JP2012098313A - Light irradiation device, light irradiation method, and liquid crystal display panel manufactured therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device capable of highly efficiently performing a PSA process while preventing the excessive irradiation.SOLUTION: This light irradiation device includes: a voltage application unit (a voltage application part 6 and a power supply 7) for allowing the application of a voltage to a liquid display panel 5 that includes a liquid crystal layer sealed in the interior and has a main surface; and a light source unit 9 for applying the light towards the main surface, with the voltage applied to the liquid crystal layer by the voltage application means. The light applied by the light source unit 9 has at least one peak wavelength within a range of not less than 300 nm but not more than 400 nm, and a full width at half maximum of the intensity distribution of the peak wavelength is 20 nm or more.

Description

  The present invention relates to a light irradiation apparatus, a light irradiation method, and a liquid crystal display panel manufactured using these.

  In a liquid crystal display panel, there is a technology called PSA (Polymer-Sustained Alignmnet) technology in order to stabilize the alignment of liquid crystal molecules. In this method, a photopolymerizable monomer is mixed in a liquid crystal, and a voltage is applied to the liquid crystal, that is, the liquid crystal is driven and exposed to light, whereby the liquid crystal molecules are memorized in a certain orientation. is there. By storing the orientation in a certain direction in the liquid crystal molecules in this manner, the orientation of the liquid crystal molecules is stabilized and the response speed is increased when used as a liquid crystal display panel.

  Prior to the use of the PSA technique, for example, measures for stabilizing the orientation by the rib shape were taken, but there was a problem that the transmittance was reduced by providing such a rib shape. On the other hand, if the PSA technique is used, such a rib shape is not necessary, so that the transmittance can be increased, the brightness range at the time of display is increased, and as a result, the contrast ratio can be increased. There was a merit.

  The PSA technology is described in Japanese Patent Application Laid-Open No. 2003-177408 (Patent Document 1). Moreover, in the said literature, performing multiple times of irradiation is described. In general, as a process related to the PSA technique (hereinafter referred to as “PSA process”), “primary irradiation” and “secondary irradiation” are performed twice in total.

  In Example 29 starting from paragraph 0191 of the above document, as a step corresponding to primary irradiation, with a driving voltage applied to the liquid crystal layer of the liquid crystal display panel, irradiation with ultraviolet rays having a maximum peak wavelength of 365 nm is performed for 300 seconds, The monomer is polymerized and cured in a predetermined liquid crystal alignment state. Next, as a step corresponding to the secondary irradiation, ultraviolet rays having a maximum peak with a wavelength of 352 nm are irradiated without driving the liquid crystal.

Japanese Patent Laid-Open No. 2003-177408

  Irradiating UV light with a driving voltage applied to the liquid crystal leads to stabilization of the alignment of the liquid crystal molecules by polymerizing the monomer to form a polymer as intended by the PSA technology. It also leads to deterioration of other components.

  Therefore, even when the PSA technology is adopted, it is necessary to carefully determine under what conditions the irradiation is performed.

  Then, an object of this invention is to provide the light irradiation apparatus and light irradiation method which can perform a PSA process efficiently so that it may not become excessive irradiation. It is another object of the present invention to provide a liquid crystal display panel in which the orientation of liquid crystal molecules is sufficiently stabilized.

  In order to achieve the above object, a light irradiation apparatus according to the present invention is a voltage for applying a voltage to a liquid crystal display panel including a liquid crystal layer enclosed therein and having a main surface. An application unit, and a light source unit for irradiating light toward the main surface in a state where a voltage is applied to the liquid crystal layer by the voltage application unit, and the light is in a range of 300 nm to 400 nm. It has at least one peak wavelength, and the full width at half maximum of the intensity distribution related to the peak wavelength is 20 nm or more.

  According to the present invention, the PSA process can be performed efficiently so as not to cause excessive irradiation. Irradiation under these conditions is sufficiently possible using a fluorescent tube, so that it is possible to omit equipment of a high-pressure mercury lamp that is expensive and generates a large amount of heat.

