JP7119375B2 - Dimming device and method for driving the dimming device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light control device used for light control screens and windows of vehicles and buildings, and a method of driving the same.

Light control function members used in light control devices include light control laminated glass in which a light control layer is sandwiched between two glass plates with transparent electrodes so that the transparent electrode sides face each other, and transparent resin substrates with transparent electrodes. A light control sheet is used which consists of a laminated body in which the transparent electrode sides of the material are sandwiched so as to face each other.

Conventionally, a solid electrode in which a transparent conductive film is formed over the surface of a glass plate or a transparent resin substrate has been used as a transparent electrode used in a light control function member.

In a light control device using such a light control function member, when an intermediate light blocking state (or light scattering state) is to be obtained, the voltage applied between the electrodes is changed to a transparent state (no light scattering state). ) and the voltage at which an opaque state with strong light scattering is obtained (translucent state). However, at an intermediate voltage, there is a problem that unevenness due to uneven alignment of the liquid crystal layer forming the light control layer of the light control function member is likely to occur.

Therefore, there has been a demand for a light control device that can realize a semi-transparent state without unevenness. However, no prior art relating to a light control device capable of achieving a semi-transparent state without unevenness could be found. As the closest technology, for example, Patent Document 1 discloses a liquid crystal display device capable of realizing excellent wide viewing angle characteristics and high-speed response at the same time, but this is not a technology related to a light control device.

WO2009/157271

In view of the above circumstances, it is an object of the present invention to provide a light control device capable of realizing a semi-transparent state without unevenness.

As a means for solving the above problems, a first aspect of the present invention provides a light control sheet formed by laminating a light control layer between the transparent electrodes of two transparent resin substrates provided with transparent electrodes. When the haze value of the light control sheet is low, the state is defined as transparent, and when the haze value of the light control sheet is sufficiently large, the state is defined as opaque. In a light control device that provides a semi-transparent display with an intermediate haze value between states , at least one transparent electrode is a comb-shaped electrode, the other transparent electrode is a solid electrode, and two opposing electrodes of the comb-shaped electrode are , the electrodes are arranged on the base material so that the comb tooth portions of the electrodes are alternate with each other, and are connected to a power source so that the voltage applied between them and the solid electrodes can be independently controlled. It is an optical device.

In this manner, a configuration is provided in which the voltages applied to the two opposing electrodes of the comb-shaped electrode can be freely set between the comb-shaped electrode and the solid electrode on the opposite side via the light-modulating layer. Thus, an opaque state can be realized by applying a voltage to one of the electrodes to make the normal mode light control layer transparent, and at the same time applying no voltage to the other electrode. The opposite is true for reverse mode dimming layers.

In a second aspect, the light control layer of the light control device according to the first aspect changes the light control device in a normal mode to a translucent state that is intermediate between a transparent state and an opaque state. A method for driving a light control device,
An alternating voltage having the same amplitude and a smaller effective value than the alternating voltage at which the light-modulating layer becomes transparent is applied to one of the comb-shaped electrodes, and the other electrode is applied with the above-described alternating voltage. A method for driving a light control device, characterized by applying an alternating voltage whose phase is shifted from the alternating voltage at which the light control layer becomes transparent.

In a third aspect, the light-modulating layer of the light-modulating device according to the first aspect makes the light-modulating device in a reverse mode into a translucent state that is intermediate between a transparent state and an opaque state. A method for driving a light control device,
An alternating voltage having the same amplitude as the alternating voltage at which the light-modulating layer becomes opaque and an effective value smaller than the alternating voltage is applied to one of the comb-shaped electrodes, and the other electrode is applied with the above-described alternating voltage. A method of driving a light control device is characterized by applying an alternating voltage whose phase is shifted from the alternating voltage that makes the light control layer opaque.

