CN106125407B

CN106125407B - Optical alignment device

Info

Publication number: CN106125407B
Application number: CN201511030501.5A
Authority: CN
Inventors: 尹炯烈; 桥诘幸司
Original assignee: WI A Corp
Current assignee: WI A Corp
Priority date: 2015-05-06
Filing date: 2015-12-31
Publication date: 2020-05-22
Anticipated expiration: 2035-12-31
Also published as: CN106125407A; TW201640203A; JP2016212376A; JP6240654B2

Abstract

The invention discloses a light alignment device. An optical alignment device according to an embodiment of the present invention is an optical alignment device that treats an alignment film for aligning liquid crystals in a non-contact manner, the optical alignment device including a light source unit in which LED elements are arranged to irradiate light and a polarization unit for performing polarization control, wherein the LED elements are arranged in a plurality of rows in the light source unit to form LED linear light, a plurality of polarizing plates are arranged in a row in the polarization unit, and a plurality of LED linear light beams enter the polarization unit at intervals that do not interfere with each other.

Description

Optical alignment device

Technical Field

The present invention relates to a photo-alignment device, and more particularly, to a photo-alignment device using an LED (light emitting diode).

Background

In order to align the alignment film of the alignment film glass of the liquid crystal display device in a predetermined direction, the photo-alignment device irradiates a polarized light beam having a predetermined wavelength to the alignment film to perform alignment, instead of a rubbing (rubbing) method in which a rubbing roller is mechanically rubbed against the alignment film. For the photo-alignment, a UV lamp such as a high-pressure mercury lamp or a metal halide lamp that irradiates light of a predetermined intensity is used.

The conventional UV lamp requires an optical system for limiting a wavelength to prevent irradiation of light of an unnecessary wavelength, but due to the optical system, light transmittance is affected so that light energy reaching the alignment film is reduced, and the lamp is considerably expensive. In addition, conventional UV lamps require complex reflectors (mirrors) to control the diffused light about the optical axis of the tube. In order to realize high precision of the alignment state, the incident light needs to be perpendicular to the alignment film, but it is difficult to extract only the light incident perpendicularly from the reflector of the UV lamp which focuses and diffuses the light to irradiate a wide range. And the switching on-off (on-off) of the conventional UV lamp requires a large amount of waiting time.

Disclosure of Invention

Technical problem to be solved

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an optical alignment device having a simple device structure.

Other objects of the present invention will become more apparent from the embodiments described below.

Means for solving the problems

An optical alignment device for processing an alignment film for aligning liquid crystals in a non-contact manner, the optical alignment device comprising a light source section in which LED elements are arranged to irradiate light and a polarization section for polarization control, characterized in that the LED elements are arranged in a plurality of rows in the light source section to form LED linear light, a plurality of polarizing plates are arranged in a row in the polarization section, and a plurality of LED linear light beams enter the polarization section at intervals not interfering with each other.

The light-directing arrangement to which the present invention relates may have one or more of the following embodiments. For example, a plurality of LED linear lights having peak wavelengths different from each other may be selected and arranged to control the irradiation intensity.

The LED elements may be individually controlled to make the amount of light received from the plurality of LED linear lights through the alignment film under the polarizing portion uniform.

The plurality of LED straight lights may cross each other while transmitting the polarization part.

The illumination angles of the plurality of LED linear lights may be symmetrical to each other, thereby forming a continuous illumination concentration portion when transmitting the polarization portion.

The light source unit may include a lens that forms the light into diffused light or straight light.

The polarizing part may include polarizing plates with a gap formed therebetween, and a light shielding member provided at a lower portion of the gap to prevent the LED light from being transmitted.

The width of the light shielding member may be 4.5mm or less.

The polarizing section may include a polarizing plate having a rotation center not at the center thereof and capable of adjusting an angle by rotation.

The rotation centers of adjacent polarizers may be disposed on opposite sides to each other.

The reaction time of the alignment film can be controlled by adjusting the vertical height of the photoalignment device with respect to the alignment film.

The alignment layer may include a fluorescence sensor for receiving fluorescence generated when the LED line light reaches the alignment layer, and the alignment degree of the alignment layer may be measured by the fluorescence sensor.

