JP5668488B2 - Photomask and method of manufacturing parallax crosstalk filter using the same - Google Patents

Description

  The present invention relates to a photomask suitable for manufacturing a parallax crosstalk filter that can be used as an image light filter for autostereoscopic viewing by parallax division.

  In a three-dimensional display device that performs autostereoscopic viewing, a method that uses parallax division of the line of sight is generally implemented, such as the parallax barrier method and the lenticular lens method disclosed in Patent Document 1. 2A and 2B are conceptual diagrams viewed from the overhead of an observer for explaining a stereoscopic viewing method in a conventional 3D display device, where FIG. 2A is a parallax barrier method, and FIG. 2B is a lenticular lens method. Indicates.

  In the parallax barrier method, the image 5 to be stereoscopically viewed includes the right-eye pixels 5R and the left-eye pixels 5L arranged alternately, and the observer and the image 5 with the right eye 4R and the left eye 4L naked eyes. Between them, a parallax barrier 61, which is a light shielding barrier having openings at the same period as the image period, is arranged in parallel with the image. The image light from the right-eye pixel 5R and the left-eye pixel 5L is reflected on the retinas of both eyes by utilizing the line-of-sight separation phenomenon caused by selectively entering the right eye 4R and the left eye 4L through the openings. Different images can be recognized three-dimensionally. Note that the image 5 may be a still image or a moving image, and various types are possible from a printed image to an electronic display such as a liquid crystal display device.

  The parallax barrier method has a defect that an image is darkened by a light-shielding barrier, and there is a lenticular lens method to improve the defect. In the lenticular lens system, a kamaboko type lenticular lens 62 is arranged between the image 5 and the observer with the naked eyes of the right eye 4R and the left eye 4L and the image 5. The retina of both eyes is utilized by utilizing the line-of-sight separation phenomenon that image light selectively enters the right eye 4R and the left eye 4L through the lenticular lens 62 from the right eye pixel 5R and the left eye pixel 5L, respectively. It is possible to recognize three-dimensionally different images displayed on the screen. Note that the image 5 may be a still image or a moving image, and various types are possible from a printed image to an electronic display such as a liquid crystal display device.

  The above-described method enables stereoscopic viewing using parallax division, but image light from each pixel is not emitted only in the direction according to the above description, and the direction of the emitted light cannot be reduced. For this reason, there is a problem of crosstalk (a phenomenon in which display images are mixed) caused by light rays leaking from the above description, and incomplete stereoscopic vision has been used practically.

Japanese Patent Laid-Open No. 9-18897

  The present invention is proposed in view of the above problems, and the problem to be solved by the present invention is to change the direction of image light in order to solve crosstalk in a three-dimensional display device that performs autostereoscopic viewing. It is to provide a parallax crosstalk filter to be limited and a manufacturing method thereof.

As means for solving the above problems, the invention according to claim 1
A photomask for selectively pattern exposure to a photosensitive material on a substrate,
The photomask includes: a light-shielding film pattern surrounding an opening on a transparent substrate; an optical path tilting mechanism that refracts light irradiated through the opening in an oblique direction; and a spacer that maintains an interval between the exposure target substrate. Become
The photomask is characterized in that the direction of refraction of light irradiated through the opening is controlled by changing a relative position between a planar position where the optical path tilting mechanism is provided and a center position of the opening.

The invention according to claim 2 is the photomask according to claim 1, wherein the optical path tilting mechanism is formed by a lens or a prism.

  The invention according to claim 3 is the photomask according to claim 1 or 2, wherein the spacer is formed including a light shielding material.

  Further, the invention according to claim 4 is a method in which the photosensitive material on the substrate is selectively subjected to pattern exposure by using the photomask according to any one of claims 1 to 3 and then developed. A manufacturing method of a parallax crosstalk filter, characterized in that a processing portion inclined with respect to a material surface is provided.

  The present invention selectively exposes a photosensitive material on a substrate by pattern exposure using a photomask having an optical path tilting mechanism that refracts light irradiated through an opening on a transparent substrate in an oblique direction. The processing portion inclined with respect to the surface of the conductive material can be provided. Therefore, it is possible to provide a parallax crosstalk filter for solving crosstalk in a three-dimensional display device that performs autostereoscopic viewing and a manufacturing method thereof. Furthermore, the photomask of the present invention can contribute to the manufacture of a processed part inclined filter having a heterogeneous part inclined with respect to the surface.

