Lighting control system

Abstract

To suppress violation of privacy even at timing at which it becomes instantaneously transparent by applying an AC voltage when a light control section changing from a transparent state to a colored state in a case where an AC voltage equal to or more than a predetermined value is applied, is used for a part of a region enclosing a vehicle interior.SOLUTION: A lighting control system 10 comprises: a light control glass inverter 12 which applies an AC voltage to a light control glass 2 which is disposed at a predetermined portion of a region enclosing a vehicle interior and of which light transmissivity is changed in accordance with the applied voltage; and a lighting control unit 14 which performs drive control of lighting 4 in the vehicle interior interlocked with control of the light control glass inverter 12. The light control glass 2 is brought into a colored state in a case where an absolute value of the applied voltage is equal to or more than a first threshold and brought into a transparent state in a case where the absolute value of the applied voltage is less than the first threshold. The lighting control unit 14 brings the lighting 4 into a turned-off state at the timing when the absolute value of the applied voltage is less than the first threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a lighting control system. [Background technology]

[0002] There are known lighting control systems for vehicles that can automate or reduce the number of operations required to create an appropriate private space inside the vehicle. Such systems use, for example, light-control glass with a light-control film attached that changes from colorless to colored when an AC voltage is applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-031808 Summary of the Invention [Problem to be solved by the invention]

[0004] When photochromic glass, which changes from colorless to colored when an AC voltage is applied, is applied to vehicle windows, the AC voltage applied to the photochromic film may decrease, causing the photochromic glass to momentarily become transparent. At such times, privacy within the vehicle may be violated. For example, there is a risk that a third party could use a high-performance camera, such as a slow-motion camera, to film the interior of the vehicle and capture an image of the inside of the photochromic glass.

[0005] The present invention provides a lighting control system that can reduce the risk of privacy violations. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the lighting control system according to the present invention is characterized as follows. a light control unit that applies an AC voltage to a light control unit that is arranged at a predetermined position in an area surrounding the vehicle interior and whose light transmittance changes in response to an applied voltage; a lighting control unit that controls driving of lighting in the vehicle cabin in conjunction with the control of the light adjustment control unit, the dimming unit is in a colored state when the absolute value of the applied voltage is equal to or greater than a first threshold, and is in a transparent state when the absolute value of the applied voltage is less than the first threshold; The lighting control unit turns off the lighting when the absolute value of the applied voltage is less than the first threshold. [Effects of the Invention]

[0007] According to the present invention, the risk of privacy violation can be reduced.

[0008] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a circuit configuration diagram of a lighting control system according to an embodiment. [Figure 2] FIG. 2 is a flowchart showing the procedure of dimming and lighting control executed by the lighting control system. [Figure 3] FIG. 3 is a timing chart of the driving voltage of the light control glass and the PWM control waveform of the lighting. [Figure 4A] FIG. 4A is a conceptual diagram of a vehicle equipped with a lighting control system according to an embodiment, in which the light control glass is in a colored state. [Figure 4B] FIG. 4B is a conceptual diagram of a vehicle equipped with a lighting control system according to an embodiment, in which the light control glass is in a transparent state and the lighting is off. [Figure 5]FIG. 5 is a conceptual diagram of a conventional vehicle not equipped with a lighting control system according to an embodiment, in which the light control glass is in a transparent state and the lighting is on. DETAILED DESCRIPTION OF THE INVENTION

[0010] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0011] 1 is a circuit diagram of a lighting control system 10 according to an embodiment. The lighting control system 10 is a system for protecting privacy inside a vehicle cabin while utilizing lighting by controlling the lighting inside the vehicle cabin and the light transmittance of the vehicle's glass. In this disclosure, light transmittance refers to the transmittance of visible light.

[0012] The lighting control system 10 includes a dimming glass inverter 12 and a lighting control unit 14. The dimming glass inverter 12 applies an AC voltage to a dimming glass 2 that is arranged at a predetermined location in an area surrounding the vehicle interior and whose light transmittance changes depending on the applied voltage. The lighting control unit 14 drives and controls the lighting 4 in the vehicle interior in conjunction with the control of the dimming glass inverter 12.

[0013] The light control glass 2, which is an example of a light control unit, is arranged in a predetermined location in the area surrounding the vehicle interior, for example, at the position of the window glass in a typical vehicle door. The light control glass 2 may also be arranged at the position of the window glass for the rear seat. The light control glass 2 includes, for example, a vehicle window glass and a light control film attached to the inner or outer surface of the window glass, or a light control film sandwiched between two window glasses.

