JP3932690B2 - Lens array substrate manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is a lens array substrate.Manufacturing methodAbout. In particular, a microlens array substrate that has a multilayer structure of a collection of minute microlenses.Manufacturing methodAbout.
[0002]
[Prior art]
As a method of performing color display using a liquid crystal display element, there is a projection type color image display system, and there are a three-plate type using three liquid crystal display elements according to three primary colors and a single-plate type using only one sheet. . However, the three-plate projection type color image display system requires a color separation system and a color synthesis system, which complicates the optical system and increases the number of parts, resulting in high costs and difficulty in miniaturization. It is. In addition, the single-plate projection type color image display method is less expensive than the three-plate type and is suitable for downsizing, but the light absorption and reflection by the color filter causes about 1 / th of incident light. Only 3 can be used, and there is a problem that the display efficiency becomes low and the display screen becomes dark.
[0003]
(First conventional example)
In order to solve such a problem, a single-plate projection type color liquid crystal display device 1 having a structure as shown in FIG. 1 has been proposed. In this apparatus, the white light W emitted from the white light source 2 or the white light W reflected by the spherical mirror 3 is converted into parallel light by the condenser lens 4, and the white parallel light is converted into dichroic mirrors 5R, 5G, 5B. Is incident on. The three dichroic mirrors 5R, 5G, and 5B reflect light in the red, green, and blue wavelength ranges, respectively. As shown in FIG. 2, the dichroic mirror 5R, 5G and 5B are respectively arranged in a fan shape with a shift of an angle θ.
[0004]
Accordingly, the white light W incident on the three dichroic mirrors 5R, 5G, and 5B passes through (1) the red light beam reflected by the dichroic mirror 5R, and (2) the dichroic mirror 5R, and is reflected by the dichroic mirror 5G. The green light beam obtained by passing through the dichroic mirror 5R again, and the blue light beam obtained by passing through the dichroic mirror 5B after passing through the dichroic mirror 5B after passing through the dichroic mirrors 5R and 5G. Are divided into three luminous fluxes. At this time, the green luminous flux is emitted with the traveling direction inclined by an angle of 2θ with respect to the red luminous flux, and the blue luminous flux is emitted with the traveling direction inclined by an angle of 2θ with respect to the green luminous flux.
[0005]
The red, blue, and green light beams divided by the dichroic mirrors 5R, 5G, and 5B are incident on the microlens array 7 disposed on the light source side of the liquid crystal display element 6 at different angles. Here, the liquid crystal display element 6 is arranged so that the green light beam is perpendicularly incident on the liquid crystal display element surface. Each light beam that has passed through the microlens array 7 is distributed and irradiated to each pixel opening driven by a signal electrode to which a corresponding color signal is independently applied according to the incident angle of each light beam. Since this apparatus does not use an absorption type color filter, the light use efficiency is improved and an extremely bright image can be provided.
[0006]
However, in the color liquid crystal display device 1 using the dichroic mirrors 5R, 5G, and 5B as the spectroscopic means, there is a problem that the image quality is deteriorated due to the following reasons.
[0007]
That is, in the projection type color liquid crystal display device 1, as shown in FIG. 3, a single-layer microlens array 7 comprising a set of microlenses corresponding to each picture element on the light incident side of the liquid crystal display element 6. Is provided. The microlens array 7 is formed at the interface between the glass substrate 8 and the high refractive index resin 9 by filling the recesses etched in the glass substrate 8 with the high refractive index resin 9. The microlens array substrate 10 in which the microlens array 7 is formed on the glass substrate 8 is bonded to the light source side of the liquid crystal display element 6. Each light beam converged on each pixel opening driven by the signal electrodes 11R, 11G, and 11B of the liquid crystal display element 6 by the microlens array 7 passes through the liquid crystal display element 6 and then diffuses in a large angle range. I will do it. For this reason, as shown in FIG. 1, the principal rays of the light beams of the respective colors transmitted through the liquid crystal display element 6 are refracted by the field lens 12, converged by the projection lens 13, and projected onto the screen 14.
