Control device, control method, and light control glass system

Abstract

To suppress radiation noise radiated from a dimming glass.SOLUTION: The control device includes a control unit that generates a sampling signal having a predetermined sampling frequency, a waveform generation unit that generates a drive signal having a predetermined drive frequency to be output to the plurality of segments of the light control glass according to the sampling frequency, and an output unit that outputs the drive signal to the plurality of segments. The waveform generation unit makes center frequencies of the drive signals output to the plurality of segments different from each other.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a control method, and a light control glass system. [Background technology]

[0002] In recent years, glass equipped with a light-control film that can switch the light transmission state by applying an electric field has been developed. For example, Patent Document 1 describes a composite pane that is divided into multiple segments and can be controlled individually. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7137702 Summary of the Invention [Problem to be solved by the invention]

[0004] In light-control glass divided into multiple segments, wiring for applying voltage is connected to each segment, and each segment may share a common ground. In such light-control glass, it is necessary to suppress the radiation noise emitted from the light-control glass.

[0005] An object of the present disclosure is to provide a control device, a control method, and a light control glass system that can suppress radiation noise emitted from light control glass. [Means for solving the problem]

[0006] The control device of the present disclosure includes a control unit that generates a sampling signal having a predetermined sampling frequency, a waveform generation unit that generates a drive signal having a predetermined drive frequency to be output to multiple segments of light-controlling glass in accordance with the sampling frequency, and an output unit that outputs the drive signals to the multiple segments, and the waveform generation unit varies the center frequency of each of the drive signals output to the multiple segments.

[0007] The control method disclosed herein generates a sampling signal having a predetermined sampling frequency, generates drive signals having a predetermined drive frequency for output to multiple segments of light-controlling glass in accordance with the sampling frequency, outputs the drive signals to the multiple segments, and makes the center frequencies of the drive signals output to the multiple segments different.

[0008] The light control glass system of the present disclosure includes the control device of the present disclosure and light control glass having a plurality of segments, the light control state of which is controlled by the control device. [Effects of the Invention]

[0009] According to the present disclosure, radiation noise emitted from light control glass can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a light control glass according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of a cross section of the light control glass according to the embodiment. [Figure 3] FIG. 3 is a diagram for explaining dimming control according to a comparative example of the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the first drive signal and the second drive signal according to the comparative example. [Figure 5] FIG. 5 is a diagram for explaining the dimming control according to the embodiment. [Figure 6]FIG. 6 is a diagram for explaining the drive signal and the reference potential according to the embodiment. [Figure 7] FIG. 7 is a block diagram showing a light control glass system according to an embodiment. [Figure 8] FIG. 8 is a diagram for explaining a method for controlling a light control glass system according to an embodiment. [Figure 9] FIG. 9 is a diagram for explaining the center frequency of the drive signal output to each segment according to the embodiment. [Figure 10] FIG. 10 is a flowchart showing the flow of the drive signal control process according to the first method of the embodiment. [Figure 11] FIG. 11 is a diagram showing drive signals input to each segment according to the embodiment. [Figure 12] FIG. 12 is a diagram for explaining noise levels according to the embodiment. [Figure 13] FIG. 13 is a diagram for explaining a method for controlling the frequency band of a drive signal according to the embodiment. [Figure 14] FIG. 14 is a flowchart showing the flow of the drive signal control process according to the second method of the embodiment. [Figure 15] FIG. 15 is a diagram for explaining a method for modulating a drive frequency according to another embodiment. [Figure 16] FIG. 16 is a diagram for explaining a method for randomly modulating a drive frequency according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0012] (Light-adjustable glass) FIG. 1 is a schematic diagram of a photochromic glass according to an embodiment. The photochromic glass 10 is, for example, laminated glass for a vehicle. The photochromic glass 10 can be applied to, for example, a vehicle roof, rear window, side window, door glass, quarter glass, extra glass, windshield, etc. The extra glass is glass attached to the rear side of a vehicle to improve the rearward visibility of the driver. The vehicle here is typically an automobile, but refers to any moving body having glass, including a train, ship, aircraft, etc. However, the use of the photochromic glass 10 is not limited to vehicles.

