JP2000206701A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device in which exposure in the perpendicular and oblique directions to the front surface can be performed at a time in the process of irradiating and polymerizing a liquid crystal containing a polymer material with ultraviolet rays, and in which various conditions such as incident angle, exposure time and illuminance of exposure light can be easily controlled. SOLUTION: In this exposure device, a part of beams from a light source 21 is separated to the optical path to irradiate the object in an oblique direction to the exposure face so that exposures in the front face direction and in an oblique direction are performed t a time. A movable mirror 23, shutter 24 and filter 25 are disposed in the optical path of the oblique exposure light and connected to the controlling system to control the incident angle, exposure time, illuminance of the exposure light. The stage 27 is rotatable and its periphery is provided with angle scales. The exposure vessel is provided with a temp. controlling function to control the temp. during exposure. Furthermore, the vessel is provided with terminals to apply a voltage, and exposure is carried out while applying a voltage by a voltage supply housed in the vessel or by an external voltage supply connected to the vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel and a PALC (Plasma Addressed).
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus that can be used in a process that requires ultraviolet irradiation under various conditions, such as a process of irradiating a liquid crystal containing a polymer material with ultraviolet light to polymerize the liquid crystal in the manufacture of a liquid crystal panel or the like.

[0002]

2. Description of the Related Art In recent years, PDLC (Pol) has been developed in order to increase the viewing angle of a liquid crystal display device, increase brightness, and improve stability.
ymer Dispersed Liquid Cry
sta) and other techniques using a liquid crystal / polymer composite system are being actively studied. In this liquid crystal / polymer composite system, a mixture containing a liquid crystal material and a polymer material is irradiated with ultraviolet rays to polymerize the polymer. At this time, the polymerization characteristics of the polymer, for example, the degree of polymerization and the presence or absence of unreacted material And its degree,
The structure of the polymer network and the like greatly affect the display characteristics of the liquid crystal display device. For this reason, it is important to control the polymerization conditions when polymerizing the polymer, for example, the exposure illuminance, the exposure amount, the temperature, the applied voltage, and the like.

In a liquid crystal display panel or a PALC panel using this liquid crystal / polymer composite system, when the ratio of polymer to liquid crystal is small, a liquid crystal material and a polymer material (monomer) are mixed in advance and injected into the panel. After that, ultraviolet exposure is often performed to cause a polymerization reaction to obtain a liquid crystal / polymer composite system.

In this case, if there is an obstacle to exposure, such as a TFT element in a liquid crystal display panel using a TFT (thin film transistor) element as a switching element, or a plasma electrode in a PALC panel, a normal element exists. It is not possible to polymerize the high polymer material that exists in the shadow of the obstacle only by exposure from the front,
This may cause display unevenness of the panel. Therefore, it is necessary to perform the exposure from the oblique direction so that the exposure is performed also on the back of the obstacle.

FIG. 3 shows a case in which a PALC panel needs to be exposed from an oblique direction.

In this PALC panel, a display cell 11 and a plasma generating substrate 12 are stacked. The display cell has a liquid crystal layer 17 sandwiched between a substrate 16 and a thin glass plate 13. The plasma generating substrate 12 forms a plasma chamber in which a space between the substrate 14 on which the anode electrode 18 and the cathode electrode 19 are provided and the thin glass plate 13 is separated by a rib partition wall 15.

When the PALC panel is exposed from the front, the rib partition 15 and the anode electrode 18 are exposed.
In addition, the cathode electrode 19 becomes an obstacle, and the area under the cathode electrode 19 cannot be exposed.

However, when ultraviolet rays (UV) are incident from the direction of the incident angle θ with respect to the normal direction of the substrate, the ultraviolet rays reach the areas a and a ′. Therefore, the display characteristics can be improved by the ultraviolet exposure even in the liquid crystal layer 17 portion a ′ below the region a. In addition, the liquid crystal layer 17 portion b ′ below the region b
In this case, the ultraviolet ray does not reach due to the oblique exposure, but this portion can be exposed from the front.

As described above, by performing the ultraviolet exposure from the oblique direction at a predetermined exposure intensity from the direction of the angle ± θ with respect to the normal direction of the substrate, the unexposed portion can be prevented from being left. . Therefore, it is possible to sufficiently polymerize even in a region where polymerization by ultraviolet light exposure cannot be sufficiently performed only by exposure from the front direction.

In some conventional exposure apparatuses, exposure can be performed in an oblique direction by tilting a sample stage. Then, it was possible to control the exposure amount and the temperature at the time of exposure.

