the (n-1)th column; and applying a second potential having a polarity different from that of the first potential to a first electrode group to which each second electrode of the plurality of reflector unit cells in the (n-1)th column is connected.

[0009] One embodiment of the present invention is a method for driving a radio wave reflecting device configured to be able to control the traveling direction of a reflected radio wave, the method including: applying a first potential to the first electrode of the reflector unit cell in the (m-1)th row and the (n-1)th column; and applying a second potential having a polarity different from that of the first potential to a first electrode group to which each second electrode of the plurality of reflector unit cells in the (m-1)th row is connected.

[0010] 1 is a plan view showing the configuration of a radio wave reflecting device according to a first embodiment of the present invention. FIG. 2 is a circuit diagram showing the configuration of a circuit of a reflector unit cell shown in FIG. 1. FIG. 3 is a diagram showing an example of a timing chart for explaining a method of driving the reflector unit cell shown in FIG. 3. FIG. 4 is a plan view showing an example of a layout of a radio wave reflecting device according to a first embodiment of the present invention. FIG. 5 is a plan view showing an example of a layout of a reflector unit cell shown in FIG. 4. FIG. 5 is a cross-sectional view showing a cut surface along line A1-A2 shown in FIG. 1, and is a diagram schematically showing that the traveling direction of a reflected wave is changed by the radio wave reflecting device according to the first embodiment of the present invention. FIG. 6 is a diagram schematically showing a state of a reflector unit cell according to the first embodiment of the present invention. FIG. 7 is a diagram schematically showing a state of a reflector unit cell according to the first embodiment of the present invention. FIG. 8 is a circuit diagram for explaining a method of driving the radio wave reflecting device according to the first embodiment of the present invention. FIG. 9 is a diagram showing an example of a timing chart for explaining a method of driving the radio wave reflecting device according to the first embodiment of the present invention. FIG. 10 is a diagram showing a potential difference between bias electrodes and common electrodes of a plurality of reflector unit cells of the radio wave reflecting device according to the first embodiment of the present invention. FIG. 1 is a diagram showing an example of a timing chart for explaining a method for driving a radio wave reflecting device according to a second embodiment of the present invention. FIG. 2 is a diagram showing an example of a timing chart for explaining a method for driving a radio wave reflecting device according to a second embodiment of the present invention. FIG. 3 is a diagram showing a potential difference between a bias electrode and a common electrode of a plurality of reflector unit cells of a radio wave reflecting device according to a second embodiment of the present invention. FIG. 4 is a diagram showing a potential difference between a bias electrode and a common electrode of a plurality of reflector unit cells of a radio wave reflecting device according to a second embodiment of the present invention. FIG. 5 is a circuit diagram showing a configuration of a radio wave reflecting device according to a third embodiment of the present invention. FIG. 6 is a diagram showing an example of a timing chart for explaining a method for driving a radio wave reflecting device according to a third embodiment of the present invention.FIG. 10 is a diagram showing an example of a timing chart for explaining a method for driving a radio wave reflecting device according to a fourth embodiment of the present invention.

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be construed as being limited to the description of the following exemplary embodiments. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals (or reference numerals with a, b, etc. suffixed thereto), and detailed descriptions may be omitted as appropriate. Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element and have no further meaning unless otherwise specified.

[0012] In this specification, when a component or region is referred to as being "on (or under)" another component or region, unless otherwise specified, this includes not only the case where it is directly above (or directly under) the other component or region, but also the case where it is above (or under) the other component or region, i.e., the case where another component is included between the component or region and above (or under) the other component or region.

[0013] In the present specification, the first direction D1 intersects the second direction D2, and the third direction D3 intersects the first direction D1 and the second direction D2 (D1D2 plane). For example, the first direction D1, the second direction D2, and the third direction D3 correspond to the X direction (x direction), the Y direction (y direction), and the Z direction (z direction).

[0014] In the present specification, when the terms "identical," "same," and "match" are used, the terms "identical" and "match" may include a margin of error within the design range.

[0015] First Embodiment A radio wave reflecting device 100 according to a first embodiment will be described with reference to FIGS.

[0016] [1-1. Overview of the Radio Wave Reflecting Device 100] An overview of the radio wave reflecting device 100 will be described with reference to Fig. 1. Fig. 1 is a functional block diagram showing the configuration of the radio wave reflecting device 100. The radio wave reflecting device 100 is a device that can control the direction of travel of reflected radio waves by using a metasurface (reflector 120) that utilizes changes in the dielectric constant due to the orientation state of liquid crystal.

[0017] The radio wave reflecting device 100 includes an IC chip 130 and a reflector 120, and has a configuration capable of biaxial reflection control. The reflector 120 includes a plurality of reflector unit cells 102 arranged in a matrix in a first direction D1 and a second direction D2. For example, the plurality of reflector unit cells 102 extending in the first direction D1 are shown arranged in the row direction, and the plurality of reflector unit cells 102 extending in the second direction D2 are shown arranged in the column direction. For example, the plurality of reflector unit cells 102 are arranged in m rows and n columns (the numbers m and n are integers of 2 or greater), and the reflector unit cell in the second row and third column may be referred to as the reflector unit cell in the second row and third column.

[0018] The plurality of reflector unit cells 102 includes at least reflector unit cells 102a to 102i. Although details will be described later, each of the plurality of reflector unit cells 102 includes a circuit 103 for driving the reflector unit cell 102, a bias electrode 108 (see FIG. 2), a common electrode 110 (see FIG. 2) that faces the bias electrode 108 and is provided spaced apart from the bias electrode 108, and a liquid crystal layer 114 (see FIG. 7) that is provided between the bias electrode 108 and the common electrode 110. Note that the circuit 103 may include the bias electrode 108 and the common electrode 110.

[0019] Furthermore, each of the plurality of reflector unit cells 102 (circuits 103) is electrically connected to a corresponding output signal line 118, a corresponding scanning line 132, and a corresponding common wiring 111. The bias electrode 108 of each of the plurality of reflector unit cells 102 is electrically connected to the corresponding output signal line 118, and the common electrode 110 of each of the plurality of reflector unit cells 102 is electrically connected to the corresponding common wiring 111.

[0020] The IC chip 130 is connected to a plurality of output signal lines 118, a plurality of scanning lines 132, and a plurality of common wirings 111. The plurality of output signal lines 118 include output signal lines 118a to 118d, the plurality of scanning lines 132 include scanning lines 132a to 132d, and the plurality of common wirings 111 include common wirings 111a to 111d. An output signal SS is supplied to the output signal line 118, a scanning signal SG is supplied to the scanning line 132, and a common signal SC is supplied to the common wiring 111. The plurality of output signals SS include output signals SS(1) to SS(m), the plurality of scanning signals SG include scanning signals SG(1) to SG(n), and the plurality of common signals SC include common signals SC(1) to SC(m).

[0021] The IC chip 130 supplies signals for driving the reflector unit cells 102 (circuits 103) to each of the reflector unit cells 102 (circuits 103), and can control the reflector 120 including the reflector unit cells 102. For example, the signals for driving the reflector unit cells 102 (circuits 103) include a scanning signal SG, an output signal SS, and a common signal SC.

[0022] The bias electrode 108 and the common electrode 110 of the radio wave reflecting device 100 may be called a first electrode and a second electrode. The IC chip 130 of the radio wave reflecting device 100 may be called a control circuit.

[0023] In the radio wave reflecting device 100, when the radio wave reflecting unit cells need to be distinguished from one another, the reflector unit cells are referred to as a plurality of reflector unit cells 102a to 102i. When it is not necessary to distinguish between the radio wave reflecting unit cells, the reflector unit cells are referred to as a plurality of reflector unit cells 102. As with the reflector unit cells, the names of the output signal lines, output signals, scanning lines, scanning signals, bias electrodes 108, common electrodes 110, and the like may also be changed depending on whether they are distinguished from one another or not. The output signal lines may be referred to as a first output signal line 118a to an mth output signal line 118d, the output signals may be referred to as a first output signal SS(1) to an mth output signal SS(m), the scanning lines may be referred to as scanning lines 132a to 132d, and the scanning signals may be referred to as a first scanning signal SG(1) to an nth scanning signal SG(n).

[0024] [1-2. Circuit Configuration of Reflector Unit Cell 102] The circuit configuration of the reflector unit cell 102 will be described with reference to Fig. 2. Fig. 2 is a schematic circuit diagram showing the configuration of the circuit 103 of the reflector unit cell 102 of the radio wave reflecting device 100. Configurations that are the same as or similar to those in Fig. 1 will be described as necessary.

[0025] The circuit 103 includes, for example, a transistor 160, a transistor 170, a connection portion 115, and a liquid crystal element LCL. The transistor 160 includes a gate electrode 161, a source electrode 163, and a drain electrode 164. The gate electrode 161 is connected to the scanning line 132. The source electrode 163 is connected to the output signal line 118. The drain electrode 164 is connected to a first electrode of the liquid crystal element LCL. The transistor 170 includes a gate electrode 171, a source electrode 173, and a drain electrode 174. The gate electrode 171 is connected to the gate electrode 161 and the scanning line 132. The source electrode 173 is connected to the common wiring 111. The drain electrode 174 is connected to a second electrode of the liquid crystal element LCL via the connection portion 115. The first electrode of the liquid crystal element LCL is electrically connected to the bias electrode 108, and the second electrode of the liquid crystal element LCL is electrically connected to the common electrode 110.

[0026] The first electrode and the second electrode of the liquid crystal element LCL are interchangeable. For convenience of explanation, the source electrodes 163 and 173 of the radio wave reflecting device 100 are referred to as source electrodes, and the drain electrodes 164 and 174 are referred to as drain electrodes. However, depending on the voltage supplied (applied) to the source and drain electrodes of the transistors 160 and 170, the source and drain functions of the respective electrodes may be interchanged. The transistor 160 may be referred to as a first switching element, and the transistor 170 may be referred to as a second switching element. Furthermore, as with the multiple radio wave reflecting unit cells, when it is necessary to distinguish between the multiple liquid crystal elements LCL, the multiple liquid crystal elements are referred to as multiple liquid crystal elements LCLa to LCLi, and when it is not necessary to distinguish between the multiple liquid crystal elements, the multiple liquid crystal elements are referred to as multiple liquid crystal elements LCL.

[0027] [1-3. Overview of Driving Method of Radio Wave Reflecting Device 100 (Reflector Unit Cell 102)] An overview of a driving method of the radio wave reflecting device 100 (reflector unit cell 102) will be described with reference to Figs. 3 and 4. Fig. 3 is a diagram showing an example of a timing chart for explaining a driving method of the reflector unit cell 102 shown in Fig. 1. Fig. 4 is a circuit diagram for explaining a driving method of the reflector unit cell 102 shown in Fig. 3. Configurations that are the same as or similar to those in Figs. 1 and 2 will be described as necessary.

