JP2006322787A - Deterioration testing device and deterioration test method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deterioration testing device capable of executing a highly-accurate deterioration test in a short time. <P>SOLUTION: This deterioration testing device is equipped with a laser light output part 11 for outputting laser light, a specimen support part 19 for supporting a liquid crystal panel (specimen) 15 irradiated with the laser light, and a temperature control means 16 for adjusting the temperature of the liquid crystal panel 15 in the abutting state on the liquid crystal panel 15 supported by the specimen support part 19. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deterioration test apparatus and a deterioration test method.

Conventionally, a light resistance test has been performed as one of the reliability evaluations of liquid crystal panels. For example, a liquid crystal panel used as a light valve in a liquid crystal projector is easily irradiated with intense light over a long period of time, and each component (component, member) is likely to deteriorate. Therefore, the light resistance test ensures a desired quality. Is important above.
In the light resistance of such a liquid crystal panel, a test period on the order of several months may be required if it is long. However, such a long-term test is unacceptable in situations where a shortened product development period is required.
On the other hand, as one of the methods for shortening the evaluation period, so-called acceleration is performed, in which a test is performed under a load under conditions more severe than the actual use situation, and the deterioration after long-term use is predicted from the result. The test is known. For example, Patent Document 1 discloses a conventional technique relating to the light resistance evaluation of such a liquid crystal panel.
JP 2001-4526 A

However, in the above conventional light resistance evaluation method, light is irradiated to the liquid crystal panel using a light source such as a metal hydro lamp, UHP lamp, or halogen lamp, so that the light condensing property is low and a high energy density cannot be obtained. It was difficult to develop the deterioration phenomenon in a short time. For this reason, it took a long time to evaluate the light resistance of the liquid crystal panel, which hindered the shortening of the product development period.
In addition, when the amount of light emitted from the light source is increased, the liquid crystal panel, which is the test object, is heated by this light and the temperature rises, so it is possible to accurately grasp the deterioration caused by the light and the deterioration caused by the temperature. There is also a problem that it is difficult to improve the accuracy of the light resistance test.
The present invention has been made in view of the above problems of the prior art, and is capable of performing a high-accuracy deterioration test in a short time and a high-accuracy test in a short time. The purpose is to provide a possible deterioration test method.

In order to solve the above problems, the present invention provides a laser beam output unit that outputs laser light, a test object support unit that supports a test object irradiated with the laser beam, and a test object support unit. There is provided a deterioration test apparatus comprising temperature control means for adjusting the temperature of the test object in contact with the supported test object.
According to such a configuration, the laser beam irradiation can be performed while adjusting the temperature of the test object by providing the temperature control means in the test object support portion. The specimen can be deteriorated in a short time, and heating of the specimen due to the laser beam irradiation can be prevented by controlling the temperature of the specimen. Therefore, according to this test apparatus, it is possible to perform a deterioration test in which a deterioration factor related to light irradiation and a deterioration factor related to heat are clearly distinguished, and a highly accurate deterioration test can be performed.

A degradation test apparatus according to the present invention includes a test object support unit that supports a liquid crystal panel, and a laser beam output that selectively irradiates laser light to one or a plurality of pixels of the liquid crystal panel supported by the test object support unit. And a temperature control means for adjusting the temperature of the liquid crystal panel in contact with the liquid crystal panel supported by the test object support section.
The deterioration test apparatus of the present invention can be suitably used for a deterioration test of a liquid crystal panel due to light irradiation or the like. That is, the alignment film or the like of the liquid crystal panel is deteriorated in a short time by laser light irradiation, and the degree of such deterioration can be evaluated to perform an acceleration test on the light resistance and heat resistance of the liquid crystal panel. Further, since the laser light can be irradiated while controlling the temperature of the liquid crystal panel by the temperature control means, it is possible to prevent the deterioration of the alignment film and the like due to the heating accompanying the laser light irradiation, and the deterioration factor related to the light irradiation. It is possible to carry out a durability test of a highly accurate liquid crystal panel in which the deterioration factors related to heat are clearly distinguished.

  In the deterioration test apparatus of the present invention, it is preferable that a thermoelectric conversion element is provided in the temperature control means. According to such a configuration, since the test object is heated / cooled by the thermoelectric conversion element, there are advantages such as small size, low noise, high speed response, and long life as compared with the temperature control means by the heat exchange method using the cooling medium. This contributes to the inexpensive provision of high-accuracy degradation test equipment.

  In the deterioration test apparatus of the present invention, the temperature control means may be provided with a heat pipe that performs latent heat transfer by the working fluid. A heat pipe is a container such as a metal tube that is vacuum-sealed with a small amount of hydraulic fluid. When a part of the container is heated, the internal hydraulic fluid is vaporized at the heating site inside the container. A series of operations in which the steam moves to the low temperature part and condenses at the low temperature part is repeated, and heat transfer from the heating part to the low temperature part is performed. By providing the heat pipe, it is possible to configure a temperature adjusting means that operates even with a slight temperature difference and requires almost no maintenance.

  In the deterioration test apparatus of the present invention, the temperature control means is provided with a heat transfer section that comes into contact with the test object, and a circulation type cooling apparatus that circulates a cooling medium through the heat transfer section. It can also be. According to this configuration, since the heat transfer section that heats / cools the test object in contact with the test object is used, it is suitable when a relatively large amount of heat energy needs to be transferred.

  In the deterioration test apparatus of the present invention, it is preferable that the temperature control means is provided with a heat transfer member that transmits heat from a heat source to the test object. By providing the heat transfer member, the contact form between the heat transfer member and the test object can be easily changed according to the shape of the test object and the irradiation mode of the laser beam, so that highly accurate temperature control is possible. It becomes possible to make the temperature distribution of the test object uniform.