On the other hand, a conventional exposure apparatus used for manufacturing a liquid crystal display panel using a liquid crystal / polymer composite system includes:
One disclosed in Japanese Patent Application Laid-Open No. 7-318911 is exemplified. This exposure apparatus is an exposure apparatus capable of performing high-precision patterning when performing exposure polymerization in a predetermined pattern using a photomask.

[0012]

However, in the conventional exposure apparatus described above, the exposure from the front direction and the exposure from the oblique direction cannot be performed simultaneously, and it is necessary to perform the exposure separately from each direction. Was. For this reason, there has been a problem that the time required for exposure becomes longer.

Further, when performing exposure in an oblique direction, it is necessary to manually tilt the stage to adjust the incident angle of the irradiation light.

Further, the exposure illuminance is fixed, and when applying a voltage, the lead wire must be taken out of the apparatus and connected to an external voltage applying apparatus.

In the exposure apparatus described in Japanese Patent Application Laid-Open No. Hei 7-318911, the exposure is performed only from the front of the liquid crystal display panel or the pattern of the photomask is formed so as to form an image on the surface of the liquid crystal display panel. For this reason,
When there is an obstacle such as a TFT element or a plasma electrode,
The area behind the obstacle could not be sufficiently exposed.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art. Even when an exposure obstacle exists, the exposure time can be reduced to perform sufficient exposure, and the incident angle, An object of the present invention is to provide an exposure apparatus capable of easily controlling various conditions such as exposure time, exposure illuminance, temperature and voltage.

[0017]

SUMMARY OF THE INVENTION An exposure apparatus according to the present invention extracts a part of light emitted from a light source to an exposure surface into an optical path irradiated from an oblique direction with respect to the exposure surface. Exposure from the direction and exposure from the oblique direction can be simultaneously performed, thereby achieving the above object.

The exposed surface can be irradiated with ultraviolet rays.

A movable mirror is arranged in the optical path irradiated from the oblique direction, and the incident angle of the light irradiated from the oblique direction can be arbitrarily changed by adjusting the angle and position of the possible mirror. Is also good.

[0020] The movable mirror may be capable of changing an angle at predetermined time intervals during exposure.

The movable mirror may be connected to a control system, and an angle and a position of the movable mirror may be adjusted by inputting a numerical value to the control system.

A shutter is arranged in the optical path irradiated from the front direction and the optical path irradiated from the oblique direction, and each shutter is opened and closed independently, so that the exposure time from the front direction and the exposure from the oblique direction The time may be independently controllable.

The shutter may be connected to a control system, and the opening and closing of each shutter may be independently controlled by inputting a numerical value to the control system.

A filter is arranged in the optical path irradiated from the front direction and the optical path irradiated in the oblique direction, and each filter is opened and closed independently, so that the exposure illuminance from the front direction and the exposure from the oblique direction The illuminance may be independently controllable.

The filter may be connected to a control system, and the opening and closing of each filter may be independently controlled by inputting a numerical value to the control system.

The stage on which the object to be exposed is set may be rotatable at an arbitrary angle in the plane.

[0027] An angle scale may be provided around the stage.

An exposure tank having a temperature control function may be provided.

An exposure tank having a voltage application terminal may be provided, and exposure may be performed while applying a voltage using a built-in voltage application device or an externally applied voltage application device.

The operation of the present invention will be described below.

In the present invention, as shown in FIG. 1, a part of the light from the light source 21 is taken out to an optical path irradiated obliquely with respect to the exposure surface by a mirror 22 or the like, and is taken out from the front. And the oblique exposure can be performed simultaneously. Therefore, as shown in FIG. 3, when exposure from an oblique direction is required, the exposure time is reduced.

As shown in FIG. 1, a movable mirror 23 is disposed in the middle of an optical path irradiated from an oblique direction, and by adjusting the angle and position of the movable mirror 23, the light emitted from the oblique direction is adjusted. Can be arbitrarily adjusted. Therefore, the optimum incident angle can be set according to the size and pitch of the exposure obstacle.

By changing the angle of the movable mirror 23 during exposure to change the incident angle of light, the unexposed area can be further reduced.

Further, as shown in FIG. 1, a shutter 24 is arranged in the optical path irradiated from the front direction and the optical path irradiated from the oblique direction, and each shutter 24 is opened and closed independently, so that the shutter 24 is opened and closed. And the exposure time from the oblique direction can be controlled independently of each other. Therefore, an optimal exposure time can be set in each direction.

