JP6986217B2 - Dimming device, dimming system and mobile - Google Patents

Description

The present invention relates to a dimming device including a liquid crystal cell, a dimming system including such a dimming device, and a moving body including such a dimming device or a dimming system.

As a dimming device capable of adaptively changing the light transmittance, a dimming device including a liquid crystal cell capable of freely controlling the light transmittance according to an applied voltage is attracting attention. The dimming device utilizing the optical orientation of the liquid crystal is not only excellent in response performance but also has a high degree of freedom in installation, and can be installed so as to form a flat surface or a curved surface in a desired space. Further, since the liquid crystal cell can transmit light without changing the color tone, it is also excellent in color harmony with other members installed in the surroundings.

A dimming device using such a versatile liquid crystal cell is expected to be used in various fields. For example, for a moving body such as a vehicle such as the dimming film disclosed in Patent Document 1. Can also be applied.

Japanese Patent No. 6024444

The liquid crystal cell can be driven by either alternating current or direct current, but when a voltage is continuously applied to the liquid crystal cell for a long period of time, the applied voltage is preferably an alternating current voltage. When the applied voltage is a DC voltage, the pair of electrodes that apply an electric field to the liquid crystal are fixed to the anode and cathode, respectively, so that the ionic components in the liquid crystal gradually become biased over time, and finally the liquid crystal display. There is a concern that the alignment may be poor and bubbles may be generated in the liquid crystal display. Therefore, in a dimming device that is expected to be continuously driven for a relatively long period of time (for example, a dimming device mounted on a moving body such as a vehicle), in order to ensure reliability regarding the light transmission performance of the liquid crystal cell. , It is preferable that the voltage applied to the liquid crystal cell is an AC voltage.

When the liquid crystal cell is driven by an AC voltage, the light transmittance of the liquid crystal decreases when the direction of the applied voltage changes. Such a decrease in light transmittance tends to be particularly noticeable in a drive type liquid crystal cell having excellent response performance, and the light transmittance of the liquid crystal cell may decrease periodically depending on the frequency of the applied voltage.

When the light transmittance of the liquid crystal cell decreases periodically, the light from the illuminant that repeats blinking periodically cannot be properly visually recognized through the liquid crystal cell, or the light incident through the liquid crystal cell (that is, an image). It may not be possible to properly record an image on the imaging device that captures the image.

For example, a traffic light installed on a road is usually rectified with a current from an AC power supply of 50 Hz (hertz) or 60 Hz, and blinks periodically at a rate of 100 or 120 times per second. ing. When the blinking cycle of the light of the traffic light and the decrease cycle of the light transmittance in the liquid crystal cell interfere with each other, the liquid crystal cell cannot properly transmit the light from the traffic light, and the vehicle occupant is forced to use the traffic light. It may not be possible to properly see the light from. Further, a commercially available drive recorder periodically records an image at a frame rate of, for example, 30 fps or 20 fps. When the shooting cycle of the drive recorder and the cycle of the decrease in light transmittance in the liquid crystal cell interfere with each other, the image pickup apparatus may not be able to properly record the light (that is, the image) transmitted through the liquid crystal cell. ..

The present invention has been made in view of the above circumstances, and when light from a light emitting body that periodically emits light is incident on a liquid crystal cell that can be driven by alternating current, the light from such a light emitting body is emitted. It is an object of the present invention to provide a technique for preventing obstruction by a liquid crystal cell. Another object of the present invention is to provide a technique for preventing the recording by the photographing device from being hindered by the liquid crystal cell when the photographing device periodically records the light incident through the liquid crystal cell that can be driven by alternating current. And.

One aspect of the present invention is a liquid crystal cell having an electrode portion, a liquid crystal portion having a liquid crystal portion whose light transmission rate changes according to a voltage applied to the electrode portion, and an electrode portion under the control of a frequency control unit. It is an applied voltage adjusting unit that adjusts the voltage to be applied, and includes an applied voltage adjusting unit that can adjust the voltage applied to the electrode unit to at least an AC voltage, and the applied voltage adjusting unit emits light that approaches the liquid crystal cell. When the information on the detection of the body and / or the information on the detection of the shooting operation of the shooting device that shoots the light passing through the liquid crystal cell is input to the frequency control unit, the frequency of the voltage applied to the electrode unit is the light emission of the light emitter. The present invention relates to a dimming device that adjusts a voltage applied to an electrode portion so that the frequency is other than a frequency that is a fraction of a positive integer of the cycle and / or the shooting cycle of the photographing device.

When the information regarding the detection of the light emitting body and / or the information regarding the detection of the shooting operation of the photographing device is not input to the frequency control unit, the applied voltage adjusting unit applies an AC voltage to the electrode unit, and the information regarding the detection of the light emitting body and / Alternatively, when information regarding the detection of the photographing operation of the photographing apparatus is input to the frequency control unit, a DC voltage may be applied to the electrode unit.

When the information regarding the detection of the light emitting body and / or the information regarding the detection of the shooting operation of the photographing device is not input to the frequency control unit, the applied voltage adjusting unit applies an AC voltage having a first frequency to the electrode unit and the light emitting body. When the information regarding the detection of and / or the information regarding the detection of the photographing operation of the photographing apparatus is input to the frequency control unit, the frequency is a second frequency different from the first frequency and the emission cycle and / or the photographing cycle is positive. An AC voltage having a second frequency, which is a frequency other than a frequency that is a fraction of an integral number, may be applied to the electrode portion.

When the information regarding the detection of the light emitting body and / or the information regarding the detection of the photographing operation of the photographing apparatus is input to the frequency control unit, the applied voltage adjusting unit sets the frequency of the voltage applied to the electrode unit to the emission cycle and / or the photographing. Adjust the frequency of the voltage applied to the electrode portion so that the frequency is other than a frequency that is 1 times a positive integer of the cycle and a frequency other than a frequency that is a positive integer multiple of the emission cycle and / or the shooting cycle. May be good.