[0008]
However, in this conventional example, unless a projection lens having a larger aperture than the projection lens used in the color liquid crystal display device using the color filter is used, the light use efficiency is lowered, and the image quality is lowered. There was a problem of high cost.
[0009]
(Second conventional example)
Therefore, a projection type color liquid crystal display device has been proposed for improving the light utilization efficiency of the projection type color liquid crystal display device and preventing the decrease in color purity and improving the image quality (Japanese Patent Laid-Open No. 7-181487). JP-A-9-90336). The overall configuration of this projection type color liquid crystal display device is almost the same as that of the first conventional example shown in FIG. 1, but the microlens arrays 13 and 14 provided in the liquid crystal display element 6 are two layers. There is a feature. That is, in the liquid crystal display element 6 used in the projection type color liquid crystal display device, as shown in FIG. 4, flat-type microlens array substrates 16 and 17 are bonded to both surfaces of a glass substrate 15 used on the light source side. Then, a cover glass (spacer) 18 for adjusting the focal length is provided on the surface of the microlens array substrate 17 on the inner surface side, and the cover glass 18 integrated with the glass substrate 15 and the microlens substrates 16 and 17 and the light emission side are provided. The liquid crystal layer 21 is sealed between the glass substrates 20. Here, each microlens array substrate 16, 17 has a lens pattern recessed in the lens substrate 22, and a high refractive index resin 24 is filled in the recess 23 of this lens pattern to flatten the surface of the lens substrate 22, Microlens arrays 13 and 14 are formed at the interface between the lens substrate 22 and the high refractive index resin 24.
[0010]
Therefore, as shown in FIG. 5, the microlens array 13 disposed on the light source side of the liquid crystal display element 6 converges the light beams of the respective colors in the pixel opening portions corresponding to the respective colors in the liquid crystal display element 6. Since the light beams of the respective colors are irradiated to the liquid crystal display element 6 from different angles, after converging by the microlens array 13, the light beams try to spread according to the direction of the principal ray of each light beam. . The microlens array 14 emits the principal rays of the light beams of these colors from the liquid crystal display element 6 so as to be substantially parallel to each other.
[0011]
The microlens array 14 on the side opposite to the light source functions in the same way as a field lens. In this way, the principal rays of the light beams of the respective colors can be made substantially parallel to each other. Even when a small-diameter projection lens is used, the entire luminous flux can be effectively used with almost no cut. Therefore, it is possible to improve the light utilization efficiency and obtain a brighter color image with good white balance. In addition, since it is not necessary to use a large-diameter projection lens or the like, the manufacturing cost can be reduced.
[0012]
Next, a method for manufacturing the glass substrate 15 having such two-layer microlenses 13 and 14 will be described with reference to FIG. First, a lens substrate 22 having a predetermined thickness as shown in FIG. 6A is prepared. As shown in FIG. 6B, a mask 26 having openings 25 at the same pitch as the lens pattern is provided on the surface of the lens substrate 22. To form. Next, as shown in FIG. 6C, an isotropic etching process is performed on the fired surface of the lens substrate 22 through the opening 25 of the mask 26, whereby a recess 23 (lens pattern) is formed on the surface of the lens substrate 22. Form. The fire-making surface refers to an unpolished surface after the molten glass is slowly cooled and laminated when the glass substrate 15 is produced by a fusion method or the like. The concave portion 23 is filled with a high refractive index resin 24 as shown in FIG. 6D, and the surface is leveled to form a lens portion, and the microlens array substrates 16 and 17 are manufactured. Thereafter, as shown in FIG. 6E, the surface of the lens substrate 22 opposite to the lens forming surface is polished, and the thickness is adjusted so that the focal lengths and the like of the microlens arrays 13 and 14 match the set values.
[0013]
As shown in FIG. 7, the microlens array substrates 16 and 17 manufactured as described above are bonded to both surfaces of the glass substrate 15 while aligning the optical axes with each other. A cover glass 18 is bonded to the surface.
