TW201333550A - Polarized light irradiating device - Google Patents

Abstract

An object of the present invention is such that in a polarized light irradiating device that comprises a wire grid polarization element, the device is constructed in such a way that during the maintenance of the device, the optic grid is not subject to damage caused by finger contact or articles falling on a grid forming surface of the wire grid polarization element of the device. The solution of the present invention is that an arrangement is made such that the grid forming surface of the wire grid polarization element faces a light source. As such, it is feasible to dispose an optic filter that protects the grid forming surface exactly above the grid forming surface (between the polarization element and the light source).

Description

Polarized light irradiation device

The present invention relates to a polarized light illuminating device that aligns a polarizing ray of a predetermined wavelength with an alignment film of a liquid crystal element, an alignment layer of a viewing angle compensation film, and the like, and particularly relates to polarized light irradiation using a wire grid polarizing element. Device.

Recently, the alignment treatment of the alignment film of the liquid crystal display element including the liquid crystal panel and the alignment layer of the viewing angle compensation film has been gradually adopted as a technique of aligning the polarized light of the wavelength of the ultraviolet ray region. Hereinafter, a film or layer which forms an alignment film by an ray to align the light, and a film or layer which generates an alignment property by light is collectively referred to as a photo-alignment film.

The light-aligning film system is increased in size as shown in the square shape of 2000 mm or more in accordance with the increase in size of the liquid crystal panel.

In order to perform optical alignment of the light-aligning film having a large area as described above, for example, Patent Document 1 proposes a light-emitting element in which a rod-shaped light tube which is a linear light source and a grating having a wire grid shape are combined (hereinafter referred to as a line). A polarized light irradiation device of a gate polarizing element).

A rod-shaped tube system can produce a longer length of illumination. For this reason, a rod-shaped bulb having a light-emitting length corresponding to the width of the photo-alignment film is used, and the light from the tube is polarized and irradiated, and the alignment film is oriented in the longitudinal direction of the alignment film orthogonal to the tube. If the direction is moving, it can be shorter. The optical alignment treatment is performed on a wide area of the alignment film.

Fig. 4 is a view showing a configuration example of a conventional polarized light irradiation device which combines a rod-shaped light tube and a wire grid polarizing element which are linear light sources.

In the same figure, the workpiece W which is a light alignment film is, for example, a strip-shaped elongated workpiece such as a viewing angle compensation film, which is sent out from the transport roller R1 and conveyed to the direction of the arrow in the figure while being irradiated by polarized light. The light is aligned and wound by the winding roller R2.

The light-irradiating portion 10 of the polarized light irradiation device is provided with a rod-shaped bulb 11 that emits light of a wavelength (ultraviolet light) required for the light-aligning treatment, for example, a high-pressure mercury lamp and a metal-halogen lamp in which other metals are added in addition to mercury, and The ultraviolet light of the bulb 11 is directed toward the groove mirror 12 reflected by the workpiece W. As described above, the length of the rod-shaped bulb 11 is such that the light-emitting portion has a length corresponding to the width in the direction orthogonal to the conveyance direction of the workpiece W.

The light-irradiating portion 10 is disposed such that the longitudinal direction of the bulb 11 is the width direction of the workpiece W (the direction orthogonal to the transport direction).

A wire grid polarizing element 81 as a polarizing element is provided on the light emitting side of the light irradiation unit 10. The light from the light-irradiating portion 10 is polarized by the wire grid polarizing element 81, and is irradiated to the workpiece W conveyed under the light-irradiating portion 10 to perform optical alignment processing.

The wire grid polarizing element is formed by forming a line and a space on a transparent substrate (for example, a glass substrate) that transmits light of a wavelength to be polarized, and is disclosed in, for example, Patent Document 2 and Patent Document 3.

When a wire grid polarizing element is inserted in the light path, most of the polarized light component of the incident light parallel to the longitudinal direction of the grating is reflected or absorbed. The polarization component orthogonal to the longitudinal direction of the grating is transmitted. Therefore, the light passing through the wire grid polarizing element is a polarized light having a polarization axis in a direction orthogonal to the longitudinal direction of the grating of the polarizing element.