It is the 1st explanatory view of the mode of irradiation based on a reference technique. It is the 2nd explanatory view of the mode of irradiation based on a reference technique. It is a spectrum distribution map of a high pressure mercury lamp. It is an exploded view of the light irradiation apparatus in Embodiment 1 based on this invention. It is a flowchart of the operation | work by the light irradiation apparatus in Embodiment 1 based on this invention. It is explanatory drawing of a mode that a liquid crystal display panel is fixed to the light irradiation apparatus in Embodiment 1 based on this invention, and light is irradiated. It is explanatory drawing of a mode that the fluorescent tube was arranged in the checkered pattern. It is explanatory drawing of a mode that the fluorescent tube was arranged simply instead of checkered. It is a distribution map of the irradiance in the main surface of the liquid crystal display panel arrange | positioned directly under one fluorescent tube. 2 is a spectral distribution of the fluorescent tube of Example 1 according to Embodiment 1. FIG. It is the figure which piled up the spectrum distribution shown in FIG. 3 and FIG. It is a spectrum distribution of the fluorescent tube of Example 2 in Embodiment 1. FIG. It is a spectrum distribution of the fluorescent tube of Example 3 in Embodiment 1. FIG. It is explanatory drawing which looked at the operation | movement of Example 4 in Embodiment 1 from the top. It is explanatory drawing which looked at the operation | movement of Example 4 in Embodiment 1 from the side. It is a graph which shows the relationship between the integrated irradiance in 300-400 nm, and a voltage holding ratio. It is a block diagram of Example 1 of this embodiment. It is a block diagram of Example 5 of this embodiment. It is the 1st explanatory view of an example of a usual shutter. It is the 2nd explanatory view of the example of a usual shutter. It is the 1st explanatory view of a shutter which can be used when applying the present invention. It is the 2nd explanatory view of a shutter which can be used when applying the present invention.

  When performing the PSA process, what is required for the primary irradiation is the ability to stabilize the alignment of liquid crystal molecules. The primary irradiation is intended to polymerize at least a certain proportion of the monomers mixed in the liquid crystal. On the other hand, the secondary irradiation is intended to eliminate the monomer that is not polymerized by the primary irradiation and remains.

Therefore, first, the inventors examined the following reference technique for primary irradiation.
(Reference technology)
The main surface of the liquid crystal display panel to be irradiated in the primary irradiation is a large area, and it is required to make uniform light as parallel as possible enter the wide area. However, the light source has a smaller size than the liquid crystal display panel. Therefore, as shown in FIG. 1, it is conceivable to irradiate the liquid crystal display panel 5 on the irradiation stage 4 by expanding the irradiation area by reflecting the light emitted radially from the light source 1 with the reflecting mirrors 2 and 3. However, since the irradiance decreases when enlarged, it is necessary to use a sufficiently strong light source.

Conventionally, in order to polymerize a monomer, it has been considered that light whose irradiance at the peak wavelength of light irradiated on the surface of the liquid crystal display panel exceeds 1 mW / cm ² is necessary. For this purpose, it is considered that a high-intensity light source such as a high-pressure mercury lamp must be used, and a high-pressure mercury lamp has been used as the light source 1 shown in FIG. Light emitted from the high-pressure mercury lamp as the light source 1 is guided by a reflecting mirror. In some cases, a wavelength selection filter is inserted in the optical path from the light source 1 toward the liquid crystal display panel 5.

  By the way, the high-pressure mercury lamp is an expensive device and consumes a large amount of power. Therefore, when a high-pressure mercury lamp is used as a light source, it is required to use a small number of light sources. As shown in FIG. 1, in the method of enlarging with the reflecting mirrors 2 and 3, even if the liquid crystal display panel 5 is smaller than a certain size, even if there is only one light source 1, it can be handled sufficiently, but the size becomes larger. I can't cope with it. Therefore, as shown in FIG. 2, a plurality of light sources 1a and 1b are installed, and each light is incident on the liquid crystal display panel 5 through a plurality of optical paths formed by the reflecting mirrors 2a, 2b, 3a and 3b. I need it. The high pressure mercury lamp has a spectrum as shown in FIG. The inventors thought that some of the spectral components had higher intensity than necessary.

