Control device, control method, and light control glass system

Abstract

To suppress generation of a rush current.SOLUTION: A control device for controlling a device having at least one functional element having an electrically controllable optical characteristic is provided with a capacitor, a comparator having a first input terminal to which a reference voltage corresponding to the charging voltage of the capacitor is inputted and a second input terminal to which a comparison voltage obtained by resistor-dividing a bias voltage to be outputted to a light control glass is inputted and comparing the reference voltage with the comparison voltage and outputting a comparison signal corresponding to the comparison result, and a voltage output control unit for controlling the comparison voltage to a value corresponding to the reference voltage on the basis of the comparison signal and feeding back the control voltage to the second input terminal.SELECTED DRAWING: Figure 6

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 be switched between transparent and opaque by applying an electric field has been developed. For example, Patent Document 1 describes a technology that enables the transmittance of a liquid crystal light control film to be controlled by a power supply device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7169528 Summary of the Invention [Problem to be solved by the invention]

[0004] To operate a liquid crystal light control film, a relatively high AC voltage must be applied. Because the liquid crystal light control film has a capacitive load, it repeatedly discharges and charges when the AC voltage waveform reverses between positive and negative. Therefore, each time the AC voltage waveform reverses between positive and negative, an inrush current may occur, the magnitude of which corresponds to the amount of voltage change per unit time. The occurrence of inrush current can lead to increased power loss and noise generation. Therefore, there is a need to suppress the occurrence of inrush current.

[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 the occurrence of inrush current. [Means for solving the problem]

[0006] The control device disclosed herein is a control device that controls a device having at least one functional element with electrically controllable optical characteristics, and includes a capacitor, a first input terminal to which a reference voltage corresponding to the charging voltage of the capacitor is input, and a second input terminal to which a comparison voltage obtained by resistively dividing a bias voltage to be output to a light-controlling glass is input, and is equipped with a comparator that compares the reference voltage with the comparison voltage and outputs a comparison signal corresponding to the comparison result, and a voltage output control unit that controls the comparison voltage to a value corresponding to the reference voltage based on the comparison signal and feeds it back to the second input terminal.

[0007] The control method disclosed herein compares a reference voltage corresponding to the charging voltage of a capacitor with a comparison voltage obtained by resistively dividing the bias voltage to be output to the light-controlling glass, outputs a comparison signal based on the comparison result between the reference voltage and the comparison voltage, controls the comparison voltage to a value corresponding to the reference voltage based on the comparison signal, and feeds it back to a comparator.

[0008] The light control glass system of the present disclosure includes the control device of the present disclosure and light control glass whose light control state is controlled by the control device. [Effects of the Invention]

[0009] According to the present disclosure, the occurrence of inrush current 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 an outline of the embodiment. [Figure 4] FIG. 4 is a block diagram showing a light control glass system according to an embodiment. [Figure 5] FIG. 5 is a diagram for explaining a method for controlling a light control glass system according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of a waveform generating unit according to the first example of the embodiment. [Figure 7] FIG. 7 is a diagram showing a drive signal for the light control glass according to the embodiment. [Figure 8] FIG. 8 is a diagram for explaining a method for controlling an output voltage according to the first example of the embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of a waveform generating unit according to the second example of the embodiment. [Figure 10] FIG. 10 is a diagram showing a drive signal for the light control glass according to the embodiment. [Figure 11] FIG. 11 is a diagram for explaining a method for controlling an output voltage according to the second example of the embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of the configuration of a waveform generating unit according to the third example of the embodiment. [Figure 13] FIG. 13 is a diagram showing a drive signal for the light control glass according to the embodiment. [Figure 14] FIG. 14 is a diagram for explaining a method for controlling an output voltage according to the third example of the embodiment. [Figure 15] FIG. 15 is a diagram illustrating a configuration example of a charge / discharge unit according to an embodiment. [Figure 16] FIG. 16 is a diagram for explaining control patterns of the switches included in the charge / discharge unit according to the embodiment. [Figure 17] FIG. 17 is a flowchart showing the flow of processing by the control device according to the embodiment. [Figure 18] FIG. 18 is a schematic diagram of a light control glass 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] (Photochromic 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] 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.