[0028] The driving method of the radio wave reflecting device 100 includes supplying a potential corresponding to the phase of each reflector unit cell 102 to each reflector unit cell 102 during a radio wave reflection period (one frame period (1 FRAME)). The driving method of the radio wave reflecting device 100 includes selecting, for each row, a plurality of bias electrodes 108 arranged in a first direction D1 during the radio wave reflection period (1 FRAME). The IC chip 130 supplies a scanning signal SG for selecting a predetermined reflector unit cell 102 to each switching element 134 (transistor 160) of the plurality of reflector unit cells 102 via a scanning line 132. The IC chip 130 also supplies a bias voltage SG electrically connected to the selected switching element 134 (transistor 160) of the plurality of reflector unit cells 102. The IC chip 130 supplies an output signal SS, including a potential corresponding to the phase of each reflector unit cell 102, to the electrodes 108 via the output signal line 118. Furthermore, the IC chip 130 supplies a common signal SC, including a potential corresponding to the phase of each reflector unit cell 102, via the common wiring 111 to the common electrode 110 electrically connected to the switching element 136 (transistor 170) selected from the plurality of reflector unit cells 102. The IC chip 130 performs this operation for each row, and the radio wave reflecting device 100 can change the orientation state of the liquid crystal molecules 116 contained in the liquid crystal element LCL in the reflector unit cell 102 based on the potential corresponding to the phase of each reflector unit cell 102. As a result, the radio wave reflecting device 100 can reflect incident radio waves in a desired direction.

[0029] The driving method of the radio wave reflecting device 100 also includes supplying signals of mutually opposite polarities to the bias electrode 108 and the common electrode 110 during the radio wave reflection period, thereby supplying (applying) potentials of mutually opposite polarities. For example, the IC chip 130 supplies a scanning signal SG for selecting a specific reflector unit cell 102 via a scanning line 132 to each switching element 134 (transistor 160) of the multiple reflector unit cells 102, supplies an output signal SS including a positive first potential (+V1) to the bias electrode 108 electrically connected to the selected switching element 134 (transistor 160), and supplies a common signal SC including a negative second potential (-V2) to the common electrode 110 electrically connected to the selected switching element 136 (transistor 170). In other words, the radio wave reflecting device 100 can supply first potentials of mutually opposite polarities (inverted) to the bias electrode 108 and the common electrode 110. As a result, burn-in of the radio wave reflecting device 100 can be suppressed. Furthermore, when the same potential but opposite polarity is supplied to the bias electrode 108 and the common electrode 110, the potential difference applied to the bias electrode 108 and the common electrode 110 (the potential difference applied to the liquid crystal layer 114) is ideally twice the same potential. Generally, a constant potential is supplied to the common electrode 110, so the radio wave reflecting device 100 can apply a larger potential difference to the liquid crystal layer 114 than when a constant potential is supplied to the common electrode 110. As a result, the radio wave reflecting device 100 can sufficiently supply a predetermined potential to the liquid crystal layer 114 and stabilize the change in the dielectric constant due to the orientation state of the liquid crystal molecules 116 (see FIG. 8 ) in the liquid crystal layer 114. Therefore, the radio wave reflecting device 100 can stabilize the direction of radio wave transmission and avoid radio wave interference.

[0030] For example, the constant potential may be a common potential (potential COM), a ground potential (GND potential), a potential of 0 V, or a potential VSS. For example, the constant potential is a reference potential that serves as a reference for the output signal SS and the common signal SC. Furthermore, for example, the potential COM is a potential at an intermediate level of the polarity inversion signal.

[0031] In the radio wave reflecting device 100, the on signal may be at a high potential (High, HI), and the off signal may be at a low potential (Low, LO). Also, in the radio wave reflecting device 100, the on signal may be at a low potential (LO), and the off signal may be at a high potential (HI). The high potential is greater than the low potential (LO). The high potential is equal to or greater than the maximum potential of the output signal SS and the common signal SC, and the low potential is equal to or less than the minimum potential of the output signal SS and the common signal SC.

[0032] In the radio wave reflecting device 100, the polarity of the potential supplied to the output signal SS is different from the polarity of the potential supplied to the common signal SC, and the polarity of the potential supplied to the output signal SS is opposite to the polarity of the potential supplied to the common signal SC. In other words, the output signal SS is a polarity-inverted signal in which the polarity of the common signal SC is inverted.

[0033] Furthermore, the potential supplied to the output signal SS and the potential supplied to the common signal SC are between -V2 and +V1. That is, the maximum potential supplied to the output signal SS and the common signal SC is +V1, and the minimum potential supplied to the output signal SS and the common signal SC is -V2. Note that when the potential supplied to the output signal SS and the common signal SC is the COM potential, the potentials supplied to the output signal SS and the common signal SC are the same, and the polarity of the potentials supplied to the output signal SS and the common signal SC is not inverted.

[0034] For example, if the potential COM is an intermediate potential COM, +V1 is higher (larger) than the potentials COM and −V2, and −V2 is lower (smaller) than the potentials COM and +V1. For example, the potential COM is 0V, −V2 is −8V, and +V1 is +8V.

[0035] 3 and 4 , an example of a driving method of the radio wave reflecting device 100 will be described. For example, the switching (on and off) of the switching elements 134 and 136 is controlled by a scanning signal SG(n) supplied to the scanning line 132. That is, the switching elements 134 and 136 are switched (on and off) at the same timing. When the switching element 134 is turned on in response to the scanning signal SG(n), the bias electrode 108 is electrically connected to the output signal line 118, and an output signal SS(m) is supplied. When the switching element 136 is turned on in response to the scanning signal SG(n), the common electrode 110 is electrically connected to the common wiring 111, and a common signal SC(m) is supplied. The switching elements 134 and 136 are formed, for example, of thin film transistors.

[0036] 3 and 4 , an example of a method for driving the radio wave reflecting device 100 will be described in more detail. The method for driving the radio wave reflecting device 100 includes a Kth radio wave reflection period (KthFRAME). The number K is a natural number equal to or greater than 1. In KthFRAME, a scanning signal SG(n) including a potential HI is supplied to the scanning line 132, the gate electrode 161 of the transistor 160, and the gate electrode 171 of the transistor 170, an output signal SS(m) including +V1 is supplied to the output signal line 118 and the source electrode 163 of the transistor 160, and a common signal SC(m) including −V2 is supplied to the common wiring 111 and the source electrode 173 of the transistor 170.

[0037] As a result, the transistor 160 is turned on, causing the source electrode 163 to be conductively connected to the drain electrode 164, and an output signal SS(m) including +V1 is supplied to the drain electrode 164 and the bias electrode 108. In addition, the transistor 170 is turned on, causing the source electrode 173 to be conductively connected to the drain electrode 174, and a common signal SC(m) including -V2 is supplied to the drain electrode 174 and the common electrode 110. Therefore, the potential difference applied between the bias electrode 108 and the common electrode 110 (the potential difference applied to the liquid crystal element CLC) is +V1-(-V2)=V1+V2. When +V1=|-V2|, the potential difference is 2×V1 (2×|-V2|).

[0038] Furthermore, the driving method of the radio wave reflecting device 100 includes a (K+1)th radio wave reflection period (K+1st FRAME) after the Kth FRAME. In the K+1st FRAME, the output signal SS(m) and common signal SC(m) are inverted compared to the Kth FRAME. That is, in the K+1st FRAME, the output signal SS(m) including -V2 is supplied to the output signal line 118 and the source electrode 163 of the transistor 160, and the common signal SC(m) including +V1 is supplied to the common wiring 111 and the source electrode 173 of the transistor 170. In other respects, the driving method is the same as the Kth FRAME. The potential difference applied between the bias electrode 108 and the common electrode 110 in the K+1st FRAME (the potential difference applied to the liquid crystal element CLC) is |-V2-(+V1)| = V2+V1. When +V1=|-V2|, the potential difference is 2×V1 (2×|-V2|).

[0039] The radio wave reflecting device 100 can supply an analog potential of −V2 or more and +V1 or less to each of the bias electrode 108 and the common electrode 110. Furthermore, the radio wave reflecting device 100 can set the potential difference applied between the potential of the bias electrode 108 and the potential of the common electrode 110 to the absolute value of the difference between a potential of −V2 or more and +V1 or less and a potential of −V2 or more and +V1 or less. Therefore, the radio wave reflecting device 100 can increase the potential difference and the number of potential differences compared to when a constant potential is supplied to either the bias electrode 108 or the common electrode 110. As a result, the radio wave reflecting device 100 can reflect radio waves in directions corresponding to more phases than a radio wave reflecting device in which the polarity of the output signal SS is not inverted from the polarity of the common signal SC.

[0040] [1-4. Layout of the Radio Wave Reflecting Device 100 and the Reflector Unit Cell 102] An example of the layout and an example of the cross-sectional structure of the radio wave reflecting device 100 and the reflector unit cell 102 will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view showing an example of the layout of the radio wave reflecting device 100. FIG. 6 is a plan view showing an example of the layout of the reflector unit cell 102 as viewed from below (the side where radio waves are incident). More specifically, it is an enlarged view of the arrangement of the switching element 134 provided between the output signal line 118 and the bias electrode 108, the switching element 136 provided between the common wiring 111 and the common electrode 110, the bias electrode 108, the common electrode 110, the output signal line 118, the common wiring 111, and the scanning line 132. Descriptions of configurations that are the same as or similar to those in FIGS. 1 to 4 will be omitted here.

[0041] As shown in Fig. 5, the radio wave reflecting device 100 includes a dielectric substrate 104, a counter substrate 106, and a peripheral region 122. The radio wave reflecting device 100 (dielectric substrate 104) has a first side 91 along a first direction D1, a third side 93 along a second direction D2 that intersects with the first side 91, a second side 92 that intersects with the third side 93 and faces parallel to the first side 91, and a fourth side 94 that intersects with the first side 91 and the second side 92 and faces parallel to the third side 93. The counter substrate 106 overlaps the dielectric substrate 104, and is bonded to the dielectric substrate 104 using a sealant 128. The region surrounded by the counter substrate 106, the dielectric substrate 104, and the sealant 128 includes a liquid crystal layer 114 (see Fig. 7). The dielectric substrate 104 may be called a first substrate, and the opposing substrate 106 may be called a second substrate.

[0042] The area of ​​the dielectric substrate 104 other than where the dielectric substrate 104 and the opposing substrate 106 overlap is called a peripheral area 122. The peripheral area 122 includes an IC chip 130 and a terminal section 126 arranged on the dielectric substrate 104. The terminal section 126 is an area for forming a connection with an external circuit. For example, a flexible printed circuit (not shown) is connected to the terminal section 126. A signal for controlling the IC chip 130 is input to the terminal section 126 from the flexible printed circuit.

[0043] 5 is disposed on the dielectric substrate 104 (array layer 180 (see FIG. 7 )) using a COG (chip on glass) method. Note that the configuration of the IC chip 130 is not limited to the above, and for example, the IC chip 130 may be disposed on an FPC (flexible printed circuit) connected to the terminal portion 126, or may be mounted using a COF (chip on film, chip on flexible, etc.) method.

[0044] A plurality of bias electrodes 108 are arranged on the dielectric substrate 104 in a matrix in the first direction D1 and the second direction D2.

