KR20060057157A - Liquid-crystal chromic mirror for reflectance rise - Google Patents

Abstract

The present invention relates to a liquid crystal variable color changing mirror device having improved reflectivity, and more particularly, an alignment member, a transparent electrode, a transparent non-conductive substrate, and a polarizing film are respectively disposed on the front and rear surfaces of a STN (Super-Twisted Nematic) liquid crystal having a wide viewing angle. Liquid crystal variability discoloration of the automotive mirror which is arranged in turn, and the transparent non-conductive base material and the reflective layer are further formed on the front and rear side polarizing films of the STN LCD to adjust the reflectance of light by the reflective layer according to the potential difference applied to the electrode. In the mirror device, in particular, a photocatalyst coating layer is formed on the transparent non-conductive substrate attached to the polarizing film on the front side of the liquid crystal, and a reflectance enhancing film is disposed between the reflecting layer and the polarizing plate on the rear side of the liquid crystal in order to improve the reflectance of the liquid crystal variable color changing mirror. At the same time, the reflective layer is composed of a single layer of zirconium (Zr) and titanium (Ti) or a composite layer thereof. And, also, each install an optical sensor in the external front / rear of such a liquid crystal variable-color transfer mirror device, and a control circuit for outputting the proper voltage to the electrodes according to the amount of light detected by the optical sensor.

Description

Liquid crystal variable color changing mirror device with improved reflectance {LIQUID-CRYSTAL CHROMIC MIRROR FOR REFLECTANCE RISE}             

1 is a cross-sectional view showing the configuration of a liquid crystal variable color changing mirror apparatus according to the present invention.

Figure 2 is a conceptual diagram illustrating the reflection effect by the reflectance enhancement film of the liquid crystal variable color changing mirror according to the present invention.

Figure 3 is a graph showing the reflectance of the liquid crystal variable color changing mirror according to the present invention.

4 is a control circuit diagram for the variable color change of the liquid crystal according to the present invention.

Explanation of symbols on the main parts of the drawings

1: liquid crystal variable color changing mirror device 2: STN liquid crystal

3: alignment body 4: electrode

5: transparent non-conductive base material 6: polarizing film

7: Reflectance Enhancement Film 8: Reflective Layer

9 photocatalyst coating layer 11 control circuit

15, 16: optical sensor 24: STN-LCD

According to the present invention, an alignment body, a transparent electrode, a transparent non-conductive substrate, and a polarizing film are sequentially disposed on the front and rear surfaces of the STN liquid crystal, and the transparent non-conductive substrate and the reflective layer are further formed on the polarizing films at the front and rear sides of the liquid crystal, respectively. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal variable color changing mirror device of an automotive mirror in which a reflectance of light by a reflective layer is adjusted in accordance with a potential difference applied to an electrode, wherein the reflectance is improved for widening a viewing angle and improving reflectance.

A side mirror or a room mirror of a car is used as a means for driving safely by securing a view of the rear or side while the vehicle is driving, but this also reflects the glare of the headlights of the vehicle running at the rear during the night. This is caused, which interferes with the normal driving of the vehicle.

In order to solve the problem, a number of techniques for reducing the reflectance of light when a predetermined amount or more is detected by measuring the amount of light irradiated from the rear has been introduced, and the most common technique is an ECM (Electrochromic Mirror) method.

However, the ECM method has a problem in that the response speed for reducing the reflectance is slow and the reflectance is so low that the rear vehicle is not properly identified, and a more advanced technique for solving this problem forms a TN (Twisted Nematic) type liquid crystal layer. In addition, a technology using at least one polarizing plate on the front and rear has been introduced in the Republic of Korea Patent Publication No. 2003-0091898, which has the advantage that the color change speed of the mirror according to the change in light quantity is fast, and the reflectance is not excessively reduced. have.

However, the liquid crystal layer of the TN type of the disclosed technology is limited to the viewing angle is 0 ° to 90 ° or less, so that the object reflected at an angle of 90 ° or more has difficulty in identifying, and when using curved glass, the viewing angle is It is natural to be narrower.