  In the deterioration test apparatus of the present invention, a temperature measuring unit that measures the temperature of the test object and outputs temperature information used for temperature adjustment of the test object to the temperature control unit is provided. preferable. According to this configuration, temperature control based on the temperature information of the test object is possible, and improvement in the accuracy of the deterioration test can be realized by increasing the accuracy of the temperature control.

  In the deterioration test apparatus of the present invention, a first light quantity measuring unit that measures the light quantity of the laser light that irradiates the test object, and a second light quantity measurement unit that measures the light quantity of the laser light after irradiating the test object. Are preferably provided. According to this configuration, the laser light amount immediately before irradiating the test object can be obtained by the first light quantity unit, and the laser light amount after irradiating the test object can be obtained by the second light quantity measurement unit. Therefore, the degree of deterioration of the test object according to the parameter of the laser beam output from the laser beam output unit can be easily measured.

  In the deterioration test apparatus of the present invention, it is preferable that at least the test object and the test object support part are housed in a temperature control tank in which the internal temperature and / or humidity is controlled. According to this configuration, it is possible to easily change the environmental temperature and / or environmental humidity of the test object to perform a deterioration test, and to perform an appropriate deterioration test according to the use environment of the test object. become.

  In the deterioration test apparatus of the present invention, at least the test object, the test object support section, and the laser beam output section may be housed in a temperature control chamber in which the internal temperature and / or humidity is controlled. preferable. According to this configuration, since the laser beam output unit and the like can be operated in a stable environment, a change in the operating state of the laser beam output unit and the like due to a change in the operation environment can be excluded from the measurement result, and high accuracy A deterioration test can be performed. Furthermore, in the deterioration test apparatus including the first light quantity measurement unit, the second light quantity measurement unit, and the like, it is preferable that the first light quantity measurement unit and the second light quantity measurement unit are also arranged in the temperature control chamber. .

The degradation test method of the present invention includes a first step of irradiating a test object with laser light, and a first step of irradiating the test object with observation light and detecting the state of the observation light after irradiating the test object. 2 steps, and a third step of evaluating the light resistance of the test object based on the difference in the observation light before and after irradiating the test object. In the first process, the test object is fixed. The laser light is irradiated while maintaining the temperature.
According to this degradation test method, in the first step of irradiating the test object with laser light, the test object is irradiated with laser light while maintaining the i temperature at a constant temperature. The accompanying increase in the temperature of the test object can be suppressed, and the test object can be prevented from being deteriorated by heat. Thereby, the deterioration factor resulting from heat can be excluded from the observation result in the second step, and the degree of deterioration of the test object due to light irradiation can be accurately obtained. Therefore, according to the deterioration test method of the present invention, the test object can be deteriorated in a short time by laser light irradiation, and the degree of deterioration can be measured with high accuracy.

  In the deterioration test method of the present invention, in the first step, at least one of the wavelength, irradiation energy, and irradiation time of the laser beam is set as a variable parameter, and the test object is irradiated, and the third step It is preferable that the light resistance of the test object is evaluated based on the difference in the observation light according to the variable parameter. With this deterioration test method, it is possible to easily obtain a change in the degree of deterioration of the test object with respect to a change in the variable parameter.

  In the deterioration test method of the present invention, the laser beam can be used as the observation light, and the first step and the second step can be performed in parallel. According to this deterioration test method, it is possible to simultaneously perform the measurement of the degree of deterioration of the test object due to the irradiation of the laser beam as the observation light and the deterioration process of the test object due to the irradiation of the laser light, which is extremely efficient. A good and rapid deterioration test can be performed.

  In the deterioration test method of the present invention, a liquid crystal panel is used as the test object, and the laser beam can be selectively irradiated to one or a plurality of pixels of the liquid crystal panel. That is, when the test object is a liquid crystal panel, it is preferable that a test target region to be irradiated with laser light is in units of one pixel or a plurality of pixels. Since a narrow pixel region is irradiated with laser light, deterioration of the pixel can be caused in a short time even if the irradiation energy is small, shortening the test time, reducing power consumption, and reducing the apparatus cost. be able to. In addition, since a large number of pixels are formed on the liquid crystal panel, it is possible to continuously perform a deterioration test by changing the test conditions, and to perform a deterioration test of a plurality of conditions extremely efficiently with one liquid crystal panel. be able to.

  In the deterioration test method of the present invention, in the first step, it is possible to use a test method in which the alignment property of the alignment film included in the liquid crystal panel is lowered by the laser light irradiation. The main factor of deterioration of the liquid crystal panel due to light irradiation is deterioration of the alignment film. Therefore, if the above-described test method causes the alignment film to be deteriorated by laser light irradiation, the deterioration test method can carry out an acceleration test in accordance with the actual deterioration over time of the liquid crystal panel. Lifetime can be evaluated more accurately.

  In the deterioration test method of the present invention, it is preferable that the laser light applied to the liquid crystal panel is linearly polarized light substantially parallel to the transmission axis of the polarizing plate on the light incident side of the liquid crystal panel. When performing a deterioration test of a liquid crystal panel, if a polarizing plate is provided on the liquid crystal panel, a part of the laser light irradiated to the liquid crystal panel (a polarizing component parallel to the absorption axis of the polarizing plate) is absorbed by the polarizing plate. The polarizing plate may be deteriorated, and such a deterioration factor may be mixed into the test result. Therefore, if the laser light incident on the liquid crystal panel is linearly polarized light parallel to the transmission axis of the polarizing plate, light absorption at the polarizing plate hardly occurs, so that deterioration of the polarizing plate can be prevented. It becomes possible to accurately observe the change in optical characteristics due to the.

  In the deterioration test method of the present invention, it is preferable to control the temperature of the liquid crystal panel via a heat transfer section that is in surface contact with one or both surfaces of the liquid crystal panel. With such a test method, the liquid crystal panel can be efficiently heated / cooled, so that the accuracy of temperature control of the liquid crystal panel is improved and the accuracy of the deterioration test is also improved.