The polarized light in the ultraviolet region is used in the light alignment treatment. In order to make the light incident on the wire grid polarizing element into a polarized light, the width and interval of the grating formed on the transparent substrate must be shorter than the wavelength of the polarized light (for example, 100 nm).

Therefore, the formation of the grating requires a fine processing technique, and is fabricated by using lithography techniques and etching techniques for semiconductor fabrication. Therefore, the size of the workpiece that can be processed by the lithography apparatus and the etching apparatus used herein is limited. Therefore, it is not possible to make a large-sized wire grid polarizing element, and the current size can be made up to a diameter of 300 mm.

Therefore, for example, Patent Document 4 proposes that when a rod-shaped light source having a long light-emitting length, for example, a large (long) polarizing element of a rod-shaped high-pressure mercury lamp or a metal halide lamp having a length of 1 m to 3 m is required, The rectangular wire grid polarizing elements are aligned in the direction of the grating and are arranged side by side along the longitudinal direction of the tube in the frame to be used as a polarizing element.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2011-145381

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2002-328234

[Patent Document 3] Japanese Patent Publication No. 2003-508813

[Patent Document 4] Japanese Patent No. 4506412

As described above, the grating of the wire grid polarizing element is manufactured by fine processing, and the width and interval of the grating are, for example, 100 nm, so that accidental finger contact or falling of an object thereon may damage the grating structure and fail to function as a polarized light. The function of the component. However, it is difficult to visually confirm the condition of forming a grating on the surface of a transparent substrate (glass) because of the fineness.

Therefore, during the maintenance inspection of the polarized light irradiation device, etc., there may be a case where the grating forming surface of the polarizing element mounted on the device or some of the articles are dropped on the polarizing element, and the fine grating is broken.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a polarized light irradiation device including a linear light source and a wire grid polarizing element that polarizes light from the light source, during maintenance of the device, and the like. The device is constructed in such a manner that the finger is not in contact with the grating forming surface of the wire grid polarizing element mounted on the device or the article is dropped to break the condition of the grating.

In order to solve the above problems, the grating forming surface of the wire grid polarizing element used in the polarized light irradiation device is disposed in the direction of the light source. That is, in the lamp chamber constituting the light-irradiating portion, the surface of the grating on which the wire grid polarizing element is not formed is directed to the outside of the lamp chamber (lamp).

Further, a filter for protecting the grating forming surface is provided directly above the grating forming surface of the wire grid polarizing element (between the polarizing element and the light source). Filter It is transmitted by light that uses the wavelength of the light to be polarized.

Since the wire grid polarizing element is disposed so that the grating forming surface faces the light source in the light exiting opening formed on the outer wall of the light source, the grating forming surface cannot be contacted from the outside of the lamp. For example, even if it is in contact with the polarizing element, since the outer side of the lamp chamber is not the surface of the grating forming surface, the grating is not broken.

Further, by providing a filter directly above the grating forming surface, for example, even in the condition of maintaining the lamp chamber, the finger hardly contacts the grating surface, and even if the article falls, the filter can prevent it from falling to the grating formation. surface. Therefore, the grating is not destroyed.

Fig. 1 is a view showing a schematic configuration of a lamp chamber (lamp) of a polarized light irradiation device according to a first embodiment of the present invention. The same figure is a cross-sectional view in the direction in which the longitudinal direction of the lamp chamber is orthogonal. In the same figure, the structure of the lighting device or the like for explaining the lamp tube is omitted.

The lamp chamber 1 includes a light irradiation unit 10, a water-cooled cooler (heat sink) 20 and an air blower (air blower) 30 on the upper portion thereof. The light irradiation unit 10 has a bulb 11 and a mirror 12 that reflects light from the bulb 11. As indicated by the solid arrows in the figure, the light from the bulb 11 is directly or reflected by the mirror 12, and is transmitted to the workpiece W through the wire grid polarizing element 81.

The blower 30 generates a cooling lamp 11 and a counter when the lamp 11 is lit. The cooling air of the mirror 12 has a function of lowering the temperature of the cooling air for cooling the bulb 11 and the mirror 12.