[0014] The light-controlling glass 10 is configured to be switchable between a transparent state and a light-blocking state. The light-controlling state refers to, for example, haze or visible light transmittance. In the following example, the light-controlling glass 10 is configured to be switchable between two different states, but the light-controlling 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 may be appropriately set (adjusted) according to requirements. 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-controlling 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-controlling 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.

[0015] The first glass plate 21 is a glass plate located on 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 located on the other surface of the light control glass 10. The shape and material of the second glass plate 22 may be arbitrary.

[0016] 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.

[0017] The light-control film 25 includes, for example, a PDLC (Polymer Dispersed Liquid Crystal) film. The light-control film 25 has a structure in which a transparent electrode is provided on the surface and a PDLC layer is sandwiched between two transparent substrates. The substrate can be formed of, for example, a transparent resin sheet such as PET, but is not limited to this. The transparent electrode can be, for example, ITO (Indium Tin Oxide), but is not limited to this. The light-control film 25 is configured so that it can be switched between a transparent state and a light-blocking state by applying a voltage. However, it 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.

[0018] [overview] Before describing the embodiments, an overview of the embodiments will be described. FIG. 3 is a diagram for explaining the overview of the embodiments. As shown in FIG. 3, the light control glass 10 is provided with a first electrode 31 and a second electrode 32. The first electrode 31 and the second electrode 32 are each connected to a transparent electrode included in the light control film. An AC signal (AC voltage) for controlling the light control state of the light control glass 10 is input to the light control glass 10 from the first electrode 31 and the second electrode 32.

[0019] One possible way to reduce the inrush current to the light control glass 10 is to make the slope of the AC signal waveform gentler, thereby easing the amount of voltage change per unit time between the first electrode 31 and the second electrode 32. However, because the transmittance of the light control film 25 depends on the effective voltage, if the AC signal is a sine wave, the maximum voltage peak value required to obtain the desired effective voltage will be √2 times the effective voltage value, which may exceed the dielectric strength voltage of the light control film 25. Furthermore, a large maximum voltage peak value requires the use of circuit components with high voltage resistance, which may make it difficult to reduce the cost and size of the product.

[0020] To avoid the problems associated with using a sine wave, it is possible to use a trapezoidal wave. When using a trapezoidal wave, there are generally three methods for adjusting the slope of the waveform:

[0021] The first method is to control the time constant by inserting a resistive element and configuring an RC delay circuit using the resistive element and the capacitance of the light control film 25. However, this method may result in a decrease in electricity or fuel efficiency because the inserted resistive element generates heat, resulting in power loss. In addition, it may be time-consuming to adjust the constant of the resistive element according to the characteristics of the light control film 25.

[0022] The second method is to raise the waveform in a stepped manner. However, this method requires a sampling frequency to raise the waveform in a stepped manner. Therefore, the sampling frequency becomes a new noise generation band, which may have a negative impact on EMC (Electro Magnetic Compatibility).

[0023] The third method is to generate the desired waveform and amplify it with an operational amplifier. However, this method requires a large circuit scale, which may make it difficult to reduce product costs and miniaturize the product. Furthermore, a sampling frequency is required to generate the digital waveform, which may create a new noise band. Furthermore, the operational amplifier's power loss may increase, which may worsen electricity or fuel economy.

[0024] Therefore, the present disclosure provides a circuit configuration for reducing inrush power while reducing the circuit scale and power loss level.

[0025] (dimming glass system) Fig. 4 is a block diagram showing a light control glass system according to an embodiment. As shown in Fig. 4, 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 a vehicle, for example.

[0026] 5 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.

[0027] The power supply 100 outputs a predetermined output voltage to the booster 110. The output voltage output by the power supply 100 is, for example, DC 12V, but is not limited to this.

[0028] 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 slope of the waveform of the drive signal. 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.

[0029] The control device 120 includes a boosting unit 110 , a waveform generating unit 121 , and an output unit 122 .

[0030] 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 the input voltage of DC 12V to DC 80V and outputs it to the control device 120, but is not limited to this.