It is a schematic cross section for demonstrating the manufacturing method of the parallax crosstalk filter using the photomask of this invention. It is a conceptual diagram for demonstrating the system of the stereoscopic vision in the conventional three-dimensional display apparatus, (a) shows a parallax barrier system, (b) shows a lenticular lens system. It is a schematic cross section for explaining a method for manufacturing a parallax crosstalk filter using different examples (a) and (b) in the photomask of the present invention. It is a conceptual diagram which shows the example seen stereoscopically using the parallax crosstalk filter by this invention. It is a conceptual diagram which shows the other example stereoscopically viewed using the parallax crosstalk filter by this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view for explaining a method of manufacturing a parallax crosstalk filter using a photomask of the present invention.

  The photomask 1 is a photomask for selectively performing pattern exposure on the photosensitive material 22 on the substrate 21, and is irradiated through the light shielding film pattern 12 surrounding the opening 13 on the transparent substrate 11 and the opening 13. The optical path tilting mechanism 14 using a microlens or the like that refracts the straight traveling light 3 in an oblique direction and a spacer 15 that keeps a distance from the substrate to be exposed.

  The transparent substrate 11 secures sufficient transparency corresponding to the properties such as the wavelength of the light 3 emitted from the light source when using a photomask, and has a coefficient of thermal expansion according to the necessity to control to fine dimensional accuracy. It is desirable that it is small, and it is selected in consideration of characteristics such as surface flatness and hardness. Although a fused quartz substrate is generally suitable as a transparent substrate for a photomask, it is not limited.

  It is desirable that the light-shielding film pattern 12 is thin and has sufficient light-shielding properties, has good adhesion to the transparent substrate 11, has excellent mechanical and chemical strength, and can be easily processed for micropatterning. In general, various materials mainly composed of metals such as chrome, titanium, molybdenum silicide compounds have been put into practical use and are not particularly limited.

  For example, the optical path tilting mechanism unit 14 can be provided with a microlens made of a material with a controlled refractive index at a predetermined position with respect to the opening 13. As shown in FIG. 1, if the position of the central axis of the microlens 14 coincides with the center position of the opening 13, the linearly radiated light 3 goes straight as it is (the lens displayed in the center of FIG. 1), but the microlens 14. By shifting the position of the center axis of the light source from the center position of the opening 13 and changing the relative position, the refraction direction of the light irradiated through the opening 13 is controlled in an oblique direction (lens displayed on the left and right in FIG. 1). 31 can be obtained.

  The spacer 15 is formed at a higher height than the optical path tilting mechanism part 14 at a uniform height on the optical path tilting mechanism part 14 side in the region on the transparent substrate where the opening 13 and the optical path tilting mechanism part 14 are not provided. Since a photosensitive resin can be applied to a uniform thickness and formed by a photolithographic method in the same manner as a method of manufacturing a microlens as an optical path tilting mechanism described later, it can be a simultaneous process depending on the specification conditions. However, it is not limited.

  By providing the spacer 15 having a uniform height in a predetermined region, the optical path tilting mechanism 14 such as a microlens can be brought into contact with the exposed surface when the contact exposure is performed using the photomask 1 of the present invention. In addition, since a stable exposure gap can be maintained, it is possible to prevent the resolution from being lowered due to the diffraction effect due to light scattering. By forming the spacer in a particularly possible region using a light-shielding material containing a light-shielding pigment or the like, the refracted light 31 by the optical path tilting mechanism unit 14 does not affect the external region and from the external region. It can be made to act more completely without being affected by incident light.

  When a photolithographic process including exposure and development on the photosensitive material 22 applied on the transparent substrate 21 to be formed with the parallax crosstalk filter 2 is performed using the photomask 1 described above, the direction of the refracted light 31 Depending on the property, it is possible to form the processed portion 23 having a certain inclination angle with respect to the surface of the photosensitive material. The directionality of the refracted light 31 depends on the refractive index and shape of the lens material. The direction can be controlled by the relative positional relationship.

The optical path tilting mechanism 14 can be formed by a lens or a prism. A method for manufacturing the microlens will be described as an example.
After the light shielding film pattern 12 surrounding the opening 13 is formed on the transparent substrate 11 by film forming, photolithography, and etching processes, a photosensitive positive resist, which is a transparent resin that becomes a lens material, is applied to the light shielding film pattern. Cover and form. Then, after pre-baking and selective exposure, developing with an organic alkali developing aqueous solution, for example, TMAH (tetramethylammonium hydroxide) 0.5% aqueous solution, adding a heat treatment step and utilizing thermal reflow behavior, A lens shape is formed at a predetermined position. As described above, it is important to change the relative position by shifting the position of the center axis of the microlens 14 from the center position of the opening 13. The relative positional relationship with the photomask pattern used in the exposure process of the light shielding film pattern 12 in the process can be accurately defined.