In addition, the polarizing plate is used to prevent the reflectance of light from being excessively reduced, rather than the aforementioned ECM type. However, the technique of using a polarizing layer in the liquid crystal of LCD has already been registered in Korea before the patent application. It is a generalized technology introduced in 0223068 'Auto glare prevention device using polarization technology'.

The prior patent and the prior utility model are both a configuration in which a polarizing layer is formed on the liquid crystal, but as a result of experiments by the inventors, the initial reflectance is 40 before the discoloration mirror using only the polarizing layer without applying any other reflectance enhancement technology. The problem of not being able to sufficiently secure the rear view while driving is still a problem to be solved because the figure is very low as%.

Accordingly, the present invention was created to solve the above problems, the present invention is to increase the reflectance of the rear by the mirror to increase the reflectance of the light and the liquid crystal variable color changing mirror device does not have a limitation on the viewing angle The purpose is to provide.                         

In addition, an object of the present invention is to apply a curved mirror, and to prevent the surface of the transparent non-conductive base material located in the outermost part of the discoloration mirror from being contaminated or fogged.

In addition, an object of the present invention is to provide a circuit for sensing and controlling the illumination applied to the liquid crystal variable color changing mirror sufficiently and accurately during the day or night.

The objective is to adopt a super-twisted nematic (STN) LCD with a wide viewing angle, allowing the viewing angle to be secured from 180 ° to 270 ° out of the limited viewing angle of 0 ° to 90 ° of the conventional TN LCD, and also to discolor mirror operation. Improve the previous technology that the total initial reflectance stays at 40% to maintain the initial reflectance of 50% or more, and arrange the alignment body, the transparent electrode, the transparent non-conductive base material and the polarizing film on the front and the rear of the STN LCD, respectively. And forming a transparent non-conductive substrate and a reflective layer on the polarizing films on the front and rear sides of the liquid crystal, respectively, and forming a photocatalyst coating layer on the transparent non-conductive substrate attached to the polarizing film on the front side of the liquid crystal. In order to improve the reflectance, the reflecting layer is embedded between the reflecting layer and the polarizing plate on the rear side of the liquid crystal, and at the same time, the reflecting layer is made of conventional aluminum (Al), chromium (Cr), In addition to silver (Ag) deposition, it can be achieved by constructing a deposition layer in which multiple layers of zirconium (Zr), titanium (Ti) and the like are selectively stacked.

In addition, the present invention is to install an optical sensor for detecting the front and rear of the liquid crystal variable color changing mirror device, that is, the light sensor for detecting the amount of light of the headlight irradiated from the rear traveling vehicle, respectively, these optical signals And a control circuit for outputting an optimal variable voltage.

Hereinafter, with reference to the accompanying drawings, a preferred configuration and embodiments of the present invention will be described in more detail.

1 is a cross-sectional view showing the configuration of a liquid crystal variable color changing mirror apparatus according to the present invention, the liquid crystal variable color changing mirror apparatus 1 of the present invention with reference to FIG. 1 includes a super-twist nematic (STN) LCD 24 do.

The STN LCD 24 has an advantage that can be observed without limiting the driver's visual position for observing the rear while driving, since the angle capable of reflecting light is 180 ° to 270 °, and it is possible to apply curved glass, and its configuration. In this case, the alignment body 3, the transparent electrode 4, the transparent non-conductive base material 5, and the polarizing film 6 are laminated and arranged on both surfaces of the STN liquid crystal 2, respectively.

The alignment body 3 is used to induce molecules inside the liquid crystal 2, the transparent electrode 4 is applied with a voltage output from the control circuit 11, and the transparent floating substrate 5 is made of transparent glass. Alternatively, as referring to a transparent synthetic resin, such STN LCD 24 may be generally used, and since it is a known technology, a description of specific operations thereof may obscure the gist of the present invention. Shall be.