The optical alignment method according to one embodiment of the present invention is characterized in that optical alignment is performed using an LED linear light that is a linear light formed by a plurality of LED elements and a plurality of polarizing plates, the plurality of polarizing plates are arranged in a line for polarization control of the LED linear light, and a plurality of LED linear lights in the form of parallel lights are incident on the plurality of polarizing plates at intervals that do not interfere with each other.

Effects of the invention

The invention can provide an optical alignment device with a simple structure.

Drawings

Fig. 1 and 2 are perspective views illustrating an optical alignment device according to an embodiment of the present invention.

Fig. 3 is a plan view illustrating an LED module in which LED (light emitting diode) elements are arranged in the photoalignment device illustrated in fig. 2.

Fig. 4 is a schematic view illustrating a state in which a lens is disposed at a lower portion of an LED element to form LED linear light.

Fig. 5 is a schematic view illustrating a degree of light concentration according to an interval between the LED element and the lens.

Fig. 6 is a schematic diagram illustrating a state where LED straight light in the form of diffused light reaches the alignment film.

Fig. 7 is a schematic diagram illustrating a state where a plurality of LED straight lights cross after passing through a polarizing plate.

Fig. 8 is a schematic view illustrating a state in which a tilt angle is given to the LED module so that LED straight lights intersect.

FIG. 9 is a top view illustrating a polarizing portion of the photoalignment device illustrated in FIG. 1.

Fig. 10 is a front view of the polarization part illustrated in fig. 9.

Fig. 11 is a plan view illustrating a state before the polarizing plate of the polarizing portion is adjusted.

Fig. 12 is a plan view illustrating a state after the polarizing plate in fig. 11 is adjusted.

Reference numerals:

100: photo-alignment device 110: light source unit

112: LED element 116: lens and lens assembly

120: the LED module 122: LED straight line light

130: the polarizing section 132: polarizing plate

140: light-shielding member 150: cover glass sheet

160: alignment film glass

Detailed Description

While the invention is susceptible to various modifications and alternative embodiments, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. However, it should be understood that the present invention is not limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. In describing the present invention, if it is considered that detailed description of related known techniques may obscure the gist of the present invention, detailed description thereof will be omitted.

The terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In this application, terms such as "including" or "having" are used only to indicate that there are features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the possibility of one or more other features, numbers, steps, actions, components, parts, or combinations thereof being present or added.

The terms first, second, etc. may be used to describe various components, however, the components should not be limited by the terms. The terms are only used to distinguish one constituent element from another constituent element.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings, and in the description with reference to the drawings, the same reference numerals are given to the same or corresponding components regardless of the figure numbers, and the repetitive description thereof will be omitted.

Fig. 1 and 2 are perspective views illustrating a light alignment device 100 according to an embodiment of the present invention, in which fig. 1 illustrates a state of outputting one LED linear light 122, and fig. 2 illustrates a state of outputting three LED linear lights 122. Fig. 3 is a plan view illustrating an LED module 120 in which LED (light emitting diode) elements 112 are arranged in the light alignment device 100, and fig. 4 is a schematic view illustrating a state in which a lens 116 is disposed below the LED elements 112 to form LED linear light 122. Further, fig. 5 is a schematic diagram illustrating the degree of light condensation according to the interval a between the LED element 112 and the lens 116.

Referring to fig. 1 to 5, an optical alignment apparatus 100 according to an embodiment of the present invention includes: a light source unit 110 including a plurality of LED elements 112 for emitting linear LED light 122 in a linear state; a polarizing unit 130 including a plurality of polarizing plates 132 arranged in a line to control the polarization of the LED linear light 122; the cover glass sheet 150 is disposed between the polarizing section 130 and the alignment film glass 160 on which the alignment film 162 is formed.