[0014]
[Problems to be solved by the invention]
However, the conventional microlens array substrate having the two-layer microlens arrays 13 and 14 is manufactured by bonding the two microlens array substrates 16 and 17 to the glass substrate 15 as described above. For the reasons described above, there are problems that optical axis alignment is difficult, optical characteristics are poor, manufacturing is difficult, the number of processes is large, and cost is high.
[0015]
▲ 1 ▼ Difficult to position micro lens arrays
First, since the separately produced flat-type microlens arrays 13 and 14 are bonded together via a glass substrate, it is difficult to position (optical axis alignment) the two microlens arrays 13 and 14 by bonding. In fact, mass production was impossible. That is, the vertical direction, the horizontal direction, and the angle (rotation direction) of the two microlens arrays 13 and 14 must all coincide with each other. However, since the lens pattern is fine, this is very difficult and the positioning device has high accuracy. Or a laminating machine is required.
[0016]
In addition, the biggest reason for making it difficult to attach the microlens arrays 13 and 14 is that there is a gap between the lens patterns to be positioned. That is, if there is a gap between the lens patterns, optical distortion occurs due to the difference in refractive index of each layer, and the size of the alignment mark for positioning appears to be different, and the two microlens arrays 13 and 14 are provided. It becomes difficult to align the alignment marks.
[0017]
Furthermore, importantly, due to optical distortion caused by the gap, if the alignment mark is not viewed from a direction completely perpendicular to the lens pattern, the alignment mark seen by the camera becomes a virtual image, and the actual alignment mark Is at a position deviated from the optical axis of the camera, and even if it is aligned by the alignment mark, it is not actually aligned. This is the biggest factor that makes it difficult to position the microlens arrays 13 and 14. For example, if you put a coin in the bottom of an opaque cup and see it from an oblique direction, you may or may not see the coin depending on whether you put water in the cup or not. This is due to the difference in refractive index between air and water. In the fine alignment, positioning is impossible due to the slight change in the mark size and the displacement between the real image and the virtual image.
[0018]
Further, although a normal camera (CCD camera or the like) is used for positioning, it is difficult to focus on the alignment mark in the microlens arrays 13 and 14. In other words, the alignment mark is generally drawn relatively large, but since the margins of the microlens arrays 13 and 14 are limited, it is usually necessary to align the position with a small alignment mark. There are many cases. When viewing fine marks with a camera, the depth of focus becomes shallow, so the focus range is narrowed. For this reason, if the microlens arrays 13 and 14 are tilted to some extent, the focus cannot be easily achieved. For these reasons, it is very difficult to position the microlens arrays 13 and 14.
[0019]
▲ 2 ▼ Mixing of foreign matter and air bubbles during pasting
Since it is difficult to integrate the microlens arrays 13 and 14 with a uniform gap (space) between them, the microlens arrays 13 and 14 are bonded to both surfaces of the glass substrate 15 without any gaps. . Therefore, even if the two microlens arrays 13 and 14 are accurately aligned, if even one foreign object is caught between the microlens arrays 13 and 14 and the glass substrate 15, the microlens arrays 13 and 14 Is bent or tilted, the optical axes of the microlens arrays 13 and 14 are shifted.
[0020]
Further, when a partial gap (for example, air bubbles due to mixing of air or the like) is generated between the microlens arrays 13 and 14 and the glass substrate 15, it is stuck on both surfaces of the glass substrate as in the case of mixing of fine foreign matters. The optical axes of the microlens arrays 13 and 14 are shifted.
[0021]
Furthermore, if a foreign object or bubble is bitten, an unintended refractive index difference is created there, resulting in a shift of the optical axis of the light beam passing therethrough.
[0022]
▲ 3 ▼ Yield reduction
In the conventional manufacturing method of the microlens arrays 13 and 14, the yield of the microlens array substrate manufacturing is deteriorated due to the reasons (1) and (2) above, and those that can be used as mass-produced products are almost zero. The practical application was difficult. In addition, such poor yields have increased product unit prices.