On the other hand, a transparent non-conductive base material 5 made of transparent glass or synthetic resin is disposed on the front surface of the STN LCD 24, which constitutes the outermost surface of the room mirror or the side mirror of the vehicle, and the photocatalyst is formed on the surface thereof. By forming the photocatalyst coating layer 9, it is preferable to minimize the fog and contamination caused by temperature and humidity.

In addition, a reflectance enhancement film 7, a reflection layer 8, and a transparent non-conductive base material 5 are disposed in order on the rear surface of the STN LCD 24, and the reflection layer 8 is transparent at the rear surface. In addition to the deposition of aluminum (Al), chromium (Cr), and silver (Ag) on the non-conductive substrate 5, a deposition layer in which multiple layers of zirconium (Zr), titanium (Ti), etc. are selectively laminated is formed. It will be embodied below.

Conventionally, a general reflective layer in a liquid crystal variable color changing mirror is used by vacuum evaporation of aluminum (Al), chromium (Cr), silver (Ag) and the like on a transparent non-conductive substrate.

However, the reflectance of the reflectors deposited with these materials showed about 80% as shown in Table 1 below, which is below the size of the desired reflectance of 90%, which has a limit in discrimination.

In the experiment of Table 1 below, the reflectance of a pure reflector without using a liquid crystal, that is, a reflector in which aluminum, chromium, and silver were deposited as a single layer on a transparent non-conductive substrate was measured, and according to the present invention, zirconium-titanium was measured. It is the data which measured the reflectance of the reflector which deposited four to nine layers of zirconium.

TABLE 1

Reflective layer structure reflectivity Aluminum (Al) fault 78.8% Chrome (Cr) 85.9% Silver (Ag) 83.4% Zirconium (Zr) 83.3% Titanium (Ti) 83.4% Zr / Ti / Zr 4th floor 92.2% Zr / Ti / Zr 5th floor 92.4% Zr / Ti / Zr 7th floor 92.5% Zr / Ti / Zr 8th floor 92.9% Zr / Ti / Zr 9th floor 92.6%

As shown in Table 1, the lowest reflectance of the discolored mirror in which aluminum is deposited as a single layer is 78.8%, and in the case of chromium, the maximum reflectance is 85.9%.

In addition, in addition to the above-described deposition materials, reflectance results were not good even when zirconium (Zr) and titanium (Ti) were deposited in a single layer as shown in Table 1.

However, the reflectance value of the zirconium-titanium-zirconium deposited according to the present invention showed a minimum value of 92.2% for four-layer deposition, and 92.9%, the highest value for eight-layer deposition, and the identification of the reflected object was good.

The deposition conditions of the zirconium and titanium were deposited using a DC magnetic sputtering of 300W to 500W power source to the selected deposition target glass plate that is a transparent non-conductive substrate, the vacuum during deposition was 20mTorr.

When four or more layers of zirconium (Zr) -titanium (Ti) -zirconium (Zr) are deposited under these deposition conditions, the light reflectance is 92% or more, and the good reflectivity is obtained. Since zirconium and titanium have almost the same crystal structure, In addition, it can be maintained for a long time in a state that is firmly fixed by the deposition, there is an advantage in that the refractive index is improved because it does not peel off each other and at the same time have durability.

Figure 2 is a conceptual diagram illustrating the reflection action by the reflectance enhancement film of the liquid crystal variable color changing mirror according to the present invention.

Referring to FIG. 2, the reflectance enhancement film 7 is a film having a structure having a high brightness enhancement film (DBEF), and the material is a polyester-based resin having a multilayer structure, and has a vertical wave and a horizontal wave of light. It serves to pass all of them.

As is well known, light is transmitted with wave and granularity, and the wave is composed of vertical wave (P) and horizontal wave (S), and as shown in FIG. 2, a typical STN LCD 24, that is, a reflectance enhancement film The STN LCD without (7) has a property of passing only vertical waves P and absorbing horizontal waves S, among the waves of light reflected from the reflective layer 8, so that the reflectance is lowered.

