TW518427B - Light irradiating device - Google Patents

Abstract

A light irradiating device for a photo-alignment process comprises an optical system and a first polarizer polarizing the light from the optical system. The light from the first polarizer is obliquely irradiated at an angle with respect to a normal direction of a stage on which a substrate is placed.

Description

518427 _Case No. 88121545_ Modification of the year and month _ V. Description of the invention (1) Field of the invention The field of invention of the present invention relates to light irradiation devices, especially large-size light irradiation devices, which are suitable for multi-domain liquid crystal display devices. Light alignment processing. Description of the Conventional Technology Generally, a multi-domain liquid crystal display device includes an upper and lower substrate arranged to face each other, wherein a partition is provided with a designated gap, and a liquid crystal layer is formed between the upper and lower substrates. The upper and lower substrates each have an electrode with a specified pattern on one side, and an alignment layer on the electrode. This alignment layer determines the alignment of the liquid crystal. A rubbing or light alignment method, or other method is used as the alignment method for processing the alignment layer. The rubbing method involves coating a pair of homogeneous materials, such as polyamide (ρ ο 1 y a m i d e, PI) on a substrate, and then mechanically rubbing the substrate with a rubbing cloth. The alignment direction of the liquid crystal molecules on the substrate can be obtained from the above processing procedure. In this way, large-size L C D can be manufactured and processed quickly. However, in the previously described rubbing method, since the pattern of the micro-grooves formed on the alignment layer changes with the rubbing strength, the alignment of the liquid crystal molecules is not uniform. Moreover, this will cause light scattering and random phase distortion. In addition, dust particles and electrostatic discharge generated by friction will cause lower yields.

518427

Reduction, and repeated photolithography for pixel division (photolithography) of 0 ^ into multiple image fields will affect the reliability of the alignment layer and stabilize the rate of another million facets, and determine the initial tilt of the liquid crystal (LC); A toothless substrate with an alignment layer will cause electrostatic discharge and will not produce. Compared to the friction method, both. In particular, in this way, dust particles ’can be maintained

LCD% has been published with pixel-separated wide-angle publishing) and editions) to expose the above-mentioned light alignment JP-A-10-90684 (April 10, 1998 JP-A-10 — 1 6 1 1 2 6 (1 The light irradiation device used in the treatment on June 19, 1998. F, is the structure of the traditional light irradiation device proposed in the 乂 乂 0-9 0 684, which is about polarized light The irradiating device is used to irradiate polarized light on the alignment layer of the LCD as the light alignment processing of the alignment layer. The light beam containing the ultraviolet light emitted from the light source 1 is collected in the condenser 2 and in the first reflector 3 Reflected and passed through the condenser 5. The light beam from the? Κ mirror 5 via the shutter 4 is reflected in the first mirror 6, and the beam is parallelized by the collimator lens 7 and then passes through the polarizer 8. The polarizer contains multiple A glass plate 8a is placed in parallel at a fixed interval, and the corresponding insertion light is placed at a Brewster angle. Most of the vertically polarized light will be reflected back 'and the polarized light is transmitted horizontally. From Horizontally polarized light of polarizer 8 is masked

518427 _Case No. 88121545_Year Month Day__ V. Description of the invention (3) The curtain 13 is irradiated onto the substrate 35. In the light irradiation device having the above-mentioned architecture, the polarization ratio (s / p, where s is a vertically polarized light, and p is a horizontally polarized light) is set to be less than 0.1. In order to align the alignment layers of the LCD, polarized light having the same polarization direction is irradiated. This device has quite good penetrability, wavelength dependence, tolerance and life cycle. Therefore, in order to produce a large-sized LCD, the glass plate 8a of the polarizer 8 needs to be made sufficiently large. Moreover, the range of the polarization ratio of the device is not suitable for efficiently introducing light alignment processing. FIG. 2 is a schematic diagram of the structure of a conventional light irradiation device. See JP-A-10-161126. The exposure device includes a light source 1, a condenser lens 2, a collimator lens 7, a homogenizer 19, and a condenser lens 5. Or one or more mirrors 3 and 6, which guide the light from the light source 1 to the base body 35. Moreover, at least one of the reflecting mirrors includes a reflective diffraction grating (g r a t i ng), which mainly reflects the first polarized light. Since the size of the first reflecting mirror 3 is smaller than that of the second reflecting mirror 6, when the first reflecting mirror 3 includes a diffraction grating, a small-sized diffraction grating can be used. Because the diffraction grating is positioned in front of the homogenizer 19, the light passing through the homogenizer can be prevented from being affected by the diffraction grating. With the structure described above, the reflected light can be irradiated through the reflective diffraction grating that mainly reflects the first polarized light, and the light irradiation device can irradiate a large amount of polarized light at a time. Polarity of a diffraction grating in a light irradiation device