▲ 4 ▼ Many manufacturing steps
Even if the yield of manufacturing the microlens array substrate is improved, in the conventional manufacturing method, the separately manufactured microlens arrays 13 and 14 are polished and bonded to both surfaces of the glass substrate. As this increases, the polishing operation takes time. Furthermore, since it takes a lot of time to position a fine lens pattern, the production efficiency is low and the mass productivity is low.
[0023]
The above-described problem can be applied to a microlens array substrate having a structure in which microlens arrays are directly joined without using a glass substrate.
[0024]
The present invention has been made to solve the above-mentioned technical problems, and it is an object of the present invention to simplify the optical axis alignment between microlens arrays and to simplify the manufacturing process when manufacturing a microlens array substrate. To do.
[0027]
DISCLOSURE OF THE INVENTION
  A method of manufacturing a lens array substrate according to the present invention is a method of manufacturing a lens array substrate having a lens array having a plurality of layers.A step of curing the resin material in a state where the first stamper is pressed against the uncured resin material and molding the first light-transmitting resin layer; and the light-transmitting resin layer on the first light-transmitting resin layer. An uncured resin material having a refractive index different from that of the light-sensitive resin layer is supplied, and the second light-transmitting resin layer is formed by curing the resin material with the second stamper pressed against the light-transmitting resin layer. Forming and forming a lens array on the boundary surface between the first and second translucent resin layers, and an uncured material having a refractive index different from that of the translucent resin layer on the second translucent resin layer Supplying and curing the resin material, forming a third translucent resin layer, and forming another lens array on the boundary surface between the second and third translucent resin layers;HasThe Furthermore, it is possible to form a lens array having three or more layers by repeating this process.
[0028]
The refractive index of the transparent resin layer is different from each other. For example, when three refractive resin layers are considered and the refractive indexes are n1, n2, and n3 in this order, n1 <n2 <n3 increases in order. Alternatively, the sizes may be alternately combined such as n1 <n2> n3. When a lens array is manufactured by pouring a resin with a high refractive index into the concave portion of the glass substrate as in the prior art, there is no freedom in design, but a multi-layer lens array is manufactured by molding as in the present invention. In this case, the combination of refractive indexes can be freely changed, and the degree of freedom in designing the lens array substrate is increased.
[0029]
In the lens array substrate and the method for manufacturing the same according to the present invention, the lens array is automatically aligned when each translucent resin layer is molded. Therefore, positioning at the time of bonding the microlens array as in the prior art becomes unnecessary, and high-precision lens positioning is possible. As a result, a lens array substrate having good accuracy and optical characteristics can be mass-produced.
[0030]
In addition, since a multi-layer microlens array can be formed by molding, it is difficult for foreign matter to enter between the light-transmitting resin layers or the like, as in the case of bonding, and bubbles are difficult to enter. The yield of the lens array substrate is improved. In addition, when sticking together hard substrates as in the bonding method, foreign matter and air bubbles will be mixed, resulting in a failure of the entire microlens array substrate. Even if enters, it remains a partial failure.
[0031]
Furthermore, according to the manufacturing method of the present invention, since high-precision processing and positioning are not required, the number of manufacturing steps is reduced, the manufacturing equipment is simplified, and the cost can be reduced.