[0031] The waveform generating unit 121 generates a drive signal for controlling the light control state of the light control glass 10. The waveform generating unit 121 controls the slope of the waveform of the drive signal so as to prevent an inrush current from occurring. Details of the waveform generating unit 121 will be described later.

[0032] The output unit 122 outputs the drive signal generated by the waveform generation unit 121 to the light control glass 10 .

[0033] (Waveform control) A method for controlling the waveform of a drive signal according to an embodiment will be described. In this embodiment, the drive signal is classified into three regions and control is performed according to the region.

[0034] (First example) FIG. 6 is a diagram illustrating an example of the configuration of a waveform generating unit according to a first example of an embodiment. As shown in FIG. 6, the waveform generating unit 121 includes a capacitor C1, a resistive element R1, a resistive element R2, a waveform control unit 130, a constant current source 140, and a comparator 150. FIG. 7 is a diagram illustrating a drive signal for the light control glass 10 according to an embodiment. As shown in FIG. 7, the waveform generating unit 121 illustrated in FIG. 6 controls the slope of the waveform of the drive signal S1 in a region R11 where the drive signal rises from the ground voltage GND to the voltage V+. Although not shown in FIG. 6, a filter circuit, a switch circuit, or the like is connected downstream of the waveform generating unit 121.

[0035] The waveform control unit 130 controls the slope of the waveform of the drive signal output to the light control glass 10. The waveform control unit 130 includes a bias voltage generation unit 131 and a voltage output control unit 132.

[0036] The bias voltage generation unit 131 generates a constant voltage and outputs a bias voltage (voltage Vout). The bias voltage generation unit 131 outputs, for example, the voltage Vout according to the output voltage input from the boost unit 110. The bias voltage generation unit 131 outputs, for example, the voltage Vout having the same voltage value as the voltage input from the boost unit 110. The voltage Vout is output to the outside via, for example, a filter circuit or a switch circuit (not shown).

[0037] One end of the capacitor C1 is connected to the constant current source 140. The other end of the capacitor C1 is connected to a reference potential. The reference potential is, for example, but not limited to, ground. The capacitor C1 outputs the charging voltage as a reference voltage Vref to a first input terminal of the comparator 150.

[0038] The constant current source 140 charges the capacitor C1. Specifically, the constant current source 140 charges the capacitor C1 with a fixed amount of electric charge per unit time. Therefore, the charging voltage of the capacitor C1 increases linearly until the capacitor C1 is fully charged, and then shows a constant value. The rate at which the constant current source 140 charges the capacitor C1 is controlled to a rate that does not generate an inrush current in the light control glass 10.

[0039] One end of the resistor element R1 is connected to the output terminal of the waveform control unit 130. The other end of the resistor element R1 is connected to one end of the resistor element R2. The other end of the resistor element R2 is connected to a reference potential. The resistor elements R1 and R2 form a resistive voltage divider circuit. The resistor elements R1 and R2 resistively divide the bias voltage and output the generated voltage as a comparison voltage Vfb to the second input terminal of the comparator 150.

[0040] The comparator 150 compares a reference voltage Vref input to a first input terminal with a comparison voltage Vfb input to a second input terminal. When the reference voltage Vref is smaller than the comparison voltage Vfb, the comparator 150 outputs a high-level comparison signal Sc. When the reference voltage Vref is larger than the comparison voltage Vfb, the comparator 150 outputs a low-level comparison signal Sc. The comparator 150 outputs the comparison signal Sc to the voltage output control unit 132 according to the comparison result between the reference voltage Vref and the comparison voltage Vfb.

[0041] The voltage output control unit 132 controls the voltage value of the voltage Vout based on the comparison signal Sc. For example, when the comparator 150 outputs a high-level comparison signal Sc, the voltage output control unit 132 stops the voltage Vout. For example, when the comparator 150 outputs a low-level comparison signal Sc, the voltage output control unit 132 outputs the voltage Vout.