(Deterioration test equipment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The deterioration test method of this embodiment is a deterioration test method for a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates, and the liquid crystal panel is deteriorated by irradiating the liquid crystal panel with laser light. Thereafter, the liquid crystal panel is optically observed using laser light as observation light, and the degree of deterioration of the liquid crystal panel is evaluated.

  FIG. 1 is a schematic configuration diagram of a deterioration test apparatus according to the present embodiment. A degradation test apparatus 100 shown in FIG. 1 includes a laser device 10, an ND filter 12, a mirror 13, a laser beam output unit 11 including a condenser lens 14, and a liquid crystal panel 15 that is a test object. Provided on the specimen support section 19, the temperature control section 16 disposed in contact with the liquid crystal panel 15 supported on the specimen support section 19, and the front side (laser beam output section 11 side) of the liquid crystal panel 15. The first light quantity measuring unit 21 and the second light quantity measuring unit 22 provided on the rear side of the liquid crystal panel 15 (the side opposite to the laser light output unit 11) are configured.

  An imaging unit 17 that partially shares the optical system of the laser light output unit 11 and an image processing unit 18 that processes and displays image information obtained by the imaging unit 17 are provided. These imaging unit 17 and image processing The unit 18 functions as a positioning unit that aligns the test target region on the liquid crystal panel 15 with the laser beam, and an image processing unit that evaluates the degree of deterioration of the liquid crystal panel 15.

  The laser device 10 is a laser device that outputs, for example, a blue-violet laser beam having an oscillation wavelength of 406 nm, and can output at least one of the wavelength, irradiation energy, and irradiation time as a variable parameter. . Since the deterioration test apparatus 100 of the present embodiment deteriorates the alignment film or the like of the liquid crystal panel 15 by irradiating laser light, and evaluates the light resistance of the liquid crystal panel 15 by observing the degree of decrease in the alignment of the liquid crystal. As the laser device 10, a laser device that can cause desired deterioration of the liquid crystal panel 15 in a short time is used.

The laser light output from the laser device 10 is narrowed down to an amount of light necessary for measurement by the ND filter 12, then reflected by the mirror 13 and incident on the condensing lens 14, and the condensing lens 14 makes a predetermined spot diameter. After the adjustment, the light enters the test target area of the liquid crystal panel 15 that is the test object.
Note that the laser beam output unit 11 shown in FIG. 1 is a simplified display of only the main part thereof, and does not hinder the change / addition of components according to the design of the test apparatus. Therefore, for example, the optical system of the laser light output unit 11 can be provided with a homogenizer or an integrator for making the laser light uniform, and can be provided with a mask for changing the spot shape of the laser light.

The liquid crystal panel 15, which is the test object, is cooled or heated by the temperature control unit 16 while being supported by the test object support unit 19. Further, a temperature measuring unit 33 is connected to the liquid crystal panel 15 while being supported by the test object support unit 19, and the temperature information of the liquid crystal panel 15 detected by the temperature measuring unit 33 is as follows. It is output to the temperature measurement unit 33. And the temperature control of the liquid crystal panel 15 can be performed now by operating control of the temperature control part 16a based on the said temperature information which the temperature measurement part 33 was input.
By having the above configuration, for example, the temperature control unit 16 can cool the liquid crystal panel 15 while irradiating the laser beam, thereby deteriorating the liquid crystal panel 15 due to heating due to the laser beam irradiation. Since the light resistance test can be performed while suppressing, it is possible to exclude the portion caused by heat from the deterioration factors of the liquid crystal panel 15 and accurately observe the deterioration phenomenon of the liquid crystal panel 15 due to light irradiation.

  The test object support unit 19, the liquid crystal panel 15, and the temperature control unit 16 are accommodated in a temperature control tank 26 having a temperature adjustment device 27, and are output from the laser beam output unit 11 to the liquid crystal panel 15. When the laser beam is incident, the environmental temperature and humidity of the liquid crystal panel 15 and the like can be controlled. With such a configuration, the light resistance test of the liquid crystal panel 15 can be performed while arbitrarily controlling the temperature and humidity during light irradiation, and a high-precision light resistance test can be performed. .

  Further, each device constituting the deterioration test apparatus 100 is accommodated in the temperature control chamber 25 and operates in a temperature / humidity environment controlled by a temperature adjustment device 29 provided in the temperature control chamber 25. By having such a configuration, it is possible to operate each device stably and to eliminate the influence caused by fluctuations in the operating state due to the operating environment from the test data, so a highly accurate light resistance test is possible. is there.

The first light quantity measurement unit 21 and the second light quantity measurement unit 22 provided in the front stage and the rear stage of the temperature control tank 26 with respect to the laser light path are connected to power meters 23 and 24, respectively, and enter the liquid crystal panel 15. The first light amount measurement unit 21 can detect the light amount of the immediately preceding laser light and read it by the power meter 23, and the second light amount measurement unit 22 can detect the light amount of the laser light transmitted through the liquid crystal panel 15 and the power meter 24. Can be read. Therefore, the transmittance of the liquid crystal panel 15 can be measured by comparing the laser light amount read by the power meter 23 with the laser light amount read by the power meter 24.
The first light quantity measurement unit 21 on the front side of the liquid crystal panel 15 can move forward and backward with respect to the optical path of the laser light, and is arranged on the laser optical path to detect the light quantity before the liquid crystal panel 15 is irradiated with the laser light. When the liquid crystal panel 15 is deteriorated and when the transmittance of the liquid crystal panel 15 is measured, the liquid crystal panel 15 moves backward from the laser light path.