[0032]
  In particular,Embodiment of manufacturing method of lens array substrate according to the present inventionIf the first stamper and the second stamper (more preferably all the stampers) are the same stamper, the three-dimensional shapes of the lens arrays are all the same as described in claim 3. Since the stamper does not need to be replaced at the time of molding, the alignment operation between the lens arrays can be performed with higher accuracy. In this case, the focal length of each lens array is adjusted by the refractive index ratio of each translucent resin layer.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 8 is a cross-sectional view showing the overall structure of a projection type color liquid crystal display device 31 according to an embodiment of the present invention. FIG. 9 shows a liquid crystal display element 32 and a microlens array 33 used in the color liquid crystal display device 31. FIG. In the projection type color liquid crystal display device 31, a spherical mirror 36 is provided behind the white light source 35, and the center of the spherical mirror 36 is arranged so as to coincide with the center of the light emitting unit in the white light source 35. A condenser lens 37 is provided in front of the white light source 35, and the condenser lens 37 is arranged so that its focal point coincides with the center of the light emitting part of the white light source 35. Thus, the white light beam W emitted from the white light source 35 or the white light beam W emitted from the white light source 35 and reflected by the spherical mirror 36 passes through the condenser lens 37 and becomes a substantially parallel white light beam W.
[0038]
Here, the parallelism θa of the white light beam W after passing through the condenser lens 37 in the arc length direction (direction perpendicular to the paper surface in FIG. 8) and the arc diameter direction (direction parallel to the paper surface in FIG. 8). The degree θb is obtained from the following equation.
θa = arctan (L / fc) (1)
θb = arctan (Φ / fc) (2)
Here, L and Φ are the arc length and arc diameter of the white light source 35, and fc is the focal length of the condenser lens 37.
[0039]
The means for obtaining the parallel light beam from the white light source is not limited to the above configuration, and for example, a method using a rotating parabolic mirror, a method using a spheroid mirror and an integrator, and the like are appropriately selected.
[0040]
Three types of dichroic mirrors 38R, 38G, and 38B are disposed at different angles in front of the condenser lens 37, respectively. The dichroic mirrors 38R, 38G, and 38B selectively reflect light in each wavelength band corresponding to red, green, and blue, respectively, and have the other characteristics of transmitting, and are arranged on the optical axis in this order. Yes. Hereinafter, the symbols R, G, and B represent red, green, and blue colors, respectively.
[0041]
The blue, green, and red wavelength ranges are 400 to 495 nm, about 495 to 575 nm, and about 570 to 700 nm, respectively. However, if all the light in each wavelength region is used, the screen illuminance increases, but the color purity of each primary color decreases. Therefore, when the color purity is important, the light near 495 nm and 575 nm is cut off. In some cases.
[0042]
The dichroic mirrors 38R, 38G, and 38B are formed by a well-known multilayer thin film coating technique. The conditions of the multilayer thin film are set so that the red dichroic mirror 38R reflects visible light having a wavelength longer than about 600 nm, and the blue dichroic mirror 38B is made of a multilayer reflective film so as to reflect visible light having a wavelength shorter than about 500 nm. The conditions of the multilayer thin film are set so that the green dichroic mirror 38G reflects visible light in the range of about 570 nm to 500 nm. Further, if any of the dichroic mirrors 38R, 38G, and 38B is designed to transmit infrared rays, the infrared rays do not reach the liquid crystal display element 32, which is effective in reducing the temperature rise of the liquid crystal display element 32. .
[0043]
Of the three dichroic mirrors 38R, 38G, and 38B, the dichroic mirror 38R provided closest to the white light source 35 is arranged so that the light beam from the white light source 35 is incident at about 30 °, for example. Yes. The other dichroic mirrors 38G and 38B are sequentially inclined from the state parallel to the dichroic mirror 38R by an angle θ with the axis in the direction perpendicular to the paper surface in the figure as the rotation axis. The relative angle θ can be obtained from a pixel arrangement pitch P of the liquid crystal display element 32 described later and a focal length fμ of the microlens arrays 33 and 34 provided in the liquid crystal display element 32.
[0044]
Thus, the parallel white light beam W transmitted through the condenser lens 37 enters the dichroic mirrors 38R, 38G, and 38B, and is decomposed into a red light beam, a green light beam, and a blue light beam, and is provided in the liquid crystal display element 32. The light enters the microlens arrays 33 and 34. When the dichroic mirrors 38R, 38G, and 38B are tilted by θ as described above, the respective light fluxes in the red wavelength region, the green wavelength region, and the blue wavelength region are angled 2θ with respect to the microlens arrays 33 and 34, respectively. Incidently shifted.