[0013] The light control glass 10 is configured so that the light control state can be controlled. Examples of the light control state include haze and visible light transmittance. In the following example, the light control glass 10 is configured so that it can be switched between two different states, but the light control state may be changed in three or more stages. In the following example, the two different states are described as a "transparent state" and a "light-blocking state," but the haze and visible light transmittance can be set (adjusted) as needed. The "transparent state" is, for example, a state in which the haze is so small that light is hardly scattered and the opposite side of the light control glass 10 can be seen. The "light-blocking state" is a state in which the haze is so large that light is strongly scattered and the opposite side of the light control glass 10 cannot be seen. However, the present invention is not limited to these. For example, when a light-controlling film with variable visible light transmittance is used, the "transparent state" may be a state in which the visible light transmittance is high enough that almost no light is absorbed and the opposite side of the light-controlling glass 10 can be seen, and the "light-blocking state" may be a state in which the visible light transmittance is low enough that light is strongly absorbed and the opposite side of the light-controlling glass 10 cannot be seen.

[0014] The switchable glass 10 has, for example, a first segment 11, a second segment 12, a third segment 13, a fourth segment 14, a fifth segment 15, a sixth segment 16, a seventh segment 17, and an eighth segment 18. The switchable glass 10 is formed so that the transparent state and the light-blocking state of the first segment 11 to the eighth segment 18 can be controlled independently. That is, the switchable light-control region of the switchable light-control region 10, which can be switched between the transparent state and the light-blocking state, is divided into multiple regions. In the example shown in FIG. 1 , the switchable glass 10 is divided into eight regions, the first segment 11 to the eighth segment 18, but the present disclosure is not limited to this. The switchable glass 10 can be divided into, for example, 2 to 20 switchable regions.

[0015] Fig. 2 is a schematic diagram of a cross section of a light control glass according to an embodiment. Fig. 2 shows an AA cross section of the light control glass 10 shown in Fig. 1. As shown in Fig. 2, the light control glass 10 has a first glass plate 21, a second glass plate 22, a first interlayer film 23, a second interlayer film 24, and a light control film 25.

[0016] The first glass plate 21 is a glass plate that forms one surface of the light control glass 10. The shape and material of the first glass plate 21 may be arbitrary. The second glass plate 22 is a glass plate that forms the other surface of the light control glass 10. The shape and material of the second glass plate 22 may be arbitrary.

[0017] The first interlayer film 23 is located between the first glass plate 21 and the light control film 25. The first interlayer film 23 is an adhesive layer that bonds the first glass plate 21 and the light control film 25 together. The second interlayer film 24 is located between the second glass plate 22 and the light control film 25. The second interlayer film 24 is an adhesive layer that bonds the second glass plate 22 and the light control film 25 together.

[0018] The light control film 25 includes, for example, a PDLC (Polymer Dispersed Liquid Crystal) film. For example, the light control film 25 has a structure in which a PDLC layer is sandwiched between two PET films with an ITO (Indium Tin Oxide) electrode formed on one main surface. The light control film 25 is configured to be switchable between a transparent state and a light-blocking state by applying a voltage. However, this is not limited to this, and light control films driven by AC voltage, such as SPD (Suspended Particle Device) and GHLC (Guest Host Liquid Crystal), may also be used. In the present disclosure, the ITO electrode is divided into multiple segments, so that the light control glass 10 has multiple segments. Specifically, by applying a voltage to the divided ITO electrodes, the light control film 25 in that region can be partially switched between a transparent state and a light-blocking state. This allows the transparent state and the light-blocking state of the first segment 11 to the eighth segment 18 of the light control glass 10 to be independently controlled. However, the method of dividing the segments is not limited to this.

[0019] [Dimming control] (Comparative Example) Before describing this embodiment, a comparative example of this embodiment will be described. Fig. 3 is a diagram for explaining dimming control according to the comparative example of this embodiment.

[0020] As shown in FIG. 3, in the comparative example, electrodes are connected to each segment in order to independently control the dimming state of the first segment 11 to the eighth segment 18.

[0021] One end of the first electrode 31 and one end of the second electrode 41 are connected to the first segment 11. A first drive signal and a second drive signal for controlling the dimming state of the first segment 11 are input from the other end of the first electrode 31 and the other end of the second electrode 41, respectively.

[0022] One end of the first electrode 32 and one end of the second electrode 42 are connected to the second segment 12. A first drive signal and a second drive signal for controlling the dimming state of the second segment 12 are input from the other end of the first electrode 32 and the other end of the second electrode 42, respectively.