Another aspect of the present invention includes an electrode portion, a liquid crystal portion having a liquid crystal portion whose light transmission rate changes according to the voltage applied to the electrode portion, and a liquid crystal cell having the electrode portion, and an applied voltage adjustment for adjusting the voltage applied to the electrode portion. A dimming device including a unit, a illuminant detection unit that detects the approach of the illuminant to the liquid crystal cell, and a frequency control unit that controls an applied voltage adjustment unit based on the detection result of the illuminant detection unit. When the detection result of the light emitter detection unit indicates that the light emitter exists within the approach range determined based on the liquid crystal cell, the frequency control unit determines the frequency of the voltage applied to the electrode unit as the light emission cycle of the light emitter. The present invention relates to a dimming system that controls an applied voltage adjusting unit to adjust the voltage applied to the electrode unit so that the frequency is other than a frequency that is one times a positive integer of.

The illuminant detection unit may detect the approach of the illuminant to the liquid crystal cell based on the position information acquired by the global positioning system and the map information including the position information of the illuminant.

The light emitter detection unit includes an image sensor that acquires an image of an object approaching the liquid crystal cell, and an image analysis unit that analyzes the image acquired by the image sensor and detects the approach of the light emitter to the liquid crystal cell. You may have.

Another aspect of the present invention includes an electrode portion, a liquid crystal portion having a liquid crystal portion whose light transmission rate changes according to the voltage applied to the electrode portion, and a liquid crystal cell having the electrode portion, and an applied voltage adjustment for adjusting the voltage applied to the electrode portion. Controls the applied voltage adjustment unit based on the detection results of the dimming device including the unit, the imaging device that captures the light that has passed through the liquid crystal cell, the imaging detection unit that detects the operation of the imaging device, and the imaging detection unit. When the detection result of the imaging detection unit indicates that the imaging device performs an imaging operation, the frequency control unit is provided with a frequency control unit, and the frequency of the voltage applied to the electrode unit is the positive of the imaging cycle of the imaging device. The present invention relates to a dimming system that controls an applied voltage adjusting unit to adjust the voltage applied to the electrode unit so that the frequency is other than a frequency that is one integral of a fraction of the above.

Another aspect of the present invention relates to a moving body including the above-mentioned dimming device.

Another aspect of the present invention relates to a mobile body including the above dimming system.

According to the present invention, when light from a light emitting body that emits light periodically is incident on a liquid crystal cell that can be driven by AC, the light from such a light emitting body is prevented from being obstructed by the liquid crystal cell. be able to. Further, according to the present invention, when the photographing apparatus periodically records the light incident through the AC-driving liquid crystal cell, it is possible to prevent the recording by the photographing apparatus from being hindered by the liquid crystal cell.

FIG. 1 is a diagram showing a vehicle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a typical example of a liquid crystal cell. FIG. 3 is a block diagram showing a configuration example of a dimming device and a dimming system. FIG. 4 is a flowchart showing a control flow of the first drive control method, and particularly shows a control flow performed based on information regarding detection of a light emitting body. FIG. 5 is a flowchart showing a control flow of the second drive control method, and particularly shows a control flow performed based on information regarding detection of a light emitting body. FIG. 6 is a block diagram showing a modified example of the light emitting body detection unit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, in order to facilitate illustration and understanding, the size of each element shown in the drawings, the size ratio between the elements, etc. do not always match between the drawings, but those skilled in the art can refer to the elements shown in the drawings. You can easily understand the size and size ratio.

FIG. 1 is a diagram showing a vehicle 10 according to an embodiment of the present invention.

In the following description, the vehicle 10 is exemplified as a moving body on which the dimming device 21 and the dimming system 22 according to the embodiment of the present invention are mounted, but other moving bodies and stationary bodies are also described below. Similar to the vehicle 10 described, the dimming device 21 and the dimming system 22 can be mounted. Further, in FIG. 1, the dimming device 21 and the dimming system 22 are collectively shown in the front portion of the vehicle 10, but as will be described later, each element constituting the dimming device 21 and the dimming system 22 is shown. , They are provided separately from each other, and the actual installation position of each element is not particularly limited.

The liquid crystal cell 25 mounted on the vehicle 10 shown in FIG. 1 is embedded between the laminated glasses constituting the windshield 11, and is provided as a sun visor in a part (particularly the upper portion) of the windshield 11. .. Therefore, the voltage applied to the liquid crystal cell 25 is adjusted according to the traveling environment of the vehicle 10, and the light transmittance of the liquid crystal cell 25 is optimized. For example, during normal operation, by increasing the light transmittance of the liquid crystal cell 25 so that the liquid crystal cell 25 becomes transparent, a clear view of the vehicle occupant can be ensured. On the other hand, when the sunlight inside the vehicle 10 is strong, the light transmittance of the liquid crystal cell 25 is lowered to protect the eyes of the vehicle occupants from the direct sunlight and secure the field of view. Such adjustment of the light transmittance of the liquid crystal cell 25 may be performed manually in response to an instruction from the passenger, or directly or indirectly detects the intensity of the sunlight shining into the vehicle 10. It may be performed automatically according to the detection result of the device.

The specific method for adjusting the light transmittance of the liquid crystal cell 25 is not particularly limited. For example, the light transmittance of the liquid crystal cell 25 can be adjusted by changing the magnitude of the voltage applied to the electrode portion of the liquid crystal cell 25. Further, while fixing the magnitude of the voltage applied to the electrode portion of the liquid crystal cell 25, the voltage is periodically applied and not applied to the electrode portion, and the "time for applying the voltage to the electrode portion and the electrode portion" per cycle are performed. It is also possible to adjust the light transmittance of the liquid crystal cell 25 by changing the ratio (that is, the duty ratio) with the time when no voltage is applied to the liquid crystal cell 25. It is also possible to adjust the light transmittance of the liquid crystal cell 25 by shifting the phases of the voltages applied to the pair of electrode portions (that is, the two electrode portions) that apply an electric field to the liquid crystal. Since each of these light transmittance adjusting methods has a unique advantage, the liquid crystal cell 25 can adopt an arbitrary light transmittance adjusting method that can be AC-driven according to the required performance and the like.

When the liquid crystal cell 25 is installed on the windshield 11 as shown in FIG. 1, the driver of the vehicle 10 uses the light emitting body 16 of the traffic light 15 (for example, an LED (Light Emitting Diode) that emits a blue-red-yellow signal or an arrow signal. )) Needs to be visually recognized via the liquid crystal cell 25. Further, when a photographing device 17 such as a drive recorder is installed at a position close to the liquid crystal cell 25 (for example, a ceiling portion in the vehicle 10), the photographing device 17 captures light (that is, an image) that has passed through the liquid crystal cell 25. become.