[0045]
In this embodiment, as shown in FIG. 8, a green light beam is perpendicularly incident on the microlens arrays 33 and 34, and each of the red and blue light beams is in a direction parallel to the paper surface in the figure with the green light beam as the center. The angle is set so as to be symmetrical. The order of red, blue, and green is determined in consideration of the spectral distribution of the white light source 35 and the characteristics of the dichroic mirrors 38R, 38G, and 38B, and is not necessarily limited to the order shown in FIG.
[0046]
The liquid crystal display element 32 includes a glass substrate 39 and a microlens array substrate 40, and a liquid crystal layer 41 is sealed between the glass substrate 39 and the microlens array substrate 40 as shown in FIG. Striped signal electrodes 42R, 42G, and 42B for changing the phase of the liquid crystal layer 41 are formed on the inner surface of the glass substrate 39 located on the light emitting side. A scanning electrode 43 orthogonal to the signal electrodes 42R, 42G, and 42B is provided on the inner surface of the microlens array substrate 40 located on the light incident side. The signal electrodes 42R, 42G, 42B and the scanning electrode 43 are formed of a transparent electrode (ITO film).
[0047]
The microlens array substrate 40 is provided with two layers of microlens arrays 33 and 34. This microlens array substrate 40 is obtained by sandwiching three transparent lens resin layers 46, 47, 48 having different refractive indexes between two base glasses (glass substrates) 44, 45. The interface between the different lens resin layers 46, 47, 48 is formed into a lens pattern shape, and the first micro lens array 33 is formed by the interface between the lens resin layers 46, 47 having different refractive indexes, and is refracted from each other. The second microlens array 34 is formed by the interface between the lens resin layers 47 and 48 having different rates. Here, the lens pattern of the microlens arrays 33 and 34 may be a spherical lens shape, a honeycomb shape (hexagonal lens shape), or a semi-cylindrical lens shape (lenticular lens).
[0048]
The optical axes of the lenses constituting the microlens array 33 located on the light source side and the optical axes of the lenses constituting the microlens 34 located on the opposite side of the light source are parallel to each other. The optical axes of the opposing lenses coincide with each other.
[0049]
In the liquid crystal display element 32, since the white light beam W is dispersed by the dichroic mirrors 38R, 38G, and 38B, a color filter is not necessary, and the light use efficiency is increased. A video signal corresponding to each color is applied to the signal electrodes 42R, 42G, and 42B. In FIG. 9, a polarizing plate, an alignment film, and the like, which are components of the liquid crystal display element 32, are omitted for simplification.
[0050]
Thus, as shown in FIG. 10, when the microlens array 33 is irradiated with a parallel light beam from a predetermined direction, the microlens array 33 transmits the light beam of each color at the interval corresponding to the pitch of the lens pattern to the second microlens array. The light is collected in the form of dots in the vicinity of 34 on the emission side. The condensing spot width W is expressed by the following equation (3) with respect to the parallelism θb of the white light source 35 when the focal length of the first microlens array 33 is fμ.
W = fμ x tan (θb) (3)
Substituting the above equation (2) into this equation (3),
W = (fμ × Φ) / fc (4)
It becomes. Since the thickness of the scanning electrode 43 and the liquid crystal layer 41 is very small compared to the focal length fμ of the first microlens array 33, the thickness of this portion can be ignored, and the condensing spot width W remains as it is as the signal electrode 42R. , 42G, 42B may be considered to be the width We of each light beam.
[0051]
The relative angles of the dichroic mirrors 38R, 38G, and 38B are as follows: P is the pixel arrangement pitch, fμ is the focal length of the microlens array 33, and 2θ is the difference between the incident angles of the light beams.