The photo-alignment device 100 aligns the alignment film 162 by polarizing a plurality of LED linear lights 122 formed by the light source unit 110 after being incident on the polarizing plate 132, wherein the light source unit 110 uses the plurality of LED elements 112 as a light source. The light source unit 110 using the LED elements 112 has advantages over the conventional UV lamp in that it has low power consumption, can be easily turned on and off (on-off), and can be rapidly heated in a short time after the lamp is turned on. Further, the light source unit 110 based on the LED element 112 can be formed to be long (for example, 1m), and thus can correspond to the large-area oriented film glass 160, and the configuration can be simplified because it is not necessary to provide a cold mirror (cold mirror), a reflector, or the like.

The light source unit 110 may include at least one LED module 120 including a plurality of LED elements 112. The LED modules 120 may be arranged in one row or two or more rows, and the light source unit 110 according to the present embodiment includes three LED modules 120 arranged in three rows. Each LED module 120 can be independently controlled.

The plurality of LED modules 120 may output LED light of different wavelengths. For example, the peak wavelength of the LED light output from one LED module 120 may be 365nm, the peak wavelength of the LED light output from another LED module 120 may be 385nm, and the peak wavelength of the LED light output from another LED module 120 may be 395 nm. In this way, the LED modules 120 can output LED lights with different wavelengths, and thus can output LED lights with wavelengths that optimize the alignment characteristics of the alignment film 162.

The LED module 120 is illustrated as having one board 114, however, a plurality of boards 114 may be provided. In this way, the LED module 120 may be provided with a plurality of plates 114, and the output intensity, wavelength, and the like of the LED elements 112 mounted on the plates 114 may be made different from each other.

The optical alignment device 100 according to the present embodiment is characterized in that a plurality of LED linear lights 122 are incident on the polarizing portion 130 in which a plurality of polarizing plates 132 are arranged in a row at intervals that do not interfere with each other. In this way, by transmitting the plurality of LED linear lights 122 through the optical system formed in a row, it is possible to prevent an alignment error from occurring on the irradiation surface, and by using the plurality of LED linear lights, it is possible to improve productivity.

Referring to fig. 4, a lens 116 is provided at a lower portion of each LED module 120. The lens 116 condenses or forms the LED light output from the LED element 112 into parallel light. The LED light is formed into LED straight light 122 by the lens 116, or is formed into LED straight light 122 by itself without passing through the lens 116. The LED linear light 122 is a long rectangular light continuously formed in a direction perpendicular to the moving direction of the stage 170 (the arrow direction in fig. 1 and 2). The LED straight line light 122 may be formed to have a length enough to be entirely contained in the plurality of polarizing plates 132 arranged in a line.

The lens 116 may be a rod lens (rodtens) formed long and circular in cross section (see fig. 4 and 5). The rod lens may be disposed along the length direction of the LED module 120, and as shown in fig. 4, forms LED light rays corresponding to diffused light into LED straight light 122 in the form of parallel light.

Of course, the lens 116 according to the present embodiment may be any type as long as it can condense or form the LED light output from the LED element 112 into parallel light, as long as it is not only a rod lens.

Referring to fig. 5, the LED straight light 122 may be formed into diffused light or parallel light by adjusting an interval a between the LED element 112 and the rod lens. That is, as shown in fig. 4, the interval between the LED elements 112 and the rod lens may be reduced so that the LED light output from the LED elements 112 is all incident on the rod lens 116 to form LED straight light 122 in the form of parallel light. Further, as shown in fig. 5, the interval a between the LED elements 112 and the rod lenses 116 may be made slightly larger so that a part (for example, 20%) of the LED light output from the LED elements 112 is not incident on the rod lenses 116 but output as diffused light, and the rest (for example, 80%) of the LED light is incident on the rod lenses 116 to form LED straight light 122 in the form of parallel light.

Of course, the light source unit 110 may form the LED linear light 122 in the form of diffused light without using the lens 116. Even if the LED elements 112 are arranged in the same LED module 120, the LED elements 112 provided with the lens 116 and the LED elements 112 not provided with the lens 116 may be used in combination.

Fig. 6 is a schematic diagram illustrating a state in which the LED straight light 122 in the form of diffused light output from the LED element 112 reaches the alignment film 162.