As shown in FIG. 1, filters 25 are arranged in the optical path irradiated from the front direction and the optical path irradiated from the oblique direction, and each filter 25 is opened and closed independently, so that the filter 25 is opened from the front direction. And the exposure illuminance from an oblique direction can be controlled independently of each other. The exposure illuminance affects the polymerization speed of the polymer material, affects the display characteristics of the panel, and may require changing the exposure illuminance between the front exposure and the oblique exposure. , The optimum exposure illuminance can be set in each direction. Preferably, a plurality of such filters are provided, and it is preferable that the filters can be easily replaced.

If the movable mirror, shutter and filter are connected to a control system and can be controlled by numerical input,
Parameters such as an incident angle, exposure time, and exposure illuminance can be easily adjusted.

Further, as shown in FIG.
Is rotatable at an arbitrary angle in the plane, the incident direction of light obliquely (in-plane angle on the exposure plane) can be changed depending on the shape of the exposure obstacle.

By providing an angle scale around the stage 27, the angle can be easily set. Furthermore, it is easy to determine the angle when the panel is first installed.

Further, since the temperature at the time of exposure affects the polymerization rate of the polymer and the display characteristics of the panel,
It is preferable to provide a temperature control function in the exposure tank.

In some cases, it is necessary to perform exposure while applying a voltage. Therefore, it is preferable to provide a voltage application terminal in the exposure tank. In this case, exposure can be performed while applying a voltage by using a built-in voltage application device or an externally applied voltage application device.

[0041]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment) In this embodiment, a 5-inch ASM mode PALC panel was manufactured, and an n-type liquid crystal material (Δε = −4.0, Δn = 0.08, cell gap 6 μm) was used.
A mixture consisting of a photoreactive monomer (a bifunctional acrylate) and a polymerization initiator was injected.

By arranging the mirror 22 as shown in FIG. 1, a part of the light from the light source 21 is taken out to an optical path irradiated obliquely with respect to the exposure surface, and is exposed from the front. The PALC panel was exposed to ultraviolet light by using an exposure apparatus capable of performing exposure from an oblique direction.

At this time, the amount of light extracted to the optical path irradiated obliquely to the exposure surface is adjusted by the arrangement of the mirror 22. In the present embodiment, the mirror 22 is arranged so that the amount of light extracted to the right side of the drawing of FIG. 1, the amount of light extracted to the left side of the drawing, and the amount of light from the front direction are the same.

Then, the shutter 24 shown in FIG. 1 is controlled.
The system was connected and exposure from the front direction was performed for 20 minutes.
On the other hand, the exposure from the oblique direction is performed by the movable mirror 2 shown in FIG.
3 to the control system, and θ = 50 ° and θ = -5 shown in FIG.
The angle of incidence was adjusted to 0 °, and the shutter 24 shown in FIG.
Connect to the control system and irradiate for 10 minutes from each direction
Was. At this time, connecting the filter 25 to the control system
Illuminance of 4.3 mW / cm ^TwoAnd

At this time, as shown in FIG.
By rotating the stage 27 on which 6 is installed,
By changing the incident angle in the in-plane direction of the exposure surface, the angle can be set so that the influence of the exposure obstacle is minimized. For example, in a PALC panel, rib barriers, anode electrodes, and cathode electrodes, which are exposure obstacles, are shown in FIG.
When the panel is installed so as to be parallel to the 0 ° direction, it is most preferable to irradiate ultraviolet rays from the 0 ° and 180 ° directions. However, it is not necessary to change the incident angle in the in-plane direction unless the exposure obstacle has a complicated shape. Further, when the panel is first installed, the angle can be easily determined by using the rotatable stage 27 and the angle scale.

The temperature at the time of exposure was adjusted to 25 ° C. by a temperature controller provided in the exposure tank. Then, a voltage application terminal provided in the exposure tank is used to drive the liquid crystal from the external power supply.
A rectangular wave of V was applied, and a pulse wave of 400 V was applied for plasma driving.

For comparison, a panel similar to this PALC panel was exposed to ultraviolet light only from the front direction for 2 hours.
Performed for 0 minutes. The exposure illuminance at this time was the same illuminance as before the light was extracted in the oblique direction.

Here, whether the exposure amount is sufficient can be determined by observing the state of switching of picture elements under a microscope. In the ASM mode, when the exposure is insufficient and the polymerization of the polymer is not sufficiently advanced, since the alignment regulating force is insufficient, it takes about several hundred msec for the ASM alignment to stabilize, and the Is possible.

In the PALC panel of this embodiment in which the ultraviolet exposure is performed from the front direction and the oblique direction, the response speed is sufficiently fast for any of the picture elements, and the ASM is instantaneously displayed under the microscope under the microscope.
The orientation appeared to be stable. Further, since the light from the light source 21 can be taken out to the optical path from an oblique direction and can be exposed simultaneously from the front direction and the oblique direction, the exposure time can be shortened.