However, when the reflectance enhancement film 7 is interposed between the reflective layer 8 and the STN LCD 24 as in the present invention, the vertical wave P normally passes through the STN LCD 24, and the horizontal wave S is By continuously reflecting on the reflectance enhancement film 7 and the reflective layer 8, the light is converted in the same direction as the vertical wave P and passes through the STN LCD 24, so that the horizontal wave S is converted into the vertical wave P. As a result, as much light passes outside the liquid crystal variable color changing mirror, the reflectance is improved.

Figure 3 is a graph showing the reflectance of the liquid crystal variable color changing mirror according to the present invention, the reflection layer of the comparison object formed a reflection layer under the same conditions formed with eight layers of Zr-Ti-Zr layer as before, There is a difference in whether or not the enhancement film 7 is applied.

Referring to FIG. 3, it can be seen that the reflectance (Reflection) value for the wavelength is higher for the entire wavelength range than that of the discolored mirror in which the reflectance enhancement film (DBEF) 7 is interposed. .

Such a graph result is not limited only to the Example which formed the Zr-Ti-Zr layer by eight layers.

That is, as shown in Table 2 below, the Zr-Ti-Zr layer may be variously applied to four or more than nine layers, or as a result of depositing a deposition material forming a general reflective layer as a single layer as described above. ), The reflectance was measured higher than otherwise.

TABLE 2

Reflective layer structure DBEF not applied Apply DBEF Aluminum (Al) fault 78.8% 80.7% Chrome (Cr) 85.9% 88.4% Silver (Ag) 83.4% 85.6% Zirconium (Zr) 83.3% 85.4% Titanium (Ti) 83.4% 85.5% Zr / Ti / Zr 4th floor 92.2% 94.1% Zr / Ti / Zr 5th floor 92.4% 94.3% Zr / Ti / Zr 7th floor 92.5% 94.7% Zr / Ti / Zr 8th floor 92.9% 95.1% Zr / Ti / Zr 9th floor 92.6% 94.7%

As can be seen from the above experimental data, the reflectance of the zirconium-titanium-zirconium deposited in eight layers was 92.9%, as in the experimental results of the pure reflector described above. When applied, the reflectance improved to 95.1%.

As a result, the reflectance (95.1%) when the deposited layer characteristic and the reflectance enhancement film according to the present invention were applied was 16.3% higher than the reflectance (78.8%) when aluminum was deposited as a single layer, and the maximum reflectance (85.9) of chromium was increased. 9.2% reflectivity is improved rather than%).

In addition, the reflectance of the liquid crystal variable color changing mirror of the present invention is higher by depositing a material constituting the reflective layer in a multilayer rather than a single layer, and is a polyester resin having a multilayer structure regardless of multilayer deposition of the reflective layer. The addition of a reflectance enhancement film improves the reflectance over the entire area of the mirror that is not.

Meanwhile, after the zirconium-titanium-zirconium is deposited in eight layers and the reflectance enhancement film is applied, the liquid crystal variable color changing mirror of the STN LCD 24 is manufactured, and the initial reflectance before the variable color change is measured. One result is 50%, which improves the initial reflectance from 40% to 10% before.

4 is a control circuit diagram for the liquid crystal variable color change according to the present invention.

The control circuit 11 of the liquid crystal variable color changing mirror apparatus of the present invention with reference to FIG. 4 includes an optical sensor 15 for detecting the amount of light outside the vehicle and an amount of light for the vehicle traveling behind. A proper voltage output circuit (17) (18) including a sensor (16) and outputting a proper voltage in accordance with signals input from these optical sensors (15) and (16), and a voltage output from the appropriate voltage output circuit. According to the present invention, a voltage variable circuit 19 for varying a voltage by analyzing a result in a microchip in which a predetermined program is memorized, and an LCD negative voltage output integrated circuit for outputting the variable voltage to the electrode 4 of the STN LCD 24. 22, a switch 21 for allowing the liquid crystal variable color changing mirror device to be turned on and off by a user, and an overvoltage protection circuit 23 for blocking a reverse voltage and maintaining a constant voltage with a constant voltage diode. Additionally liquid crystal variability It may include an LED lamp 20 for displaying the operations of the device.