[0045] The plurality of output signal lines 118 arranged on the dielectric substrate 104 extend in the second direction D2 and also extend into the peripheral region 122, and are connected to the IC chip 130. The plurality of output signal lines 118 are supplied with output signals SS corresponding to each of the plurality of output signal lines 118 from the IC chip 130.

[0046] The plurality of scanning lines 132 arranged on the dielectric substrate 104 extend, for example, in a first direction D1 and are connected to the IC chip 130. The plurality of scanning lines 132 are supplied with scanning signals SG corresponding to each of the plurality of scanning lines 132 from the IC chip 130.

[0047] The plurality of common wirings 111 arranged on the dielectric substrate 104 extend, for example, in the second direction D2 and are connected to the IC chip 130. The plurality of common wirings 111 are supplied with a common signal SC corresponding to each of the plurality of common wirings 111 from the IC chip 130.

[0048] A plurality of common electrodes 110 are arranged on the counter substrate 106 in a matrix in the first direction D1 and the second direction D2.

[0049] 5 and 6, the reflector unit cell 102 is arranged so that the common electrode 110, the liquid crystal layer 114 (see FIG. 7), and the bias electrode 108 overlap in a plan view. The reflector unit cell 102 includes a switching element 134 and a switching element 136.

[0050] For example, the switching element 134 is a transistor 160 (see FIG. 2 ) including a semiconductor layer 142 a, a gate electrode 161, a source electrode 163, and a drain electrode 164. The switching element 134 is connected to the output signal line 118 via a contact hole 163 a, and to the bias electrode 108 via a contact hole 164 a. That is, the switching element 134 connects the output signal line 118 and the bias electrode 108. For example, the switching element 136 is a transistor 170 (see FIG. 2 ) including a semiconductor layer 142 b, a gate electrode 171, a source electrode 173, and a drain electrode 174. The switching element 136 is connected to the common wiring 111 via a contact hole 173 a, and to the common electrode 110 via a connection portion 115. That is, the switching element 136 connects the common wiring 111 and the common electrode 110. As a result, the reflector unit cell 102 (the switching element 134 and the switching element 136 ) is electrically connected to the scanning line 132 , the output signal line 118 and the common wiring 111 .

[0051] The connection portion 115 connects the switching element 136 on the dielectric substrate 104 to the common electrode 110 on the counter substrate 106. The connection portion 115 is formed by penetrating or removing the alignment film 112a (see FIG. 7 ) on the dielectric substrate 104 side and the alignment film 112b (see FIG. 7 ) on the counter substrate 106 side. For example, the connection portion 115 includes a conductive member such as a photospacer or conductive beads. Because the liquid crystal layer 114 is disposed between the alignment film on the dielectric substrate 104 side and the alignment film on the counter substrate 106 side, the connection portion 115 is surrounded by the liquid crystal layer 114 (see FIG. 7 ) in a cross-sectional view. While the connection portion 115 shown in FIG. 6 is illustrated as having the same size (area) as the contact holes 163a, 164a, and 173a, the size of the connection portion 115 can be changed as needed depending on the application or specifications of the radio wave reflecting device 100, the specifications of the power transmitting member, and the like.

[0052] The radio wave reflecting device 100 can control the propagation direction of the reflected wave incident on the reflector 120 in the left-right direction on the drawing, with a reflection axis VR parallel to the second direction D2 (Y direction) as the central axis, and can also control the propagation direction of the reflected wave in the up-down direction on the drawing, with a reflection axis HR parallel to the first direction D1 (X direction) as the central axis. In other words, the radio wave reflecting device 100 includes a reflection axis VR parallel to the second direction D2 (Y direction) and a reflection axis VH parallel to the first direction D1 (X direction), and can control the reflection angle in the direction about the reflection axis VR as the rotation axis and in the direction about the reflection axis HR as the rotation axis.

[0053] The bias electrode 108 has a side length corresponding to the frequency of the radio wave, and the plurality of bias electrodes 108 are formed as a collection of rectangles. That is, the plurality of bias electrodes 108 constitute the radio wave reflecting surface of the radio wave reflecting device 100. The plurality of bias electrodes 108 and the plurality of common electrodes 110 are formed separately so that potentials can be individually supplied (applied) to the liquid crystal. The common electrodes 110 are also arranged so as to overlap with the bias electrodes 108.

[0054] When it is necessary to distinguish between the multiple switching elements of the reflector unit cells 102a to 102i, they are called switching elements 134a to 134d or switching elements 136a to 136d, and when it is not necessary to distinguish between the multiple switching elements, they are called multiple switching elements 134 or switching elements 136.

[0055] [1-5. Overview of Operation of Reflector 120 (Reflector Unit Cell 102)] An overview of operation of the reflector 120 (reflector unit cell 102) will be described with reference to FIGS. 7 to 9. FIG. 7 is a diagram schematically illustrating how the direction of travel of a reflected wave is changed by the reflector 120, and is a diagram schematically illustrating a cross section taken along A1-A2 in FIG. 1. FIG. 8 is a diagram schematically illustrating a state in which no potential difference occurs between the bias electrode 108 and the common electrode 110 in the reflector unit cell 102. FIG. 9 is a diagram illustrating a state in which a potential difference occurs between the bias electrode 108 and the common electrode 110 in the reflector unit cell 102. Descriptions of configurations that are the same as or similar to those in FIGS. 1 to 6 will be omitted here.

[0056] The radio wave reflecting device 100 reflects radio waves in the direction of travel of the reflected wave relative to the direction of travel of the incident wave. There are no restrictions on the frequency of radio waves that the radio wave reflecting device 100 (reflector unit cell 102) can reflect. For example, the frequency of radio waves that the reflector unit cell 102 can reflect is 400 MHz to 300 GHz. Typically, the radio wave reflecting device 100 can be used to reflect radio waves in the 400 MHz to 6.0 GHz band, the 2.5 GHz to 4.7 GHz band, and the 24 GHz to 300 GHz band.

[0057] For example, one reflector unit cell 102 includes a part of the dielectric substrate 104, a part of the array layer 180, one bias electrode 108, a part of the alignment film 112a, a part of the liquid crystal layer 114, a part of the alignment film 112b, a part of the common electrode 110, and a part of the opposing substrate 106. A plurality of reflector unit cells 102 share the dielectric substrate 104. The dielectric substrate 104 can be regarded as a single dielectric layer. The dielectric substrate 104 may also be referred to as a dielectric layer.

[0058] A plurality of common electrodes 110 and a plurality of common wirings 111a to 111d are provided on the first surface 106a of the counter substrate 106. An alignment film 112b is provided on the plurality of common electrodes 110 and the plurality of common wirings 111a to 111d. An array layer 180 including switching elements 134 and the like and a bias electrode 108 are provided on the first surface 104a of the dielectric substrate 104. The first surface 104a of the dielectric substrate 104 is disposed to face the first surface 106a of the counter substrate 106. A liquid crystal layer 114 is provided between the alignment films 112a and 112b. Although not shown, a spacer may be provided between the dielectric substrate 104 and the counter substrate 106 to maintain a constant gap.

[0059] The thickness T of the liquid crystal layer 114 may be, for example, 20 μm or more and less than 50 μm, and typically 30 μm or more and less than 40 μm. For example, the thickness T of the liquid crystal layer 114 of the radio wave reflecting device 100 is 35 μm. The thickness T of the liquid crystal layer 114 is sufficiently thicker than the thickness of a liquid crystal layer used in a liquid crystal display device (for example, 2.0 μm or more and 5 μm or less).

[0060] The layers formed on the dielectric substrate 104 are formed using, for example, the following materials. The semiconductor layer 142 is formed of a silicon semiconductor such as amorphous silicon or polycrystalline silicon, or an oxide semiconductor including a metal oxide such as indium oxide, zinc oxide, or gallium oxide. The gate electrode 161 may be formed of, for example, molybdenum (Mo), tungsten (W), or an alloy thereof. The output signal line 118, common wiring 111, and scanning line 132 are formed using a metal material such as titanium (Ti), aluminum (Al), or molybdenum (Mo). The bias electrode 108, common electrode 110, and common wirings 111a to 111d are formed of a metal film such as aluminum (Al) or copper (Cu), or a transparent conductive film such as indium tin oxide (ITO).

[0061] 7, the reflector unit cell 102a includes a bias electrode 108a, and the reflector unit cell 102b includes a bias electrode 108b. The reflector unit cell 102a and the reflector unit cell 102b are adjacent to each other in the first direction D1 (or the second direction D2). The bias electrode 108a is electrically connected to the output signal line 118a, and the bias electrode 108b is electrically connected to the output signal line 118b.

[0062] For example, when radio waves are incident on the reflector unit cell 102a and the reflector unit cell 102b in the same phase, the potential V １ is supplied to the reflector unit cell 102b, and a potential VP ２ For example, an output signal SS(2) including a potential VP １ is the potential VP ２ Unlike the potential VP １ is the potential VP ２ The phase change of the reflected wave by the reflector unit cell 102b is larger than the phase change of the reflected wave by the reflector unit cell 102a. The phase of the reflected wave R1 reflected by the reflector unit cell 102a is different from the phase of the reflected wave R2 reflected by the reflector unit cell 102b, and the traveling direction of the reflected wave appears to change obliquely. For example, in the example shown in FIG. 7, the phase of the reflected wave R2 leads the phase of the reflected wave R1.

[0063] An output signal SS that controls the orientation of the liquid crystal molecules 116 in the liquid crystal layer 114 is supplied to the bias electrode 108. For example, the output signal SS is a DC voltage signal or a polarity inversion signal in which a positive DC voltage and a negative DC voltage are alternately inverted. As an example, the radio wave reflecting device 100 supplies the polarity inversion signal to the bias electrode 108. As an example, a common signal SC that controls the orientation of the liquid crystal molecules 116 in the liquid crystal layer 114 is supplied to the common electrode 110. For example, the common signal SC is a mid-level potential COM of the polarity inversion signal. When the output signal SS is supplied to the bias electrode 108 and the common signal SC is supplied to the common electrode 110, the orientation state of the liquid crystal molecules 116 included in the liquid crystal layer 114 changes.

[0064] The reflector unit cell 102 can change the dielectric constant of the liquid crystal layer 114 by changing the orientation state of the liquid crystal molecules 116. As a result, when the radio wave reflecting device 100 (reflector 120) reflects radio waves, it can delay the phase of the reflected waves.

[0065] The orientation state of the liquid crystal molecules 116 in the liquid crystal layer 114 changes in response to the output signal SS supplied to the bias electrode 108 and the common signal SC supplied to the common electrode 110, but does not change substantially with the frequency of the radio wave incident on the bias electrode 108. Therefore, the reflector unit cell 102 can control the phase of the reflected radio wave without being affected by the incident radio wave.

[0066] 8 shows a state (referred to as the "first state") in which no potential difference occurs between the bias electrode 108 and the common electrode 110. Fig. 8 shows a case in which the alignment films 112a and 112b are horizontal alignment films. In the first state, the long axes of the liquid crystal molecules 116 are aligned horizontally with respect to the surface of the bias electrode 108 by the alignment films 112a and 112b.