[0014] The light control film is composed of a film-like light control membrane whose light transmittance and light reflectance in the thickness direction can be electrically adjusted. The light control membrane has multiple transparent electrodes, and the light transmittance and light reflectance change when a predetermined AC voltage is applied between the electrodes. Therefore, the light control glass 2 changes, for example, from colorless transparent to colored (tinted) or from colored to colorless transparent by applying an AC voltage. When in the colored state, the light control glass 2 does not substantially transmit visible light, and when in the transparent state, it substantially transmits visible light.

[0015] The dimming glass inverter 12, which is an example of a dimming control unit, is a device that converts the voltage of a DC power source (e.g., an on-board battery) of the vehicle (not shown) into AC voltage of a specific frequency (Hz), and applies this AC voltage, i.e., drive voltage, to the dimming glass 2 to drive the dimming glass 2. The dimming glass inverter 12 includes an inverter, a noise filter, etc. (not shown).

[0016] The light control glass inverter 12 may be driven by a switch operation by the vehicle user to apply AC voltage to the light control glass 2, or may be driven automatically under predetermined conditions to apply AC voltage to the light control glass 2.

[0017] In this embodiment, the light control glass 2 is in a colored state (tinted state) when the absolute value of the voltage applied to the light control glass 2 by the light control glass inverter 12 is equal to or greater than a predetermined first threshold, and is in a transparent state when the absolute value of the applied voltage is less than the first threshold.

[0018] The lighting 4 is a light source that includes, for example, a lighting lamp (LED) or an illumination lamp (LED) set in the vehicle interior, and ensures brightness in the vehicle interior and creates an illuminated state.

[0019] The lighting control unit 14, which is a lighting control section, is a device that turns on the lights 4 using, for example, general PWM (Pulse Width Modulation) control. In this embodiment, the lighting control unit 14 is connected to the light control glass inverter 12. The light control glass inverter 12 can transmit waveform information of the AC voltage to be applied to the light control glass 2 to the lighting control unit 14.

[0020] The lighting control unit 14 receives waveform information of the AC voltage from the light control glass inverter 12. Based on the received waveform information, the lighting control unit 14 performs control so that the timing at which the voltage of the light control glass inverter 12 increases or decreases coincides with the timing at which the PWM waveform of the PWM control is turned off, i.e., the timing at which the lights 4 are turned off.

[0021] That is, the lighting control unit 14 turns off the lighting 4 at the timing when the absolute value of the voltage applied to the light control glass 2 by the light control glass inverter 12 is less than the first threshold value described above. The control will be specifically described below.

[0022] 2 is a flowchart showing the procedure of dimming and lighting control executed by the lighting control system 10. When a user turns on the switch of the light control glass inverter 12 (Yes in step S1), application of AC voltage to the light control glass 2 begins (step S2).

[0023] If the absolute value of the AC voltage is not less than the predetermined first threshold (No in step S3), that is, if the absolute value of the AC voltage is equal to or greater than the first threshold, the light control glass 2 remains in the colored state. On the other hand, if the absolute value of the AC voltage is less than the predetermined first threshold (Yes in step S3), the light control glass 2 becomes transparent.

[0024] The lighting control unit 14 receives waveform information of the AC voltage from the dimming glass inverter 12, and turns off the lights 4 when the absolute value of the AC voltage falls below a predetermined first threshold (step S4). If the user turns off the switch of the dimming glass inverter 12 (Yes in step S5), the processing ends. If the switch is not turned off (No in step S5), the operations from step S3 onwards are repeated. As another control pattern, the lighting control unit 14 may perform the control of steps S3 to S4 only the first time the AC voltage is applied, and thereafter perform PWM control at a constant frequency (twice the frequency of the AC voltage waveform).

[0025] 3 is a timing chart of the drive voltage (applied AC voltage) of the light control glass 2 and the PWM control waveform of the lighting 4. This diagram shows the procedure from step S2 onwards in FIG. 2 in the form of a timing chart.

[0026] The drive voltage from the light control glass inverter 12 is an AC voltage with an AC waveform as shown in the figure, and therefore fluctuates repeatedly between maximum and minimum values, with zero voltage as the center. The first threshold is an absolute value that is the turning point at which the light control glass 2 changes from a colored state to a transparent state. That is, when the drive voltage of the light control glass 2 is equal to or greater than the negative first threshold and equal to or less than the positive first threshold, the light control glass 2 is in a transparent state, and when the drive voltage of the light control glass 2 is less than the negative first threshold or greater than the positive first threshold, the light control glass 2 is in a colored state. The first threshold may be, for example, zero.