  Between the first light quantity measuring unit 21 and the laser device 10, a polarizer for making laser light incident on the liquid crystal panel 15 a predetermined polarization state can be provided. In general, since a polarizing plate is provided on the outer surface side of the liquid crystal panel 15, if such a polarizer is provided so that linearly polarized light parallel to the transmission axis of the polarizing plate of the liquid crystal panel 15 is incident, Light absorption by the polarizing plate of the liquid crystal panel 15 can be eliminated. Thereby, the heating deterioration of the polarizing plate due to light absorption can be prevented, and the portion related to the deterioration of the polarizing plate among the deterioration caused in the liquid crystal panel 15 can be eliminated, so that the deterioration of a specific portion (alignment film) in the liquid crystal panel 15 is increased. It becomes possible to detect with accuracy. In addition, when the polarizing plate is not provided in the liquid crystal panel 15, a polarizer is provided also in the back | latter stage side of the liquid crystal panel 15 with the said front | former stage side polarizer.

<LCD panel>
The liquid crystal panel 15 which is a test object can have various configurations as the test object. Here, an example of the liquid crystal panel 15 will be described with reference to FIG. FIG. 2A is a partial cross-sectional configuration diagram of a TFT active matrix type liquid crystal panel 15 having a TN mode liquid crystal layer. In FIG. 2, only three pixels P1 to P3 are shown, but in actuality, a pixel having a configuration similar to that of the pixels P1 to P3 is arranged in a matrix in a plan view. Further, illustration of TFTs (thin film transistors) which are switching elements provided corresponding to the respective pixels P1 to P3 is omitted.

  The liquid crystal panel 15 shown in FIG. 2A includes a pair of substrates 151 and 152 that face each other with a liquid crystal layer 155 interposed therebetween. The substrates 151 and 152 are transparent substrates such as quartz, glass, and plastic, and are separated at a predetermined interval by a spacer (not shown) interposed between opposing surfaces of both substrates. A plurality of pixel electrodes 156 and an alignment film 153 covering the pixel electrodes 156 are formed on the inner surface side (liquid crystal layer 155 side) of the substrate 151, and a polarizing plate 159 is disposed on the outer surface side of the substrate 151. ing. A light shielding film (black matrix) 158, a counter electrode 157, and an alignment film 154 are stacked on the inner surface side of the substrate 152, and a polarizing plate 160 is disposed on the outer surface side of the substrate 152.

  The liquid crystal layer 155 is mainly composed of nematic liquid crystal, and is twist-aligned between the substrates 151 and 152 by the alignment regulating force of the alignment films 153 and 154. The alignment films 153 and 154 can be formed of a polyimide film or a silicon oxide film, and when a polyimide film is used, a rubbing process for aligning the liquid crystal in a desired direction is performed. In the case where a silicon oxide film is used, a concavo-convex shape is imparted to the film surface by an oblique deposition method or the like, and the liquid crystal is aligned by an alignment regulating force resulting from the shape.

The pixel electrode 156 is formed for each pixel and applies a driving voltage to the liquid crystal layer 155 in the region. The pixel electrode 156 can be formed by forming a transparent conductive film such as ITO (Indium Tin Oxide) on the substrate 151 and patterning it. A TFT (switching element) (not shown) is electrically connected to each pixel electrode 156, and a voltage corresponding to an image signal is written based on the switching operation of the TFT. The counter electrode 157 applies a voltage to the liquid crystal layer 155 together with the pixel electrodes 156 described above, and is formed on substantially the entire surface of the substrate 152. The counter electrode 157 is a common electrode shared by each pixel, and is connected to a predetermined potential such as a ground potential. The counter electrode 157 can also be formed of a transparent conductive film such as ITO.

  The light shielding film 158 covers the boundary of each pixel and blocks leakage light in the region, and is formed on the substrate 152. The light-shielding film 158 is made of a low-reflection metal material (for example, chromium) and is formed in a substantially lattice shape in plan view having openings in regions corresponding to the respective pixels.

<Temperature control unit>
In the deterioration test apparatus 100 of the present embodiment, a temperature control unit 16a shown in FIG. 3 is used as the temperature control unit 16 that adjusts the temperature of the liquid crystal panel 15. 3A is a plan configuration diagram of the temperature control unit 16a, and FIG. 3B is a sectional configuration diagram taken along the line AA ′ in FIG. 3A.
The temperature control unit 16a shown in FIG. 3 is configured to include a heat transfer member 32 disposed in part contact with the liquid crystal panel 15 and two temperature control elements 34 disposed on the heat transfer member 32. ing. The heat transfer member 32 is a base made of a material having good thermal conductivity such as a metal plate, and has an opening 32 a corresponding to the position where the liquid crystal panel 15 is disposed. The opening 32a is formed in a rectangular shape that is slightly smaller than the liquid crystal panel 15, and as shown in FIG. 3B, the temperature control unit 16a is disposed on the liquid crystal panel 15 and the periphery of the opening 32a. The heat transfer member 32 and the peripheral portion of the liquid crystal panel 15 are arranged in contact with each other, and the liquid crystal panel 15 can be heated / cooled via the heat transfer member 32.

[Temperature control element]
As the temperature control element 34 according to the present embodiment, a temperature control element 34a shown in FIG. 4 is used.
FIG. 4A is a perspective configuration diagram of the temperature control element 34a, and FIG. 4B is a sectional configuration diagram taken along line BB ′ in FIG. The temperature adjustment element 34a includes a thermoelectric conversion element (Peltier element) 36 that becomes a heat source when the liquid crystal panel 15 is heated / cooled via the heat transfer member 32, and a pair of cold substrates 35a that sandwich the thermoelectric conversion element 36. 35b and a liquid circulation type cooling / heating unit 37 disposed on the outer surface side (the side opposite to the thermoelectric conversion element 36) of the cooling / heating substrate 35b.