  As a manufacturing method of the microlens 14, in addition to the above-described method utilizing the thermal reflow behavior, the photosensitive positive resist constituting the microlens is exposed with a light intensity distribution inclined and removed in the development process. It is possible to directly form the lens shape by gently changing the resist amount. As a photomask having a gradient density distribution used in this method, for example, the average density of a fine region is continuously changed by changing the aggregate state of a fine pattern of a light shielding film such as a dot (halftone dot) arrangement or a line and space. It is possible to apply a gray scale mask of a multi-tone type that changes in a changing manner.

  In addition, a method of manufacturing a microlens using the surface tension of an ink jet droplet is also possible. A transparent resin droplet having a predetermined refractive index and viscosity is dropped at a predetermined position to obtain a predetermined shape, and then cured by heat or UV light. In this method, the accuracy of the microlens formation position is inferior to that of the method using the photolithography method described above, but it can be used as a simple process within the range of possible specifications.

  Further, as another method of providing a microlens as a constituent element of the photomask, a method of aligning and pasting a previously formed integral lens sheet on the light shielding film pattern 12 surrounding the opening 13 is also possible.

FIG. 3 is a schematic cross-sectional view for explaining a method of manufacturing a parallax crosstalk filter using different examples (a) and (b) in the photomask of the present invention.
Both (a) and (b) schematically show a method of making a parallax crosstalk filter 2 having four processed parts 23 inclined in two directions, and the photomask 1 and (b) in (a). The photomask 1 ′ is different from the photomask 1 ′ only in the microlenses 14 and 16 forming the optical path tilting mechanism, and the others are the same. As an example, the microlens 14 includes four microlenses individually formed corresponding to one opening 13, whereas the microlens 16 forms two microlenses corresponding to two openings. doing.

  When a photolithography process including exposure and development on the photosensitive material 22 applied on the transparent substrate 21 on which the parallax crosstalk filter 2 is to be formed is performed using the above-described photomasks 1 and 1 ′, refracted light Due to the directionality 31, the processed portion 23 having a certain inclination angle with respect to the surface of the photosensitive material can be formed. Although the directionality of the refracted light 31 depends on the refractive index and shape of the lens material, the central axis position of the microlenses 14 and 16 and the central position of the opening 13 are formed even if lenses having the same shape are formed of the same material. The direction can be controlled by the relative positional relationship between

  The parallax crosstalk filter 2 is formed by selectively using the inclined processing portion 23 as a light path. Therefore, the substrate 21 is preferably a transparent substrate such as a transparent plastic. If a positive type is used for the photosensitive material 22, the inclined processed portion 23 becomes an inclined perforation due to the exposure and development processes, and light is selectively transmitted from the residual resin in the surrounding unexposed portions, but the residual resin is shielded from light. If so, the selectivity of the inclined processing portion 23 as a light path is further increased.

  As described above, a parallax crosstalk filter can be formed using the photomask of the present invention. In addition, as described above, by providing the spacer 15 having a uniform height in a predetermined region in the photomask of the present invention, when performing close contact exposure using the photomask 1 of the present invention, the optical path of a micro lens or the like is inclined. It is convenient that the mechanical part 14 is not brought into contact with the surface to be exposed, and a stable exposure gap can be maintained. In addition, by forming the spacer in a possible region including a light shielding material, the refracted light 31 by the optical path tilting mechanism unit 14 is not affected by the incident light from the outer region without affecting the outer region. Without being able to act more completely. However, when non-contact type proximity exposure such as proximity exposure is performed with high-precision gap control and the influence of light entering and exiting the external region can be ignored, it is easy to omit the formation of the spacer in the present invention. Can be considered.

  The above description is an example of the parallax crosstalk filter 2, and a filter that allows light to pass only in a selective direction by forming an inclined perforated shape. However, the photosensitive content and optical characteristics of the photosensitive material 22 are described. The parallax crosstalk filter in other forms is also possible by changing the relationship between the inclined processed portion 23 and the surrounding material by changing the above-mentioned variously. For example, a parallax crosstalk filter in another form can be realized by using a photosensitive material that changes the exposed tilted processed portion 23 so as to improve the transparency with respect to a certain wavelength from the surrounding unexposed portion. . That is, the present invention is not necessarily limited to creating a geometric perforation shape, and the photomask of the present invention can produce an inclined and inclined processed portion 23 having different optical characteristics from the surroundings.

  Furthermore, the photomask of the present invention is not limited to the purpose of geometrically processing the path of the light beam, but is widely useful in the manufacture of a processed part inclined filter having a heterogeneous part inclined with respect to the surface. It is clear that

  FIG. 4 is a conceptual diagram viewed from the overhead of an observer to show an example of stereoscopic viewing using the parallax crosstalk filter according to the present invention. In order to stereoscopically view the image 5 in which the right-eye pixels 5R and the left-eye pixels 5L are alternately and alternately arranged, the parallax crosstalk filter 2 having the inclined processing portion 23 serving as a light path on the substrate 21, They are arranged in parallel at a predetermined position between the image 5 and the arrangement of the right eye 4R and the left eye 4L of the observer. For the sake of simplicity, an example in which two sets of pixels are observed through two sets of inclined processing portions will be described. However, the same applies to the case where a large number of sets of pixels are observed through multiple sets of inclined processing portions.