On the other hand, in the PALC panel of the comparative example in which the ultraviolet exposure was performed only from the front direction, the picture element on the plasma electrode, which becomes a shadow at the time of exposure, took a little time until the ASM orientation was stabilized. It took. Such a phenomenon was not observed in the other pixels.

In this embodiment, the mirror 22 is provided to extract light to the optical path irradiated from an oblique direction. However, a prism or the like may be used. However, it is preferable to use a mirror because a very large one is required, and at present it is not practical in terms of cost.

[0053]

As described above in detail, in the case of the present invention, a part of the light from the light source is taken out to the optical path irradiated from the oblique direction to the exposure surface, and the exposure from the front direction and the oblique Since exposure from different directions can be performed simultaneously, the exposure time can be greatly reduced when oblique exposure is required.

Further, by arranging a movable mirror, a shutter and a filter in the middle of an optical path irradiated from an oblique direction and connecting them to a control system, parameters such as an incident angle, an exposure time and an exposure illuminance can be easily adjusted. Optimal exposure conditions can be set.

Further, the object to be exposed is set on a stage rotatable at an arbitrary angle in the plane, and the angle can be set by an angle scale provided around the stage. Can easily change the incident direction of light.

The temperature at the time of exposure can be adjusted by providing a temperature control function in the exposure bath. By providing a voltage application terminal in the exposure bath, a built-in voltage application device or a voltage application device connected to the outside can be used. Exposure can be performed while applying a voltage. Therefore, exposure can be performed under optimal polymerization conditions.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic configuration of an exposure apparatus according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a stage of the exposure apparatus according to the present invention.

FIG. 3 is a diagram showing a region exposed by oblique exposure in a PALC panel.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 display cell 12 plasma generating substrate 13 thin glass plate 14, 16 substrate 15 rib partition 17 liquid crystal layer 18 anode electrode 19 cathode electrode 21 light source 22 mirror 23 movable mirror 24 shutter 25 filter 26 object to be exposed 27 stage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 HA04 KA08 NA60 QA12 TA17 TA18 2H097 AA11 BA02 BB01 BB03 CA07 CA12 EA03 LA12

Claims (13)

[Claims] 1. A part of light emitted from a light source to an exposure surface is taken out to an optical path irradiated from an oblique direction to the exposure surface, and exposure from a front direction and exposure from an oblique direction are performed. Exposure equipment that can be used at the same time. 2. The method according to claim 1, wherein the exposure surface is irradiated with ultraviolet rays.
3. The exposure apparatus according to claim 1. 3. A movable mirror is arranged in the optical path irradiated from the oblique direction, and the incident angle of the light irradiated from the oblique direction can be arbitrarily changed by adjusting the angle and position of the possible mirror. Claim 1 or Claim 2
3. The exposure apparatus according to claim 1. 4. The exposure apparatus according to claim 3, wherein the movable mirror is capable of changing an angle at regular time intervals during exposure. 5. The exposure apparatus according to claim 3, wherein the movable mirror is connected to a control system, and an angle and a position of the movable mirror can be adjusted by inputting a numerical value to the control system. 6. A shutter is arranged in the optical path irradiated from the front direction and the optical path irradiated from the oblique direction, and each shutter is independently opened and closed to thereby control the exposure time from the front direction and the oblique direction. 6. The exposure apparatus according to claim 1, wherein the exposure time can be controlled independently of each other. 7. The exposure apparatus according to claim 6, wherein the shutter is connected to a control system, and opening and closing of each shutter can be independently controlled by inputting a numerical value to the control system. 8. A filter is arranged in the optical path irradiated from the front direction and the optical path irradiated from the oblique direction, and each filter is independently opened and closed to thereby control the exposure illuminance from the front direction and the oblique direction. 8. The exposure apparatus according to claim 1, wherein the exposure illuminance can be independently controlled. 9. The exposure apparatus according to claim 8, wherein the filter is connected to a control system, and opening and closing of each filter can be independently controlled by inputting a numerical value to the control system. 10. The exposure apparatus according to claim 1, wherein the stage on which the object to be exposed is set is rotatable at an arbitrary angle in a plane. 11. The exposure apparatus according to claim 10, wherein an angle scale is provided around the stage. 12. The exposure apparatus according to claim 1, further comprising an exposure tank having a temperature control function. 13. An exposure tank provided with a voltage application terminal,
13. The exposure apparatus according to claim 1, wherein exposure is performed while applying a voltage by a built-in voltage application apparatus or an externally applied voltage application apparatus.