  FIG. 5 is an explanatory diagram showing an electrical configuration of the thermoelectric conversion element 36. The thermoelectric conversion element 36 has a configuration in which an N-type semiconductor block 36n and a P-type semiconductor block 36p made of silicon or the like are sandwiched between a first electrode 36b and two second electrodes 36c and 36c. The second electrodes 36c and 36c are connected to a power source through a wiring 36a derived from the second electrodes 36c and 36c. When the thermoelectric conversion element 36 is operated by being connected to a power source, the P-type semiconductor block 36p and the N-type semiconductor block 36n are operated according to the polarity of the power source via the first electrode 36b and the second electrodes 36c and 36c. When the connection is made as shown in the figure, the temperature of the first electrode 36b is lowered and cooled, and the temperature of the second electrodes 36c and 36c on the opposite side is increased. And heated. The thermoelectric conversion element 36 heats / cools the object using the difference in temperature generated between the electrodes 36b and 36c in this way. In FIG. 5, when the polarity of the power source is reversed, the first electrode 36b is heated and the second electrode 36b is cooled.

  The cooling / heating substrates 35a and 35b are substrates made of copper or aluminum, and the temperature control element 34a is disposed in a state where the cooling / heating substrate 35a is opposed to the heat transfer member 32 shown in FIG. Is done. The liquid circulation cooling / heating unit 37 provided in contact with the outer surface side of the cooling / heating substrate 35b is a rectangular parallelepiped member having a liquid channel formed therein, as shown in FIG. The circulation hoses 38 and 38 connected to the liquid flow path communicate with each other inside. Then, the cooling substrate 35b is cooled or heated by a circulation operation in which, for example, water is introduced into the liquid channel via one circulation hose 38 and discharged from the liquid channel via the other circulation hose 38. ing.

  The temperature control element 34a including the thermoelectric conversion element 36 is electrically cooled / heated. Therefore, as compared with a general cooling apparatus using a compressor (compressor) and a refrigerant (CFC etc.), Thus, it is possible to construct a temperature control element that has such advantages, is excellent in reliability, has a long lifetime, and is excellent in silence and mountability.

(1) Since no heat medium such as Freon is used, there is no adverse effect on the environment.
(2) Small and lightweight.
(3) The shape can be selected freely.
(4) Cooling / heating can be easily switched by simply changing the direction of the current.
(5) Since both cooling and heating can be performed, temperature control near room temperature can be performed.
(6) Good temperature responsiveness (rapid heating / cooling).
(7) Since there are no moving parts, there is no vibration or noise.
(8) Long life and high reliability because there are no mechanical parts that are fatigued or damaged.
(9) It can be connected only by electric wiring and is easy to handle.

<Deterioration test method>
Using the deterioration test apparatus 100 having the above-described configuration, the liquid crystal panel 15 is set with various conditions such as wavelength and irradiation time to cause laser light to be deteriorated, and the laser light is simultaneously emitted. By monitoring the transmitted light as the observation light, it is possible to evaluate the light resistance of the liquid crystal panel 15 as the test object. For example, it is possible to evaluate the light resistance of the liquid crystal panel by plotting a graph with the irradiation time of the laser light on the horizontal axis and the intensity (transmittance) of light passing through the liquid crystal panel 15 on the vertical axis. By calculating the acceleration coefficient from the evaluation result, the service life of the liquid crystal panel 15 can be estimated.

  Specifically, as shown in FIG. 2B, first, at least one of the wavelength, irradiation energy, and irradiation time of the laser beam LB is set as a variable parameter, and the test target region of the liquid crystal panel 15 is irradiated. (First step). The test target area can be arbitrarily set. For example, in the illustrated case, an area corresponding to one pixel P2 of the liquid crystal panel 15 is set. By applying relatively high energy to the liquid crystal panel 15 using the laser beam LB, each member (for example, an alignment film or liquid crystal molecules) included in the pixel P2 of the liquid crystal panel 15 is deteriorated. At this time, the degree of deterioration of the liquid crystal panel 15 varies depending on the setting contents of the variable parameter of the laser beam LB. In the present embodiment, it is assumed that the orientation film in the pixel P2 is altered by irradiation with the laser beam LB, and the orientation of the liquid crystal molecules is locally reduced. By making the laser beam LB continuous wave (CW), energy can be given more efficiently.

In this embodiment, as shown in FIGS. 1 and 3, the temperature control unit 16 is disposed in contact with the liquid crystal panel 15. Therefore, when the laser beam LB is irradiated in the first step, the liquid crystal panel is used. The temperature of 15 can be kept constant. As a result, the heating of the liquid crystal panel 15 by the laser beam LB can be suppressed, the deterioration factor due to heat can be eliminated, and only the degree of deterioration due to light irradiation can be accurately evaluated.
Further, according to the deterioration test apparatus of the present embodiment, the liquid crystal panel 15 is heated by the temperature control unit 16 and the temperature control tank 26 to cause the liquid crystal panel 15 to deteriorate, and the transmittance of the liquid crystal panel 15 before and after the deterioration is increased. The change can also be measured using laser light as observation light. Even in this case, a deterioration test of the liquid crystal panel 15 using laser light as observation light can be performed in parallel with the heat treatment by the temperature control unit 16 and the temperature control tank 26.

  Next, as shown in FIG. 2C, the observation light OB is irradiated onto the liquid crystal panel 15, and the state of the observation light OB that has passed through the liquid crystal panel 15 is detected by the second light quantity measurement unit 22 (second). Process). In the present embodiment, the amount of light (light intensity) is assumed as the state (optical characteristics) of the observation light OB to be detected. However, the present invention is not limited to this, and various things such as polarization state and spectral characteristics are conceivable. . That is, if a light source that outputs the observation light OB according to the content to be detected as the state of the observation light OB and its detection means are prepared, various detection objects can be measured. Even if the detection target (light quantity, polarization state, spectral characteristics, etc.) is changed, if the test target area of the liquid crystal panel 15 has deteriorated, different optical characteristics are detected before and after the laser beam LB is irradiated. The degree of deterioration of the liquid crystal panel 15 can be observed.