  It is not preferable to install a plurality of high-pressure mercury lamps because the apparatus is expensive. Moreover, since the high pressure mercury lamp generates a large amount of heat, a cooling facility is also required, and the apparatus is expensive and large. Moreover, if it is going to comprise a some optical path, a reflection mechanism will also be enlarged and a lot of space will be wasted.

  Therefore, the inventors have studied to determine essentially preferable conditions for the primary irradiation in the PSA process. In order to stably polymerize the monomer, the inventors do not need the intensity of light at the peak wavelength, but it is important that an intensity of a certain value or more is secured in a certain wavelength band. I found out. That is, in the past, by increasing the overall irradiance by using a light source having a high intensity, the wavelength band having an intensity equal to or greater than a predetermined value has been expanded. However, if a light source having a wide wavelength band is originally used. It was found that the monomer can be polymerized stably even at low irradiance. As a result, the inventors have reached the present invention.

(Embodiment 1)
(Light irradiation device)
With reference to FIGS. 4-9, the light irradiation apparatus in Embodiment 1 based on this invention is demonstrated. As shown in FIG. 4, the light irradiation device in the present embodiment applies a voltage to the liquid crystal layer with respect to the liquid crystal display panel 5 including the liquid crystal layer sealed inside and having the main surface. And a light source unit 9 for irradiating light toward the main surface in a state where a voltage is applied to the liquid crystal layer by the voltage applying unit. The light has at least one peak wavelength within a range of 300 nm to 400 nm, and the full width at half maximum of the intensity distribution relating to the peak wavelength is 20 nm or more. The voltage application unit includes a voltage application jig 6 and a power source 7. The voltage application jig 6 also serves as an irradiation stage. Electrodes 6 a are arranged on the upper surface of the voltage application jig 6. Preferably, the voltage application unit includes a pressing jig 8. The light source unit 9 includes a plurality of fluorescent tubes 10 arranged in a checkered pattern.

  The details of the wavelength of light will be described later. First, the operation of this apparatus will be described. FIG. 5 shows a flowchart of work by this light irradiation device.

  First, as step S1, the liquid crystal display panel 5 is carried into the light irradiation device as indicated by an arrow 81 in FIG. The liquid crystal display panel 5 has a terminal near the outer edge for applying a voltage to the liquid crystal layer. The electrodes 6 a of the voltage application jig 6 are arranged so as to correspond to the arrangement of terminals of the liquid crystal display panel 5.

  Next, as step S2, the voltage application jig 6 and the terminals of the liquid crystal display panel 5 are aligned.

  Next, as step S3, the pressing jig 8 is operated as shown by an arrow 83 in FIG. 4, and the liquid crystal display panel 5 is sandwiched and fixed between the pressing jig 8 and the voltage applying jig 6. As a result, the liquid crystal display panel 5 is fixed as shown in FIG. In this embodiment, the pressing jig 8 is described on the assumption that the liquid crystal display panel 5 is sandwiched by moving from the top to the bottom as shown in FIG. 4, but the liquid crystal display panel 5 is correctly fixed. If possible, the pressing jig 8 may move in another direction.

  Next, as step S <b> 4, the power supply 7 connected to the voltage application jig 6 is operated to start applying a voltage to the liquid crystal layer of the liquid crystal display panel 5.