[0027] The PWM control waveform by the lighting control unit 14 is a square wave that fluctuates between on and off as shown in the figure. When the control waveform indicates on, the light 4 is on (lit), and when the control waveform indicates off, the light 4 is off (unlit).

[0028] As shown in the figure, the lighting control unit 14 controls the lighting 4 so that the lighting 4 is turned off when the absolute value of the voltage applied to the light control glass 2 by the light control glass inverter 12 is less than a first threshold. Specifically, the lighting control unit 14 performs PWM control so that the square wave indicates off when the absolute value of the applied voltage is less than the first threshold, and turns off (exits) the lighting 4.

[0029] According to the lighting control system 10 of this embodiment, the light control glass 2 becomes transparent when the absolute value of the applied voltage of the AC waveform is less than the first threshold, but turning off the interior lighting 4 makes it difficult to see inside the vehicle, especially at night when it is dark. Therefore, when the light control glass 2 that changes from a transparent state to a colored state when an AC voltage equal to or greater than a predetermined value is applied is used in part of the area surrounding the vehicle interior, the risk of privacy being violated can be reduced even when the light control glass momentarily becomes transparent due to the application of an AC voltage.

[0030] For example, if a high-performance camera (slow-motion camera) were to photograph the interior of a vehicle with the lights on at night when it is dark, there is a high risk that the interior of the vehicle will be photographed. However, according to the lighting control system 10 of this embodiment, the light control glass 2, such as a so-called reverse mode light control glass, turns off the lights 4 when in a transparent state, making the interior of the vehicle dark and reducing the risk of being photographed.

[0031] Furthermore, the dimming glass inverter 12 sends information about the AC voltage waveform for controlling the dimming glass 2 to the lighting control unit 14, and the lighting control unit 14 switches the on / off state of the light 4 based on the information about the AC voltage waveform. By using the information about the AC voltage waveform for controlling the dimming glass 2 for control by the lighting control unit 14, it is possible to easily match the timing at which the voltage of the AC voltage waveform decreases with the timing at which the light 4 is turned off.

[0032] As in the embodiment, the lighting control unit 14 can switch the on / off state of the lighting 4 by PWM control based on information about the AC voltage waveform from the light control glass inverter 12. The frequency of the PWM waveform used for PWM control may be set to twice the frequency of the AC voltage waveform from the light control glass inverter 12. This setting ensures that the lighting 4 is turned off when the absolute value of the AC voltage becomes less than the first threshold.

[0033] Fig. 4A is a conceptual diagram of a vehicle 20 equipped with a lighting control system 10 according to an embodiment, in which the light control glass 2 is in a colored state. Fig. 4B is a conceptual diagram of a vehicle 20 equipped with a lighting control system 10 according to an embodiment, in which the light control glass 2 is in a transparent state and the lights 4 are off.

[0034] In the present example, vehicle 20 is required by law to have normal window glass in the front seats, allowing passenger H1 to be seen through the window glass. On the other hand, the window glass in the rear seats is a light control glass 2 to ensure privacy for the rear seats. In the state shown in FIG. 4A , the light control glass inverter 12 applies a voltage whose absolute value is equal to or greater than the first threshold value to the light control glass 2, and the light control glass 2 is in a colored state. Therefore, whether the light 4 is on or off, it is difficult to photograph the interior of the rear seats, ensuring privacy.

[0035] On the other hand, in the state shown in Fig. 4B, the dimming glass inverter 12 applies an applied voltage whose absolute value is less than the first threshold to the dimming glass 2, and the dimming glass 2 is in a transparent state. Then, as shown in Fig. 3, the lighting control unit 14 controls the lighting 4 so that it is turned off at this timing when the absolute value of the applied voltage is less than the first threshold. Even if the dimming glass 2 is in a transparent state, because the lighting 4 is off, it is difficult to photograph the interior of the vehicle at the rear seats using a high-performance camera or the like, thereby reducing the risk of privacy violations.

[0036] 5 is a conceptual diagram of a conventional vehicle 20 not equipped with the lighting control system 10 according to the embodiment, in which the light control glass 2 is in a transparent state and the lights 4 are on. In the vehicle 20 of this example, the window glass in the front seats is also normal window glass, and the window glass in the rear seats is light control glass 2.