[0042] FIG. 8 is a diagram illustrating a method for controlling the output voltage according to the first example of the embodiment. In FIG. 8, the horizontal axis represents time and the vertical axis represents voltage. Waveform 41 represents the reference voltage Vref. Waveform 42 represents the voltage Vout controlled by the voltage output control unit 132. The slope of the waveform 41 is controlled so that no inrush current occurs when a drive signal with that slope is input to the light control glass. As shown in FIG. 8, the voltage output control unit 132 controls the voltage Vout based on the comparison signal Sc in accordance with the time variation of the reference voltage Vref. The voltage output control unit 132 outputs the controlled voltage Vout to the light control glass 10. The voltage output control unit 132 also feeds back the controlled voltage Vout to the second input terminal of the comparator 150. As a result, the voltage Vout becomes a voltage that fluctuates in accordance with changes in the reference voltage Vref. Therefore, the comparison voltage Vfb obtained by dividing the voltage Vout shown in FIG. 8 between the resistor elements R1 and R2 becomes a voltage that matches the reference voltage Vref.

[0043] That is, in the first example, the voltage output control unit 132 can control the slope of the drive signal S1 in the region R11 in accordance with the reference voltage Vref indicated by the waveform 41. Therefore, in the first example, it is possible to prevent an inrush current from occurring in the light control glass 10 due to the drive signal S1 in the region R11.

[0044] (Second example) Fig. 9 is a diagram showing an example of the configuration of a waveform generating unit according to a second example of the embodiment. The waveform generating unit 121A includes a capacitor C1, resistive elements R1 and R2, a waveform control unit 130, a constant current source 140, and a comparator 150. Fig. 10 is a diagram showing a drive signal for the light control glass 10 according to the embodiment. As shown in Fig. 10, the waveform generating unit 121A shown in Fig. 9 controls the slope of the waveform of the drive signal S1 in a region R12 where the signal falls from voltage V+ to ground voltage GND and in a region R13 where the signal rises from voltage V- to ground voltage GND.

[0045] The waveform generating unit 121A differs from the waveform generating unit 121 shown in FIG. 6 in that one end of the capacitor C1 is connected only to the first input terminal of the comparator 150, and the other end is connected to the constant current source 140, and in that the constant current source 140 is connected to a reference potential.

[0046] The constant current source 140 discharges the capacitor C1. Specifically, the constant current source 140 discharges a fixed amount of charge from the capacitor C1 per unit time. Therefore, the charging voltage of the capacitor C1 decreases linearly from the value when the capacitor C1 is fully charged to 0 V.

[0047] FIG. 11 is a diagram illustrating a method for controlling an output voltage according to a second example of the embodiment. In FIG. 11, the horizontal axis represents time and the vertical axis represents voltage. Waveform 43 represents the reference voltage Vref. Waveform 44 represents the voltage Vout controlled by the voltage output control unit 132. The slope of waveform 43 is controlled so that no inrush current occurs when a drive signal with that slope is input to the light control glass. As shown in FIG. 11, the voltage output control unit 132 controls the voltage Vout based on the comparison signal Sc in accordance with the time variation of the reference voltage Vref. The voltage output control unit 132 feeds back the controlled voltage Vout to the second input terminal of the comparator 150. As a result, the voltage Vout becomes a voltage that fluctuates in accordance with changes in the reference voltage Vref. Therefore, the comparison voltage Vfb obtained by dividing the voltage Vout shown in FIG. 11 between the resistor elements R1 and R2 becomes a voltage that matches the reference voltage Vref.

[0048] That is, in the second example, the voltage output control unit 132 can control the slope of the drive signal S1 in the regions R12 and R13 in accordance with the reference voltage Vref indicated by the waveform 43. Therefore, in the second example, it is possible to prevent an inrush current from occurring in the light control glass 10 due to the drive signal S1 in the regions R12 and R13.

[0049] (Third example) Fig. 12 is a diagram showing an example of the configuration of a waveform generating unit according to a third example of the embodiment. The waveform generating unit 121A includes a capacitor C1, a resistive element R1, a resistive element R2, a waveform control unit 130, a constant current source 140, and a comparator 150. Fig. 13 is a diagram showing a drive signal for the light control glass 10 according to the embodiment. As shown in Fig. 13, the waveform generating unit 121B shown in Fig. 12 controls the slope of the drive signal S1 in a region R14 where the drive signal S1 rises from the ground voltage GND to the voltage V-.