[0067] 9 shows a state (hereinafter referred to as the "second state") in which an output signal SS is supplied to the bias electrode 108. In the second state, for example, the liquid crystal molecules 116 are subjected to the action of an electric field, and their major axes are oriented perpendicular to the surface of the bias electrode 108. The angle at which the major axes of the liquid crystal molecules 116 are oriented can be changed depending on the potential of the output signal SS supplied to the bias electrode 108 and the potential of the common signal SC supplied to the common electrode 110. For example, the major axes of the liquid crystal molecules 116 can be oriented in a direction intermediate between the horizontal and vertical directions.

[0068] When the liquid crystal molecules 116 have a positive dielectric anisotropy, the apparent dielectric constant is larger in the second state than in the first state. When the liquid crystal molecules 116 have a negative dielectric anisotropy, the apparent dielectric constant is smaller in the second state than in the first state. The liquid crystal layer 114 having dielectric anisotropy can be regarded as a variable dielectric layer. The reflector unit cell 102 can delay (or not delay) the phase of the reflected wave by utilizing the dielectric anisotropy of the liquid crystal layer 114.

[0069] [1-6. Driving Method of Radio Wave Reflecting Device 100] A driving method of the radio wave reflecting device 100 will be described with reference to FIGS. 10 to 13. FIG. 10 is a diagram showing a state in which a voltage is supplied (applied) between the bias electrode 108 and the common electrode 110 in a reflector unit cell 102 used in the radio wave reflecting device 100. FIG. 11 is a circuit diagram for explaining an example of a driving method of the radio wave reflecting device 100. FIG. 12 is a diagram showing an example of a timing chart for explaining a driving method of the radio wave reflecting device 100. FIG. 13 is a diagram showing a potential difference VLC between the bias electrode 108 and the common electrode 110 of a plurality of reflector unit cells 102. Descriptions of configurations that are the same as or similar to those in FIGS. 1 to 9 will be omitted here.

[0070] In the description of the driving method of the radio wave reflecting device 100 with reference to FIGS. 10 to 13, the driving method of the radio wave reflecting device 100 includes, as an example, the Kth FRAME and the K+1st FRAME. The output signals SS(1) to SS(3) and the common signals SC(2) and SC(3) in the Kth FRAME are supplied with a potential of −8 V or more and +8 V or less. The output signals SS(1) to SS(3) and the common signals SC(2) and SC(3) in the K+1st FRAME are supplied with polarity-inverted signals of the signals in the Kth FRAME. The common signal SC(1) in the Kth FRAME and the K+1st FRAME is supplied with a potential LO. The COM potential is 0 V. As an example, the potential difference VLC between the bias electrode 108 and the common electrode 110 of each of the reflector unit cells 102a to 102i is supplied to the value shown in FIG. 13. A blank period may be included between the period in which the ON signal of the scanning signal SG(3) in the Kth FRAME is supplied and the period in which the ON signal of the scanning signal SG(1) in the K+1st FRAME is supplied. Also, a blank period may be included between the periods in which ON signals are supplied to adjacent scanning lines.

[0071] As shown in FIG. 10 , the bias electrode 108a is electrically connected to the output signal line 118a via the switching element 134a. The switching element 134a is turned on in response to the supply of a scanning signal SG(1) from the IC chip 130 via the scanning line 132a (see FIG. 11 ). Therefore, the bias electrode 108a is electrically connected to the output signal line 118a via the switching element 134a, and an output signal SS(1) is supplied from the IC chip 130 via the output signal line 118a. The switching element 136a is electrically connected to the common wiring 111a via the switching element 136a, and a common signal SC(1) is supplied from the IC chip 130 via the common wiring 111a. As a result, by applying a potential difference between the output signal SS(1) and the common signal SC(1) between the bias electrode 108a and the common electrode 110a, the radio wave reflecting device 100 can reflect radio waves in a direction corresponding to the phase based on the potential difference.

[0072] 11 , the reflector 120 of the radio wave reflecting device 100 includes nine reflector unit cells 102a to 102i arranged in three rows and three columns (m=n=3). The reflector unit cells 102a to 102c are electrically connected to a scanning line 132a, the reflector unit cells 102d to 102f are electrically connected to a scanning line 132b, and the reflector unit cells 102g to 102i are electrically connected to a scanning line 132c. The reflector unit cells 102a, 120d, and 102g are electrically connected to the output signal line 118a and the common wiring 111a, the reflector unit cells 102b, 120e, and 102h are electrically connected to the output signal line 118b and the common wiring 111b, and the reflector unit cells 102c, 120f, and 102i are electrically connected to the output signal line 118c and the common wiring 111c. The scanning lines 132a to 132c are supplied with scanning signals SG(1) to SG(3), the output signal lines 118a to 118c are supplied with output signals SS(1) to SS(3), and the common wirings 111a to 111c are supplied with common signals SC(1) to SC(3).

[0073] 11 or 12 , for example, a driving method of the reflector unit cell 102a in KthFRAME includes supplying a scanning signal SG(1) including a potential HI to the scanning line 132a, the transistor 160a, and the transistor 170a, supplying an output signal SS(1) including a potential COM (0V) to the output signal line 118a and the transistor 160a, and supplying a common signal SC(1) including a potential COM (0V) to the common wiring 111a and the transistor 170a. As a result, the transistor 160a and the transistor 170a are turned on at the same time, and 0V is supplied to the bias electrode 108a and the common electrode 110a. Therefore, the potential difference VLCa applied between the bias electrode 108a and the common electrode 110a (the potential difference applied to the liquid crystal element CLCa) is 0V.

[0074] The driving method of the reflector unit cell 102a in the K+1st FRAME includes supplying a signal to the reflector unit cell 102a similar to the driving method of the reflector unit cell 102a in the Kth FRAME, and the potential difference VLCa applied between the bias electrode 108a and the common electrode 110a (the potential difference applied to the liquid crystal element CLCa) is 0 V.

[0075] For example, a driving method for the reflector unit cell 102h in KthFRAME includes supplying a scanning signal SG(3) including a potential HI to the scanning line 132c, the transistor 160h, and the transistor 170h, supplying an output signal SS(2) including -8V to the output signal line 118b and the transistor 160h, and supplying a common signal SC(2) including +4 to the common wiring 111b and the transistor 170h. As a result, the transistor 160h is turned on, and -8V is supplied to the bias electrode 108h. Furthermore, the transistor 170i is turned on, and -8V is supplied to the common electrode 110h. Therefore, the potential difference VLCh applied between the bias electrode 108h and the common electrode 110h (the potential difference applied to the liquid crystal element CLCh) is 12V.

[0076] The method of driving the reflector unit cell 102h in the (K+1)th FRAME includes supplying signals in which the polarities of the output signal SS(2) and common signal SC(2) in the Kth FRAME are inverted to the reflector unit cell 102h. That is, the method of driving the reflector unit cell 102h in the (K+1)th FRAME includes supplying the output signal SS(2) including +8 V to the output signal line 118b and the transistor 160h, and supplying the common signal SC(2) including −4 V to the common wiring 111h and the transistor 170h. As a result, the potential difference VLCh applied between the bias electrode 108h and the common electrode 110h (the potential difference applied to the liquid crystal element CLCh) is 12 V, similar to the potential difference VLCh in the Kth FRAME.

[0077] Furthermore, for example, a driving method for the reflector unit cell 102i in KthFRAME includes supplying a scanning signal SG(3) including a potential HI to the scanning line 132c, the transistor 160i, and the transistor 170i, supplying an output signal SS(3) including +8V to the output signal line 118c and the transistor 160i, and supplying a common signal SC(3) including -8V to the common wiring 111c and the transistor 170i. As a result, the transistor 160i is turned on, and +8V is supplied to the bias electrode 108i. Furthermore, the transistor 170i is turned on, and -8V is supplied to the common electrode 110a. Therefore, the potential difference VLCi applied between the bias electrode 108i and the common electrode 110i (the potential difference applied to the liquid crystal element CLCi) is 16V.

[0078] For example, a method of driving the reflector unit cell 102i in the (K+1)th FRAME includes supplying signals in which the polarities of the output signal SS(3) and common signal SC(3) in the Kth FRAME are inverted to the reflector unit cell 102i. That is, a method of driving the reflector unit cell 102i in the (K+1)th FRAME includes supplying the output signal SS(3) including −8 V to the output signal line 118c and the transistor 160i, and supplying the common signal SC(3) including +8 V to the common wiring 111c and the transistor 170i. As a result, the potential difference VLCi applied between the bias electrode 108i and the common electrode 110i (the potential difference applied to the liquid crystal element CLCi) becomes 16 V, similar to the potential difference VLCi in the Kth FRAME.

[0079] The driving methods of the reflector unit cells 102 other than the reflector unit cells 102a, 102h, and 102i include the driving methods shown in FIGS. 10 to 13, similar to the driving methods of the reflector unit cells 102a, 102h, and 102i.

[0080] As described above, the driving method of the radio wave reflecting device 100 is such that output signals with mutually inverted polarities are supplied to the output signal lines connected to adjacent reflector unit cells, and common signals with mutually inverted polarities are supplied to the common wirings connected to adjacent reflector unit cells.

[0081] As a result, the radio wave reflecting device 100 can supply signals (potentials) whose polarities are inverted to each other to the bias electrode 108 or the common electrode 110. In other words, the radio wave reflecting device 100 can increase the potential difference provided between the bias electrode 108 and the common electrode 110 and can also increase the number of potential differences compared to when signals (potentials) whose polarities are inverted to each other are not supplied to the bias electrode 108 and the common electrode 110. Therefore, the radio wave reflecting device 100 can reflect radio waves in directions corresponding to many phases.

[0082] [1-7. Modifications] Although not shown in the drawings, an array layer may be provided on the first surface 106a of the counter substrate 106, similar to the dielectric substrate 104. For example, the array layer may include part of the drive circuit included in the IC chip 130, and may include a configuration capable of driving the transistors 170. Furthermore, part of the drive circuit included in the IC chip 130 may be formed using a plurality of transistors included in the array layer 180 of the dielectric substrate 104. For example, part of the drive circuit included in the IC chip 130 may be a drive circuit (so-called gate driver) for supplying a scanning signal SG to a plurality of scanning lines 132, or may be a plurality of multiplexers for selecting an output signal SS or a common signal SC and supplying it to each output signal line or each common wiring.

[0083] Furthermore, although not shown, a terminal portion having a configuration similar to that of the terminal portion 126 may be formed on the first surface 106a of the counter substrate 106, an IC chip including a part of the drive circuit included in the IC chip 130 may be disposed, or an IC chip including a function different from that of the IC chip 130 may be disposed. In this case, the terminal portion on the counter substrate 106 side and the terminal portion on the dielectric substrate 104 side are connected using an FPC.

[0084] As described above, the radio wave reflecting device 100 may include various configurations, and the method of driving the radio wave reflecting device 100 may include driving the reflector unit cells using various configurations.