The light irradiation portion 10 is surrounded by the partition wall 40, and the outer wall 60 of the lamp chamber 1 covers the outer side thereof. A gap is formed between the partition wall 40 and the outer wall 60. This gap is the ventilation path 50 through which the cooling air passes.

The cooling air system is sent out from the air blower 30 and passes through the air passage 50 through the air passage 50, and is cooled by the light emitting portion of the mirror 12 while being cooled to the inside of the light irradiation portion 10 while cooling the bulb 11 and the mirror 12. It is cooled by the radiator 20 and sent again by the blower 30.

Further, a light exit port 70 through which the light irradiated from the light irradiation unit 10 toward the workpiece W passes is formed on the outer wall 60 of the lamp chamber 1.

A light-emitting element unit 80 having a wire grid polarizing element 81 that polarizes the passing light is attached to the light exit port 70.

The wire grid polarizing element 81 of the polarizing element unit 80 is a surface of a transparent substrate (glass substrate) that transmits light of a wavelength for performing optical alignment processing, and forms a wire grid (hereinafter also referred to as a grating) G. Here, the formation surface of the grating G is disposed toward the side of the bulb 11 (inside of the outer wall 60).

In Fig. 1, the grating G of the wire grid polarizing element 81 extends in the left-right direction of the drawing.

FIG. 2 is a view showing the configuration of the polarizing element unit 80. 2(a) is a plan view of the polarizing element unit 80, FIG. 2(b) is a side cross-sectional view of the polarizing element unit 80, and FIG. 2(c) is a perspective view of the polarizing element unit 80.

The polarizing element unit 80 is a plurality of wire grid polarizing elements (hereinafter also referred to as polarizing plates) 81 along the longitudinal direction of the rod-shaped tube 12 (left of FIG. 2) The right direction) is placed side by side in the frame (holding frame) 82 to hold the holder. The holding frame 82 holds and holds the respective polarizing plates 81 from above and below.

A gap of about 1 mm to 2 mm is provided between the adjacent polarizing plate and the polarizing plate. In order to perform the alignment so that the directions of the gratings G of the polarizing plates are parallel, the gap is used to rotate the polarizing plate 81 to perform position adjustment. Then, this gap is covered by the light shielding plate 83 in the polarizing element unit 80 so that the polarized light does not leak therefrom.

As described above, each of the wire grid polarizing elements (polarizing plates) 81 is disposed such that the surface on which the grating G is formed becomes the lamp (light source) side (inside of the lamp chamber) as shown in FIG. 2(b).

Fig. 3 is a view showing a schematic configuration of a lamp chamber (lamp) of a polarized light irradiation device according to a second embodiment of the present invention. The same as Fig. 1, the same drawing is a cross-sectional view orthogonal to the longitudinal direction of the lamp chamber.

The difference from the configuration of the first embodiment of Fig. 1 is that a filter 90 for protecting the grating G face of the polarizing plate 81 is disposed on the polarizing element unit 80 (on the side of the lamp). The filter 90 is the same as the polarizing plate 81, and the plurality of filter plates 91 are arranged side by side in the longitudinal direction of the bulb 11 in the holding frame 92. As indicated by the solid arrows in the figure, the light from the bulb 11 is directly or reflected by the mirror 12, and is transmitted through the filter 90 and the polarizing plate 81 to the workpiece W.

The holding frame 92 of the filter plate is erected on the holding frame 82 of the polarizing element unit 80 as a support rod 93 as a ventilation path forming member, and is mounted thereon. As the filter plate 91, a quartz plate that transmits a wavelength of polarized ultraviolet light can be used. Moreover, it is not necessary to use the formation of the blocked light alignment process. Interference filters for visible light and infrared interference films are also available.

When the overlapping filter plate 91 is brought into contact with the polarizing plate 81, since the possibility of the grating G of the polarizing plate 81 can be damaged, the two are arranged at intervals. When the interval is too narrow, since it is difficult for the cooling air to flow on the polarizing plate 81, the polarizing plate 81 may be heated by the heat from the bulb 11, so that a sufficient interval at which the cooling air can flow is provided. However, if the interval is too wide, since the grating G forming surface of the polarizing plate 81 cannot be protected, it is preferable to set the interval at which the finger cannot enter.