[0050] The constant current source 140 negatively charges the capacitor C1. Specifically, the constant current source 140 charges the capacitor C1 with a fixed amount of electric charge per unit time. Therefore, the charging voltage of the capacitor C1 increases linearly in the negative direction until the capacitor C1 is fully charged, and then shows a constant value.

[0051] FIG. 14 is a diagram illustrating a method for controlling an output voltage according to a third example of the embodiment. In FIG. 14, the horizontal axis represents time and the vertical axis represents voltage. Waveform 45 represents the reference voltage Vref. Waveform 46 represents the voltage Vout controlled by the voltage output control unit 132. The slope of waveform 45 is controlled so that no inrush current occurs when a drive signal with that slope is input to the light control glass. As shown in FIG. 14, the voltage output control unit 132 controls the voltage Vout based on the comparison signal Sc in accordance with the time variation of the reference voltage Vref. The voltage output control unit 132 feeds back the controlled voltage Vout to the second input terminal of the comparator 150. As a result, the voltage Vout becomes a voltage that fluctuates in accordance with changes in the reference voltage Vref. Therefore, the comparison voltage Vfb obtained by dividing the voltage Vout shown in FIG. 14 between the resistor elements R1 and R2 becomes a voltage that matches the reference voltage Vref.

[0052] That is, in the third example, the voltage output control unit 132 can control the slope of the drive signal S1 in the region R14 in accordance with the reference voltage Vref indicated by the waveform 45. Therefore, in the third example, it is possible to prevent an inrush current from occurring in the light control glass 10 due to the drive signal S1 in the region R14.

[0053] 6 to 14, in this embodiment, the slope of the drive signal S1 in the region R11 to region R14 can be controlled to a slope that does not generate an inrush current in the light control glass 10. Furthermore, in this embodiment, as shown in Fig. 6 to 14, the slope of the drive signal S1 can be controlled in an analog manner based on the result of comparison between the reference voltage Vref and the comparison voltage Vfb by the comparator 150.

[0054] (Charge / discharge section) FIG. 15 is a diagram illustrating an example of the configuration of a charging / discharging unit according to an embodiment. As illustrated in FIG. 15, the charging / discharging unit 160 includes a constant current source 140-1, a constant current source 140-2, a constant current source 140-3, a first switch SW1, a second switch SW2, a third switch SW3, and a fourth switch SW4. The charging / discharging unit 160 controls the first switch SW1 to the fourth switch SW4 to charge or discharge the capacitor C1. The first switch SW1 to the fourth switch SW4 are, for example, but not limited to, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The first switch SW1 to the fourth switch SW4 may also be mechanical switches.

[0055] Node N1 of charging / discharging unit 160 is connected to a first input terminal of comparator 150. A reference voltage Vref according to the control pattern of first switch SW1 to fourth switch SW4 is output from node N1 to the first input terminal of comparator 150. That is, by connecting node N1 of charging / discharging unit 160 to the first input terminal of comparator 150 and controlling the ON / OFF of first switch SW1 to fourth switch SW4, any one of waveform generating unit 121, waveform generating unit 121A, and waveform generating unit 121B can be realized.

[0056] 16 is a diagram for explaining the control patterns of the switches included in the charge / discharge unit according to the embodiment. The management table TM1 shows four control patterns for the first switch SW1 to the fourth switch SW4.

[0057] In region R11, the charge / discharge unit 160 controls the first switch SW1 to be ON, the second switch SW2 to be OFF, the third switch SW3 to be ON, and the fourth switch SW4 to be OFF. In region R11, the constant current source 140-1 charges the capacitor C1 with a fixed amount of charge per unit time. That is, in region R11, the waveform generation unit 121 is realized, and control of the drive signal S1 in region R11 shown in FIG. 7 can be performed.

[0058] In region R12, the charge / discharge unit 160 controls the first switch SW1 to be OFF, the second switch SW2 to be OFF, the third switch SW3 to be OFF, and the fourth switch SW4 to be ON. In region R12, the constant current source 140-2 discharges a fixed amount of charge per unit time from the capacitor C1. That is, in region R12, the waveform generation unit 121A is realized, and the drive signal S1 shown in FIG. 10 can be controlled in region R12.