[0085] Second Embodiment A radio wave reflecting device 200 according to a second embodiment will be described with reference to FIGS.

[0086] Fig. 14 is a circuit diagram showing the configuration of the radio wave reflecting device 200. Figs. 15 and 16 are diagrams showing examples of timing charts for explaining a method of driving the radio wave reflecting device 200. Figs. 17 to 19 are diagrams showing the potential difference VLC between the bias electrode 108 and the common electrode 110 of a plurality of reflector unit cells 102.

[0087] Like the radio wave reflecting device 100, the radio wave reflecting device 200 is a device that can control the direction of travel of reflected radio waves by using a metasurface (reflector 220) that utilizes changes in dielectric constant due to the orientation state of liquid crystal. The reflector 220 has a similar configuration to the reflector 120, but the configuration of the reflector unit cell 102 of the radio wave reflecting device 200 (reflector 220) is different from the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 (reflector 120). Therefore, here, differences from the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 will be explained, and similarities to the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 will be explained as necessary.

[0088] 2-1. Overview of the Radio Wave Reflecting Device 200 An overview of the radio wave reflecting device 200 will be described with reference to Fig. 14. Descriptions of configurations that are the same as or similar to those in Figs. 1 to 13 will be omitted here.

[0089] The reflector unit cells 102a, 102d, and 102g, which are connected to the output signal line 118a and the common wiring 111a of the radio wave reflecting device 200, have their common electrodes 110a, 110d, and 110g connected by a common electrode connection line 211a. The common electrodes 110a, 110d, and 110g and the common electrode connection line 211a constitute a common electrode group 210a. That is, the common electrodes of three reflector unit cells adjacent to each other along the direction in which the common wiring 111a extends are electrically connected to form one common electrode group 210a, and the drain electrodes 174 of the transistors 170 of the reflector unit cells 102 are electrically connected to the common electrode group 210a. In one example of the radio wave reflecting device 200, the common electrodes of the three reflector unit cells are electrically connected to form one common electrode group 210a, but the number of common electrodes that make up the common electrode group 210a can be selected appropriately depending on the application and specifications of the radio wave reflecting device 200, etc.

[0090] Similar to the output signal line 118a and common wiring 111a of the radio wave reflecting device 200, the reflector unit cells 102b, 102e, and 102h connected to the output signal line 118b and common wiring 111b have their respective common electrodes 110b, 110e, and 110h electrically connected by a common electrode connection line 211b, and the common electrodes 110b, 110e, and 110h and the common electrode connection line 211b constitute a common electrode group 210b. Furthermore, similar to the output signal line 118a and common wiring 111a, and the output signal line 118b and common wiring 111b of the radio wave reflecting device 200, the common electrodes 110c, 110f, and 110i are electrically connected by a common electrode connection line 211c, and the common electrodes 110c, 110f, and 110i, and the common electrode connection line 211c constitute a common electrode group 210c.

[0091] 12 to 19, an example of a method for driving the radio wave reflecting device 200 will be described. Descriptions of configurations that are the same as or similar to those in FIGS. 1 to 13 will be omitted here.

[0092] The scanning signals SG(1) to SG(3) supplied corresponding to the scanning lines 132a to 132c, the output signals SS(1) to SS(3) supplied corresponding to the output signal lines 118a to 118c, and the common signals SC(1) to SS(3) supplied corresponding to the common wirings 111a to 111c are the same as the signals shown in Fig. 12. Also, as an example, the potential difference VLC between the bias electrode 108 and the common electrode 110 of each of the reflector unit cells 102a to 102i is supplied so as to have the value shown in Fig. 13, similar to the first embodiment.

[0093] First, a driving method in which a scanning signal SG(1) including a potential HI is supplied to the scanning line 132a will be described with reference to FIGS. 12 to 14 and 17. FIG.

[0094] For example, the driving method of the radio wave reflecting device 200 (reflector unit cell 102a) in KthFRAME includes a method similar to the example of the driving method of the radio wave reflecting device 100 described with reference to Fig. 12. That is, as shown in Fig. 12, 14, or 17, a scanning signal SG(1) including a potential HI is supplied to the scanning line 132a and the transistors 160a and 170a, and the transistors 160a and 170a are turned on at the same timing. As a result, 0 V is supplied to the bias electrode 108a, 0 V is supplied to the common electrode 110a, and the potential difference VLCa applied between the bias electrode 108a and the common electrode 110a (the potential difference applied to the liquid crystal element CLCa) is 0 V. 12 and 17, −4 V is supplied to the bias electrode 108b, and 0 V is supplied to the common electrode 110b, and the potential difference VLCb (the potential difference applied to the liquid crystal element CLCb) applied between the bias electrode 108b and the common electrode 110b is 4 V. In addition, the scanning signal SG(1) including the potential HI is also supplied to the transistors 160b, 160c, 170b, and 170c, and the transistors 160b, 160c, 170b, and 170c are turned on. The reflector unit cells 102b and 102c of the radio wave reflecting device 200 are driven in the same manner as the reflector unit cell 102a of the radio wave reflecting device 200. For example, as shown in FIG. 12 and FIG. 17, −4 V is supplied to the bias electrode 108b, and 0 V is supplied to the common electrode 110b, and the potential difference VLCb applied between the bias electrode 108b and the common electrode 110b (the potential difference applied to the liquid crystal element CLCb) is 4 V. Also, as shown in Figures 12 and 17, +8 V is supplied to the bias electrode 108c, 0 V is supplied to the common electrode 110c, and the potential difference VLCc applied between the bias electrode 108c and the common electrode 110c (the potential difference applied to the liquid crystal element CLCc) is 8 V.

[0095] 14 to 16 and 18, a driving method in which the scanning signal SG(2) including the potential HI is supplied to the scanning line 132b will be described. For example, a driving method for the reflector unit cells 102e and 102f of the radio wave reflecting device 200 in KthFRAME will be described.

[0096] 14, 15, or 16, a method for driving the reflector unit cells 102d to 102f of the radio wave reflecting device 200 in KthFRAME includes supplying a scanning signal SG(2) including a potential HI to the scanning line 132b and the transistors 160d to 160f and 170d to 170f, which turns on the transistors 160d to 160f and 170d to 170f.

[0097] 15, the driving method of the reflector unit cell 102e of the radio wave reflecting device 200 in KthFRAME includes supplying an output signal SS(2) including +8 V to the output signal line 118b and the transistor 160e, and supplying a common signal SC(2) including a potential COM (0 V) to the common wiring 111b and the transistor 170e. As a result, as shown in FIGS. 15 and 18, +8 V is supplied to the bias electrode 108e, 0 V is supplied to the common electrode 110e, and the potential difference VLCe applied between the bias electrode 108e and the common electrode 110e (the potential difference applied to the liquid crystal element CLCe) is 8 V. At this time, a scanning signal SG(1) including a potential LO is supplied to the scanning line 132a and the transistors 160b and 170b of the reflector unit cell 102b, and the transistors 160b and 170b are in the off state. However, because the common electrode 110e is connected to the common electrode 110b via the common electrode connection line 211b, 0 V is supplied to the common electrode 110b. Therefore, the potential supplied to the common electrode 110b is the same as when the scanning signal SG(1) including the potential HI is supplied to the scanning line 132a. As a result, the potential difference VLCb applied between the bias electrode 108b and the common electrode 110b remains at 4 V.

[0098] 14, 16, or 18, the method of driving the reflector unit cell 102f of the radio wave reflecting device 200 in KthFRAME includes supplying an output signal SS(3) including −4 V to the output signal line 118c and the transistor 160f, and supplying a common signal SC(3) including +8 V to the common wiring 111c and the transistor 170f. As a result, as shown in FIGS. 16 and 18, −4 V is supplied to the bias electrode 108f, +8 V is supplied to the common electrode 110f, and the potential difference VLCf applied between the bias electrode 108f and the common electrode 110f (the potential difference applied to the liquid crystal element CLCf) is |−12 V|, that is, 12 V. At this time, the scanning signal SG(1) including the potential LO is supplied to the scanning line 132a and the transistors 160c and 170c of the reflector unit cell 102c, and the transistors 160c and 170c are in the off state. Also, at this time, the common electrode 110c holds 0V, which was the voltage when the scanning signal SG(1) including the potential HI was supplied to the scanning line 132a, and the bias electrode 108c holds +8V, which was the voltage when the scanning signal SG(1) including the potential HI was supplied to the scanning line 132a. However, since the common electrode 110f is connected to the common electrode 110c via the common electrode connection line 211c, +8V is supplied to the common electrode 110c. Therefore, the potential supplied to the common electrode 110c varies from 0 V to +8 V, and due to coupling between the common electrode 110c and the bias electrode 108c, the potential supplied to the bias electrode 108c varies from +8 V to +16 V (see FIGS. 16 and 18). As a result, the potential difference VLCc applied between the bias electrode 108c and the common electrode 110c can be maintained at 8 V.

[0099] 14 to 16, 18, and 19, a driving method in which a scanning signal SG(3) including a potential HI is supplied to the scanning line 132c will be described. For example, a driving method for the reflector unit cells 102h and 102i of the radio wave reflecting device 200 in KthFRAME will be described.

[0100] 14, 15, or 16, a method for driving the reflector unit cells 102g to 102i of the radio wave reflecting device 200 in KthFRAME includes supplying a scanning signal SG(3) including a potential HI to the scanning line 132c and the transistors 160g to 160i and 170g to 170i, which turns on the transistors 160g to 160i and 170g to 170i.

[0101] 15, the method of driving the reflector unit cell 102h of the radio wave reflecting device 200 in KthFRAME includes supplying an output signal SS(2) including −8 V to the output signal line 118b and the transistor 160h, and supplying a common signal SC(2) including +4 V to the common wiring 111b and the transistor 170h. As a result, as shown in FIGS. 15 and 19, −8 V is supplied to the bias electrode 108h, +4 V is supplied to the common electrode 110h, and the potential difference VLCh applied between the bias electrode 108h and the common electrode 110h (the potential difference applied to the liquid crystal element CLCh) is |−8 V−(+4 V)|, that is, 12 V. At this time, a scanning signal SG(1) including a potential LO is supplied to the scanning line 132a and the transistors 160b and 170b of the reflector unit cell 102b, and the transistors 160b and 170b are in an off state. Also, at this time, the common electrode 110b maintains 0 V, which was the voltage when the scanning signal SG(1) including a potential HI was supplied to the scanning line 132a, and the bias electrode 108b maintains −4 V, which was the voltage when the scanning signal SG(1) including a potential HI was supplied to the scanning line 132a. Meanwhile, a scanning signal SG(2) including a potential LO is supplied to the scanning line 132b and the transistors 160e and 170e of the reflector unit cell 102e, and the transistors 160e and 170e are in an off state. At this time, the common electrode 110e maintains 0 V, which was the potential when the scanning signal SG(2) including the HI potential was supplied to the scanning line 132b, and the bias electrode 108e maintains +8 V, which was the potential when the scanning signal SG(1) including the HI potential was supplied to the scanning line 132a. However, because the common electrodes 110b and 110e are connected to the common electrode 110h via the common electrode connection line 211b, +4 V is supplied to the common electrodes 110b and 110e. Therefore, the potential supplied to the common electrode 110b fluctuates from 0 V to +4 V, and due to coupling between the common electrode 110b and the bias electrode 108b, the potential supplied to the bias electrode 108b fluctuates from -4 V to 0 V (see FIGS. 15 and 19). As a result, the potential difference VLCb applied between the bias electrode 108b and the common electrode 110b can be maintained at 4 V.Furthermore, the potential supplied to the common electrode 110e varies from 0 V to +4 V, and due to coupling between the common electrode 110e and the bias electrode 108e, the potential supplied to the bias electrode 108e varies from +8 V to +12 V (see FIGS. 15 and 19). As a result, the potential difference VLCe applied between the bias electrode 108b and the common electrode 110b can be maintained at 8 V.