  Next, as step S5, the light source unit 9 is driven to start irradiating the liquid crystal display panel 5 with light. This is shown in FIG. More specifically, any one of the following methods can be selected for this light irradiation. As a first method, the fluorescent tube 10 of the light source unit 9 is simply turned on. As a second method, the fluorescent tube 10 is turned on in advance with the shutter disposed between the liquid crystal display panel 5 and the fluorescent tube 10 closed, and then the shutter is opened. The shutter will be described in detail in Embodiment 4. As a third method, the light source unit 9 in which the fluorescent tube 10 is previously turned on at a position where the light does not reach the liquid crystal display panel 5 is moved to a position where the light hits the liquid crystal display panel 5.

  Next, as step S6, the irradiation from the light source unit 9 is stopped after the predetermined irradiance is accumulated or after a predetermined time has elapsed.

  Next, as step S7, the power source 7 is stopped, and voltage application to the liquid crystal layer of the liquid crystal display panel 5 is stopped.

Next, as step S8, the pressing jig 8 is raised to release the fixation of the liquid crystal display panel 5.
Next, as step S9, the liquid crystal display panel 5 is carried out of the light irradiation device.

  Regarding step S6 and step S7, in this embodiment, step S7 is performed after step S6, but this order may be reversed. When step S6 is performed after step S7, the irradiation until the voltage application is stopped in step S7 corresponds to the primary irradiation, and the irradiation after the voltage application is stopped in step S7 corresponds to the secondary irradiation.

In the present embodiment, it is preferable that the integrated irradiance relating to the wavelength of the wavelength component of 300 nm or more and 400 nm or less contained in the light reaching the main surface of the liquid crystal display panel 5 is 100 mW / cm ² or less. The “integrated irradiance related to wavelength” in this case is obtained by integrating the irradiance by the wavelength. “Integrated irradiance related to wavelength” corresponds to the area of a region sandwiched between the waveform and the horizontal axis in a graph with the horizontal axis representing wavelength and the vertical axis representing intensity. The reason why this value in the section of 300 nm or more and 400 nm or less is preferably 100 mW / cm ² or less is that the results of Examples 1 to 4 described later and FIG. Details will be described later together with the description of FIG.

  It is preferable that the light source unit 9 includes a black light fluorescent tube as a light source of light irradiated toward the main surface of the liquid crystal display panel 5. This is because a black light fluorescent tube is cheaper than a high-pressure mercury lamp, generates less heat, and can be used efficiently.

  The light source unit 9 includes a plurality of fluorescent tubes 10 arranged as light sources of the light, and it is preferable that the minimum value in the main surface of the irradiance on the main surface is 85% or more of the maximum value. If the difference in irradiance in the main surface becomes larger than this, the unevenness of the tilt of the liquid crystal molecules, that is, the so-called tilt unevenness becomes too large, and the unevenness can be visually recognized when an image is displayed on the obtained liquid crystal display panel. Because it will become like this. In order to suppress the unevenness to a level where it cannot be visually recognized, the minimum value in the main surface of the irradiance on the main surface should be 85% or more of the maximum value.

  The plurality of fluorescent tubes 10 in the light source unit 9 are preferably arranged in a checkered pattern in a plane parallel to the main surface of the liquid crystal display panel 5. In the present embodiment, the fluorescent tubes 10 are arranged in a checkered pattern, but the “checkered” array is as shown in FIG. When arranged in this way, the irradiance can be made more uniform than when simply arranged in parallel as shown in FIG. The inventors measured the distribution of irradiance on the main surface of the liquid crystal display panel arranged immediately below when one fluorescent tube was arranged in the light source section. As a result, a distribution as shown in FIG. 9 was obtained. The “distance” on the horizontal axis indicates the position in the longitudinal direction of the fluorescent tube, with the end of the light emitting portion of the fluorescent tube being zero. The “distance” on the vertical axis indicates how far away from the central axis of the fluorescent tube in the width direction. In this graph, the irradiance at each part is expressed with the maximum value of irradiance in the main surface being 100. From FIG. 9, it can be seen that it is effective to arrange the irradiance in a checkered pattern so that the minimum value in the main surface is 85% or more of the maximum value. When arranging in a checkered pattern as shown in FIG. 7, how long is the length A of the overlap in the longitudinal direction between the fluorescent tubes adjacent in the diagonal direction, and what is the distance B between the centers in the width direction? Or the like may be appropriately determined with reference to a graph of irradiance as shown in FIG. For example, when the fluorescent tubes are arranged in a plane 8 cm away from the main surface, it is preferable that A is 4 cm and B is 4 cm.