[0023] One end of the first electrode 33 and one end of the second electrode 43 are connected to the third segment 13. A first drive signal and a second drive signal for controlling the dimming state of the third segment 13 are input from the other end of the first electrode 33 and the other end of the second electrode 43, respectively.

[0024] One end of the first electrode 34 and one end of the second electrode 44 are connected to the fourth segment 14. A first drive signal and a second drive signal for controlling the dimming state of the fourth segment 14 are input from the other end of the first electrode 32 and the other end of the second electrode 42, respectively.

[0025] One end of the first electrode 35 and one end of the second electrode 45 are connected to the fifth segment 15. A first drive signal and a second drive signal for controlling the dimming state of the fifth segment 15 are input from the other end of the first electrode 35 and the other end of the second electrode 45, respectively.

[0026] One end of the first electrode 36 and one end of the second electrode 46 are connected to the sixth segment 16. A first drive signal and a second drive signal for controlling the dimming state of the sixth segment 16 are input from the other end of the first electrode 36 and the other end of the second electrode 46, respectively.

[0027] One end of the first electrode 37 and one end of the second electrode 47 are connected to the seventh segment 17. A first drive signal and a second drive signal for controlling the dimming state of the seventh segment 17 are input from the other end of the first electrode 37 and the other end of the second electrode 47, respectively.

[0028] One end of the first electrode 38 and one end of the second electrode 48 are connected to the eighth segment 18. A first drive signal and a second drive signal for controlling the dimming state of the eighth segment 18 are input from the other end of the first electrode 38 and the other end of the second electrode 48, respectively.

[0029] 4 is a diagram illustrating a first drive signal and a second drive signal according to a comparative example. As shown in FIG. 4, the first drive signal S1 and the second drive signal S2 are AC signals of opposite phases. That is, the first drive signal S1 and the second drive signal S2 are differential signals.

[0030] (Embodiment) Fig. 5 is a diagram for explaining dimming control according to an embodiment. As shown in Fig. 5, in the embodiment, an electrode to which a drive signal is input is connected to each segment, and a reference potential (for example, ground) is shared among the segments. In the embodiment, by sharing the reference potential among the segments, the number of electrodes can be reduced, which is advantageous for miniaturization.

[0031] One end of an electrode 51 is connected to the first segment 11. A drive signal for controlling the dimming state of the first segment 11 is input from the other end of the electrode 51.

[0032] One end of an electrode 52 is connected to the second segment 12. A drive signal for controlling the dimming state of the second segment 12 is input from the other end of the electrode 52.

[0033] One end of an electrode 53 is connected to the third segment 13. A drive signal for controlling the dimming state of the third segment 13 is input from the other end of the electrode 53.

[0034] One end of an electrode 54 is connected to the fourth segment 14. A drive signal for controlling the dimming state of the fourth segment 14 is input from the other end of the electrode 54.

[0035] One end of an electrode 55 is connected to the fifth segment 15. A drive signal for controlling the dimming state of the fifth segment 15 is input from the other end of the electrode 55.

[0036] One end of an electrode 56 is connected to the sixth segment 16. A drive signal for controlling the dimming state of the sixth segment 16 is input from the other end of the electrode 56.

[0037] One end of an electrode 57 is connected to the seventh segment 17. A drive signal for controlling the dimming state of the seventh segment 17 is input from the other end of the electrode 57.

[0038] One end of an electrode 58 is connected to the eighth segment 18. A drive signal for controlling the dimming state of the eighth segment 18 is input from the other end of the electrode 58.

[0039] One end of a common ground electrode 60 is connected to the first segment 11 to the eighth segment 18, and the other end is connected to the reference potential layer.

[0040] 6 is a diagram illustrating a drive signal and a reference potential according to an embodiment. As shown in FIG. 6, the drive signal S3 is an AC signal. The reference potential S4 indicates the signal level of the reference potential connected to the ground electrode 60.

[0041] In the embodiment, the drive signal input to each segment is a single-ended output. Therefore, while a differential signal cancels out the in-phase noise signals contained in the positive and negative signals, the embodiment does not achieve the noise signal cancellation effect of a differential signal, which may increase radiated noise. Because the light control glass 10 is constructed by covering the light control film 25 with the first glass plate 21 and the second glass plate 22, the reference potential layer is prone to emitting noise. Therefore, in the embodiment, radiated noise is suppressed by controlling the drive signal output to each segment of the light control glass 10.