[0102] 14, 16, or 19, a method of driving the reflector unit cell 102i of the radio wave reflecting device 200 in KthFRAME includes supplying an output signal SS(3) including +8 V to the output signal line 118c and the transistor 160i, and supplying a common signal SC(3) including −8 V to the common wiring 111c and the transistor 170i. As a result, as shown in FIG. 16 and FIG. 19, +8 V is supplied to the bias electrode 108i, −8 V is supplied to the common electrode 110i, and the potential difference VLCi (potential difference applied to the liquid crystal element CLCi) applied between the bias electrode 108i and the common electrode 110i is |+8V−(−8V)|, that is, 16 V. At this time, the scanning signal SG(1) including the potential LO is supplied to the scanning line 132a and the transistors 160c and 170c of the reflector unit cell 102c, and the transistors 160c and 170c are in the off state. Also, at this time, the common electrode 110c holds +16 V, which fluctuated due to coupling when the scanning signal SG(2) including the potential HI is supplied to the scanning line 132b, and the bias electrode 108c holds +8 V, which fluctuated due to coupling when the scanning signal SG(2) including the potential HI is supplied to the scanning line 132b. Meanwhile, the scanning signal SG(2) including the potential LO is supplied to the scanning line 132b and the transistors 160f and 170f of the reflector unit cell 102f, and the transistors 160f and 170f are in the off state. At this time, the common electrode 110f holds +8 V when the scanning signal SG(2) including the potential HI is supplied to the scanning line 132b, and the bias electrode 108f holds −4 V when the scanning signal SG(2) including the potential HI is supplied to the scanning line 132b. However, because the common electrode 110i is connected to the common electrode 110c and the common electrode 110f via the common electrode connection line 211c, −8 V is supplied to the common electrode 110c and the common electrode 110f. Therefore, the potential supplied to the common electrode 110c changes from +8 V to 0 V, and due to coupling between the common electrode 110c and the bias electrode 108c, the potential supplied to the bias electrode 108c changes from +16 V to +8 V (see FIGS. 16 and 19 ).As a result, the potential difference VLCc applied between the bias electrode 108c and the common electrode 110c can be maintained at 8 V. Furthermore, the potential supplied to the common electrode 110f fluctuates from +8 V to 0 V, and due to coupling between the common electrode 110f and the bias electrode 108f, the potential supplied to the bias electrode 108f fluctuates from −4 V to −12 V (see FIGS. 15 and 19). As a result, the potential difference VLCe applied between the bias electrode 108b and the common electrode 110b can be maintained at 12 V.

[0103] 12 to 19 as the driving method of the reflector unit cell 102. In addition, the driving method of the reflector unit cells 102 other than the reflector unit cells 102a, 102h, and 102i described here as the driving method of the reflector unit cells 102 includes the driving methods shown in FIGS.

[0104] As described above, in the radio wave reflecting device 200, the common electrodes of adjacent reflector unit cells are electrically connected along the direction in which the common wiring extends to form one common electrode group. Also, the driving method of the radio wave reflecting device 200, like the driving method of the radio wave reflecting device 100, includes supplying output signals of mutually inverted polarities to output signal lines connected to adjacent reflector unit cells, and supplying common signals of mutually inverted polarities to common wirings connected to adjacent reflector unit cells.

[0105] As a result, the radio wave reflecting device 200 can supply signals (potentials) of opposite polarity to the bias electrode 108 or the common electrode 110, and can maintain the potential difference between the common electrode and the bias electrode by coupling between the common electrode and the bias electrode. In other words, the radio wave reflecting device 200 can increase the potential difference between the bias electrode 108 and the common electrode 110 by coupling between the bias electrode 108 and the common electrode 110, and can increase the number of potential differences, compared to when signals (potentials) of opposite polarity are not supplied to the bias electrode 108 and the common electrode 110. Therefore, the radio wave reflecting device 100 can reflect radio waves in directions corresponding to many phases.

[0106] Third Embodiment A radio wave reflecting device 300 according to a third embodiment will be described with reference to FIGS. 20 and 21. FIG.

[0107] Fig. 20 is a circuit diagram showing the configuration of the radio wave reflecting device 300. Fig. 21 is a diagram showing an example of a timing chart for explaining a method of driving the radio wave reflecting device 300. Explanations of configurations that are the same as or similar to those in Figs. 1 to 19 will be omitted here.

[0108] Like radio wave reflecting device 100 and radio wave reflecting device 200, radio wave reflecting device 300 is a device that can control the direction of reflected radio waves by using a metasurface (reflector 320) that utilizes the change in dielectric constant due to the orientation state of liquid crystal.

[0109] On the other hand, the configuration of the reflector unit cell 302 of the radio wave reflecting device 300 (reflector 320) is different from the configurations of the reflector unit cell 102 of the radio wave reflecting device 100 (reflector 120) and the reflector unit cell 102 of the radio wave reflecting device 200 (reflector 220). More specifically, the configuration related to the transistor 370 of the reflector unit cell 302 is different from the configuration related to the transistor 170 included in the reflector unit cell 102 of the radio wave reflecting device 200 (reflector 220). Therefore, here, differences between the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 and the configuration of the reflector unit cell 102 of the radio wave reflecting device 200 will be explained, and similarities between the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 and the configuration of the reflector unit cell 102 of the radio wave reflecting device 200 will be explained as necessary.

[0110] The reflector unit cell 102 of the radio wave reflecting device 200 (reflector 220) includes one transistor 170 for each reflector unit cell 102, and the common electrodes 110 of three adjacent reflector unit cells along the direction in which the common wiring 111 extends are electrically connected to form one common electrode group 210.

[0111] On the other hand, in the reflector unit cell 302 of the radio wave reflecting device 300 (reflector 320), a transistor 370 corresponds to the transistor 170 included in the reflector unit cell 102 of the radio wave reflecting device 200 (reflector 220). One transistor 370 is provided for three reflector unit cells 302 adjacent to each other along the direction in which the common wiring 111 extends. The common electrodes 110 of the three reflector unit cells 302 adjacent to each other along the direction in which the common wiring 111 extends are electrically connected to form one common electrode group 310. In the example of the radio wave reflecting device 300 shown in FIG. 20 , the common electrodes of the three reflector unit cells are electrically connected to form one common electrode group 310, but the number of common electrodes that form the common electrode group 210 can be appropriately selected depending on the application, specifications, etc. of the radio wave reflecting device 300.

[0112] More specifically, for example, one transistor 370a is provided for each of three reflector unit cells 302a, 302d, and 302g that are adjacent along the direction in which the common wiring 111a extends. That is, the transistor 370a is provided in common to the three reflector unit cells 302a, 302d, and 302g. Furthermore, the common electrodes 110a, 110d, and 110g of the three reflector unit cells 302a, 302d, and 302g that are adjacent along the direction in which the common wiring 111a extends are electrically connected to each other to form one common electrode group 310a.

[0113] The transistor 370a includes a gate electrode 371a, a source electrode 373a, and a drain electrode 374a. The gate electrode 371a is connected to a common control line 332. The common control line 332 is supplied with a common control signal GCOM. The source electrode 373a is connected to a common wiring 111a. The drain electrode 374a is electrically connected to the common electrode group 310a (common electrodes 110a, 110d, and 110g) via a connection portion 315a. The connection portion 315a can be configured in the same manner as the connection portion 115a.

[0114] The transistors 370b and 370c have the same configuration as the transistor 370a and are therefore described as necessary. Note that the transistors 370b and 370c are connected to the common control line 332, just like the transistor 370a.

[0115] 20 or 21, transistors 370a to 370c are switching elements similar to transistor 170, and their switching (on and off) is controlled by a common control signal GCOM supplied to a common control line 332. For example, when a common control signal GCOM including a potential HI is supplied to the common control line 332 and transistors 370a to 370c, the transistors 370a to 370c are turned on at the same time, and the source electrodes and drain electrodes of the transistors 370a to 370c become conductive. As a result, the common signals SC(1) to SC(3) supplied to the corresponding common wirings 111a to 111c are supplied to the drain electrodes 374, i.e., the common electrode groups 310.

[0116] Note that the scanning signals SG(1) to SG(3) supplied corresponding to the scanning lines 132a to 132c, the output signals SS(1) to SS(3) supplied corresponding to the output signal lines 118a to 118c, and the common signals SC(1) to SS(3) supplied corresponding to the common wirings 111a to 111c are the same as those in the first or second embodiment. In addition, the driving method of each reflector unit cell in the third embodiment may be the same as that in the first and second embodiments, and the driving methods of the first and second embodiments can be changed as appropriate depending on the third embodiment.

[0117] As described above, in the radio wave reflecting device 300, the common electrodes of adjacent reflector unit cells along the direction in which the common wiring extends are electrically connected to form one common electrode group. One common electrode group is controlled by a transistor provided in common to adjacent reflector unit cells along the direction in which the common wiring extends. The provided transistor is connected to the common wiring. The radio wave reflecting device 300 can control the conduction between the common wiring and the common electrode group by the transistor provided in common to the reflector unit cells and connected to the common wiring, thereby reducing the number of transistors connected to the common wiring. As a result, the layout of the reflector (reflector unit cells) is simplified, the design of the radio wave reflecting device 300 is simplified, and complex processing in the manufacture of the radio wave reflecting device 300 is suppressed. Furthermore, the transistor connected to the common wiring can be controlled independently of the scanning line by a common control line that is different from the scanning line.

[0118] Fourth Embodiment A radio wave reflecting device 400 according to a fourth embodiment will be described with reference to FIGS.

[0119] Fig. 22 is a circuit diagram showing the configuration of the radio wave reflecting device 400. Fig. 23 is a diagram showing an example of a timing chart for explaining a method of driving the radio wave reflecting device 400.

[0120] Similar to the radio wave reflecting device 100, the radio wave reflecting device 400 is a device capable of controlling the direction of reflected radio waves by using a metasurface (reflector 420) that utilizes the change in dielectric constant due to the orientation state of liquid crystal.

[0121] On the other hand, the configuration of the reflector unit cell 402 of the radio wave reflecting device 400 is different from the configuration of the reflector unit cell 102 of the radio wave reflecting device 100. Therefore, here, differences from the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 will be explained, and similarities to the configuration of the reflector unit cell 102 of the radio wave reflecting device 100 will be explained as necessary.