  Furthermore, as a light irradiation apparatus in the present embodiment, by operating a plurality of fluorescent tubes 10, the minimum value in the main surface of the integrated irradiance with respect to time on the main surface is 85% or more of the maximum value. It is preferable to include a control unit 11 (see FIG. 4) for performing the light irradiation. If such a control unit is provided, the minimum value in the main surface of the integrated irradiance with respect to time becomes 85% or more of the maximum value, and tilt unevenness can be suppressed. As a result, unevenness is visually recognized during image display. This is because it can be avoided. The “integrated irradiance related to time” is a value obtained by integrating the irradiance at each part by the irradiation time.

(Action / Effect)
According to the light irradiation apparatus in the present embodiment, the PSA process can be performed efficiently so as not to cause excessive irradiation. According to the knowledge obtained by the inventors, it is not important that the light used for the primary irradiation is merely high in intensity, and has at least one peak wavelength within a range of 300 nm to 400 nm, and the peak wavelength It can be said that it is important that the full width at half maximum of the intensity distribution is about 20 nm or more. Irradiation under this condition is also possible with a fluorescent tube. Therefore, it has been found that a high-pressure mercury lamp, which has been considered necessary in the prior art, is not actually necessary in the primary irradiation, and it can be sufficiently dealt with using a fluorescent tube. If primary irradiation is possible even with a fluorescent tube, a high-pressure mercury lamp that is expensive and generates a large amount of heat is not necessary, and this is extremely meaningful for the production site of liquid crystal display panels.

In addition, inventors performed the following Examples 1-5 in order to confirm the effect of this invention.
Example 1
As a light source, a fluorescent tube FHF32BLB manufactured by Sankyo Electric was used. The distance between the fluorescent tube and the main surface of the liquid crystal display panel was 70 mm, and the value of B when arranged in a checkered pattern was 40 mm. The irradiation time was 120 seconds.

In this fluorescent tube, the spectrum distribution is as shown in FIG. 10, the position of the peak wavelength is 355 nm, and the full width at half maximum is 33 nm. The integrated irradiance for wavelengths from 300 nm to 400 nm was 6.2 mW / cm ² .

  In this case, the minimum value of the irradiance on the main surface was 85% or more of the maximum value, and the alignment of the liquid crystal molecules could be stabilized without any problem. FIG. 11 shows the spectral distribution of the fluorescent tube of Example 1 shown in FIG. 10 superimposed on the conventional spectral distribution shown in FIG. In FIG. 11, the spectral distribution of Example 1 is indicated by a solid line, and the spectral distribution of the high-pressure mercury lamp is indicated by a broken line. In Example 1 using a fluorescent tube, although the light intensity was much smaller than in the prior art, the purpose of primary irradiation of stabilizing the alignment of liquid crystal molecules could be achieved.

(Example 2)
As a light source, a fluorescent tube FHF32UVB manufactured by Sankyo Electric was used. The irradiation time was 60 seconds. Other conditions were the same as in Example 1.

In this fluorescent tube, the spectrum distribution is as shown in FIG. 12, the position of the peak wavelength is 314 nm, and the full width at half maximum is 38 nm. The integrated irradiance for wavelengths from 300 nm to 400 nm was 12.8 mW / cm ² .

In this case, the alignment of the liquid crystal molecules could be stabilized without problems.
(Example 3)
The same light source as in Example 2 was used. The irradiation time was 120 seconds. Other conditions were the same as in Example 1.