  A large number of right-eye pixels 5R are projected on the observer's right eye 4R by image light 6R from the right-eye pixels indicated by dashed arrows, and a large number of left-eye pixels 5L are images from the left-eye pixels indicated by solid arrows. Stereoscopic viewing is possible by projecting on the left eye 4L of the observer with the light 6L. The parallax crosstalk filter 2 can selectively determine the path of each image light by appropriately arranging the inclined processing portions 23.

  The parallax crosstalk filter 2 is manufactured by changing the tilt angle of the tilted processing portion 23 in multiple steps, thereby enabling more natural and smooth stereoscopic viewing. FIG. 5 is a conceptual diagram showing another example called an integral imaging method for stereoscopic viewing using a parallax crosstalk filter according to the present invention. In the integral imaging method, a plurality of images having different positions and angles are simultaneously displayed according to the observation position. Therefore, the viewer can capture different images with the left and right eyes, and can recognize the images as stereoscopic images without using dedicated stereoscopic display glasses.

  The parallax crosstalk filter 2 shown in FIG. 5 has the same structure as the parallax crosstalk filter 2 shown in FIGS. 3 and 4 and is omitted in FIG. It is made by changing the stage. It is assumed that the observation position changes according to the block arrow from the position of the left and right eyes 41L and 41R shown in the upper right of the figure to the position of the left and right eyes 47L and 47R shown in the upper left of the figure. The images that can be observed at both ends and at each observation position are composed of an aggregate of right-eye pixels 51R to 57R and an aggregate of left-eye pixels 51L to 57L arranged and divided in consideration of each observation position. From the original image 5, selectively appropriate pixels can be seen corresponding to the left and right eyes at each position.

The internal design of the image 5 and the parallax crosstalk filter 2 and the positional relationship between them must be individually designed according to the actual observation position. An inclined processing portion 23 (not shown) inside the parallax crosstalk filter 2 can be formed by the photomask of the present invention. The image light that selectively passes through the parallax crosstalk filter 2 corresponds to each pixel, and the image light 61R to 67R from the right-eye pixel represented by the broken-line arrow and the left-eye image represented by the solid-line arrow. The image lights 61L to 67L from the pixels are obtained.

  The photomask of the present invention can be used not only for the production of the above-described parallax crosstalk filter 2 but also as an exposure mask in a photolithography method for providing various controlled tilted light.

DESCRIPTION OF SYMBOLS 1, 1 '... Photomask 2 ... Parallax crosstalk filter 3 ... Straight irradiation light 4R ... Observer (right eye)
4L ... observer (left eye)
5 ... Image 5R ... Right eye pixel 5L ... Left eye pixel 6R ... Image light 6L from right eye pixel ... Image light 11 from left eye pixel ... Transparent Substrate 12 ... light shielding film pattern 13 ... openings 14, 16 ... optical path tilting mechanism (microlens)
DESCRIPTION OF SYMBOLS 15 ... Spacer 21 ... Transparent substrate 22 ... Photosensitive material 23 ... Inclined process part 31 ... Refraction light 41R-47R ... Observer (right eye) of a different position
41L to 47L ... observers at different positions (left eye)
51R to 57R ... right eye pixels 51L to 57L corresponding to different observation positions 51L to left eye pixels 61 corresponding to different observation positions ... parallax barrier 62 ... lenticular lenses 61R to 67R ..Image light 61L to 67L from right eye pixels corresponding to different observation positions Image light from left eye pixels corresponding to different observation positions

Claims (4)

A photomask for selectively pattern exposure to a photosensitive material on a substrate,
The photomask includes: a light-shielding film pattern surrounding an opening on a transparent substrate; an optical path tilting mechanism that refracts light irradiated through the opening in an oblique direction; and a spacer that maintains an interval between the exposure target substrate. Do Ri,
A photomask characterized by controlling a refraction direction of light irradiated through the opening by changing a relative position between a plane position where the optical path tilting mechanism is provided and a center position of the opening . The photomask of claim 1, wherein said optical path inclined mechanism is formed by the lens or prism. The photomask according to claim 1 or 2, wherein the spacers are formed comprising a light-blocking material. Using the photomask according to any one of claims 1 to 3 , a photosensitive material on the substrate is selectively subjected to pattern exposure and then developed to provide a processing portion inclined with respect to the surface of the photosensitive material. A method of manufacturing a parallax crosstalk filter characterized by the above.

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