[0122] 4-1. Overview of the Radio Wave Reflecting Device 400 An overview of the radio wave reflecting device 400 will be described with reference to Fig. 22. Descriptions of configurations that are the same as or similar to those in Figs. 1 to 21 will be omitted here.

[0123] The common electrode 110 included in the reflector unit cell 102 of the radio wave reflecting device 100 (reflector 120 ) is provided one for each reflector unit cell 102 .

[0124] On the other hand, in the reflector unit cell 402 of the radio wave reflecting device 400 (reflector 420), the common electrodes 110 included in the plurality of reflector unit cells 402 adjacent to each other in the direction in which the scanning lines 132 extend are electrically connected to each other to form one common electrode group 410. Furthermore, the common electrodes 110 included in the plurality of reflector unit cells 402 adjacent to each other in the direction in which the scanning lines 132 extend are electrically connected to one of the transistors 170 included in the plurality of reflector unit cells 402 adjacent to each other in the direction in which the scanning lines 132 extend. In the example of the radio wave reflecting device 400 shown in FIG. 22 , the common electrodes of three reflector unit cells are electrically connected to each other to form one common electrode group 410, and each common electrode of the three reflector unit cells is electrically connected to one of the transistors 170 included in the three reflector unit cells. However, the number of common electrodes constituting the common electrode group 410 and any one of the transistors 170 to which each common electrode is connected can be selected appropriately depending on the application and specifications of the radio wave reflecting device 400, etc.

[0125] More specifically, for example, the common electrodes 110a to 110c included in three reflector unit cells 402a to 402c adjacent to each other in the direction in which the scanning line 132a extends are electrically connected to each other using the common electrode connection line 411a to form one common electrode group 410a. Also, for example, the common electrodes 110d to 110f included in three reflector unit cells 402d to 402f adjacent to each other in the direction in which the scanning line 132b extends are electrically connected to each other using the common electrode connection line 411a to form one common electrode group 410a. That is, the common electrodes 110a to 110f included in the three reflector unit cells 402a to 402f are electrically connected to each other using the common electrode connection line 411a to form one common electrode group 410a.

[0126] Each of the common electrodes 110a to 110c included in three reflector unit cells 402a to 402c adjacent to each other in the direction in which the scanning line 132a extends is electrically connected to one transistor 170c among the transistors 170a to 170c included in each of the reflector unit cells 402a to 402c via a connection portion 415c. At this time, the transistor 170a is electrically connected to the common wiring 111a but is not connected to any of the common electrodes 110, and the transistor 170b is electrically connected to the common wiring 111b but is not connected to any of the common electrodes 110. Therefore, the common electrodes 110a to 110c are controlled by a scanning signal GS(1) supplied to the scanning line 132a and a common signal SC(3) supplied to the common wiring 111c.

[0127] Each of the common electrodes 110d-110f included in three reflector unit cells 402d-402f adjacent to each other in the direction in which the scanning line 132b extends is electrically connected to one transistor 170f among the transistors 170d-170f included in each of the reflector unit cells 402d-402f via a connection portion 415f. At this time, the transistor 170d is electrically connected to the common wiring 111a but is not connected to any of the common electrodes 110, and the transistor 170e is electrically connected to the common wiring 111b but is not connected to any of the common electrodes 110. Therefore, the common electrodes 110d-110f are controlled using the transistor 170f. More specifically, the common electrodes 110d-110f are controlled by a scanning signal GS(2) supplied to the scanning line 132b and a common signal SC(3) supplied to the common wiring 111c.

[0128] For example, the common electrodes 110g-110i included in three reflector unit cells 402g-402i adjacent to each other in the direction in which the scanning line 132c extends are electrically connected to each other using a common electrode connection line 411b to form one common electrode group 410b. The common electrodes 110g-110i included in three reflector unit cells 402g-402i adjacent to each other in the direction in which the scanning line 132c extends are electrically connected to one transistor 170h among the transistors 170g-170i included in each reflector unit cell 402g-402i via a connection portion 415h. In this case, the transistor 170g is electrically connected to the common wiring 111a but is not connected to any of the common electrodes 110, and the transistor 170i is electrically connected to the common wiring 111c but is not connected to any of the common electrodes 110. Therefore, the common electrodes 110g to 110i are controlled using the transistor 170f. More specifically, the common electrodes 110g to 110i are controlled by a scanning signal GS(3) supplied to the scanning line 132c and a common signal SC(2) supplied to the common wiring 111b.

[0129] The connection portions 415c, 415f, and 415h can be configured in the same manner as the connection portion 115a.

[0130] 22 and 23, an example of a method for driving the radio wave reflecting device 400 will be described. Descriptions of configurations that are the same as or similar to those in FIGS. 1 to 21 will be omitted here.

[0131] The scanning signals SG(1) to SG(3) supplied corresponding to the scanning lines 132a to 132c, the output signal SS(1) supplied corresponding to the output signal line 118a, and the common signal SC(1) supplied corresponding to the common wiring 111a are the same as the signals shown in Fig. 12. Also, as an example, the potential difference VLC between the bias electrode 108 and the common electrode 110 of each of the reflector unit cells 102a to 102i is supplied so as to have the value shown in Fig. 13, similar to the first embodiment.

[0132] First, a driving method in which a scanning signal SG(1) including a HI potential is supplied to the scanning line 132a will be described. The driving method of the radio wave reflecting device 400 in KthFRAME involves supplying a scanning signal SG(1) including a HI potential to the scanning line 132a. When the scanning signal SG(1) including a HI potential is supplied to the scanning line 132a, the transistors 160 of the reflector unit cells 102a to 102c are turned on, and an output signal SS(1) including a COM potential (0V) is supplied to the bias electrode 108a, an output signal SS(2) including a +4V is supplied to the bias electrode 108b, and an output signal SS(3) including a +8V is supplied to the bias electrode 108c. In other words, the output signal lines and bias electrodes connected to adjacent reflector unit cells are supplied with potentials of the same polarity. Furthermore, the transistor 170c is turned on, and the common signal SC(3) including the COM potential (0V) is supplied to the common electrodes 110a to 110c. As a result, the potential difference VLCa becomes 0V, VLCb becomes 4V, and VLCc becomes 8V.

[0133] Next, a driving method in which a scanning signal SG(2) including a potential HI is supplied to the scanning line 132b will be described. The driving method of the radio wave reflecting device 400 in KthFRAME includes supplying a scanning signal SG(2) including a potential HI to the scanning line 132a, and supplying a scanning signal SG(1) including a potential LO to the scanning line 132a. Based on the supply of the scanning signal SG(1) including the potential LO to the scanning line 132a, the transistors 160 of the reflector unit cells 102a to 102c are turned off, and the potential differences VLCa, VLCb, and VLCc are maintained at 0V, 4V, and 8V, respectively. Furthermore, when a scanning signal SG(2) including a potential HI is supplied to the scanning line 132b, the transistors 160 of the reflector unit cells 102d to 102f are turned on, an output signal SS(1) including a COM potential (0V) is supplied to the bias electrode 108d, an output signal SS(2) including -4V is supplied to the bias electrode 108e, and an output signal SS(3) including -8V is supplied to the bias electrode 108f. In other words, the output signal lines and bias electrodes connected to adjacent reflector unit cells are supplied with potentials of the same polarity. Furthermore, the transistor 170f is turned on, and a common signal SC(3) including +4V is supplied to the common electrodes 110d to 110f. As a result, the potential difference VLCd becomes 4 V (|0 V - (+4 V)|), VLCe becomes 8 V (|-4 V - (+4 V)|), and VLCf becomes 12 V (|-8 V - (+4 V)|).

[0134] Next, a driving method in which a scanning signal SG(3) including a potential HI is supplied to the scanning line 132c will be described. The driving method of the radio wave reflecting device 400 in KthFRAME includes supplying a scanning signal SG(3) including a potential HI to the scanning line 132a, supplying a scanning signal SG(1) including a potential LO to the scanning line 132a, and supplying a scanning signal SG(2) including a potential LO to the scanning line 132b. Based on the supply of the scanning signal SG(1) including the potential LO to the scanning line 132a, the transistors 160 of the reflector unit cells 102a to 102c are turned off, and the potential differences VLCa, VLCb, and VLCc are maintained at 0V, 4V, and 8V, respectively. Furthermore, when a scanning signal SG(2) including a potential LO is supplied to the scanning line 132b, the transistors 160 in the reflector unit cells 102d to 102f are turned off, and the potential differences VLCd, VLCe, and VLCc are maintained at 4 V, 8 V, and 12 V. Furthermore, when a scanning signal SG(3) including a potential HI is supplied to the scanning line 132c, the transistors 160 in the reflector unit cells 102g to 102i are turned on, and an output signal SS(1) including a COM potential (0 V) is supplied to the bias electrode 108g, an output signal SS(2) including +4 V is supplied to the bias electrode 108h, and an output signal SS(3) including +8 V is supplied to the bias electrode 108i. In other words, potentials of the same polarity are supplied to the output signal lines and bias electrodes connected to adjacent reflector unit cells. Furthermore, the transistor 170h is turned on, and a common signal SC(2) including −8 V is supplied to the common electrodes 110g to 110i. As a result, the potential difference VLCg becomes 8 V (|0 V − (−8 V)|), VLCh becomes 12 V (|+4 V − (−8 V)|), and VLCi becomes 16 V (|+8 V − (−8 V)|).

[0135] The driving method of the radio wave reflecting device 400 in the K+1st FRAME refers to the driving method described in the driving method of the radio wave reflecting device 400 in the Kth FRAME, and includes the driving methods as shown in FIGS.

[0136] As described above, in the radio wave reflecting device 400, the common electrodes 110 included in the plurality of reflector unit cells 402 adjacent to each other in the direction in which the scanning lines 132 extend are electrically connected to each other to form one common electrode group 410, and are also electrically connected to one of the transistors 170 included in the plurality of reflector unit cells 402 adjacent to each other in the direction in which the scanning lines 132 extend. Furthermore, in the driving method of the radio wave reflecting device 400, the signals supplied to the bias electrode and the common electrode of one reflector unit cell are signals with polarities inverted from each other, and the potentials supplied to the output signal line and the bias electrode connected to adjacent reflector unit cells are potentials with the same polarity. In other words, the driving method of the radio wave reflecting device 400 includes supplying the output signal supplied to the bias electrode of one reflector unit cell and the common signal supplied to the common electrode of the one reflector unit cell with polarities inverted from each other.

[0137] As a result, the radio wave reflecting device 400 can increase the potential difference provided between the bias electrode 108 and the common electrode 110 and can also increase the number of potential differences compared to when signals (potentials) with polarities inverted from each other are not supplied to the bias electrode 108 and the common electrode 110. Therefore, the radio wave reflecting device 100 can reflect radio waves in directions corresponding to many phases.