An example of the interval in which the finger cannot enter is an IP (International Protection) standard. This is established in IEC 60529 (1989), and JIS is also defined in C0920 (1993). Therefore, as a protection for the human body, in the case of a finger, the protection content of the machine is revealed to be 12.5 mm or less in diameter.

Therefore, the distance between the polarizing plate 81 and the filter plate 91 is preferably from 5 mm to 12.5 mm.

The support bar 93 is provided along the longitudinal direction of the polarizing element unit 80 and the optical filter 90, and is provided on the both sides (the horizontal direction in FIG. 1) by a space through which the cooling air can pass.

Further, the support rod 93 is a ventilation path forming member for forming a ventilation path between the polarizing plate 81 and the filter plate 91, and may be formed as a rod as long as a ventilation path can be formed.

For example, it may be a plate-like shape or a wall shape which is a through-hole (a diameter of 5 mm or more) through which a cooling air can pass, as a block shape of a rectangular shape. Also, as long as the distance between the polarizing element unit 80 and the filter 90 can be maintained If you are a person, you can also use it as a mesh.

In the case of a plate-shaped member or a mesh-like member that forms a through-hole, the diameter of the hole or the mesh that serves as the vent is 12.5 mm or less in diameter that the finger can not enter (that is, When the hole having a diameter of 5 mm to 12.5 mm is ensured, even if the interval between the polarizing element unit 80 and the filter 90 is expanded to an interval at which the cooling air can flow sufficiently, the finger does not come into contact with the polarizing plate 81. The grating G forms a face and is protected to the grating G.

Further, in the above-described embodiment, a light-emitting tube having a rod shape as an example of a light source has been described as an example. However, the present invention is also applicable to a case where LEDs emitting ultraviolet rays are arranged in a plurality of lines.

1‧‧‧light room (lamps)

10‧‧‧Lighting Department

11‧‧‧ rod-shaped tube

12‧‧‧Mirror

20‧‧‧ radiator (cooler)

30‧‧‧Blowing machine (air blower)

40‧‧‧ partition wall

50‧‧‧ ventilation path

60‧‧‧ outer wall

70‧‧‧Light exit

80‧‧‧Polarized element unit

81‧‧‧Wire grid polarizing element (polarizing plate)

82‧‧‧Position plate retaining frame

83‧‧ ‧ visor

90‧‧‧Filter unit

91‧‧‧Filter plate

92‧‧‧Retaining frame of the filter plate

93‧‧‧Support bar

G‧‧‧ wire grid

R1‧‧‧ conveying roller

R2‧‧‧ winding roller

W‧‧‧Workpiece

Fig. 1 is a view showing a schematic configuration of a lamp chamber (lamp) of a polarized light irradiation device according to a first embodiment of the present invention.

FIG. 2 is a view showing the configuration of a polarizing element unit.

Fig. 3 is a view showing a schematic configuration of a lamp chamber (lamp) of a polarized light irradiation device according to a second embodiment of the present invention.

Fig. 4 is a view showing a configuration example of a conventional polarized light irradiation device.

1‧‧‧light room (lamps)

10‧‧‧Lighting Department

11‧‧‧ rod-shaped tube

12‧‧‧Mirror

20‧‧‧ radiator

30‧‧‧Blowing machine

40‧‧‧ partition wall

50‧‧‧ ventilation path

60‧‧‧ outer wall

70‧‧‧Light exit

80‧‧‧Polarized element unit

81‧‧‧Wire grid polarizing element

82‧‧‧ Keep box

G‧‧‧ wire grid

W‧‧‧Workpiece

Claims (3)

A polarized light illuminating device comprising: a linear light source; a polarizing element that polarizes light from the light source; and an outer wall that covers the light source and forms a light exiting passage from the light source, wherein the polarizing element is A wire grid polarizing element is formed on a transparent substrate, and the wire grid polarizing element is disposed on a light exit port formed on the outer wall, and the surface on which the wire grid is formed faces the light source side. The polarized light irradiation device according to claim 1, wherein a light transmitting filter is provided between the wire grid polarizing element and the light source. The polarized light irradiation device according to claim 2, wherein the filter is provided by a ventilation path forming member at an interval spaced apart from the wire grid polarizing element by a finger.