[0042] (dimming glass system) Fig. 7 is a block diagram showing a light control glass system according to an embodiment. As shown in Fig. 7, the light control glass system 1 includes a light control glass 10, a power source 100, and a control device 120. The light control glass system 1 according to the present disclosure is mounted on, for example, a vehicle.

[0043] 8 is a diagram for explaining a method for controlling the light control glass system according to the embodiment. The light control glass system 1 is directly controlled by a higher-level control module including a body control module (BCM) 1100 that controls electrical components of the vehicle including lights.

[0044] The power supply 100 outputs a predetermined output voltage to the booster 110 of the control device 120. The output voltage output by the power supply 100 is, for example, DC 12V, but is not limited to this.

[0045] The control device 120 generates a drive signal for controlling the dimming state of the light control glass 10. The control device 120 controls the timing of outputting the drive signal to the light control glass 10. The control device 120 includes, for example, an information processing device such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The control device 120 may be realized by a combination of hardware and software.

[0046] The control device 120 includes a booster unit 110 , a control unit 121 , a waveform generator 122 , and an output unit 123 .

[0047] The boost unit 110 boosts the input voltage from the power supply 100 and outputs it to the control device 120. For example, the boost unit 110 boosts an input voltage of DC 12V to DC 80V and outputs it to the control device 120, but is not limited to this.

[0048] The control unit 121 controls the waveform generation unit 122 to generate a drive signal to be output to the light control glass 10. The control unit 121 outputs a sampling signal having a predetermined sampling frequency to the waveform generation unit 122. The sampling signal is, for example, a PWM (Pulse Width Modulation) signal. For example, the control unit 121 is configured to output, for example, four PWM signals simultaneously.

[0049] The waveform generating unit 122 generates a drive signal for controlling the dimming state of the light control glass 10. The waveform generating unit 122 determines the period, pulse width, and the like based on the PWM signal input from the control unit 121 to generate the drive signal. For example, the waveform generating unit 122 varies the center frequency of each drive signal output to the multiple segments.

[0050] The output unit 123 outputs a drive signal to each segment of the light control glass 10. Specifically, the output unit 123 outputs a drive signal to the light control film 25 of each segment of the light control glass 10. The output unit 123 controls the drive signal output to each segment of the light control glass 10. The output unit 123 outputs drive signals with different center frequencies to each segment of the light control glass 10.

[0051] [Drive signal control processing] (1st method) A drive signal control process according to a first method of the embodiment will be described. For example, if the center frequency of a drive signal input to a certain segment overlaps with the center frequency of a drive signal input to another segment, ringing may occur, potentially increasing radiation noise. Therefore, the waveform generation unit 122 generates drive signals to be output to multiple segments so that the center frequency of a drive signal input to a certain segment does not overlap with the center frequency of a drive signal input to another segment. For example, if the center frequency of a reference signal among the multiple drive signals is X kHz, the waveform generation unit 122 shifts the center frequencies of the drive signals output to the multiple segments by X × 0.2 × 2 kHz. In this case, it is preferable that the center frequency of a drive signal input to a certain segment does not overlap with the center frequencies of drive signals input to another segment. For example, if the drive frequency of a reference signal among the multiple drive signals is X kHz, the waveform generation unit 122 preferably shifts the center frequencies of the drive signals output to the multiple segments by 21 kHz.

[0052] 9 is a diagram illustrating the center frequencies of the drive signals output to each segment according to the embodiment. The management table TB1 shown in FIG. 9 shows the center frequencies of the drive signals output to the first segment 11 to the eighth segment 18, which are 1x (reference signal) to 20x (reference signal).

[0053] For example, when the drive signal is multiplied by 1, a drive signal with a center frequency of 100 kHz is input to the first segment 11. A drive signal with a center frequency of 121 kHz is input to the second segment 12. A drive signal with a center frequency of 142 kHz is input to the third segment 13. A drive signal with a center frequency of 163 kHz is input to the fourth segment 14. A drive signal with a center frequency of 184 kHz is input to the fifth segment 15. A drive signal with a center frequency of 205 kHz is input to the sixth segment 16. A drive signal with a center frequency of 226 kHz is input to the seventh segment 17. A drive signal with a center frequency of 247 kHz is input to the eighth segment 18. In other words, drive signals with center frequencies shifted by 21 kHz toward the higher band are input to the first segment 11 to the eighth segment 18, respectively. In this case, as shown in Figure 9, the center frequencies of the drive signals that can be input to each segment are unique values ​​from 1 to 20 times higher, so they do not overlap. This reduces the effects of ringing, and therefore radiation noise.