The dimming device 21 and the dimming system 22 of the present embodiment suppress the light from the light emitter 16 from being obstructed by the liquid crystal cell 25 by adjusting the voltage applied to the electrode portion of the liquid crystal cell 25. It also prevents the image recording by the photographing device 17 from being obstructed by the liquid crystal cell 25.

Hereinafter, specific configuration examples of the dimming device 21 and the dimming system 22 will be described.

FIG. 2 is a cross-sectional view schematically showing a typical example of the liquid crystal cell 25. Note that FIG. 2 shows only a part of the liquid crystal cell 25 near the center.

The liquid crystal cell 25 shown in FIG. 2 includes a layered first polarizing element 26, a first resin base material 28, a first electrode portion 30, a first alignment film 32, a liquid crystal portion 34, and a second alignment film 33, which are sequentially stacked. A second electrode portion 31, a second resin base material 29, and a second polarizing element 27 are provided.

The first polarizing element 26 and the second polarizing element 27 are composed of members that perform a desired polarization function, and are typically made by stretching PVA (polyvinyl alcohol) doped with an iodine compound. The arrangement form of the first polarizing element 26 and the second polarizing element 27 is not particularly limited, and for example, the first polarizing element 26 and the second polarizing element 27 can be arranged in the form of parallel Nicol or cross Nicol.

The first electrode portion 30 and the second electrode portion 31 are supported by the transparent first resin base material 28 and the second resin base material 29, respectively, and are configured as transparent electrodes by a material such as ITO (Indium Tin Oxide). The arrangement mode of the first electrode portion 30 and the second electrode portion 31 is not particularly limited, and the electrodes may be arranged only at predetermined positions by patterning formation, or the electrodes may be arranged in a solid shape. A conductive portion composed of an FPC (see FIG. 3) described later is connected to the first electrode portion 30 and the second electrode portion 31, and a current is passed through the first electrode portion 30 and the second electrode portion 31. The electric field acting on the liquid crystal unit 34 changes according to the voltage applied, and the orientation of the liquid crystal molecules in the liquid crystal unit 34 is adjusted.

The first alignment film 32 and the second alignment film 33 impart orientation according to the driving method to the liquid crystal of the liquid crystal unit 34. Typically, a resin layer such as polyimide is subjected to a rubbing treatment to form a first alignment film 32 and a second alignment film 33, or a polymer film is irradiated with linearly polarized ultraviolet rays to increase the height in the polarization direction. The first alignment film 32 and the second alignment film 33 are produced based on the photoalignment method in which the molecular chains are selectively reacted.

The liquid crystal portion 34 is filled with liquid crystal, and the light transmittance changes according to the voltage applied to the first electrode portion 30 and the second electrode portion 31. The drive system of the liquid crystal unit 34 is not particularly limited, and is, for example, a VA (Vertical Element) type, a TN (Twisted Nematic) type, an IPS (In-Place-Switching) type, an FFS (Fringe Field Switching) type, or a guest host type. The liquid crystal unit 34 of the above can be used in the liquid crystal cell 25. Therefore, the liquid crystal cell 25 is not necessarily limited to the configuration shown in FIG. 2, and has an arbitrary configuration according to the drive method of the liquid crystal unit 34. For example, in the liquid crystal cell 25 that employs the IPS type liquid crystal unit 34, the liquid crystal unit is not arranged at the position where the liquid crystal unit 34 is sandwiched (see the first electrode unit 30 and the second electrode unit 31 shown in FIG. 2). The electrode portion may be arranged only on one side of 34. Further, in the liquid crystal cell 25 that employs the guest-host type liquid crystal unit 34 including the dichroic dye (guest) and the liquid crystal (host), the liquid crystal is imparted to the liquid crystal by the alignment film (that is, the first alignment film 32 and the second alignment film 33). Depending on the orientation to be formed, the polarizing element may be provided only on one side of the liquid crystal unit 34, or the polarizing element may not be provided.

In general, the periodic decrease in the light transmittance of the liquid crystal cell during AC drive tends to be remarkable in the liquid crystal cell of the drive method having a high response speed. Therefore, the merits described later brought about by the dimming device 21 and the dimming system 22 of the present embodiment, which can solve the problems caused by the periodic decrease in the light transmittance, are, for example, VA type and TN type (particularly VA type). When the liquid crystal cell 25 adopts a drive system having a high response speed as described above, it is more effectively enjoyed.

Further, the liquid crystal cell 25 may include elements other than the above-mentioned elements, for example, a spacer for maintaining the space between the liquid crystal layers, a sealing portion, an index matching layer, a hard coat layer, and other functional bodies and functions. A layer may be provided.

Next, a specific example of the device configuration for driving and controlling the liquid crystal cell 25 will be described.

FIG. 3 is a block diagram showing a configuration example of the dimming device 21 and the dimming system 22. In FIG. 3, only the first electrode portion 30, the second electrode portion 31, and the liquid crystal portion 34 are shown as the elements constituting the liquid crystal cell 25, and the illustration of other elements is omitted.

The dimming device 21 includes the above-mentioned liquid crystal cell 25 and an applied voltage adjusting unit 44 that is electrically connected to the liquid crystal cell 25 via an FPC (Flexible Printed Circuits) 45. In addition to such a dimming device 21, the dimming system 22 includes a frequency control unit 46 that controls the applied voltage adjustment unit 44, a photographing detection unit 47 and a light emitting body detection unit 48 that are connected to the frequency control unit 46, respectively. A photographing device 17 connected to the detection unit 47 and a GPS (Global Positioning System) 18 connected to the light emitter detection unit 48 are provided.

The applied voltage adjusting unit 44 is electrically connected to the alternator 41 via the AC / DC converter 42, and is applied to the first electrode unit 30 and the second electrode unit 31 of the liquid crystal cell 25 via the FPC 45. The voltage is adjusted under the control of the frequency control unit 46. The applied voltage adjusting unit 44 can adjust the voltage applied to the first electrode unit 30 and the second electrode unit 31 to at least an AC voltage, and as will be described later, the applied voltage adjusting unit 44 can be applied to the first electrode unit 30 and the second electrode unit 31. The frequency of the applied AC voltage can be changed, and the voltage applied to the first electrode unit 30 and the second electrode unit 31 can be switched between the DC voltage and the AC voltage. Such an applied voltage adjusting unit 44 can be configured by an arbitrary electric circuit, and may have a so-called AC / AC converter, DC / AC converter, AC / DC converter, or DC / DC converter, if necessary.