In this fluorescent tube, the spectrum distribution is as shown in FIG. 13, the position of the peak wavelength is 340 nm, and the full width at half maximum is 41 nm. The integrated irradiance for wavelengths from 300 nm to 400 nm was 5.5 mW / cm ² .

In this case, the alignment of the liquid crystal molecules could be stabilized without problems.
As a result of considering Examples 1-3, the inventors radiated light having at least one peak wavelength within a range of 300 nm to 400 nm, and the full width at half maximum of the intensity distribution related to this peak wavelength is 20 nm or more. It came to the knowledge that there existed that it was preferable. Alternatively, more preferably, the full width at half maximum is 30 nm or more, or more preferably, the full width at half maximum is 33 nm or more as shown in the results of Example 1.

Example 4
The same light source as in Example 1 was used. As shown in FIGS. 14 and 15, the light source unit 9 i moves. The irradiation time was 120 seconds per location. After the light source unit 9i stays at one place and irradiates for 120 seconds, the light source unit 9i moves by 8 cm, and continues irradiation for another 120 seconds. By repeating this, the light source unit 9i was advanced by 8 cm.

The integrated irradiance for wavelengths from 300 nm to 400 nm was 6.2 mW / cm ² .

  In this case, although the number of light sources provided in the light source unit 9i is small, it was possible to uniformly irradiate the entire main surface.

As a result of further studies, the inventors have sought a relationship between the magnitude of integrated irradiance relating to wavelengths from 300 nm to 400 nm and the voltage holding ratio of the obtained liquid crystal display panel. The result is shown in FIG. The reason why the voltage holding ratio decreases when the integrated irradiance is large is considered to be because the liquid crystal is adversely affected by excessive irradiation. From the results, as described above, is 100 mW / cm ² or less large integrated irradiance to wavelength of 400nm or less wavelength components than 300nm is from 0 mW / cm ² that is included in the light reaching the main surface of the liquid crystal display panel 5 It can be said that it is preferable.

(Example 5)
The type and arrangement of the light sources were the same as in Example 1. Regarding the irradiation time, unlike Example 1, after irradiation for 120 seconds with a voltage applied to the liquid crystal layer, voltage application to the liquid crystal layer was stopped, and irradiation was further performed for 900 seconds. That is, this example corresponds to the case where step S6 is performed after step S7.

  Embodiments 1 and 5 are shown in block diagrams as shown in FIGS. 17 and 18, respectively. The notation “newly developed apparatus” in these figures refers to the light irradiation apparatus according to the present invention. The “liquid crystal driving device” is a device for applying a voltage to the liquid crystal layer via a terminal of the liquid crystal display panel. In Example 1, primary irradiation can be performed with the light irradiation apparatus based on this invention, and secondary irradiation can be performed with the same apparatus as the past. The PSA process is finally completed after completing these two irradiations.

  On the other hand, in the case of Example 5, primary irradiation and secondary irradiation can be performed continuously with the light irradiation apparatus based on this invention. In this case, switching between primary irradiation and secondary irradiation in the light irradiation apparatus according to the present invention is performed by cutting off the application of voltage to the liquid crystal layer.

(Embodiment 2)
(Light irradiation method)
The light irradiation method in Embodiment 2 based on this invention is demonstrated. The contents already described as the description of the invention relating to the light irradiation device in the first embodiment are summarized as follows as the invention relating to the light irradiation method.

  The light irradiation method in the present embodiment includes a step S4 of starting to apply a voltage to the liquid crystal layer with respect to the liquid crystal display panel 4 including a liquid crystal layer sealed inside and having a main surface, and the state in which the voltage is applied Step S5 for irradiating the main surface with light and Step S7 for finishing the application of the voltage after finishing the light irradiation or in the middle of the light irradiation, The light has at least one peak wavelength within a range of 300 nm to 400 nm, and the intensity distribution related to the peak wavelength is light having a full width at half maximum of 20 nm or more.