When the dimming layer is in the normal mode, in order to make it transparent, a voltage having a sufficiently large amplitude and a sufficiently large effective value should be applied to both electrodes of the comb-shaped electrode and the solid electrode. The opaque state can be achieved by turning off the alternating voltage applied between the pair of comb-shaped electrodes and the solid electrode facing each other. In addition, in order to achieve a semi-transparent state, which is intermediate between the transparent state and the opaque state, it has the same amplitude as the alternating voltage that can make the transparent state, and has a smaller effective value than the alternating voltage, Moreover, it can be implemented by shifting the phases of the alternating voltages applied to one electrode and the other electrode of the comb-shaped electrodes.

When the light control layer is in the reverse mode, a voltage having a sufficiently large amplitude and a sufficiently large effective value should be applied to both electrodes of the comb-shaped electrode and the solid electrode in order to make the layer opaque. The transparent state can be achieved by turning off the alternating voltage applied between the pair of opposed comb-shaped electrodes and the solid electrode. In addition, in order to achieve a translucent state, which is intermediate between the transparent state and the opaque state, it has the same amplitude as the alternating voltage that can cause the opaque state, and has a smaller effective value than the alternating voltage, Moreover, it can be implemented by shifting the phases of the alternating voltages applied to one electrode and the other electrode of the comb-shaped electrodes.

In the light control device of the present invention, one of the electrodes provided on both sides of the light control layer is a comb-shaped electrode, and the other is a solid electrode. In the case of the light control layer of the mode), the voltage applied between one of the comb-shaped electrodes and the solid electrode has the same amplitude as the alternating voltage and has a small effective value, and the voltage applied between the other electrode and the solid electrode. By shifting the phase of the voltage applied between the electrodes, a translucent state, which is intermediate between a transparent state and an opaque state, can be achieved.

FIG. 2 is an explanatory diagram illustrating electrode sheets used in the light control sheet of the light control device of the present invention, where (a) shows a comb-shaped electrode sheet and (b) shows a solid electrode sheet. FIG. 2 is a cross-sectional view illustrating the layer structure of the light control device of the present invention;

<Dimmer>
A light control device of the present invention will be described with reference to FIGS. 1 and 2. FIG.
As shown in FIG. 2, the light control device 40 of the present invention is a light control device formed by bonding the light control sheet 30 to the glass substrate 12 via the adhesive layer 13 .

The light control sheet 30 is composed of a comb-shaped electrode sheet 10 having a comb-shaped electrode 5 formed on a transparent resin substrate 8 and a solid electrode sheet 20 having a solid electrode 6 formed on a transparent resin substrate 9. The light control layer 11 is inserted and laminated inside the pattern electrode 5 and the solid electrode 6 facing each other.

As shown in FIG. 1, the two opposing electrodes 1 and 2 of the comb-shaped electrode 5 (see FIG. 1(a)) have a voltage applied between them and the solid electrode 6 (see FIG. 1(b)). Each is connected to a power source (not shown) so as to be independently controllable.

In this way, the voltage applied between the electrode 1 and the solid electrode 6 and the voltage applied between the electrode 2 and the solid electrode 6 are connected to the power supply so as to be independently controllable, so that, for example, light control can be achieved. If the layer 11 is a normal mode material, by applying a voltage between the electrode 1 and the solid electrode 6 that makes the light modulating layer 11 transparent, and not applying a voltage between the electrode 2 and the solid electrode 6, The light-modulating layer 11 between the electrode 1 and the solid electrode 6 can be made transparent, and the light-modulating layer 11 between the electrode 2 and the solid electrode 6 can be made opaque without causing unevenness in the light-modulating layer 11 . As a result, the light control sheet 30 can achieve a translucent state, which is an intermediate state between a transparent state and an opaque state. If the dimming layer 11 is a reverse mode material, the only difference is that it becomes opaque when a voltage is applied and becomes transparent when no voltage is applied.

A method for manufacturing the light control device 40 illustrated in FIG. 2 will be described.
The light control device 40 of the present invention can be manufactured by attaching the light control sheet 30 to the glass substrate 12 via the adhesive layer 13 .