Although the above description has been shown and described only with respect to the preferred embodiments of the present invention, the present invention is not limited thereto, and the present invention described below, as well as a change in combination and selective addition of many functions of the present invention described above. It should be understood that various changes can be made without departing from the technical spirit of the present invention provided by the claims.

As can be seen from the above description, according to the liquid crystal variable color changing mirror apparatus of the present invention, by vacuum depositing a zirconium-titanium-zirconium in a reflective layer in a multilayer, the durability can be improved and the reflectance can be improved by alleviating the peeling phenomenon. In addition, since the reflectance enhancement film is interposed regardless of the characteristics of the reflective layer deposition, it is possible to improve the reflectance, thereby preventing the glare during driving and increasing the discriminating power of the object, and the application of the STN LCD enables the reflection of the curved glass.

In addition, by forming a photocatalyst coating layer on the outermost surface of the liquid crystal variable color changing mirror device to prevent contamination and fogging of the surface, the liquid crystal variable color changing mirror device to have an optimal reflectance by a sensor for detecting the front and rear light amount Can be.

Claims (7)

In the liquid crystal variable color changing mirror device applied to the car mirror to prevent glare caused by the reflection of the headlights of the rear traveling vehicle, A transparent non-conductive substrate is attached to the front of the LCD in which an alignment member, a transparent electrode, a transparent non-conductive substrate, and a polarizing film are sequentially stacked on the front and rear of the LCD, respectively, and a vacuum-deposited reflective layer is formed on the back of the non-conductive substrate. And a reflectance enhancement film embedded between the reflective layer and the polarizer on the rear side of the liquid crystal. The method of claim 1, The reflectivity improving film is a liquid crystal variable color changing mirror device having improved reflectivity, characterized in that the polyester-based resin of a multi-layer structure. In the liquid crystal variable color changing mirror applied to the car mirror to prevent glare caused by the reflection of the headlights of the traveling vehicle, A transparent non-conductive substrate is attached to the front of the LCD in which an alignment member, a transparent electrode, a transparent non-conductive substrate, and a polarizing film are sequentially stacked on the front and rear of the LCD, respectively, and a vacuum-deposited reflective layer is deposited on the back of the non-conductive substrate. And the reflective layer is vacuum deposited with zirconium (Zr) -titanium (Ti) -zirconium (Zi) material into at least one layer. The method according to any one of claims 1 to 3, The LCD liquid crystal is a liquid crystal variable color changing mirror device having an improved reflectivity, characterized in that the STN (Super-Twisted Nematic) type. The method according to any one of claims 1 to 3, The reflectance-enhanced liquid crystal variable color changing mirror device, characterized in that the photocatalyst coating layer is formed on the outermost transparent non-conductive substrate attached to the front of the LCD. The method according to any one of claims 1 to 3, The control circuit for applying a voltage to the electrode of the liquid crystal variable color changing mirror, a pair of optical sensors for sensing the amount of light in the front and rear, and a pair of appropriate for outputting the appropriate voltage in accordance with the signal input from the optical sensor A voltage output circuit, a voltage variable circuit for varying a voltage by an operation in which a predetermined program is memorized based on a voltage output from the appropriate voltage output circuit, and a negative voltage output integrated circuit 22 for outputting the variable voltage to the electrode. Reflective liquid crystal tunable color changing mirror device characterized in that it comprises a). The method according to claim 6, The control circuit is a liquid crystal tunable mirror device with improved reflectivity, characterized in that it further comprises an overvoltage protection circuit (23) for blocking the reverse voltage and maintaining a constant voltage as a constant voltage diode.

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