518427 Case No. 88121545

Year A is called Amendment 5. Explanation of the invention (4) The characteristics of wavelength and wavelength have a considerable relationship. Since the conventional light irradiation device focuses on the toughened (a η n e X i n g) polarization device to obtain polarized light, the above-mentioned conventional technique is not applicable to actual light alignment processing. SUMMARY OF THE INVENTION An object of the present invention is to provide a light irradiation device that can irradiate a large size and can determine the alignment direction and initial tilt angle of an alignment layer by oblique light irradiation. Other features and advantages of the present invention can be understood from the following description or by the application of the action of the present invention, and the purpose and advantages of the present invention can be understood from the specified structure written in the text, the scope of the patent and the drawings. In order to achieve the purpose of the present invention described above, a light irradiation device is provided, which includes an optical system and a first polarizer, the first polarizer is used to polarize light from the optical system; a substrate is placed on the carrier, The light from the first polarizer is irradiated obliquely in a normal direction angle of the corresponding carrier. The optical system includes a light source, a lens, and one or more or second reflectors. In addition, a third polarizer can be placed between the lens and the mirror.

Page 7 518427 __Case No. 88121545_ Revised Year of the Month _ V. Description of the Invention (5) In order to achieve the purpose of the invention, a light irradiation device is provided, which includes: a light source; a first reflector that reflects from the light source A light homogenizer including a plurality of lenses; a second reflector that reflects light from the homogenizer; a collimator lens for parallelly outputting light from the second mirror; and a first A polarizer polarizes the light from the lens, places a substrate on the carrier, and obliquely irradiates the light from the first polarizer in a direction angle corresponding to the carrier. m The above light irradiation device further includes a second polarizer or a third polarizer interposed between the first reflector and the homogenizer, and the third polarizer is interposed between the homogenizer and the second reflector between. Preferably, the first polarizer has a relatively high light transmittance in a wavelength range between about 200 nm and 800 nm, and a more preferable range is between 250 nm and 40. Between 0nm. The first polarizer has a degree of polarization (PD) between about 0 and 1, preferably between about 0.2 and 0.95. Preferably, the angle ranges between 0 ° and 45 °. If necessary, the Korean Patent Application No. 199-8-474090, filed on November 6, 1998, can be incorporated into this application for reference. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT: The light irradiation device according to the present invention will be described in detail below with reference to the drawings. According to the present invention, FIGS. 3A, 3B and FIG. 4 are yz and xz of the light irradiation device.