Referring to fig. 6, the LED straight light 122 in the form of diffused light may reach the alignment film 162. The LED straight line light 122 may be formed in the form of diffused light having a total irradiation width c, which is a width of an effective region until the irradiation intensity reaches 5% of the average value, twice or less the width a of the irradiation concentration portion 126. Thus, the following relationship is established with the width b of the remaining portion excluding the width a of the irradiation concentrated portion 126 out of the total irradiation width c:

a+2b＝c

2a≥c

fig. 7 is a schematic diagram illustrating a state where the LED linear light 122 crosses after passing through the polarizing plate 132.

When the light source section 110 irradiates only the LED linear light 122 of the parallel light type, although the directional performance of the light is improved, the cumulative light amount is reduced, and the mass productivity is lowered. To solve these problems, as illustrated in fig. 7, the LED straight lines 122 in the form of diffused light output from the plurality of LED modules 120 may be crossed with each other after passing through the polarizing plate 132, thereby increasing the irradiation area, particularly the size of the irradiation concentrated portion 126 formed at the center.

Fig. 8 is a schematic view illustrating a state in which a tilt angle is formed in the LED module 120 so that the LED straight light 122 intersects.

Referring to fig. 8, in order to further concentrate the LED straight light 122 in the form of diffused light output from the three LED modules 120, the LED modules 120 on both sides are obliquely arranged in bilateral symmetry. This can increase the area of the irradiation concentration portion 126 and the concentration light amount.

Next, the polarization unit 130 of the optical alignment device 100 according to the present embodiment will be described with reference to fig. 1 to 2 and 9 to 10.

Fig. 9 is a plan view illustrating the polarizing portion 130 of the photoalignment device 100 illustrated in fig. 1, and fig. 10 is a front view of the polarizing portion 130 illustrated in fig. 9.

Referring to fig. 9 to 10, the polarization unit 130 controls the polarization of the LED linear light 122 output from the light source unit 110, and includes: a plurality of polarizing plates 132 arranged in a line; and a light shielding member 140 positioned at a vertically lower portion of the gap 138 formed between the polarizers 132.

The LED linear light 122 output from the light source unit 110 is polarized in a specific direction after passing through the polarizing plate 132. The polarizer 132 may use a brewster polarizer or a wire grid polarizer.

The brewster polarizer is a polarizer made of a dielectric multilayer film, and can be divided into a p-wave polarization component and an s-wave polarization component by the brewster angle to set a high extinction ratio (polarization ratio). The wire grid type polarizing plate can arbitrarily change a wavelength band by a gap of a metal wire (grid) arranged inside thereof. The wire grid type polarizer can be manufactured by a simple process of pattern transfer.

The polarizing plates 132 are aligned in a row, and a predetermined gap 138 is formed therebetween. By forming the gaps 138 between the polarizers 132, each polarizer 132 can be rotated to adjust the polarization direction. Both end portions of the polarizing plate 132 are provided with support members 134.

A light shielding member 140 is disposed at a lower portion of the gap 138 where the polarizer 132 is not disposed to prevent unpolarized LED linear light 122 from reaching the alignment film. The light shielding member 140 is formed of a material such as a metal that does not transmit light, has a width larger than that of the gap 138, and is longer than the polarizer 132. The width of the light shielding member 140 may be 4.5mm or less in consideration of the LED linear light 122 transmission.

The light-shielding member 140 is located at a lower portion of the polarizer 132 with a predetermined interval therebetween in order to prevent the polarizer 132 from being damaged by the light-shielding member 140.

A cover glass sheet 150 is provided at a lower portion of the polarization part 130. The cover glass sheet 150 serves to prevent water vapor (vapor) generated by irradiating the alignment film 162 from attaching to the polarizing plate 132. The cover glass sheet 150 may be formed of a material such as glass that transmits the LED linear light 12. The cover glass sheet 150 may be provided with one or more.

Fig. 11 is a plan view illustrating a state before the polarizing plate 132 of the polarizing section 130 is adjusted, and fig. 12 is a plan view illustrating a state after the polarizing plate 132 in fig. 11 is adjusted.

Referring to fig. 11 and 12, each polarizing plate 132 can be rotated by a predetermined angle about a rotation center 136. The rotation center 136 may be formed on the support member 134 for supporting both end portions of the polarizer 132 instead of the center of the polarizer 132. As shown in fig. 11, when the polarizing plates 132 are not aligned in a desired direction, each polarizing plate 132 may be rotated centering on the rotation center 136, thereby adjusting the polarizing plate 132 as shown in fig. 12.