  Here, FIG. 6 is an explanatory diagram in the case where measurement is performed with the amount of observation light OB transmitted through the liquid crystal panel 15 as a detection target in the second step, and FIG. 6A is irradiated with the laser light LB. FIG. 6B is a diagram illustrating the case where the second step is performed on the liquid crystal panel 15 before being performed (in a state in which the liquid crystal panel 15 is not deteriorated), and FIG. It is a figure shown about the case where the said 2nd process is implemented about the liquid crystal panel.

As shown in FIG. 6A, polarizing plates 159 and 160 are arranged on the light incident side and the light emission side of the liquid crystal panel 15, respectively. When the liquid crystal panel 15 is not provided with a polarizing plate, polarizing elements corresponding to the polarizing plates 159 and 160 are disposed on both sides of the liquid crystal panel 15, respectively.
The polarizing plate 159 and the polarizing plate 160 are arranged so that their transmission axes are substantially orthogonal to each other, and the transmission axis of the polarizing plate 159 on the light incident side is an average of liquid crystal molecules on the substrate 151 side of the liquid crystal panel 15. It arrange | positions so that it may become substantially parallel to the orientation direction (director). The transmission axis of the polarizing plate 160 is arranged so as to be substantially parallel to the director on the substrate 152 side of the liquid crystal panel 15.

  Only the vibration component along the optical principal axis of the polarizing plate 159 passes through the observation light OB output from the laser light output unit 11 and incident on the polarizing plate 159, and becomes linearly polarized light. When the observation light OB that has become linearly polarized light passes through the liquid crystal layer 155, the polarization direction of the observation light OB is rotated by 90 degrees by the optical rotation action of the liquid crystal layer 155, and is emitted from the liquid crystal layer 155. Thereafter, the light passes through the polarizing plate 160 having a transmission axis parallel to the polarization direction of the observation light OB, and the light amount is detected by the second light amount measurement unit 22.

  On the other hand, in the case shown in FIG. 6B, as shown in FIG. 2C, the alignment films 153 and 154 are deteriorated by the irradiation with the laser beam LB. The alignment disorder of the liquid crystal resulting from the decrease in the alignment regulation force of 154 occurs. As a result, the polarization conversion action with respect to the incident light is reduced, so that the polarization state of the observation light OB after passing through the liquid crystal layer 155 becomes, for example, elliptical polarization as shown in FIG. 6A. It will be in a different state. Therefore, the polarization component that can be transmitted through the polarizing plate 160 in the observation light OB decreases, and the light amount detected by the second light amount measurement unit 22 also decreases.

  In this way, it is possible to detect the amount of the observation light OB transmitted through the liquid crystal panel 15 before and after irradiating the liquid crystal panel 15 with the laser light LB. In FIG. 6, the polarization state of the observation light OB incident on the liquid crystal panel 15 from the laser light output unit 11 is not controlled. However, the laser light LB and the observation light OB emitted from the laser light output unit 11 are converted into the liquid crystal panel 15. It is preferable to use linearly polarized light parallel to the polarizing plate 159 on the light incident side. With such a configuration, the laser beam is not absorbed in the polarizing plate 159, so that the deterioration of the polarizing plate 159 due to heat generation or light irradiation can be prevented, and the deterioration factor related to the polarizing plate 159 can be excluded from the measurement result. it can.

  Thereafter, the light resistance of the liquid crystal panel is evaluated based on the difference in the state of the observation light OB according to the setting content of the variable parameter of the laser beam LB (third step). For example, the deterioration with time can be evaluated by comparing the difference in the state of the observation light OB depending on the irradiation time of the laser light LB. Moreover, the tolerance with respect to light intensity can be evaluated by comparing the difference in the state of the observation light OB depending on the irradiation energy of the laser light LB.

  In the present embodiment, as shown in FIG. 2C, the observation light OB is output from the laser light output unit 11, and the laser light LB is also used as the observation light OB. In this case, the first step and the second step can be performed in parallel. Further, with such a configuration, a light source that outputs the observation light OB becomes unnecessary, and the deterioration test apparatus 100 as a whole can be made compact.

  In the description of the above embodiment, the case where the liquid crystal panel 15 is in the TN (Twisted Nematic) mode has been described. ) Mode or the like, and it is not limited to the driving type (active matrix type / passive matrix type). The liquid crystal panel is not limited to a transmissive type, but may be a reflective type or a transflective type. Even when a deterioration test of a reflective liquid crystal panel is performed, it can be easily handled by simply changing the arrangement of the observation light detection means.

  Moreover, in the said embodiment, although light quantity (light intensity) is employ | adopted as a detection target of observation light OB, various things, such as a polarization state, spectral characteristics, and retardation, can be employ | adopted besides this, and according to a detection target. What is necessary is just to use a detection means instead of the 2nd light quantity measurement part 22. FIG. For example, an ellipsometer may be used as the detection means if the change in the polarization state is the detection target, and a spectrophotometer may be used as the detection means if the spectral characteristic is the detection target.

  In the above-described embodiment, the case where the test object is a liquid crystal panel has been described. However, the deterioration test apparatus according to the present invention can be used before and after laser light irradiation even when a test object other than the liquid crystal panel is used. In addition, it is possible to evaluate the light resistance, heat resistance, and the like of the test object by observing changes in the optical characteristics before and after the heat treatment. For example, it is suitable for use in an electro-optical device (such as an organic EL device) other than a liquid crystal panel, an optical film such as a polarizing plate or a retardation plate, or a deterioration acceleration test using a coloring material such as a dye or pigment as a test object. Can do.