The alternator 41 uses the rotation of the engine (not shown) of the vehicle 10 as a power source to generate AC electricity and output it to the AC / DC converter 42. The alternating current / direct current converter 42 is typically composed of a rectifier (ie, a rectifier) and a regulator, and rectifies the alternating current supplied from the alternator 41 to direct current. The direct current output from the AC / DC converter 42 is output to the applied voltage adjusting unit 44 or is output to the battery 43 and stored.

The mode of supplying electric power to the applied voltage adjusting unit 44 (that is, the mode of applying current and voltage to the applied voltage adjusting unit 44) is not particularly limited. As shown in FIG. 3, a direct current may be applied from the AC / DC converter 42 to the applied voltage adjusting unit 44, or a direct current may be applied from the battery 43 to the applied voltage adjusting unit 44. Further, as shown by the alternate long and short dash line in FIG. 3, alternating current may be directly applied from the alternator 41 to the applied voltage adjusting unit 44. Further, a device other than the alternator 41 may be used as a power source for the current supplied to the applied voltage adjusting unit 44. For example, a current may be supplied to the applied voltage adjusting unit 44 from a lithium ion battery or a capacitor provided separately from the existing battery 43. Further, a current may be supplied to the applied voltage adjusting unit 44 from a high-voltage, large-capacity drive battery that stores electricity generated by the hybrid motor. Further, the electric power from such a drive battery may be sent to the battery 43 via the DC / DC converter to be stored, and the current may be supplied from the battery 43 to the applied voltage adjusting unit 44.

The frequency control unit 46 controls the applied voltage adjustment unit 44 based on the detection result of the light emitter detection unit 48 and / or the detection result of the photographing detection unit 47. Therefore, the applied voltage adjusting unit 44, under the control of the frequency control unit 46, has the first electrode unit 30 and the second electrode unit 31 according to the detection result of the light emitter detection unit 48 and / or the detection result of the photographing detection unit 47. Adjust the voltage applied to. A specific voltage adjustment method by the frequency control unit 46 and the applied voltage adjustment unit 44 will be described later.

The light emitting body detection unit 48 detects the presence or absence of the light emitting body 16 approaching the liquid crystal cell 25. The light emitting body detection unit 48 shown in FIG. 3 is based on the position information acquired by the GPS 18 installed in the vehicle 10 and the map information MI including the position information of the light emitting body 16 (the signal 15 in this embodiment). The presence or absence of the light emitter 16 approaching the liquid crystal cell 25 is detected. That is, the light emitter detection unit 48 compares the position information continuously acquired via the GPS 18 with the map information MI, and determines a predetermined approach range based on the position of the vehicle 10 (that is, the position of the liquid crystal cell 25). It detects whether or not the traffic light 15 (that is, the light emitter 16) is present inside. The predetermined approach range referred to here is appropriately determined according to the type of the light emitting body 16 to be detected, and when the light emitting body 16 of the traffic light 15 is the detection target as in the present embodiment, it is usually in front of the vehicle 10. Moreover, the upper range is defined as a predetermined approach range. The detection result of the light emitter detection unit 48 is sent to the frequency control unit 46, and can be used as basic information when the applied voltage adjustment unit 44 is controlled by the frequency control unit 46. The illuminant detection unit 48 shown in FIG. 3 reads and uses the map information MI stored in the storage unit 49 provided separately from the illuminant detection unit 48, but the illuminant detection unit 48 is used. The map information MI may be stored in a storage unit (not shown) provided in the map information MI.

The photographing detection unit 47 detects the operation of the photographing device 17 that photographs the light that has passed through the liquid crystal cell 25. That is, the photographing detection unit 47 acquires the operation information of the photographing device 17, and detects whether or not the mode of the photographing device 17 is the photographing mode based on the operation information. The shooting mode referred to here includes not only the case where the shooting device 17 is actually shooting, but also the case where the shooting device 17 is in a state of performing a preliminary operation prior to the shooting. It can be. The detection result of the photographing detection unit 47 is sent to the frequency control unit 46, and can be used as basic information when the applied voltage adjustment unit 44 is controlled by the frequency control unit 46. The image pickup detection unit 47 may be provided integrally with the image pickup device 17 or may be provided as a separate body. For example, the image pickup detection unit 47 may be configured by a controller that controls the image pickup element of the image pickup device 17. good.

Next, a method of driving and controlling the liquid crystal cell 25 by the above-mentioned device configuration will be described.

When the information regarding the detection of the light emitting body 16 approaching the liquid crystal cell 25 is input from the light emitting body detecting unit 48 to the frequency control unit 46, the applied voltage adjusting unit 44 imparts the information to the first electrode unit 30 and the second electrode unit 31. So that the frequency Pc of the voltage to be applied is a frequency other than the frequency of "1 / positive integer" of the emission period Pi of the light emitter 16 (that is, "Pc ≠ (Pi / N)" (however, "N" is (Positive integer) is satisfied), more preferably the frequency Pc of the voltage applied to the first electrode portion 30 and the second electrode portion 31 is "one-fold of a positive integer" of the emission period Pi of the illuminant 16. (That is, "Pc ≠ (Pi / N)" and "Pc ≠ (Pi × N)" are satisfied) so that the frequency is other than the frequency of "" and other than the frequency of "positive integral multiple". The voltage applied to the electrode portion 30 and the second electrode portion 31 is adjusted.

Similarly, when the information regarding the detection of the photographing operation of the photographing apparatus 17 for photographing the light passing through the liquid crystal cell 25 is input from the photographing detection unit 47 to the frequency control unit 46, the applied voltage adjusting unit 44 is the first electrode unit. The frequency Pc of the voltage applied to the 30 and the second electrode portion 31 is set to a frequency other than the frequency "1 times a positive integer" of the photographing cycle Pp of the photographing apparatus 17 (that is, "Pc ≠ (Pp / Pp /)". N) ”is satisfied), more preferably the frequency Pc of the voltage applied to the first electrode portion 30 and the second electrode portion 31 is“ one-folder of a positive integer ”of the photographing cycle Pp of the photographing apparatus 17. 1st electrode so that the frequency is other than the frequency of and other than the frequency of "positive integral multiple" (that is, "Pc ≠ (Pp / N)" and "Pc ≠ (Pp × N)" are satisfied). The voltage applied to the portion 30 and the second electrode portion 31 is adjusted.