The rotation centers 136 of the adjacent polarizing plates 132 are disposed at opposite end portions. This is to prevent the polarizers 132 from colliding due to the small gap 138 between the polarizers 132.

The photo-alignment device 100 according to the present embodiment includes the light source unit 110 and the polarization unit 130, and does not separately include a mirror (not shown) for condensing light, and thus has a simple structure and can adjust the height of the alignment film 162. In this manner, the irradiation intensity of the LED linear light 122 reaching the alignment film 162 can be adjusted by adjusting the height of the photo-alignment device 100 with respect to the alignment film 162, and thus, light optimized for the alignment characteristics of the alignment film 162 can be irradiated.

The photo-alignment device 100 according to the present embodiment may be provided with a fluorescence sensor (no reference numeral) for receiving fluorescence generated when the LED linear light 122 reaches the alignment film 162. Since the photoalignment device 100 according to the present embodiment uses the LED element 112, the fluorescence sensor does not require a specific wavelength, and the degree of alignment can be measured only by receiving fluorescence.

The photo-alignment apparatus 100 according to this embodiment includes a stage 170 for placing the alignment film glass 160, and the stage 170 can move the alignment film glass 160 along the direction of the arrow in fig. 1. The stage 170 and a driving method thereof are conventional techniques, and thus, detailed description is omitted.

While the present invention has been described with reference to the embodiment, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as set forth in the appended claims.

Claims

1. A photo-alignment device for processing an alignment film for aligning liquid crystal in a non-contact manner, the photo-alignment device including a light source part in which LED elements are arranged to irradiate light and a polarization part for performing polarization control,

the light source unit forms a plurality of rows of LED linear light perpendicularly incident on the alignment film, each row of the LED linear light is formed by arranging a plurality of LED elements in a row,

in the polarizing section, a plurality of polarizing plates are arranged in only one row,

and the LED linear light rays enter the polaroids at intervals without interfering with each other.

2. The light directing apparatus of claim 1,

the peak wavelengths of the LED linear light in the multiple rows are different.

3. The light directing apparatus of claim 2,

the LED elements are individually controlled so that the amount of light received from the multi-beam LED linear light by the alignment film of the lower portion of the polarization part is uniform.

4. The light directing apparatus of claim 1,

the LED straight light beams cross each other when transmitting the polarization part.

5. The light directing apparatus of claim 1,

the irradiation angles of the plurality of LED straight-line lights are symmetrical with each other, so that a continuous irradiation concentrated portion is formed when the polarization portion is transmitted.

6. The light directing apparatus of claim 1,

the light source unit includes a lens that forms the LED light into diffused light or parallel light.

7. The light directing apparatus of claim 1,

a gap is formed between the polarizing plates, and a light shielding member is provided at a lower portion of the gap to prevent the LED from transmitting straight light.

8. The light directing apparatus of claim 7,

the width of the light shielding member is not more than 4.5 mm.

9. The light directing apparatus of claim 1,

the polarizing plate has a rotation center not located at the center thereof and can be adjusted in angle by rotation.

10. The light directing apparatus of claim 9,

the rotation centers of the adjacent polarizing plates are arranged on opposite sides to each other.

11. The light directing apparatus of claim 1,

adjusting the vertical height of the photoalignment device relative to the alignment film to control the reaction time of the alignment film.

12. The light directing apparatus of claim 1,

the alignment film is provided with a fluorescence sensor for receiving fluorescence generated when the LED linear light reaches the alignment film, and the alignment degree of the alignment film is measured by the fluorescence sensor.

13. A photo-alignment method, characterized in that,

forming a plurality of rows of LED linear light perpendicularly incident to the alignment film, each row of the LED linear light being formed by arranging a plurality of LED elements in a row,

in a polarizing portion formed by arranging a plurality of polarizing plates in a row, a plurality of rows of the LED linear light enters each polarizing plate at intervals without interfering with each other, and the alignment film is processed in a non-contact manner.