518427 correction

t number 881215W V. Description of the invention (6) Plane. According to the present invention, the Guangzhao Mzhuang second reflecting mirror 3, the lens 37 is small, and the ruler f includes a light source. The light mirror 2, the first mirror 6, the collimating lens 7, and the cover state 3 1 'uniform light state 1 9. Second reverse polarizer 33. The curtain 13, a carrier Π on which the base body 35 is placed, and a condenser lens 2 are placed to make the lens stop.匙 八 少 柄 # The light emitted by the first source 1 can be transmitted to the first reflection package. Each evening = lens homogenizer (for example, a compound lens or a flying eye cools the light or beam from the lens to overlap, or β first beam / A mirror 6 reflects the light from the homogenizer. The collimation 7 enables the light or beam from the second mirror 6 to be parallel and directed to the alignment layer 25 formed on the f base 35. Use-a mirror or lens as collimation The lens 7 and the homogenizer may be of a convex type or a concave type. The light S? And the emitting device according to the present invention may also include a polarizer at the position of the first polarizer μ, and if necessary, The front or rear side of the light equalizer 19 may also include a second polarizer 3 as shown in FIGS. 3A and 3B and a third polarizer 5 1 (a small-sized polarizer). The two polarizers 33 ′ 31 and 51 each include a polarizer substrate, which is a thin laminated quartz substrate, a thin layer of broken glass substrate, or a multi-clad substrate. Polarizers have fairly good thermal resistance, tolerance, and relatively low wavelength dependence. Use a thin layer of quartz The glass substrate 'corresponds to the Brewster angle of the substrate (= ta η Mn, where η is the refraction coefficient of quartz or glass). Therefore, the Brewster angle ranges from about 57. to 60 °. Thin quartz Or the glass substrate can be 518427 _ case number 88121545 _ revised month five. Description of the invention (7) In the case of large-sized irradiation, light is irradiated in a uniform manner. An inorganic layer is applied to coat a multi-layered substrate, which The inorganic layer is usually SiO 2. Preferably, the polarizer 33 is a high light transmissive in a wavelength range of 20 Onm to 80 Onm, especially in a range of 250 to 400 nm. , The best degree of polarization (PD = (Im ax-Im in) / (Im ax-Im in) is in the range of 0 < PD < 1 (that is, partially polarized light), especially in 0. 2 < PD < (K 9 5 range. The degree of polarization can be appropriately selected according to the type of the alignment layer. As shown in FIG. 4, the light irradiation device shown in the xy plane is from the optical system 1 0 An irradiation of 0 corresponds to a normal direction of a carrier used for oblique exposure is inclined at an angle, and the maximum penetration axis is vertical or flat The xz plane of the light path defined in the figure. Therefore, by synthesizing the above-mentioned irradiation device, a part of polarized light can be irradiated on the alignment layer 25 in an oblique manner. Control of the initial tilt angle in the alignment layer in the light irradiation device. The initial tilt angle of the liquid crystal molecules 27 in the alignment layer 25 ((9) is the light energy, thin layer material, or light irradiation on the alignment layer. The degree of polarization of the device is controlled. The alignment direction of the liquid crystal molecules 27 is determined by the direction of irradiation in oblique exposure. It is best to use a light irradiation angle (0) in the range of about 0 ° to 45 °, and if the light irradiation angle (0) is greater than about 45 °, then the distance between the mask 1 3 and the alignment layer 2 5 The effect of the gap error can be maximized, so that

518427 __Case No. 88121545_ Year Month Revision_ V. Description of the invention (8) The pattern position error caused by the mask pattern will become quite large. In the example where the gap error between the mask 1 3 and the alignment layer 25 is about 20 // in, the following table shows the pattern position error as a function of the light irradiation angle (0). Irradiation angle) 0 degrees 3 0 degrees 4 5 degrees 6 0 degrees Pattern error Q μ m 1 1. 5 // m 20 μ m 34. 6 / zm Figure 6 A, 6B and 6C are the first, second and A view of the xy plane of the three embodiments, which shows the control of the alignment direction of the thin layers. In these figures, the thick solid line arrows indicate the alignment direction of the substrate; the rectangle surrounded by the solid line indicates the first position 45 of the substrate, and the rectangle surrounded by the dashed line indicates the second position 47 of the substrate. As explained above, in the light irradiation device of the present invention, the light irradiation direction (ie, the azimuth angle of light) on the substrate in the light alignment process is very important, and the alignment direction is determined by the light irradiation direction in oblique exposure The reason. A method of controlling the azimuth of light is shown in Figs. 6A, 6B, and 6C. As shown in the first embodiment of FIG. 6A, when a single-domain or multi-domain liquid crystal design device is generated, the alignment direction of the length direction of the corresponding substrate may be 0 ° or 90 ° (45 °). Or 1 3 5 °), the optical system 1 0 0 is designed so that the length direction of the corresponding substrate can be about 0 ° to 4 5 °.