When "information regarding the detection of the light emitting body 16 approaching the liquid crystal cell 25" is input to the frequency control unit 46, the light emitting body 16 exists within a predetermined approach range determined based on the liquid crystal cell 25. This refers to the case where the detection result of the light emitter detection unit 48 indicating that the detection result is sent to the frequency control unit 46. Therefore, when the detection result of the illuminant detection unit 48 indicating that the illuminant 16 does not exist within the predetermined approach range is sent to the frequency control unit 46, "information regarding the detection of the illuminant 16 approaching the liquid crystal cell 25". Is not applicable when is input to the frequency control unit 46. Similarly, when "information regarding the detection of the photographing operation of the photographing apparatus 17 for photographing the light passing through the liquid crystal cell 25" is input to the frequency control unit 46, the photographing apparatus 17 performs the photographing operation (that is, photographing). Refers to the case where the detection result of the photographing detection unit 47 indicating that the mode of the apparatus 17 is the photographing mode) is sent to the frequency control unit 46. Therefore, when the detection result of the photographing detection unit 47 indicating that the photographing device 17 is not performing the photographing operation is sent to the frequency control unit 46, "the photographing operation of the photographing apparatus 17 for photographing the light passing through the liquid crystal cell 25". This does not apply when "information regarding detection" is input to the frequency control unit 46.

As a drive control method based on these "information on the detection of the light emitting body 16" and "information on the detection of the photographing operation of the photographing apparatus 17," the applied voltage adjusting unit 44 typically has the first electrode unit 30 and the second. The first drive control method for switching the voltage applied to the electrode unit 31 between the AC voltage and the DC voltage, and the frequency of the AC voltage applied to the first electrode unit 30 and the second electrode unit 31 by the applied voltage adjusting unit 44. A second drive control method for switching between the two is mentioned.

Hereinafter, these first drive control method and second drive control method will be described. In the following description, the drive control based mainly on the above-mentioned "information on the detection of the light emitting body 16" is exemplified, but the drive control based on the above-mentioned "information on the detection of the photographing operation of the photographing apparatus 17" is also basically exemplified. It can be carried out by a similar processing step.

<First drive control method>
In the first drive control method, the applied voltage adjusting unit 44 inputs the AC voltage to the first electrode when the information regarding the detection of the light emitting body 16 and / or the information regarding the detection of the photographing operation of the photographing apparatus 17 is not input to the frequency control unit 46. It is applied to the portion 30 and the second electrode portion 31. On the other hand, when the information regarding the detection of the light emitting body 16 and / or the information regarding the detection of the photographing operation of the photographing apparatus 17 is input to the frequency control unit 46, the applied voltage adjusting unit 44 applies the DC voltage to the first electrode unit 30 and the second electrode unit 30 and the second. It is applied to the electrode portion 31. Therefore, the applied voltage adjusting unit 44 used in this drive control method includes an electric circuit capable of producing both alternating current and direct current and sending them to the first electrode unit 30 and the second electrode unit 31.

FIG. 4 is a flowchart showing a control flow of the first drive control method, and particularly shows a control flow performed based on information regarding detection of the light emitting body 16.

When the liquid crystal cell 25 is driven and controlled according to the first drive control method, an AC voltage is first applied to the first electrode portion 30 and the second electrode portion 31 by the applied voltage adjusting unit 44 (see S11 in FIG. 4). The frequency of this AC voltage is not particularly limited, but when the usage conditions of the liquid crystal cell 25 are comprehensively taken into consideration, an AC voltage having a frequency of about 30 to 120 Hz (particularly about 30 to 70 Hz) is applied to the first electrode portion 30 and the second electrode unit 30 and the second. It is assumed that it can be preferably used as an AC voltage applied to the electrode unit 31, but in such a frequency band, a frequency that may interfere with the light emission cycle of the light emitter 16 of the signal device 15 or the shooting cycle of the photographing device 17 is set. Can be included. Therefore, for example, when the vehicle 10 (that is, the liquid crystal cell 25) is close to the traffic light 15 (that is, the light emitter 16), it is preferable to continue applying such an AC voltage to the first electrode portion 30 and the second electrode portion 31. It may not be.

Therefore, the frequency control unit 46 continuously monitors whether or not the light emitter 16 exists within a predetermined approach range determined based on the liquid crystal cell 25 based on the detection result of the light emitter detection unit 48 (S12). ). When it is determined that the light emitter 16 does not exist in the close range (N in S12), the frequency control unit 46 controls the applied voltage adjustment unit 44, and the first electrode unit 30 and the second electrode unit 31 have an AC voltage. Continues to be granted (S11).

On the other hand, when it is detected that the light emitting body 16 is present within the approach range (Y in S12), the frequency control unit 46 controls the applied voltage adjusting unit 44, and the applied voltage adjusting unit 44 creates a DC voltage to obtain a second voltage. 1 is applied to the electrode portion 30 and the second electrode portion 31 (S13). As a result, an electric field continues to act on the liquid crystal molecules of the liquid crystal cell 25 in a certain direction, the light transmission rate of the liquid crystal cell 25 does not decrease periodically, and the liquid crystal cell 25 interferes with the periodic blinking of the light emitter 16. The light from the light emitting body 16 can be appropriately transmitted without doing so. Therefore, the driver of the vehicle 10 can appropriately visually recognize the light (that is, the signal) emitted from the light emitting body 16 through the liquid crystal cell 25.

In the frequency control unit 46, even while the DC voltage is applied to the first electrode unit 30 and the second electrode unit 31, the light emitter 16 is within a predetermined approach range based on the detection result of the light emitter detection unit 48. It continuously monitors whether or not it exists (S14). While the presence of the light emitter 16 continues to be detected within the close range (N in S14), the frequency control unit 46 controls the applied voltage adjustment unit 44, and the first electrode unit 30 and the second electrode unit 31 are used. The DC voltage continues to be applied (S13).