The light control sheet 30 may be manufactured in a separate process. A method for manufacturing the light control sheet 30 is not particularly limited. For example, first, the solid electrode 6 is formed on the transparent resin substrate 9 . The solid electrode 6 is formed by forming a transparent conductive thin film such as ITO (Indium Tin Oxide) on the transparent resin substrate 9 using a thin film forming apparatus such as a DC magnetron sputtering apparatus. Next, after forming an etching resist pattern using a screen printing or photolithographic technique, the transparent conductive thin film is removed by etching, and then the etching resist is peeled off. Alternatively, it is also possible to form the solid electrode 6 using a vapor deposition mask made of a thin metal plate having openings only at the portions where the transparent conductive thin film is to be formed when forming the solid electrode 6 on the light resin substrate 8 with a thin film forming apparatus. is.

Next, a comb-shaped electrode 5 is formed on the transparent resin substrate 8 . It can be manufactured in the same manner as the solid electrode 6 is formed.

Thus, the solid electrode sheet 20 and the comb-shaped electrode sheet 10 can be produced.
Next, pad electrodes 3, 4 and 7 are formed on the solid electrode 6 of the solid electrode sheet 20 and the comb-shaped electrodes 5 of the comb-shaped electrode sheet 10, respectively. The pad electrodes 3, 4, and 7 may be transparent electrodes as they are, but may be formed with a solder layer in advance, or may be formed with a conductive adhesive layer or a conductive ink layer.

Next, the adhesive layer 13 is formed on the transparent resin substrate 8 or the transparent resin substrate 9 of the light control sheet 30 . The adhesive layer 13 is not particularly limited as long as it can adhere the light control sheet 30 to the glass substrate 12 and is transparent.

Next, the light control sheet 30 is adhered to the glass substrate 12 via the adhesive layer 13 . The bonding method may be a manual method, or a special device may be used to position the light control sheet 30 on the glass substrate 12 at the bonding position, and then bond the adhesive layer 13 so as not to include air bubbles. But it's okay.

Next, wiring (not shown) from an external device such as a control device or a drive device is connected to the pad electrodes 3, 4 and 7 described above.
As described above, the light control device 40 of the present invention can be manufactured.

<Driving method of light control device>
Next, a method for driving the light control device of the present invention will be described.
The driving method of the light control device of the present invention is a method of driving the light control device of the present invention to make the light control device in a translucent state that is intermediate between a transparent state and an opaque state.
When the light-modulating layer is in the normal mode, an alternating voltage having the same amplitude as the alternating voltage at which the light-modulating layer becomes transparent and a smaller effective value than that alternating voltage is applied to one of the comb-shaped electrodes. , and to the other electrode, an alternating voltage whose phase is shifted from the alternating voltage at which the light-modulating layer becomes transparent is applied.
When the light-modulating layer is in the reverse mode, an alternating voltage having the same amplitude as the alternating voltage at which the light-modulating layer becomes opaque and having a smaller effective value is applied to one of the comb-shaped electrodes. and to the other electrode, an alternating voltage whose phase is shifted from the alternating voltage at which the light-modulating layer becomes opaque is applied.

A more detailed description will be given using Table 1.
Table 1 describes an example in which a normal mode light control layer is used as the light control layer of the light control sheet used in the light control device.

The transparent state of the light control device corresponds to the case where the haze value of the light control sheet is low. Also, if the haze value is sufficiently large, it will be in an opaque state. When the haze value takes an intermediate value between those haze values, it becomes translucent.

Alternating voltage (also called alternating voltage) is used as the voltage. This is because the liquid crystal material forming the light control layer 11 can be driven by applying an alternating voltage. The alternating voltage may be a rectangular pulse voltage that alternately changes in positive and negative directions with 0 (volt) as a reference shown in Table 1, or may be a triangular wave, a sawtooth wave, a sine wave, or the like. It can be. Also, the amplitude in the positive direction and the amplitude in the negative direction do not necessarily have to match.