In this light irradiation method, it is preferable that the integrated irradiance relating to the wavelength of the wavelength component of 300 nm to 400 nm contained in the light reaching the main surface is 100 mW / cm ² or less.

  In this light irradiation method, the step of irradiating the light is preferably performed using a black light fluorescent tube as a light source.

  In this light irradiation method, the step of irradiating the light is performed using a plurality of arranged fluorescent tubes as light sources, and the minimum value of the irradiance on the main surface is maximum. It is preferably 85% or more of the value.

  In this light irradiation method, the plurality of fluorescent tubes are preferably arranged in a checkered pattern in a plane parallel to the main surface.

  In this light irradiating method, the step of irradiating the light is performed by operating the plurality of fluorescent tubes, whereby the minimum value in the main surface of the integrated irradiance with respect to time on the main surface is 85 which is the maximum value. It is preferable to irradiate the light so as to be at least%.

(Action / Effect)
According to the light irradiation method in the present embodiment, the PSA process can be performed efficiently so as not to cause excessive irradiation. Irradiation under this condition can be realized with a fluorescent tube without using a high-pressure mercury lamp. Therefore, it is possible to omit the equipment of the high-pressure mercury lamp that is expensive and generates a large amount of heat.

(Embodiment 3)
(LCD panel)
A liquid crystal display panel according to the present invention is a liquid crystal display panel manufactured by performing alignment stabilization treatment of liquid crystal molecules in a liquid crystal layer using any one of the light irradiation apparatuses described in the first embodiment.

  Alternatively, the liquid crystal display panel is manufactured by performing alignment stabilization treatment of liquid crystal molecules in the liquid crystal layer using any one of the light irradiation methods described in the second embodiment.

(Action / Effect)
The liquid crystal display panel in this embodiment is preferable because the liquid crystal display panel in which the alignment of the liquid crystal molecules is stabilized can be prevented.

(shutter)
In the first embodiment, as a second method for performing step S5, the irradiation by opening the shutter has been described. The problem and solution for the shutter will be described below.

  As a normal shutter structure, double-shelf shutters 12a and 12b can be considered as shown in FIG. In this shutter, the shutter 12a and the shutter 12b are separated and opened with the center position 13 as a boundary. The complete open state is shown in FIG. Irradiation is continued in this state. Further, when the irradiation is finished, the shutters 12a and 12b are closed by approaching from the left and right, and finally the state shown in FIG. 19, that is, the complete closed state is reached.

  The part near the both ends of the main surface of the liquid crystal display panel 5 is irradiated only when the shutter is fully open, but the part near the center position 13 is irradiated from the start of opening the shutter until it is completely closed. Therefore, it is irradiated for a long time compared with the site | parts near both ends. Specifically, the time until the shutter shifts from the fully closed state to the fully open state is equal to the time until the shutter shifts from the fully open state to the fully closed state, both of which are x seconds. Assuming that the open state lasts for a seconds, the portions near both ends are irradiated for only a seconds, whereas the portions near the center position 13 are irradiated for a + 2 × seconds. Such a difference in the length of irradiation time causes non-uniformity in the degree of alignment treatment of the liquid crystal molecules, leading to uneven visual recognition.

  Therefore, the inventors propose to use a shutter 12c as shown in FIGS. FIG. 21 shows a completely closed state. The shutter 12c is made of a material that can be bent flexibly. When the irradiation is started, the shutter 12c moves only in one direction as indicated by arrows 81 and 84 in FIG. Since the shutter 12c can bend flexibly, the shutter 12c goes around the fluorescent tube 10 as indicated by an arrow 82. FIG. 22 shows a completely open state. The shutter 12c can be moved above the fluorescent tube 10 so as not to block light from the fluorescent tube 10 toward the liquid crystal display panel 5. When the irradiation is finished, the shutter 12c turns from the upper side to the lower side of the fluorescent tube 10 as indicated by an arrow 83, enters the lower side of the fluorescent tube 10 as indicated by arrows 81 and 84, and blocks light. Thus, the state shown in FIG. 21 is restored. As described above, by adopting a structure in which the shutter moves only in one direction, the irradiation time can be constant in any of the part near the center position 13 of the liquid crystal display panel 5, the part A, and the part B. As a result, the degree of alignment treatment of liquid crystal molecules can be made uniform, and uneven viewing can be prevented.