(Other embodiments)
The deterioration test apparatus according to the present invention is not limited to the configuration of the above embodiment, and various configurations can be adopted. Hereinafter, as another embodiment, another configuration example of the temperature control element 34 and the temperature control unit 16 will be described with reference to the drawings.

<Temperature control element>
Instead of the temperature control element 34a according to the above-described embodiment, temperature control elements 34b and 34c shown in FIGS. 7 and 8, respectively, may be used.
Fig.7 (a) is a perspective block diagram of the temperature control element 34b which is the 1st modification of the temperature control element 34, FIG.7 (b) is sectional sectional drawing which follows the DD 'line of (a). It is. The temperature control element 34b shown in FIG. 7 includes a thermoelectric conversion element, similarly to the temperature control element 34a shown in FIG. That is, it includes a thermoelectric conversion element 36, and a first cooling / heating substrate 35a and a second cooling / heating substrate 35b that are opposed to each other with the thermoelectric conversion element 36 interposed therebetween. As shown in FIG. 7B, the second cooling / heating substrate 35b is provided. A configuration in which a heat sink 40 is disposed on the outer surface side is provided. A heat radiating fan 41 may be provided outside the heat sink 40 (on the side opposite to the thermoelectric conversion element 36).

  The heat sink 40 dissipates the heat of the second cold substrate 35b through a plurality of radiating fins 40a provided on the opposite side of the second cold substrate 35b, and the temperature adjustment element 34b of the present example includes the heat sink 40b. By having 40, in addition to the effect of the temperature control element 34a which concerns on previous embodiment, it has the advantage that the temperature control element can be reduced in size and silenced.

Next, FIG. 8A is a perspective configuration diagram of a temperature control element 34c which is a second modification of the temperature control element 34, and FIG. 8B is a detailed configuration of the heat pipe shown in FIG. 8A. FIG. 8C is a diagram showing a cross-sectional structure of the heat pipe shown in FIGS. 8A and 8B.
The temperature control element 34c shown in FIG. 8 is provided on the heat transfer member 32 shown in FIG. 3 and a substantially rectangular parallelepiped base 45 for heating / cooling the heat transfer member 32, and provided on one side of the base 45. One end thereof is configured to include two heat pipes 46 and 46 embedded in the base body 45 and a metal plate 47 provided between the heat pipes 46 and 46.

As shown in FIGS. 8B and 8C, the heat pipe 46 forms a capillary structure (wick) 46b on the inner wall surface of the metal tube (container) 46a and operates in a small amount in the internal space 46c. It has a configuration in which liquid (water, chlorofluorocarbon, etc.) is vacuum-sealed.
When a part (heat input part) of the heat pipe 46 is heated, the hydraulic fluid sealed inside evaporates with heat (latent heat of evaporation is absorbed). Thereafter, the vapor of the hydraulic fluid moves through the internal space 46c toward the opposite end (in the direction of the arrow denoted by reference numeral 48), and reaches the other end (heat exhaust portion) of the heat pipe 46. The vapor of the hydraulic fluid is condensed and liquefied in the exhaust heat section having a temperature lower than that of the heat input section (latent evaporation heat is released). Thereafter, the liquefied hydraulic fluid is circulated to the heat input portion by capillary action of the wick 46b provided on the inner wall of the container 46a. By such a series of phase changes continuously occurring, the heat pipe 46 can move heat from the heat input portion to the heat exhaust portion. By providing the heat pipe 46, the following advantages can be obtained.

(1) It has excellent thermal conductivity capable of rapidly transporting a large amount of thermal energy with a slight temperature difference.
(2) Since the steam flow inside the heat pipe moves at a speed close to the speed of sound, the heat responsiveness is extremely good.
(3) Even a long heat pipe can have a uniform temperature up to the tip without any temperature difference.
(4) Since there is no movable part, maintenance is unnecessary and driving power is also unnecessary.

  Even when the temperature control element 34c having the above-described configuration is used, the temperature of the liquid crystal panel 15 can be controlled via the heat transfer member 32 as in the case of the temperature control elements 34a and 34b described above. It is possible to prevent the temperature of the liquid crystal panel 15 from rising and to improve the accuracy of the deterioration test by eliminating the deterioration factor related to the temperature.

<Temperature control unit>
In the deterioration test apparatus according to the present invention, a temperature control unit 16b having the configuration shown in FIG. 9 can be used instead of the temperature control unit 16a according to the above embodiment. 9A is an overall configuration diagram of a temperature control unit 16b that is a modification of the temperature control unit 16, FIG. 9B is a perspective configuration diagram of a heat transfer unit that performs heating / cooling of the liquid crystal panel, and FIG. ) Is a cross-sectional configuration view of the heat transfer section observed from above (b).

  The temperature control unit 16 b includes a heat transfer unit 51 and a circulation type electronic cooling device 52 connected to the heat transfer unit 51 via two hoses 53 and 54. As shown in FIG. 9B, the heat transfer section 51 includes a flow path forming section 55 and two transparent substrates 56 and 57 that are opposed to each other with the flow path forming section 55 interposed therebetween. Hose 53 and 54 are connected to side portions of the portion 55 facing each other. The flow path forming unit 55 includes a liquid flow path 55a inside as shown in FIG. The liquid channel 55a communicates with the inside of the hoses 53 and 54 connected to the side surface of the channel forming unit 55, and a cooling medium such as water is formed in a space surrounded by the channel forming unit 55 and the transparent substrates 56 and 57. 59 is satisfied. The circulation type electronic cooling device 52 circulates the cooling medium 59 to the heat transfer section 51 and controls the cooling medium 59 to a desired temperature. It is connected to the heat section 51).