[0054] 9 shows an example in which the center frequencies of the drive signal multiplied by 1 to 20 do not overlap, but the present disclosure is not limited to this. In the present disclosure, it is sufficient that the center frequencies of the drive signals input to each segment are shifted so that the center frequencies of the drive signals multiplied by 1 to 10 do not overlap, for example.

[0055] FIG. 10 is a flowchart showing the flow of the drive signal control process according to the first method of the embodiment.

[0056] The control unit 121 outputs a sampling signal having a predetermined sampling period to the waveform generation unit 122 (step S100). The waveform generation unit 122 generates a drive signal for controlling the dimming state of the light control glass 10 based on the sampling signal input from the waveform generation unit 122 (step S102). The waveform generation unit 122 varies the center frequencies of the generated drive signals (step S104). The output unit 123 outputs the drive signals having different center frequencies to each segment (step S106).

[0057] (Second method) A drive signal control process according to a second method of the embodiment will now be described. Fig. 11 is a diagram showing the drive signals input to each segment according to the embodiment. In Fig. 11, the horizontal axis represents frequency and the vertical axis represents signal level. Fig. 11 shows a first drive signal S11, a second drive signal S12, a third drive signal S13, a fourth drive signal S14, a fifth drive signal S15, a sixth drive signal S16, a seventh drive signal S17, and an eighth drive signal S18.

[0058] The first drive signal S11 is a drive signal input to the first segment 11. The second drive signal S12 is a drive signal input to the second segment 12. The third drive signal S13 is a drive signal input to the third segment 13. The fourth drive signal S14 is a drive signal input to the fourth segment 14. The fifth drive signal S15 is a drive signal input to the fifth segment 15. The sixth drive signal S16 is a drive signal input to the sixth segment 16. The seventh drive signal S17 is a drive signal input to the seventh segment 17. The eighth drive signal S18 is a drive signal input to the eighth segment 18.

[0059] The first drive signal S11 and the second drive signal S12 overlap in a portion of the frequency band. The second drive signal S12 and the third drive signal S13 overlap in a portion of the frequency band. The third drive signal S13 and the fourth drive signal S14 overlap in a portion of the frequency band. The fourth drive signal S14 and the fifth drive signal S15 overlap in a portion of the frequency band. The fifth drive signal S15 and the sixth drive signal S16 overlap in a portion of the frequency band. The sixth drive signal S16 and the seventh drive signal S17 overlap in a portion of the frequency band. The seventh drive signal S17 and the eighth drive signal S18 overlap in a portion of the frequency band.

[0060] FIG. 12 is a diagram illustrating noise levels according to an embodiment. In FIG. 12, the horizontal axis represents frequency and the vertical axis represents noise level. Waveform 81 represents the noise level that may be generated in the light-controlling glass 10 when the drive signals shown in FIG. 11 are input to the segments of the light-controlling glass 10. Line L2 represents the noise threshold. The noise generated in the light-controlling glass 10 is required to be less than line 82. As shown in FIGS. 11 and 12, it is expected that the noise level will be high in areas where the frequency bands of the drive signals overlap. Peak value P1 represents the noise level in the frequency band where the first drive signal S11 and the second drive signal S12 overlap. Peak value P2 represents the noise level in the frequency band where the second drive signal S12 and the third drive signal S13 overlap. Peak value P3 represents the noise level in the frequency band where the third drive signal S13 and the fourth drive signal S14 overlap. The peak value P4 indicates the noise level of the frequency band where the fourth drive signal S14 and the fifth drive signal S15 overlap. The peak value P5 indicates the noise level of the frequency band where the fifth drive signal S15 and the sixth drive signal S16 overlap. The peak value P6 indicates the noise level of the frequency band where the sixth drive signal S16 and the seventh drive signal S17 overlap. The peak value P7 indicates the noise level of the frequency band where the seventh drive signal S17 and the eighth drive signal S18 overlap.

[0061] 12, peak values ​​P1 to P7 exceed line 82. In this case, the waveform generating section 122 controls at least one of the center frequencies and spreading factors of the first drive signal S11 to the eighth drive signal S18 as a control parameter so that peak values ​​P1 to P7 are less than line 82.