[0037] In Fig. 5, the dimming glass inverter 12 applies a voltage whose absolute value is less than the first threshold to the dimming glass 2, and the dimming glass 2 is in a transparent state. However, because the vehicle 20 is not equipped with the lighting control system 10 according to the embodiment, control such as that shown in Fig. 3 cannot be performed. Therefore, the dimming glass 2 is in a transparent state, the light 4 is on, and the interior of the vehicle remains bright. In this state, it is possible to photograph the interior of the vehicle in the rear seats using a high-performance camera or the like, and it is possible to photograph a passenger H2 in the rear seats through the dimming glass 2, increasing the risk of privacy violations.

[0038] Here, the features of the above-described embodiments of the lighting control system according to the present invention will be briefly summarized and listed below in [1] to [3].

[0039] [1] A dimming control unit (dimming glass inverter 12) that applies an AC voltage to a dimming unit (dimming glass 2) that is arranged at a predetermined position in an area surrounding the vehicle interior and whose light transmittance changes depending on the applied voltage; a lighting control unit (lighting control unit 14) that controls driving of lighting (4) in the vehicle interior in conjunction with the control of the dimming control unit, the dimming unit is in a colored state when the absolute value of the applied voltage is equal to or greater than a first threshold, and is in a transparent state when the absolute value of the applied voltage is less than the first threshold; The lighting control unit turns off the lighting at a timing when the absolute value of the applied voltage is less than the first threshold value.

[0040] According to the lighting control system described in [1] above, the dimming unit becomes transparent when the absolute value of the applied voltage is less than the first threshold. However, turning off the interior lighting makes it difficult to see inside the vehicle, especially at night when the surroundings are dark. Therefore, it is beneficial to use a dimming unit, such as a so-called reverse mode dimming glass, that changes from a transparent state to a colored state when an AC voltage equal to or greater than a predetermined value is applied in a part of the area surrounding the vehicle. Specifically, when this dimming unit is used in a part of the area surrounding the vehicle, even when the dimming unit momentarily becomes transparent due to the application of an AC voltage, the risk of privacy being violated can be reduced, for example, the risk of the interior of the vehicle being photographed by a high-performance camera can be reduced.

[0041] [2] The dimming control unit sends information about an AC voltage waveform for controlling the dimming unit to the lighting control unit, the lighting control unit switches the lighting on and off based on information about the AC voltage waveform. The lighting control system according to [1] above.

[0042] According to the lighting control system of [2] above, by using information on the AC voltage waveform for controlling the dimmer unit for control by the lighting control unit, it is possible to easily match the timing when the voltage of the AC voltage waveform becomes small with the timing when the lighting is turned off.

[0043] [3] The lighting control unit switches the on / off state of the lighting by PWM control based on the information of the AC voltage waveform, The frequency of the PWM waveform used in the PWM control is twice the frequency of the AC voltage waveform. The lighting control system according to [2] above.

[0044] According to the lighting control system of [3] above, the lighting can be reliably turned off at the timing when the absolute value of the AC voltage becomes less than the first threshold value. [Explanation of symbols]

[0045] 2. Dimming glass (dimming part) 4. Lighting 10 Lighting Control System 12 Dimming glass inverter (dimming control unit) 14 Lighting control unit (lighting control section) 20 vehicles

Claims

1. a light control unit that applies an AC voltage to a light control unit that is arranged at a predetermined position in an area surrounding the vehicle interior and whose light transmittance changes in response to an applied voltage; a lighting control unit that controls driving of lighting in the vehicle cabin in conjunction with the control of the light adjustment control unit, the dimming unit is in a colored state when the absolute value of the applied voltage is equal to or greater than a first threshold, and is in a transparent state when the absolute value of the applied voltage is less than the first threshold; The lighting control unit turns off the lighting at a timing when the absolute value of the applied voltage is less than the first threshold.

2. the dimming control unit sends information about an AC voltage waveform for controlling the dimming unit to the lighting control unit; the lighting control unit switches the lighting on and off based on information about the AC voltage waveform. The lighting control system of claim 1 .

3. the lighting control unit switches the on / off state of the lighting by PWM control based on information about the AC voltage waveform; The frequency of the PWM waveform used in the PWM control is twice the frequency of the AC voltage waveform.

3. The lighting control system of claim 2.

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