On the other hand, when it is determined that the light emitter 16 does not exist within the approach range (Y in S14), the frequency control unit 46 controls the applied voltage adjusting unit 44, and the applied voltage adjusting unit 44 creates an AC voltage. It is applied to the first electrode portion 30 and the second electrode portion 31 (S15). As a result, it is possible to prevent the ionic components in the liquid crystal of the liquid crystal cell 25 from being biased, and to prevent the liquid crystal from being misaligned and the generation of bubbles in the liquid crystal.

By performing drive control of the liquid crystal cell 25 according to a control flow in which the above-mentioned series of steps S11 to S15 are continuously repeated, interference between the cycle of decrease in the light transmittance of the liquid crystal cell 25 and the light emission cycle of the light emitter 16 is caused. While preventing this, it is possible to effectively prevent the ionic component from being biased in the liquid crystal of the liquid crystal cell 25. In particular, when the light emitting body 16 is detected within the close range, a DC voltage is applied to the first electrode portion 30 and the second electrode portion 31, so that the light emitting cycle of the light emitting body 16 does not depend on the specific value. It is possible to surely prevent the interference between the cycle of the decrease in the light transmittance of the liquid crystal cell 25 and the light emission cycle of the light emitting body 16. Therefore, high reliability can be ensured regarding the light transmission performance of the liquid crystal cell 25, and the driver of the vehicle 10 can appropriately visually recognize the light signal from the light emitting body 16 of the traffic light 15.

The first drive control method shown in FIG. 4 described above can be similarly applied to drive control based on "information on detection of imaging operation of the imaging device 17". That is, the frequency control unit 46 continuously monitors whether or not the photographing apparatus 17 performs a photographing operation based on the detection result of the photographing detecting unit 47. While it is determined that the photographing device 17 does not perform the photographing operation, the frequency control unit 46 controls the applied voltage adjusting unit 44 and continues to apply the AC voltage to the first electrode unit 30 and the second electrode unit 31 (S11). And S15). On the other hand, while the photographing device 17 is determined to perform the photographing operation, the frequency control unit 46 controls the applied voltage adjusting unit 44 and continues to apply the DC voltage to the first electrode unit 30 and the second electrode unit 31 ( See S13).

As described above, the above-mentioned first drive control method is applied to both the drive control based on "information regarding the detection of the light emitting body 16" and the drive control based on "information regarding the detection of the photographing operation of the photographing apparatus 17". can do. Further, even when both of these drive controls are performed at the same time, the liquid crystal cell 25 is adjusted by adjusting the voltage applied to the first electrode portion 30 and the second electrode portion 31 according to the control flow of the first drive control method described above. While preventing the cycle of decrease in the light transmittance of the can.

<Second drive control method>
In the second drive control method, the applied voltage adjusting unit 44 sets the first frequency P1 when the information regarding the detection of the light emitting body 16 and / or the information regarding the detection of the photographing operation of the photographing apparatus 17 is not input to the frequency control unit 46. The AC voltage to be possessed is applied to the first electrode portion 30 and the second electrode portion 31. On the other hand, when the information regarding the detection of the light emitting body 16 and / or the information regarding the detection of the photographing operation of the photographing apparatus 17 is input to the frequency control unit 46, the applied voltage adjusting unit 44 uses an AC voltage having a second frequency P2. 1 is applied to the electrode portion 30 and the second electrode portion 31. Therefore, the applied voltage adjusting unit 44 used in this drive control method includes an electric circuit capable of creating AC voltages having different frequencies and sending them to the first electrode unit 30 and the second electrode unit 31.

FIG. 5 is a flowchart showing a control flow of the second drive control method, and particularly shows a control flow performed based on information regarding detection of the light emitting body 16.

When the liquid crystal cell 25 is driven and controlled according to the second drive control method, first, the applied voltage adjusting unit 44 applies an AC voltage of the first frequency P1 to the first electrode unit 30 and the second electrode unit 31 (FIG. 5). See S21). The first frequency P1 is not particularly limited, but it is assumed that a frequency of about 30 to 120 Hz (particularly about 30 to 70 Hz) can be preferably used as the first frequency P1 in consideration of the usage conditions of the liquid crystal cell 25. When the vehicle 10 is close to the signal 15, it may not be preferable to continue applying the AC voltage of the first frequency P1 to the first electrode portion 30 and the second electrode portion 31.

Therefore, the frequency control unit 46 continuously monitors whether or not the light emitter 16 exists within a predetermined approach range determined based on the liquid crystal cell 25 based on the detection result of the light emitter detection unit 48 (S22). ). When it is determined that the light emitter 16 does not exist within the close range (N in S22), the frequency control unit 46 controls the applied voltage adjustment unit 44, and the first electrode unit 30 and the second electrode unit 31 have the first The AC voltage of the frequency P1 of is continuously applied (S21).

On the other hand, when it is detected that the light emitter 16 is present within the approach range (Y in S22), the frequency control unit 46 controls the applied voltage adjustment unit 44, and the AC voltage of the second frequency P2 is set to the first electrode. It is applied to the portion 30 and the second electrode portion 31 (S23). This second frequency P2 is a frequency different from that of the first frequency P1, and is a frequency other than a frequency that is a multiple of a positive integer of the light emission cycle of the light emitter 16 and / or the shooting cycle of the photographing device 17. It is preferable that the frequency is other than a frequency that is a fraction of a positive integer and / or a frequency that is not a positive integer multiple of the light emission cycle of the light emitting body 16 and / or the photographing cycle of the photographing device 17. As a result, it is possible to prevent the periodic decrease in the light transmittance of the liquid crystal cell 25 from interfering with the periodic blinking of the light emitting body 16, and the liquid crystal cell 25 appropriately transmits the light from the light emitting body 16. .. Therefore, the driver of the vehicle 10 can appropriately visually recognize the light (that is, the signal) emitted from the light emitting body 16 through the liquid crystal cell 25.

The second frequency P2 may be a predetermined frequency or a frequency appropriately determined according to the type of the detected illuminant 16. As described above, if the detection target is the light emitting body 16 of the traffic light 15, the light emitting cycle is usually predetermined, so that the light emitting cycle of the light emitting body 16 of such a traffic light 15 is not interfered with in advance. The frequency can be used as the second frequency P2. Further, the frequency control unit 46 may receive information regarding the light emission cycle of the light emitting body 16 and determine a frequency that does not interfere with the light emission cycle of the light emitting body 16 as the second frequency P2 according to the received information. This also applies to the drive control based on "information regarding the detection of the photographing operation of the photographing device 17," and the second frequency P2 may be a predetermined frequency, or the detected photographing device 17 may have a second frequency P2. The frequency may be appropriately determined according to the shooting cycle.