[0062] For example, the waveform generating unit 122 may control at least one of the center frequencies and spreading rates of the first drive signal S11 to the eighth drive signal S18 as control parameters so that the frequency bands of the first drive signal S11 to the eighth drive signal S18 do not overlap.

[0063] FIG. 13 is a diagram illustrating a method for controlling the frequency band of a drive signal according to an embodiment. FIG. 13 illustrates the first drive signal S11 to the fourth drive signal S14. FIG. 13 illustrates an example of the first drive signal S11 to the fourth drive signal S14 when only the first segment 11 to the fourth segment 14 are used among the first segment 11 to the eighth segment 18. In this case, as shown in FIG. 13, the waveform generation unit 122 preferably controls at least one of the center frequencies and the spreading factors of the first drive signal S11 to the fourth drive signal S14 as control parameters so that the frequency bands of the first drive signal S11 to the fourth drive signal S14 do not overlap. When using only four drive signals such as the first drive signal S11 to the fourth drive signal S14, even if the frequency bands of the drive signals are controlled so as not to overlap, the frequency bands used do not become too wide toward the high frequency side. This prevents the center frequency of a drive signal input to one segment from overlapping with the center frequency of a drive signal input to another segment. This makes it possible to reduce radiation noise.

[0064] FIG. 14 is a flowchart showing the flow of the drive signal control process according to the second method of the embodiment.

[0065] The processes from step S200 to step S204 are the same as the processes from step S100 to step S104 shown in FIG. 10, respectively, and therefore will not be described again.

[0066] The waveform generating unit 122 determines whether the frequency bands of the drive signals input to each segment overlap (step S206). If it is determined that the frequency bands overlap (step S206; Yes), the process proceeds to step S208. If it is determined that the frequency bands do not overlap (step S206; No), the process proceeds to step S212.

[0067] If the determination in step S206 is Yes, the waveform generating unit 122 determines whether the noise level of the noise signal included in the drive signal is equal to or greater than a threshold (step S208). If it is determined that the noise level is equal to or greater than the threshold (step S208; Yes), the process proceeds to step S210. If it is not determined that the noise level is equal to or greater than the threshold (step S208; No), the process proceeds to step S212.

[0068] If the determination in step S208 is Yes, the waveform generating unit 122 controls at least one of the center frequency and the spreading factor of each drive signal so that the noise level becomes less than the threshold (step S210), and then proceeds to step S212.

[0069] The process of step S212 is the same as the process of step S106 shown in FIG. 10, and therefore a description thereof will be omitted.

[0070] [Other embodiments] Other embodiments will be described. FIG. 15 is a diagram illustrating a method for modulating a drive frequency according to other embodiments. In other embodiments, the waveform generation unit 122 may randomly modulate the drive frequency of the first drive signal S11. Specifically, the waveform generation unit 122 performs spread spectrum frequency modulation (SSFM) on the drive signal S21 to spread the drive frequency to a low frequency range like drive signal S22 or to a high frequency range like drive signal S23. The waveform generation unit 122 randomly modulates the drive frequency of the drive signal S21, for example, by spreading the drive frequency within a range of ±20% around the drive frequency of the drive signal S21. By spreading the drive frequency band of the drive signal S21 over a wide band, the noise signal included in the drive signal S21 is also spread over a wide band. As a result, this embodiment can reduce the noise level of a noise signal in a specific frequency range, thereby reducing radiated noise.

[0071] The drive frequency may be, for example, in the range of 50 kHz to 60 kHz. If the drive frequency is lower than a certain level, flickering may occur in the light control glass 10, which may adversely affect the user's visibility. Therefore, it is preferable that the waveform generating unit 122 modulates the drive frequency to a higher frequency band. By modulating the drive frequency to a higher frequency band by the waveform generating unit 122, the occurrence of flickering can be suppressed.

[0072] FIG. 16 is a diagram illustrating a method for randomly modulating a drive frequency according to another embodiment. Management table TB2 is a table for managing the drive frequency after modulation of the drive frequency of drive signal S21. In management table TB2, No. 1 to No. 20 are associated with "frequencies" f#1 to f#20, respectively. In management table TB2, "frequency" is conceptually shown as, for example, f#1, but in reality, a specific drive frequency is shown. f#1 to f#20 indicate drive frequencies within a range of ±20% around the frequency of drive signal S21, for example. Management table TB2 is stored, for example, in a storage device (not shown) of control device 120.