In the normal mode light control sheet 30, between one electrode 1 of the comb-shaped electrodes 5 in FIG. and the voltage applied between the electrode 2 and the solid electrode 6 are set to 0 (state in which no voltage is applied) as shown in the column of "opaque state" in Table 1, the light control sheet 30 becomes opaque.

As shown in the "transparent state" column of Table 1, the voltages applied between the electrode 1 and the solid electrode 6 and between the electrode 2 and the solid electrode 6 are alternating voltages with a certain amplitude or more and the same phase. By doing so, a transparent state with a sufficiently small haze value is obtained.

Further, as shown in the column of "semitransparent state" in Table 1, the amplitude of the pulse voltage between the electrode 1 and the solid electrode 6 is the same as that shown in the column of the transparent state, but the amplitude is maintained. A case is exemplified in which a pulse voltage is applied for a short time, that is, a small effective voltage. At that time, the voltage applied between the electrode 2 and the solid electrode 6 has the same amplitude as the pulse voltage applied between the electrode 1 and the solid electrode 6, but is out of phase. Therefore, when the electrode 1 side is transparent, the electrode 2 side is opaque, and conversely, when the electrode 2 side is transparent, the electrode 1 side is opaque. In this way, an intermediate state between transparent and opaque can be created.

In reverse mode, these relationships are reversed. In other words, the opaque state is realized when a voltage is applied, and the transparent state is realized when no voltage is applied.

Further, in the column of "semi-transparent state" in Table 1, the magnitude of the amplitude of the applied pulse voltage remains unchanged, and the phases of the voltages applied to the electrodes 1 and 2 are kept shifted. By lengthening or shortening the time occupied in one cycle of the light control sheet, that is, by increasing or decreasing the effective voltage, the haze value of the light control sheet, that is, the translucent state, is changed. things are possible. The unevenness of the light control layer occurs when the amplitude of the applied voltage is not large enough. As in the driving method of the present invention, since a voltage with a sufficiently large amplitude is applied, the haze can be changed by increasing or decreasing the effective value of the voltage without causing unevenness.

Next, examples of the present invention will be described.

<Production of light control sheet>
As a transparent resin substrate, a 100 nm thick ITO (Indium Tin Oxide) thin film was formed on a 50 μm thick PET (polyethylene terephthalate) film using a direct current magnetron sputtering apparatus to prepare a transparent conductive sheet. .

Next, the transparent conductive sheet was cut into a size of 30 cm long×30 cm wide to prepare two transparent conductive sheets of the same size.

Next, an etching resist pattern for forming a solid electrode is printed by screen printing on the ITO thin film side of one of the transparent conductive sheets. After drying, the ITO thin film is etched, and the etching resist is peeled off to form a solid electrode. got a sheet. The ITO thin film pattern was used as it was for the pad electrode (pad electrode 7 in FIG. 1(b)).

Similarly, a photosensitive resist is applied to the ITO thin film side of the other transparent conductive sheet by a roll coater, and after drying, the photosensitive resist is exposed using a photomask for forming a comb-shaped electrode, developed and washed with water. - A resist pattern was obtained by heat treatment. Using the resist pattern as an etching mask, the ITO thin film was etched, and then the resist pattern was peeled off to obtain a comb-shaped electrode sheet.

The pitch of the comb-shaped electrodes was 5 mm, and the line width of the comb-shaped electrodes was 4 mm. Therefore, a comb-shaped electrode sheet having a shape similar to that shown in FIG. 1 was produced with a gap of 1 mm between the comb-shaped electrodes.

Also, the ITO thin film pattern was used as it was for the pad electrodes (pad electrodes 3 and 4 in FIG. 1(a)) which are connection electrodes with an external device.

Next, a reverse mode light control material is applied onto the comb electrodes of the comb electrode sheet using a bar coater. They were laminated to obtain a light control sheet.