The frequency control unit 46 has a predetermined approach range based on the detection result of the light emitter detection unit 48 even while the AC voltage of the second frequency P2 is applied to the first electrode unit 30 and the second electrode unit 31. The presence or absence of the illuminant 16 is continuously monitored (S24). While the presence of the light emitter 16 continues to be detected within the close range (N of S24), the frequency control unit 46 controls the applied voltage adjustment unit 44, and the first electrode unit 30 and the second electrode unit 31 are second. The AC voltage of frequency P2 continues to be applied (S23).

On the other hand, when it is determined that the light emitter 16 does not exist within the approach range (Y in S24), the frequency control unit 46 controls the applied voltage adjusting unit 44, and the applied voltage adjusting unit 44 controls the first frequency P1. The AC voltage of the above is generated and applied to the first electrode portion 30 and the second electrode portion 31 (S25).

By performing drive control of the liquid crystal cell 25 according to a control flow in which the above-mentioned series of steps S21 to S25 are continuously repeated, interference between the cycle of decrease in the light transmittance of the liquid crystal cell 25 and the light emission cycle of the light emitter 16 is caused. Can be prevented. Therefore, high reliability can be ensured with respect to the light transmission performance, and the driver of the vehicle 10 can appropriately visually recognize the optical signal from the light emitting body 16 of the traffic light 15.

The second drive control method shown in FIG. 5 described above can be similarly applied to drive control based on "information regarding detection of imaging operation of the imaging device 17". That is, the frequency control unit 46 continuously monitors whether or not the photographing apparatus 17 performs a photographing operation based on the detection result of the photographing detecting unit 47. While it is determined that the photographing device 17 does not perform the photographing operation, the frequency control unit 46 controls the applied voltage adjusting unit 44, and the AC voltage of the first frequency P1 is applied to the first electrode unit 30 and the second electrode unit 31. (See S21 and S25). On the other hand, while the photographing device 17 is determined to perform the photographing operation, the frequency control unit 46 controls the applied voltage adjusting unit 44, and the first electrode unit 30 and the second electrode unit 31 are connected to the alternating current of the second frequency P2. Continue to apply voltage (see S23). Further, when the drive control based on the "information on the detection of the light emitting body 16" and the drive control based on the "information on the detection of the photographing operation of the photographing apparatus 17" are simultaneously performed, the control flow of the second drive control method described above is followed. By adjusting the voltage applied to the first electrode portion 30 and the second electrode portion 31, the cycle of decrease in the light transmittance of the liquid crystal cell 25 interferes with both the light emission cycle of the light emitter 16 and the shooting cycle of the photographing device 17. You can prevent it from happening.

As described above, according to the above-mentioned dimming device 21 and dimming system 22, the liquid crystal cell 25 has a light emitting body 16 that approaches the liquid crystal cell 25 or a light that has passed through the liquid crystal cell 25 is photographed. The voltage applied to the electrode portions 30 and 31 is adjusted to prevent the cycle of decrease in the light transmittance of the liquid crystal cell 25 from interfering with the light emission cycle of the light emitter 16 and the shooting cycle of the photographing device 17. As a result, high reliability is ensured regarding the light transmission performance of the liquid crystal cell 25, the driver of the vehicle 10 can appropriately visually recognize the light signal from the light emitting body 16 of the traffic light 15, and the photographing device 17 such as a drive recorder captures an image. Can be recorded properly.

[Modification example]
The present invention is not limited to the above-described embodiment, and various modifications may be applied to each element.

For example, the light emitting body detection unit 48 shown in FIG. 3 detects the light emitting body 16 of the signal 15 by comparing the position information acquired via the GPS 18 with the map information MI, as shown in FIG. In addition, the light emitting body 16 may be detected by analyzing the image data acquired by the image pickup element 51 with the image analysis unit 52. That is, the image sensor 51 is installed at a position where the light emitting body 16 can be photographed, and the image data of the object approaching the liquid crystal cell 25 is continuously acquired by the image sensor 51 and sequentially sent to the image analysis unit 52. The image analysis unit 52 analyzes the image data acquired by the image sensor 51, determines whether or not the target light emitter 16 is included in the image data, and approaches the light emitter 16 to the liquid crystal cell 25. To detect. The detection result of the image analysis unit 52 is sent to the frequency control unit 46. The frequency control unit 46 controls the applied voltage adjusting unit 44 based on the detection result of the image analysis unit 52, and adjusts the voltage applied to the first electrode unit 30 and the second electrode unit 31 to adjust the voltage applied to the first electrode unit 30 and the second electrode unit 31 of the liquid crystal cell 25. It is possible to prevent interference between the cycle of decrease in light transmittance and the light emission cycle of the light emitter 16.

Further, in the above-described embodiment, the light emitting body 16 of the traffic light 15 is exemplified as a light emitting body that can prevent interference with the liquid crystal cell 25, but the specific target of the light emitting body is not particularly limited. The dimming device 21 and the dimming system 22 according to the above-described embodiments and modifications are general light emitters (for example, tail lamps and headlamps of other vehicles) capable of causing light to enter the liquid crystal cell 25 by periodically blinking. It is also possible to effectively prevent interference with). Further, the photographing device 17 is not limited to the drive recorder. The light emitting body 16 and the photographing device 17 can be appropriately determined depending on the type of the moving body on which the dimming device 21 and the dimming system 22 are mounted and the place where the dimming device 21 and the dimming system 22 are installed. .. Therefore, the liquid crystal cell 25 may be provided at a position other than the windshield 11 of the vehicle 10.