[0073] When modulating the drive frequency of the first drive signal S11, the waveform generation unit 122 randomly selects one drive frequency (e.g., f#1) from among f#1 to f#20 in the management table TB2, and modulates the drive frequency of the first cycle of the drive signal S21 to the selected drive frequency. When modulating the drive frequency of the second cycle of the drive signal S21, the waveform generation unit 122 randomly selects one of the remaining f#2 to f#20, and modulates the drive frequency of the second cycle of the drive signal S21 to the selected drive frequency. The waveform generation unit 122 repeats the modulation until it has selected all of f#1 to f#20 indicated in the management table TB2. After selecting all of the drive frequencies from f#1 to f#20, the waveform generation unit 122 resets itself and again selects a drive frequency from f#1 to f#20 and performs the process of modulating to the selected drive frequency. This allows the waveform generation unit 122 to randomly modulate the drive signal S21.

[0074] In this way, in other embodiments, the level of radiation noise from the light control glass 10 can be reduced by randomly modulating the drive signal.

[0075] In other embodiments, the sampling frequency may be randomly modulated to reduce radiated noise.

[0076] In other embodiments, the control unit 121 randomly modulates the sampling frequency and outputs it to the waveform generation unit 122. The method by which the control unit 121 randomly modulates the sampling frequency is the same as the method by which the waveform generation unit 122 randomly modulates the drive frequency, and therefore a description thereof will be omitted.

[0077] In other embodiments, the waveform generating unit 122 generates the drive signal according to a sampling signal whose sampling frequency is randomly modulated. This allows the waveform generating unit 122 to generate a drive signal whose drive frequency is randomly modulated. Therefore, in other embodiments, radiated noise can also be reduced by randomly modulating the sampling frequency.

[0078] Furthermore, in the present disclosure, only the drive frequency may be randomly modulated, only the sampling frequency may be modulated, or both the drive frequency and the sampling frequency may be modulated.

[0079] (effect) The control device 120 according to the first aspect of the present disclosure includes a control unit 121 that generates a sampling signal having a predetermined sampling frequency, a waveform generation unit 122 that generates drive signals having a predetermined drive frequency to be output to multiple segments of the light control glass 10 according to the sampling frequency, and an output unit 123 that outputs the drive signals to the multiple segments. The waveform generation unit 122 differentiates the center frequencies of the drive signals output to the multiple segments. This makes it possible for the present disclosure to prevent radiation noise from being emitted from the light control glass 10.

[0080] A control device 120 according to a second aspect of the present disclosure is the control device 120 according to the first aspect, and when the frequency bands of the drive signals output to the multiple segments overlap, the waveform generating unit 122 changes at least one of the center frequency and the diffusion factor of the drive signals so that the frequency bands of the drive signals do not overlap. This makes it possible to appropriately prevent radiation noise from being emitted from the light control glass 10.

[0081] A control device 120 according to a third aspect of the present disclosure is the control device 120 according to the first or second aspect, in which the waveform generating unit 122 shifts the center frequencies of the drive signals output to the multiple segments by X × 0.2 × 2 kHz when the drive frequency of the reference signal among the multiple drive signals is X kHz. This makes it possible to appropriately prevent radiation noise from being emitted from the light control glass 10.

[0082] A control device 120 according to a fourth aspect of the present disclosure is the control device according to any one of the first to third aspects, in which the waveform generating unit 122 generates drive signals to be output to multiple segments so that the multiplied center frequency of the drive signal to be output to one segment does not overlap with the center frequency of the drive signal to be output to the other segment. This makes it possible to appropriately prevent radiation noise from being emitted from the light control glass 10.

[0083] A control device 120 according to a fifth aspect of the present disclosure is the control device 120 according to the fourth aspect, in which the waveform generating unit 122 shifts the center frequencies of the drive signals output to the plurality of segments by 21 kHz when the center frequency of a reference signal among the plurality of drive signals is X kHz. This allows the present disclosure to appropriately prevent radiation noise from being emitted from the light control glass 10.

[0084] A control device 120 according to a sixth aspect of the present disclosure is the control device according to any one of the first to fifth aspects, in which the waveform generating unit 122 randomly modulates the drive frequency. This makes it possible to appropriately prevent radiation noise from being emitted from the light control glass 10.