As shown in FIG. 9B, the temperature control unit 16b having the above-described configuration is configured such that the liquid crystal panel 15 as the test object is supported on the outer surface side of the transparent substrate 56 of the heat transfer unit 51. As shown in FIG. 9C, the liquid crystal panel 15 and the transparent substrate 56 are arranged in a state where their main surfaces are in contact with each other. The temperature of the liquid crystal panel 15 is controlled by the circulation operation of the cooling medium 59.
The heat transfer section 51 is disposed so as to overlap the liquid crystal panel 15 in a planar manner, but the two substrates 56 and 57 that sandwich the flow path forming section 55 are both transparent, and the cooling medium 59 Also, a colorless and transparent material can be used. Therefore, when irradiating the liquid crystal panel 15 with the laser beam, the laser beam can be irradiated through the heat transfer section 51. There is no impact.

  In the temperature control unit 16b of this example, since the transparent substrate 56 of the heat transfer unit 51 is disposed in surface contact with the liquid crystal panel 15, temperature control can be performed while keeping the temperature of the entire liquid crystal panel 15 uniform. . Thereby, accurate temperature control is possible and test accuracy can be improved.

The schematic block diagram of the deterioration test apparatus which concerns on embodiment. The figure explaining the cross-sectional structure of the liquid crystal panel which is a test object, and the effect | action of a test apparatus. The figure which shows the structure of a temperature control part. The figure which shows the structure of a temperature control element. Operation | movement explanatory drawing of a thermoelectric conversion element. Explanatory drawing of a deterioration test method. The figure which shows the 1st modification of a temperature control element. The figure which shows the 2nd modification of a temperature control element. The figure which shows the modification of a temperature control part.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... Laser apparatus, 11 ... Laser beam output part, 12 ... ND filter, 13 ... Mirror, 14 ... Condensing lens, 15 ... Liquid crystal panel (test object), 16, 16a, 16b ... Temperature control part, 17 ... Imaging , 18 ... Image processing part, 19 ... Test object support part, 21 ... First light quantity measurement part, 22 ... Second light quantity measurement part, 23, 24 ... Power meter, 25 ... Temperature control chamber, 26 ... Temperature control tank 27, 29 ... Temperature adjusting device, 32 ... Heat transfer member, 33 ... Temperature measuring part, 34, 34a to 34c ... Temperature control element, 36 ... Thermoelectric conversion element, 46 ... Heat pipe, 51 ... Heat transfer part, 52 ... Circulating electronic cooling / heating device, 100 ... Deterioration testing device, LB ... Laser light, OB ... Observation light

Claims (17)

A laser beam output unit for outputting a laser beam;
A test object support for supporting the test object irradiated with the laser beam;
A deterioration test apparatus comprising: temperature control means for adjusting the temperature of the test object in contact with the test object supported by the test object support section. A test object support for supporting the liquid crystal panel;
A laser beam output unit for selectively irradiating one or a plurality of pixels of the liquid crystal panel supported by the test object support unit with a laser beam;
A deterioration test apparatus comprising: temperature control means for adjusting the temperature of the liquid crystal panel in contact with the liquid crystal panel supported by the test object support portion.   The deterioration test apparatus according to claim 1, wherein a thermoelectric conversion element is provided in the temperature control means.   The deterioration test apparatus according to claim 1, wherein the temperature control means is provided with a heat pipe that performs latent heat transfer by vaporization / condensation of the hydraulic fluid.   The temperature control means is provided with a heat transfer section that comes into contact with the test object, and a circulation type cooling device that circulates a cooling medium through the heat transfer section. 2. The deterioration test apparatus according to 2.   6. A temperature measuring unit that measures the temperature of the test object and outputs temperature information used for temperature adjustment of the test object to the temperature control unit is provided. The deterioration test apparatus according to any one of the above.   A first light amount measuring unit for measuring the light amount of the laser light applied to the object and a second light amount measuring unit for measuring the light amount of the laser light after being applied to the object; The deterioration test apparatus according to any one of claims 1 to 6, characterized in that:   8. The apparatus according to claim 1, wherein at least the test object and the test object support part are accommodated in a temperature control tank whose internal temperature and / or humidity is controlled. Degradation test equipment described in 1.   9. At least the test object, the test object support section, and the laser beam output section are accommodated in a temperature control chamber whose internal temperature and / or humidity is controlled. The deterioration test apparatus according to any one of the above.   The deterioration test apparatus according to claim 9, wherein the first light quantity measurement unit and the second light quantity measurement unit are accommodated in the temperature control chamber. A first step of irradiating a test object with laser light;
A second step of irradiating the object with observation light and detecting the state of the observation light after irradiating the object;
A third step of evaluating the light resistance of the test object based on the difference in the observation light before and after irradiating the test object;
Including
In the first step, the laser beam is irradiated while the test object is kept at a constant temperature. In the first step, at least one of the wavelength, irradiation energy, and irradiation time of the laser beam is set as a variable parameter to irradiate the test object,
The deterioration test method according to claim 11, wherein in the third step, light resistance of the test object is evaluated based on a difference in the observation light according to the variable parameter.   The deterioration test method according to claim 11 or 12, wherein the laser light is also used as the observation light, and the first step and the second step are performed in parallel. Using a liquid crystal panel as the test object,
The deterioration test method according to claim 11, wherein the laser light is selectively irradiated to one or a plurality of pixels of the liquid crystal panel.   The deterioration test method according to claim 14, wherein in the first step, alignment of an alignment film included in the liquid crystal panel is lowered by irradiation with the laser beam.   The deterioration test method according to claim 15, wherein the laser light applied to the liquid crystal panel is linearly polarized light substantially parallel to a transmission axis of a polarizing plate on a light incident side of the liquid crystal panel.   The deterioration test method according to any one of claims 14 to 16, wherein the temperature of the liquid crystal panel is controlled via a heat transfer member that is in surface contact with one or both surfaces of the liquid crystal panel.

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