  Such a solution may be adopted as appropriate in the light irradiation apparatus or the light irradiation method based on the present invention.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Light source, 2, 2a, 2b, 3a, 3b Reflector, 4 Irradiation stage, 5 Liquid crystal display panel, 6 Voltage application jig, 7 Power supply, 8 Pushing jig, 9, 9i Light source part, 10 Fluorescent tube, 11 Control unit, 12a, 12b, 12c shutter, 13 center position, 81, 82, 83 arrows.

Claims (14)

A voltage application unit for applying a voltage to the liquid crystal layer with respect to a liquid crystal display panel including a liquid crystal layer sealed inside and having a main surface;
A light source unit for irradiating light toward the main surface in a state where a voltage is applied to the liquid crystal layer by the voltage applying unit;
The light irradiation apparatus, wherein the light has at least one peak wavelength within a range of 300 nm to 400 nm, and a full width at half maximum of an intensity distribution related to the peak wavelength is 20 nm or more. The light irradiation apparatus according to claim 1, wherein an integrated irradiance relating to a wavelength component of a wavelength component of 300 nm or more and 400 nm or less contained in the light reaching the main surface is 100 mW / cm ² or less.   The light source device according to claim 1, wherein the light source unit includes a black light fluorescent tube as a light source of the light.   The light source unit includes a plurality of fluorescent tubes arranged as a light source of the light, and a minimum value in the main surface of irradiance on the main surface is 85% or more of a maximum value. The light irradiation apparatus in any one.   5. The light irradiation device according to claim 1, wherein the plurality of fluorescent tubes are arranged in a checkered pattern in a plane parallel to the main surface.   Control for irradiating the light so that the minimum value in the main surface of the integrated irradiance with respect to time on the main surface is 85% or more of the maximum value by operating the plurality of fluorescent tubes. The light irradiation apparatus in any one of Claim 1 to 5 provided with a part.   A liquid crystal display panel produced by performing alignment stabilization treatment of liquid crystal molecules in the liquid crystal layer using the light irradiation device according to claim 1. A step of starting to apply a voltage to the liquid crystal layer with respect to a liquid crystal display panel including a liquid crystal layer sealed inside and having a main surface;
Irradiating light toward the main surface with the voltage applied;
A step of finishing the application of the voltage after finishing the light irradiation or during the light irradiation,
The light irradiation method, wherein the light has at least one peak wavelength within a range of 300 nm or more and 400 nm or less, and the intensity distribution related to the peak wavelength is light having a full width at half maximum of 20 nm or more. The light irradiation method according to claim 8, wherein an integrated irradiance relating to a wavelength of a wavelength component of 300 nm to 400 nm contained in the light reaching the main surface is 100 mW / cm ² or less.   The light irradiation method according to claim 8 or 9, wherein the light irradiation step is performed using a black light fluorescent tube as a light source.   The step of irradiating the light is performed using a plurality of fluorescent tubes arranged as a light source, and the minimum value in the main surface of the irradiance on the main surface is 85% or more of the maximum value. The light irradiation method according to claim 8.   The light irradiation method according to claim 11, wherein the plurality of fluorescent tubes are arranged in a checkered pattern in a plane parallel to the main surface.   The step of irradiating the light includes operating the plurality of fluorescent tubes so that the minimum value in the main surface of the integrated irradiance with respect to time on the main surface is 85% or more of the maximum value. The light irradiation method according to claim 12, wherein light irradiation is performed.   A liquid crystal display panel manufactured by performing alignment stabilization treatment of liquid crystal molecules in the liquid crystal layer using the light irradiation method according to claim 8.

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