[0138] The various configurations of the radio wave reflecting device and the various configurations of the driving method of the radio wave reflecting device exemplified as one embodiment of the present invention can be combined as appropriate as long as they are not mutually contradictory. Furthermore, the various configurations of the radio wave reflecting device and the various configurations of the driving method of the radio wave reflecting device exemplified as one embodiment of the present invention can be interchanged as appropriate as long as they are not mutually contradictory. A radio wave reflecting device and a radio wave reflecting device driving method disclosed in this specification and drawings, to which a person skilled in the art appropriately adds, deletes, or modifies the design, or adds, omits, or modifies a process, is also included in the scope of the present invention as long as it maintains the gist of the present invention.

[0139] Even if there are other effects and advantages different from those brought about by the aspects of the embodiments disclosed in this specification, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention.

[0140] 91: first side, 92: second side, 93: third side, 94: fourth side, 100: radio wave reflecting device, 102: reflector unit cell, 102a: reflector unit cell, 102b: reflector unit cell, 102c: reflector unit cell, 102d: reflector unit cell, 102e: reflector unit cell, 102f: reflector unit cell, 102g: reflector unit cell, 102h: reflector unit cell, 102i: reflector unit cell, 103: circuit, 104: dielectric substrate, 104a: first surface, 106: opposing substrate, 106a: first surface, 108: bias electrode, 1 108a: bias electrode, 108b: bias electrode, 108c: bias electrode, 108d: bias electrode, 108e: bias electrode, 108f: bias electrode, 108g: bias electrode, 108h: bias electrode, 108i: bias electrode, 110: common electrode, 110a: common electrode, 110b: common electrode, 110c: common electrode, 110d: common electrode, 110e: common electrode, 110f: common electrode, 110g: common electrode, 110h: common electrode, 110i: common electrode, 111: common wiring, 111a: common wiring, 111b: common wiring, 1 11c: common wiring, 111d: common wiring, 111h: common wiring, 112a: alignment film, 112b: alignment film, 114: liquid crystal layer, 115: connection portion, 115a: connection portion, 116: liquid crystal molecules, 118: output signal line, 118a: output signal line, 118b: output signal line, 118c: output signal line, 118d: output signal line, 120: reflector, 120d: reflector unit cell, 120e: reflector unit cell, 120f: reflector unit cell, 122: peripheral region, 126: terminal portion, 128: sealing material, 130: IC chip, 132: scanning line, 132a: scanning line, 132b : scanning line, 132c: scanning line, 132d: scanning line, 134: switching element, 134a: switching element, 134b: switching element, 134c: switching element, 134d: switching element, 136: switching element, 136a: switching element, 136b: switching element, 136c: switching element, 136d: switching element, 142: semiconductor layer, 142a: semiconductor layer, 142b: semiconductor layer, 160: transistor, 160a: transistor, 160b: transistor, 160c: transistor, 160d: transistor,160e: transistor, 160f: transistor, 160g: transistor, 160h: transistor, 160i: transistor, 161: gate electrode, 163: source electrode, 163a: contact hole, 164: drain electrode, 164a: contact hole, 170: transistor, 170a: transistor, 170b: transistor, 170c: transistor, 170d: transistor, 170e: transistor, 170f: transistor, 170g: transistor, 170 h: transistor, 170i: transistor, 171: gate electrode, 173: source electrode, 173a: contact hole, 174: drain electrode, 180: array layer, 200: radio wave reflecting device, 210: common electrode group, 210a: common electrode group, 210b: common electrode group, 210c: common electrode group, 211a: common electrode connecting line, 211b: common electrode connecting line, 211c: common electrode connecting line, 220: reflector, 300: radio wave reflecting device, 302: reflector unit cell, 302a: reflector unit 302d: reflector unit cell, 302g: reflector unit cell, 310: common electrode group, 310a: common electrode group, 315a: connection portion, 320: reflector, 332: common control line, 370: transistor, 370a: transistor, 370b: transistor, 370c: transistor, 371a: gate electrode, 373a: source electrode, 374: drain electrode, 374a: drain electrode, 400: radio wave reflecting device, 402: reflector unit cell, 402a: reflector unit cell, 402b: reflector unit cell, 402c: reflector unit cell, 402d: reflector unit cell, 402e: reflector unit cell, 402f: reflector unit cell, 402g: reflector unit cell, 402h: reflector unit cell, 402i: reflector unit cell, 410: common electrode group, 410a: common electrode group, 410b: common electrode group, 411a: common electrode connecting line, 411b: common electrode connecting line, 415c: connecting portion, 415f: connecting portion, 415h: connecting portion, 420: reflector,

Claims

1. A driving method of a radio wave reflection device including a reflection plate unit cell having a first electrode, a second electrode provided opposite to and spaced apart from the first electrode, and a liquid crystal layer provided between the first electrode and the second electrode, and configured to be able to control the traveling direction of the reflected radio wave, the method comprising: applying a first potential to the first electrode; and applying a second potential having a polarity different from that of the first potential to the second electrode.

2. The driving method of the radio wave reflection device according to claim 1, including turning on a first switching element connected to the first electrode and a second switching element connected to the second electrode at the same timing.

3. The driving method of the radio wave reflection device according to claim 1, wherein the potential difference between the first potential and the second potential is not more than twice the absolute value of the difference between the first potential and a reference potential, or not more than twice the absolute value of the difference between the second potential and the reference potential, with the reference potential between the first potential and the second potential as a reference.

4. The driving method includes a first radio wave reflection period and a second radio wave reflection period, and the polarities of the potentials supplied to the first electrode and the second electrode in the second radio wave reflection period are reversed from the polarities of the potentials supplied to the first electrode and the second electrode in the first radio wave reflection period.

5. The driving method of the radio wave reflection device according to claim 1, wherein the thickness of the liquid crystal layer is 30 μm or more and less than 40 μm.

6. A driving method of a radio wave reflection device including a plurality of reflection plate unit cells provided in an m-row and n-column (m and n are integers of 2 or more) matrix, each of the plurality of reflection plate unit cells including a first electrode, a second electrode provided opposite to and spaced apart from the first electrode, and a liquid crystal layer provided between the first electrode and the second electrode, and configured to be able to control the traveling direction of the reflected radio wave, the method comprising: applying a first potential to the first electrode of the reflection plate unit cell at the (m - 1)th row and (n - 1)th column; and applying a second potential having a polarity different from that of the first potential to a first electrode group to which the second electrodes of the plurality of reflection plate unit cells in the n - 1th column are connected.

7. Apply a third potential having a polarity different from that of the first potential to the first electrode of the reflector unit cell at the (m - 1)-th row and n-th column, and apply a fourth potential having a polarity different from that of the third potential to a second electrode group to which the second electrodes of a plurality of reflector unit cells in the n-th column are connected. The driving method of the radio wave reflection device according to claim 6 includes this.

8. Turn on or off the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the (m - 1)-th row at the same timing, turn on or off the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the m-th row at the same timing. When the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the (m - 1)-th row are in the on state, turn off the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the m-th row. When the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the (m - 1)-th row are in the off state, turn on the first switching element connected to the first electrode and the second switching element connected to the second electrode of the reflector unit cell at the m-th row. The driving method of the radio wave reflection device according to claim 7 includes this.

9. Apply a fifth potential having a polarity different from that of the third potential to the first electrode of the reflector unit cell at the m-th row and n-th column, and apply a sixth potential having a polarity different from that of the fourth potential to the second electrode group. The driving method of the radio wave reflection device according to claim 8 includes this.

10. When the sixth potential is applied to the second electrode group, the potential of the second electrode of the reflector unit cell at the (m - 1)-th row and n-th column varies from the fourth potential to the sixth potential. Based on the fact that the potential of the second electrode of the reflector unit cell at the (m - 1)-th row and n-th column varies from the fourth potential to the sixth potential, the potential of the first electrode of the reflector unit cell at the (m - 1)-th row and n-th column varies from the third potential to the sixth potential. The driving method of the radio wave reflection device according to claim 9 includes this.

11. Turning on or off the second switching element connected to the first electrode group and the second switching element connected to the second electrode group at the same timing, which is included in the driving method of the radio wave reflection device according to claim 7.

12. When the second switching element connected to the first electrode group and the second switching element connected to the second electrode group are in the on state, turning on the first switching element connected to the first electrode of the reflector unit cell at the (m - 1)th row and (n - 1)th column and turning off the first switching element connected to the first electrode of the reflector unit cell at the (m - 1)th row and nth column; when the second switching element connected to the first electrode group and the second switching element connected to the second electrode group are in the on state, turning off the first switching element connected to the first electrode of the reflector unit cell at the (m - 1)th row and (n - 1)th column and turning on the first switching element connected to the first electrode of the reflector unit cell at the (m - 1)th row and nth column, which is included in the driving method of the radio wave reflection device according to claim 11.

13. The potential difference between the first potential and the second potential is not more than twice the absolute value of the difference between the first potential and the reference potential or not more than twice the absolute value of the difference between the second potential and the reference potential, with the reference potential between the first potential and the second potential as a reference, which is the driving method of the radio wave reflection device according to claim 6.

14. The driving method includes a first radio wave reflection period and a second radio wave reflection period. The polarities of the potentials supplied to the first electrode and the second electrode of the reflector unit cell at the (m - 1)th row and (n - 1)th column in the second radio wave reflection period are reversed from the polarities of the potentials supplied to the first electrode and the second electrode of the reflector unit cell at the (m - 1)th row and (n - 1)th column in the first radio wave reflection period, which is the driving method of the radio wave reflection device according to claim 6.

15. The thickness of the liquid crystal layer is 30 μm or more and less than 40 μm, which is the driving method of the radio wave reflection device according to claim 6.

16. A driving method for a radio wave reflection device including a plurality of reflector unit cells provided in a matrix of m rows and n columns (m and n are integers of 2 or more), each of the plurality of reflector unit cells including a first electrode, a second electrode facing the first electrode and provided spaced apart from the first electrode, and a liquid crystal layer provided between the first electrode and the second electrode, and configured to be able to control the traveling direction of the reflected radio wave, the method comprising: applying a first potential to the first electrode of the reflector unit cell at the (m - 1)th row and (n - 1)th column; and applying a second potential having a polarity different from that of the first potential to a first electrode group to which the second electrodes of the plurality of reflector unit cells in the (m - 1)th row are connected.

17. The driving method for a radio wave reflection device according to claim 16, further comprising applying a third potential having the same polarity as the first potential to the first electrode of the reflector unit cell at the (m - 1)th row and nth column.

18. The driving method for a radio wave reflection device according to claim 17, further comprising turning on or off a first switching element connected to the first electrode of the reflector unit cell in the (m - 1)th row and a second switching element connected to the first electrode group at the same timing.

19. The potential difference between the first potential and the second potential is not more than twice the absolute value of the difference between the first potential and a reference potential, or not more than twice the absolute value of the difference between the second potential and the reference potential, based on the reference potential between the first potential and the second potential, in the driving method for a radio wave reflection device according to claim 16.

20. The thickness of the liquid crystal layer is 30 μm or more and less than 40 μm, in the driving method for a radio wave reflection device according to claim 16.

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