Page 11 518427 _Case No. 88121545_ Year and month Amendment_ V. Description of the invention (9) The purpose of establishing this purpose is to rotate the substrate about 90 ° in a single way. Therefore, in order to form a certain alignment direction, FIGS. 6B and 6C are better designs, and the design in FIG. 6C is better. Fig. 6B shows that the required alignment direction can be formed by rotating the carrier 11 through the angle (Φ), wherein the substrate is placed on the carrier. However, in the above design, in order to generate a multi-domain liquid crystal design device, it is necessary to maintain the gap between the mask and the substrate so as to rotate the mask together. FIG. 6C shows that the objective of the multi-image domain is achieved by rotating the optical system 100 through an angle (0), and then forming the first and second alignment directions, wherein the image domain has two or more alignment directions. The xz plane of FIG. 7 shows the exposed areas of the alignment layer of the present invention. When a mask is used to produce a multi-image-domain liquid crystal display device, a specified gap needs to be maintained between the mask 13 of the base 35 and the alignment layer 25, and preferably the size of the gap is between about 30 / zm to 1 0 0 // m. As shown in the figure above, if light inclined at an angle (Θ) is irradiated on the alignment layer 25 through the mask 13, the exposure area is moved by a distance of △ χ (Δ x = d tan0) corresponding to the angle, and The pattern of the mask 13 is then formed in the moving position. Therefore, in the actual light alignment process, it is necessary to maintain a specified gap between the mask 13 and the base 35, and it is preferable to place the mask and the base in parallel. Moreover, after the gap is accurately measured, it is necessary to move the substrate from the initial position according to the measured gap and the angle of light irradiation, and then irradiate the light.

518427 _Case No. 88121545_ year, month, day, amendment_ V. Description of the invention (10) In order to explain the above processing procedure, it is best to use a gap measurement device and a light source (such as a laser) to measure the gap. A gap correction device needs to be installed below the carrier 11 and three or four gap positions to be measured are selected to reduce the gap error between the measurement positions. According to the light irradiation device of the present invention, the light of the polarizer is irradiated obliquely at an angle corresponding to the carrier by irradiating only once, to determine the alignment direction of the alignment layer and the initial tilt angle, and then to irradiate part of the polarized light obliquely . Moreover, the gap between the mask and the substrate can be accurately measured to effectively understand the large-size and multi-image-domain liquid crystal display device, and then form a uniform pattern on the alignment layer. Those skilled in the art must understand that the above-mentioned preferred embodiments of the present invention can be modified and changed without departing from the spirit and perspective of the present invention. The present invention is defined in the following patent application scope and its equivalent meaning in the patent application scope, and its modifications and alterations.

518427 __Case No. 88121545_Year Month Day__ Brief Description of the Drawings The features and advantages of the present invention can be further understood from the description below. Please refer to the drawings when reading. The drawings are used to enable those skilled in the art to understand the present invention, and are incorporated into the description of the present invention. The embodiments and descriptions of the present invention can be used to understand the principles of the present invention by those skilled in the art; FIG. 1 shows a conventional light Illumination device; Fig. 2 shows another conventionally used light irradiation device; Figs. 3A and 3B show yz plan views of the light irradiation device according to the present invention; Fig. 4 is a view of the xz plane of the light irradiation device according to the present invention; Is an xz plan view showing how to control the initial tilt angle of the alignment layer according to the present invention; FIGS. 6A, 6B and 6C are xz plan views of the first, second and third embodiments of the present invention, illustrating how to control The alignment direction of the alignment layer of the present invention; and an xz plan view of FIG. 7 showing the exposed area of the alignment layer of the present invention. Explanation of drawing numbers 1 light source 2 condenser 3 first reflector 6 second reflector 7 collimator lens 11 carrier 13 mask

518427

Page 15

Claims (1)