[0059] In region R13, the charge / discharge unit 160 controls the first switch SW1 to be OFF, the second switch SW2 to be ON, the third switch SW3 to be ON, and the fourth switch SW4 to be OFF. In region R13, the constant current source 140-3 negatively charges the capacitor C1 with a fixed amount of charge per unit time. That is, in region R13, the waveform generation unit 121B is realized, and control of the drive signal S1 in region R13 shown in FIG. 10 can be performed.

[0060] In region R14, the charge / discharge unit 160 controls the first switch SW1 to be OFF, the second switch SW2 to be OFF, the third switch SW3 to be OFF, and the fourth switch SW4 to be ON. That is, in region R14, the first switch SW1 to the fourth switch SW4 are controlled in the same manner as in region R12. In region R14, the waveform generation unit 121A is realized, and the constant current source 140-2 discharges a constant amount of charge per unit time from the negatively charged capacitor C1.

[0061] (control processing) 17 is a flowchart showing the flow of processing by the control device according to the embodiment. The bias voltage generation unit 131 outputs a bias voltage to be output to the light control glass 10 (step S100).

[0062] The voltage output control unit 132 controls the bias voltage based on the comparison result between the reference voltage and the bias voltage by the comparator 150 (step S102). Specifically, the voltage output control unit 132 controls the bias voltage so that the bias voltage changes according to the reference voltage. For example, the voltage output control unit 132 controls the bias voltage so that the divided voltage obtained by dividing the bias voltage using a voltage divider circuit matches the reference voltage.

[0063] The voltage output control section 132 outputs the controlled bias voltage to the comparator (step S104). That is, the voltage output control section 132 feeds back the controlled bias voltage to the comparator.

[0064] The voltage output control unit 132 determines whether or not to end the process (step S106). For example, when the power supply 100 is turned off, the voltage output control unit 132 determines to end the process. If it is determined to end the process (step S106; Yes), the process of FIG. 17 ends. If it is not determined to end the process (step S106; No), the process returns to step S102 and is repeated. This makes it possible to appropriately suppress the occurrence of inrush current in the light control glass 10 in this embodiment.

[0065] [Other embodiments] Fig. 18 is a schematic diagram of a light control glass according to another embodiment. As shown in Fig. 18, the light control glass 10A has 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 first segment 11 to the eighth segment 18 are each configured so that the light control state can be controlled independently. In other words, in the present disclosure, the light control region of the light control glass 10A may be divided into multiple regions whose light control states can be controlled independently.

[0066] In other embodiments, for example, a control device 120 shown in Fig. 4 is provided for each segment of the light control glass 10A. This makes it possible to suppress the occurrence of inrush current for each segment of the light control glass 10A.

[0067] (effect) A control device 120 according to a first aspect of the present disclosure is a control device that controls a device having at least one functional element with electrically controllable optical characteristics, and includes a capacitor C1, a first input terminal to which a reference voltage corresponding to the charging voltage of the capacitor C1 is input, and a second input terminal to which a comparison voltage obtained by resistively dividing a bias voltage to be output to the light control glass 10 is input, and includes a comparator 150 that compares the reference voltage with the comparison voltage and outputs a comparison signal Sc corresponding to the comparison result, and a voltage output control unit 132 that controls the comparison voltage to a value corresponding to the reference voltage based on the comparison signal Sc and feeds it back to the second input terminal. According to the present disclosure, it is possible to suppress the generation of inrush current in the light control glass 10.

[0068] The control device 120 according to the second aspect of the present disclosure is the control device 120 according to the first aspect, and the comparator 150 outputs a high-level comparison signal Sc when the comparison voltage is higher than the reference voltage, and outputs a low-level comparison signal Sc when the comparison voltage is lower than the reference voltage. This makes it possible to suppress the occurrence of inrush current in the light control glass 10.

[0069] The control device 120 according to the third aspect of the present disclosure is the control device 120 according to the first or second aspect, and the voltage output control unit 132 controls the bias voltage so that the reference voltage and the comparison voltage match. This makes it possible to suppress the occurrence of inrush current in the light control glass 10.