[0085] A control method according to a seventh aspect of the present disclosure generates a sampling signal having a predetermined sampling frequency, generates drive signals having a predetermined drive frequency to be output to multiple segments of the light control glass 10 in accordance with the sampling frequency, outputs the drive signals to the multiple segments, and varies the center frequencies of the drive signals output to the multiple segments. This makes it possible to prevent radiation noise from being emitted from the light control glass 10.

[0086] A light control glass system 1 according to an eighth aspect of the present disclosure includes a control device 120 according to any one of the first to sixth aspects, and a light control glass 10 having a plurality of segments, the light control state of which is controlled by the control device 120. This makes it possible for the present disclosure to prevent radiation noise from being emitted from the light control glass 10. This makes it possible for the present disclosure to prevent radiation noise from being emitted from the light control glass 10.

[0087] A light control glass system 1 according to a ninth aspect of the present disclosure is the light control glass system 1 according to the seventh aspect, in which the light control glass 10 includes a light control film 25 that is driven by an AC voltage. This makes it possible for the present disclosure to prevent radiation noise from being emitted from the light control glass 10.

[0088] A light control glass system 1 according to a tenth aspect of the present disclosure is the light control glass system 1 according to the ninth aspect, in which the light control film 25 driven by AC voltage is any one of PDLC (Polymer Dispersed Liquid Crystal), SPD (Suspended Particle Device), or GHLC (Guest Host Liquid Crystal). According to the present disclosure, it is possible to prevent radiation noise from being emitted from the light control glass 10 used in a vehicle.

[0089] The components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads and usage conditions. This distribution and integration configuration may also be performed dynamically.

[0090] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments. [Explanation of symbols]

[0091] 1. Dimmable glass system 10. Photochromic Glass 11 First Segment 12 Second Segment 13 Third Segment 14 4th Segment 15 5th Segment 16 6th Segment 17 7th Segment 18 8th Segment 21 First glass plate 22 Second glass pane 23 First interlayer 24 Second interlayer 25 Light-controlling film 31,32,33,34,35,36,37,38 1st electrode 41,42,43,44,45,46,47,48 2nd electrode 51,52,53,54,55,56,57,58 electrode 60 Ground electrode 100 power supply 110 Booster section 120 Control device 121 Control Unit 122 Waveform generator 123 Output section 1100 Body Control Module

Claims

1. a control unit that generates a sampling signal having a predetermined sampling frequency; a waveform generating unit that generates a drive signal having a predetermined drive frequency to be output to a plurality of segments of the light control glass in accordance with the sampling frequency; an output unit that outputs the drive signals to the plurality of segments; Equipped with the waveform generating unit varies the center frequencies of the drive signals output to the plurality of segments, respectively; Control device.

2. When frequency bands of the drive signals output to the plurality of segments overlap, the waveform generation unit changes at least one of a center frequency and a spreading factor of the drive signals so that the frequency bands of the drive signals do not overlap. The control device according to claim 1 .

3. the waveform generating unit shifts the center frequencies of the drive signals output to the plurality of segments by X×0.2×2 kHz when the drive frequency of a reference signal among the plurality of drive signals is X kHz; The control device according to claim 1 or 2.

4. the waveform generating unit generates the drive signals to be output to the plurality of segments so that a multiplied center frequency of the drive signal to be output to one of the segments does not overlap with a center frequency of the drive signal to be output to the other of the segments. The control device according to claim 1 or 2.

5. the waveform generating unit shifts the center frequencies of the drive signals output to the plurality of segments by 21 kHz when the center frequency of a reference signal among the plurality of drive signals is X kHz; The control device according to claim 4.

6. The waveform generating unit randomly modulates the drive frequency. The control device according to claim 1 or 2.

7. generating a sampling signal having a predetermined sampling frequency; generating a drive signal having a predetermined drive frequency to be output to a plurality of segments of the light control glass in accordance with the sampling frequency; outputting the drive signals to a plurality of the segments; different center frequencies of the drive signals output to the plurality of segments; Control method.

8. The control device according to claim 1 ; a light control glass having a plurality of segments, the light control state of which is controlled by the control device; Including, Dimmable glass system.

9. The light-control glass includes a light-control film driven by an AC voltage. The light control glass system according to claim 8.

10. The light-control film driven by an AC voltage is any one of PDLC (Polymer Dispersed Liquid Crystal), SPD (Suspended Particle Device), and GHLC (Guest Host Liquid Crystal); The light control glass system according to claim 9.

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