Further, other processing steps may be incorporated into the above-mentioned drive control method as needed. For example, in the above-mentioned first drive control method (see FIG. 4), when the DC voltage is applied to the first electrode portion 30 and the second electrode portion 31 for a long time, the liquid crystal cell 25 A refreshing process may be performed to prevent the ionic component from being biased in the liquid crystal display. The specific content of this refresh process is not particularly limited as long as it is a process effective for preventing the bias of the ionic component in the liquid crystal of the liquid crystal cell 25, and is applied to the first electrode portion 30 and the second electrode portion 31. The process of changing the direction of the voltage can be called the refresh process. Therefore, for example, a process of sporadically changing the direction of the DC voltage applied to the first electrode portion 30 and the second electrode portion 31, or the first electrode portion 30 and the second electrode portion for a predetermined time (for example, about several seconds to one minute). The process of applying an AC voltage to 31 can be a refresh process. Further, the execution timing of such a refresh process is not particularly limited, and for example, the frequency control unit 46 counts the time when the DC voltage is applied to the first electrode unit 30 and the second electrode unit 31, and this time. When the voltage reaches a predetermined time (for example, 1 minute to several tens of minutes or 1 hour to several tens of hours), the applied voltage adjusting unit 44 may periodically perform the refresh process under the control of the frequency control unit 46.

Embodiments of the present invention also include some components and / or methods included in one embodiment of the present invention and some components and / or methods included in other embodiments of the present invention. include. Therefore, the components and / or methods contained in each of the above-described embodiments and modifications and the embodiments of the present invention other than the above may be combined, and the embodiments related to such combinations are also the embodiments of the present invention. Included in the form. Further, the effect produced by the present invention is not limited to the above-mentioned effect, and a peculiar effect according to the specific configuration of each embodiment can be exhibited.

10 Vehicle 11 Front glass 15 Signal 16 Light emitter 17 Photographing device 21 Dimming device 22 Dimming system 25 Liquid crystal cell 26 First polarizing element 27 Second polarizing element 28 First resin base material 29 Second resin base material 30 First electrode Part 31 2nd electrode part 32 1st alignment film 33 2nd alignment film 34 Liquid crystal part 41 Alternate 42 AC / DC converter 43 Battery 44 Applied voltage adjustment part 46 Frequency control part 47 Imaging detection part 48 Luminous body detection part 49 Storage unit 51 Imaging element 52 Image analysis unit

Claims (10)

A liquid crystal cell having an electrode portion and a liquid crystal portion having a liquid crystal portion whose light transmittance changes according to a voltage applied to the electrode portion.
An applied voltage adjusting unit that adjusts the voltage applied to the electrode unit under the control of the frequency control unit, and includes an applied voltage adjusting unit that can adjust the voltage applied to the electrode unit to at least an AC voltage. ,
The applied voltage adjusting unit has input to the frequency control unit information regarding detection of a light emitter approaching the liquid crystal cell and / or information regarding detection of an imaging operation of an imaging device that captures light that has passed through the liquid crystal cell. In this case, the electrode portion is provided with a frequency other than a frequency that is a fraction of a positive integer of the emission cycle of the light emitter and / or the imaging cycle of the imaging device. A dimming device that adjusts the applied voltage. The applied voltage adjusting unit is
When the information regarding the detection of the light emitter and / or the information regarding the detection of the photographing operation of the photographing apparatus is not input to the frequency control unit, an AC voltage is applied to the electrode unit.
The dimming device according to claim 1, wherein when information regarding the detection of the light emitter and / or information regarding the detection of the photographing operation of the photographing apparatus is input to the frequency control unit, a DC voltage is applied to the electrode portion. The applied voltage adjusting unit is
When the information regarding the detection of the light emitter and / or the information regarding the detection of the imaging operation of the imaging apparatus is not input to the frequency control unit, an AC voltage having a first frequency is applied to the electrode unit.
When the information regarding the detection of the light emitting body and / or the information regarding the detection of the shooting operation of the shooting device is input to the frequency control unit, the light emission cycle and / or the light emitting cycle are at a second frequency different from the first frequency. / Or the dimming device according to claim 1, wherein an AC voltage having a second frequency, which is a frequency other than a frequency 1 times a positive integer of the photographing cycle, is applied to the electrode portion. When the information regarding the detection of the light emitter and / or the information regarding the detection of the photographing operation of the photographing apparatus are input to the frequency control unit, the applied voltage adjusting unit determines the frequency of the voltage applied to the electrode unit. On the electrode portion so that the frequency is other than a frequency other than a frequency that is a fraction of a positive integer of the light emission cycle and / or the shooting cycle, and a frequency other than a frequency that is a positive integral multiple of the light emission cycle and / or the shooting cycle. The dimming device according to any one of claims 1 to 3, wherein the frequency of the applied voltage is adjusted. Dimming including an electrode unit, a liquid crystal unit having a liquid crystal unit whose light transmission rate changes according to a voltage applied to the electrode unit, and an applied voltage adjusting unit for adjusting the voltage applied to the electrode unit. With the device
A light emitter detection unit that detects the approach of the light emitter to the liquid crystal cell,
A frequency control unit that controls the applied voltage adjustment unit based on the detection result of the light emitter detection unit is provided.
When the detection result of the light emitter detection unit indicates that the light emitter exists within the approach range determined based on the liquid crystal cell, the frequency control unit determines the frequency of the voltage applied to the electrode unit. A dimming system that controls the applied voltage adjustment unit to adjust the voltage applied to the electrode unit so that the frequency is other than a frequency that is one-folder of a positive integer of the emission cycle of the light emitter. The fifth aspect of claim 5, wherein the illuminant detection unit detects the approach of the illuminant to the liquid crystal cell based on the position information acquired by the global positioning system and the map information including the position information of the illuminant. Dimming system. The illuminant detection unit analyzes an image pickup element that acquires an image of an object approaching the liquid crystal cell and an image acquired by the image pickup element to detect the approach of the illuminant to the liquid crystal cell. The dimming system according to claim 5, further comprising an analysis unit. Dimming including an electrode unit, a liquid crystal unit having a liquid crystal unit whose light transmission rate changes according to a voltage applied to the electrode unit, and an applied voltage adjusting unit for adjusting the voltage applied to the electrode unit. With the device
An imaging device that captures the light that has passed through the liquid crystal cell, and
An imaging detection unit that detects the operation of the imaging device, and
A frequency control unit that controls the applied voltage adjustment unit based on the detection result of the imaging detection unit is provided.
When the detection result of the imaging detection unit indicates that the imaging device performs the imaging operation, the frequency control unit has a voltage frequency applied to the electrode unit equal to a positive integer of the imaging cycle of the imaging device. A dimming system that controls the applied voltage adjusting unit to adjust the voltage applied to the electrode unit so that the frequency is other than 1 times the frequency. A mobile body including the dimming device according to any one of claims 1 to 4. A mobile body comprising the dimming system according to any one of claims 5 to 8.

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