[0070] The control device 120 according to a fourth aspect of the present disclosure is the control device 120 according to the third aspect, and the voltage output control unit 132 stops outputting the bias voltage when the comparator 150 outputs a high-level comparison signal Sc, and outputs the bias voltage when the comparator 150 outputs a low-level comparison signal Sc. This makes it possible for the present disclosure to suppress the occurrence of inrush current in the light control glass 10.

[0071] A control device 120 according to a fifth aspect of the present disclosure is the control device 120 according to any one of the first to fourth aspects, and the reference voltage is a voltage that varies over time. This allows the present disclosure to use an appropriate AC voltage as the reference voltage, thereby suppressing the occurrence of inrush current in the light control glass 10.

[0072] A control device 120 according to a sixth aspect of the present disclosure is the control device 120 according to any one of the first to fifth aspects, and includes a constant current source 140 connected to the capacitor C1, and the constant current source 140 charges or discharges a constant amount of charge per unit time to the capacitor C1. This allows the present disclosure to appropriately generate a reference voltage, thereby suppressing the occurrence of inrush current in the light control glass 10.

[0073] A control method according to a seventh aspect of the present disclosure compares a reference voltage corresponding to the charging voltage of the capacitor C1 with a comparison voltage obtained by resistively dividing a bias voltage to be output to the light control glass 10, outputs a comparison signal Sc based on the comparison result between the reference voltage and the comparison voltage, controls the comparison voltage to a value corresponding to the reference voltage based on the comparison signal Sc, and feeds it back to the comparator 150. According to the present disclosure, it is possible to suppress the occurrence of inrush current in the light control glass 10.

[0074] 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 light control glass 10 whose dimming state is controlled by the control device 120. According to the present disclosure, it is possible to suppress the occurrence of inrush current in the light control glass 10.

[0075] 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 eighth 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.

[0076] 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, and 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 suppress the generation of inrush current in the light control glass 10 used in a vehicle.

[0077] 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.

[0078] 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]

[0079] 1. Dimmable glass system 10,10A 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 Control Film 31 1st electrode 32 2nd electrode 100 power supply 110 Booster section 120 Control device 121,121A,121B Waveform generator 122 Output section 130 Waveform control section 131 Bias voltage generation unit 132 Voltage output control section 140 constant current source 150 Comparator 1100 Body Control Module

Claims

1. A control device for controlling a device having at least one functional element with electrically controllable optical properties, comprising: A capacitor, a comparator having a first input terminal to which a reference voltage corresponding to the charging voltage of the capacitor is input, and a second input terminal to which a comparison voltage obtained by resistor-dividing a bias voltage to be output to the light control glass is input, the comparator comparing the reference voltage with the comparison voltage and outputting a comparison signal corresponding to the comparison result; a voltage output control section that controls the comparison voltage to a value corresponding to the reference voltage based on the comparison signal and feeds the control voltage back to the second input terminal; A control device comprising:

2. The comparator outputs the comparison signal at a high level when the comparison voltage is higher than the reference voltage, and outputs the comparison signal at a low level when the comparison voltage is lower than the reference voltage. The control device according to claim 1 .

3. the voltage output control unit controls the bias voltage so that the reference voltage and the comparison voltage coincide with each other. The control device according to claim 2 .

4. the voltage output control unit stops output of the bias voltage when the comparator outputs the comparison signal at a high level, and outputs the bias voltage when the comparator outputs the comparison signal at a low level. The control device according to claim 3 .

5. The reference voltage is a voltage that varies over time. The control device according to any one of claims 1 to 4.

6. a constant current source connected to the capacitor; The constant current source charges or discharges a constant amount of charge per unit time to the capacitor. The control device according to claim 5 .

7. The reference voltage corresponding to the capacitor's charging voltage is compared with a comparison voltage obtained by resistively dividing the bias voltage to be output to the light-control glass. outputting a comparison signal based on a comparison result between the reference voltage and the comparison voltage; based on the comparison signal, the comparison voltage is controlled to a value corresponding to the reference voltage, and the controlled value is fed back to the comparator; Control method.

8. The control device according to claim 1 ; a light control glass whose light control state 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 either a PDLC (Polymer Dispersed Liquid Crystal), an SPD (Suspended Particle Device), or a GHLC (Guest Host Liquid Crystal); The light control glass system according to claim 9.

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