Next, after screen-printing an adhesive layer on the transparent resin base material of the comb-shaped electrode sheet of the prepared light control sheet, an alkali-free glass plate of 30 cm long×30 cm wide×0.7 mm thick was placed through the adhesive layer. pasted on.

Next, the pad electrodes 3 and 4 and the pad electrode 7 were connected to wiring from a power source for applying an alternating voltage to the light control sheet. A conductive adhesive sheet was used to connect the wiring from the power supply side to the pad electrodes 3 and 4 and the pad electrode 7 .

In this way, a light control device was produced in which the light control sheet was attached to the glass plate. An experiment was conducted in which an alternating voltage was applied to this dimmer through a wire from a power supply.

The applied alternating voltage had a frequency of 50 Hz, a ratio of +15 volts and -15 volts in one period of 1:1, an amplitude of 15 volts, and a reference of 0 volts, as conditions corresponding to the transparent state in Table 1. A pulse voltage of ±15 volts was synchronously applied to the pad electrodes 3 and 4, and it was visually confirmed that the film became transparent.

In addition, the opaque state was confirmed by visual observation in the state where no voltage was applied. In this state, it was confirmed that the image on the opposite side of the viewer could not be seen at all through the dimmer.

In addition, as a condition corresponding to the translucent state, the frequency is 50 Hz, the ratio of +15 volts and -15 volts to one cycle is 1:5, the amplitude is 15 volts, and the pulse voltage is ±15 volts with 0 volts as the reference. Voltages were applied to the pad electrodes 3 and 4 out of phase, and it was confirmed visually that they became translucent. The semi-transparent state was confirmed by confirming that the image on the opposite side of the viewer was visible through the dimmer, although the image was unclear.

1...Electrode (one of comb-shaped electrodes) 2...Electrode (other of comb-shaped electrodes) 3...Electrode pad (of electrode 1) 4...Electrode pad 5 (of electrode 2) Comb-shaped electrode 6 Solid electrode 7 Pad electrode (solid electrode) 8 Transparent resin substrate 9 Transparent resin substrate 10 Comb-shaped electrode sheet 11 Light control layer 12 Glass substrate 13 Adhesive layer 20 Solid electrode sheet 30 Light control sheet 40 Light control device

Claims (3)

The haze of the light control sheet is obtained by bonding a light control sheet formed by laminating a light control layer between two transparent electrodes of a transparent resin base material provided with a transparent electrode to a glass substrate via an adhesive layer. When the haze value of the light control sheet is low, the state is transparent; when the haze value of the light control sheet is sufficiently large, the state is opaque ;
one transparent electrode is a comb-shaped electrode, the other transparent electrode is a solid electrode,
The comb-shaped electrodes are arranged on the base material so that the comb tooth portions of the electrodes are alternated with each other, and are connected to a power source so that alternating voltages applied between them and the solid electrodes can be independently controlled. A light control device characterized by: 2. A method of driving a light control device according to claim 1, wherein the light control layer of the light control device is in a normal mode, and the light control device is brought into a translucent state between a transparent state and an opaque state. ,
An alternating voltage having the same amplitude and a smaller effective value than the alternating voltage at which the light-modulating layer becomes transparent is applied to one of the comb-shaped electrodes, and the other electrode is applied with the above-described alternating voltage. A method of driving a light control device, comprising applying an alternating voltage whose phase is shifted from an alternating voltage that makes a light control layer transparent. 2. A method of driving a light control device according to claim 1, wherein the light control layer of the light control device is in a reverse mode, and changes the light control device to a translucent state between a transparent state and an opaque state. ,
An alternating voltage having the same amplitude as the alternating voltage at which the light-modulating layer becomes opaque and an effective value smaller than the alternating voltage is applied to one of the comb-shaped electrodes, and the other electrode is applied with the above-described alternating voltage. A method of driving a light control device, comprising applying an alternating voltage whose phase is shifted from an alternating voltage that makes a light control layer opaque.

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