518427 __Case No. 88121545_ Amendment of the month of the year _ 6. The scope of patent application 1. A light irradiation device includes: an optical system and a first polarizer to polarize light from the optical system, where The light from the first polarizer is obliquely illuminated in the ^^ direction angle, and the substrate having the alignment layer is placed on the carrier, so a single oblique irradiation is used to determine the alignment direction and initial tilt angle of the child # | layer. 2. The light irradiation device according to item 1 of the application, wherein the optical system includes a light source, a lens, and a reflector. 3. The light irradiation device according to item 2 of the patent application scope, wherein the optical system includes one or more reflectors. 4. The light irradiation device according to item 1 of the application, wherein the first polarizer includes a polarizer substrate, and the substrate includes a thin glass substrate. 5. The light irradiation device according to item 1 of the patent application, wherein the first polarizer includes a polarizer substrate, and the substrate includes a thin layer of quartz substrate. 6. The light irradiation device according to item 1 of the patent application, wherein the first polarizer includes a polarizer substrate, and the substrate includes a multi-layer substrate. 7. The light irradiation device according to item 1 of the patent application, wherein the first polarizer is inclined at a Brewster angle corresponding to the substrate. Page 16 518427 _ Case No. 88121545 _ Amendment Month _ Sixth, the scope of patent application 8. For example, the light irradiation device of the sixth scope of the patent application, wherein the polarizer substrate is a multi-layered substrate coated with an inorganic layer . 9. The light irradiation device according to item 2 of the scope of patent application, further comprising a second polarizer disposed between the lens and the reflector. 10. The light irradiation device according to item 9 of the patent application, wherein the second polarizer includes a polarizer substrate, and the substrate includes a thin glass substrate. 1 1. The light irradiation device according to item 9 of the patent application, wherein the second polarizer includes a polarizer substrate, and the substrate includes a thin layer of quartz substrate. 12. The light irradiation device according to item 9 of the patent application, wherein the second polarizer includes a polarizer substrate, and the substrate includes a multi-layer substrate. 13. The light irradiation device according to item 9 of the scope of patent application, wherein the second polarizer is inclined at a Brewster angle with respect to the substrate. 14. The light irradiation device according to item 12 of the scope of patent application, wherein the polarizer substrate is a multi-layer substrate coated with an inorganic layer. 15. The light irradiating device according to item 1 of the scope of patent application, wherein the wavelength of the light from the first polarizer is between 200 nm and 800 nm. Page 17 518427 _ Case No. 88121545_ Year Month Date Amendment _ Sixth, the scope of the patent application 16. For example, the light irradiation device of the first 15th scope of the patent application, wherein the wavelength range of light from the first polarizer Between 250 nm and 400 nm. 17. The light irradiation device according to item 1 of the patent application, wherein the polarization degree of the first polarizer is between 0 and 1. 18. The light irradiation device according to item 1 of the scope of patent application, wherein the polarization degree of the first polarizer is between 0.2 and 0.95. 19. The light irradiation device according to item 1 of the scope of patent application, wherein the angle is about 0 to 45. . 20. The light irradiation device according to item 1 of the scope of patent application, wherein the carrier is a rotatable one. 2 1. The light irradiation device according to item 1 of the patent application scope, wherein the optical system is rotatable. 2 2. The light irradiation device according to item 1 of the scope of patent application, further comprising a multi-field mask on the substrate. 2 3. The light irradiation device according to item 22 of the scope of patent application, wherein a gap is maintained between the cover and the substrate. 518427 Case No. 88121545 Amendment VI. Patent application scope 24. A light irradiation device includes: a light source; a first reflector that reflects light from the light source; a homogenizer that includes a plurality of lenses; A second reflector that reflects light from the homogenizer; a collimating lens that outputs light from the second mirror in parallel; and A first polarizer polarizes the light from the collimator, wherein a substrate is placed on the carrier, and the light from the first polarizer is irradiated obliquely in the angle corresponding to the direction of the carrier. 25. The light irradiation device according to item 24 of the scope of patent application, further comprising a second polarizer disposed between the first reflector and the light equalizer. 26. The light irradiating device according to item 25 of the patent application scope, further comprising a third polarizer disposed between the homogenizer and the second reflector. The light irradiating device according to item 26 of the patent application scope, wherein the first polarizer partially polarizes light from the collimating lens. Page 19