P = fμ x tan (2θ) (5)
If the above relationship is satisfied, the first condensing line (the condensing line by the light reflected by the dichroic mirror 38R disposed at the position closest to the white light source 35 among the three dichroic mirrors 38R, 38G, and 38B). On the other hand, the other condensing lines are sequentially formed at positions shifted by the pitch. As a result, the condensing lines of the corresponding colors are accommodated in the three adjacent signal electrodes 42R, 42G, and 42B corresponding to one microlens constituting the microlens array 33.
[0052]
The focal length of the microlens array 34 is also set to the same focal length fμ as that of the microlens array 33 on the light source side.
[0053]
As shown in FIG. 8, a field lens 49 and a projection lens 50 as projection means are provided in front of the light emitting direction in the liquid crystal display element 32. Further, a screen is provided in front of the projection lens 50. 51 is provided. The focal length of the field lens 49 is set to the distance between the field lens 49 and the projection lens 50, and the light beams of the respective colors emitted from the liquid crystal display element 32 are positions where the projection lens 50 is provided by the field lens 49. And is projected onto the screen 51 by the projection lens 50. It is also possible to adopt a configuration in which light is directly incident on the projection lens 50 from the liquid crystal display element 32 without using the field lens 49.
[0054]
Thus, when white light is irradiated from the white light source 35 toward the dichroic mirrors 38R, 38G, and 38B, the dichroic mirrors 38R, 38G, and 38B reflect the light beams of different colors, respectively, so that the white light is separated into the three primary colors. The As shown in FIG. 10, the light beams of the respective colors are incident on the first microlens array 33 at different angles as described above according to the angles at which the dichroic mirrors 38R, 38G, and 38B are disposed.
[0055]
The light from the microlens array 33 is condensed on the signal electrodes 42R, 42G, and 42B corresponding to the respective colors through the microlens array 34. At this time, the signal electrodes 42R, 42G, and 42B are placed thereon. When driven by the video signal corresponding to the condensed color, the intensity of each color beam is modulated in accordance with the signal. The modulated light beam passes through the field lens 49 and the projection lens 50 and is then projected onto the screen 51, and color image display is performed on the screen 51.
[0056]
By the way, in the conventional projection type color liquid crystal display device (first conventional example), the optical axis (chief ray) of the two light beams of red and blue other than the normal incidence is an angle of 2θ even after exiting the liquid crystal display element 32. Therefore, in order to capture and project all of these, a projection lens with a large aperture was necessary. However, in the projection type color liquid crystal display device 31 of this embodiment, the second microlens array 34 is provided in order to reduce the spread of the emitted light. The focal length of the first microlens array 33 is the above (5) so that the focal point of the light beam emitted from the first microlens array 33 is located in the vicinity of the emission side of the second microlens array 34. It is set so as to satisfy the expression relationship.
[0057]
The second microlens array 34 arranged in this way performs the same function as the field lens 49, and parallelizes the optical axes of the light beams of the respective colors, so that the emission direction thereof is relative to the liquid crystal display element 32. It is possible to reduce the spread angle of the light emitted from the liquid crystal display element 32. Therefore, even when the small-diameter projection lens 50 is used, the total luminous flux can be used effectively. This makes it possible to obtain a color image with high light utilization efficiency and good white balance, and eliminates the need for an expensive large-diameter lens that has been a cause of cost increase. It becomes possible to avoid an increase in the cost of the entire liquid crystal display device 31.
[0058]
The method for adjusting the focal length of the microlens arrays 33 and 34 may be as follows. First, in the first method, the refractive indexes of the lens resin layers 46, 47, and 48 that constitute the microlens arrays 33 and 34 may be changed. For example, in FIG. 11A, the microlens array 33 is formed at the interface between the lens resin layers 46 and 47 having the refractive indexes of n1 and n2 (n1 <n2). As shown in FIG. If the lens resin layer 47 having the refractive index n2 is replaced with one having a larger refractive index n3 (> n2), the focal length of the microlens array 33 can be shortened. As a second method, the curvature of the microlens arrays 33 and 34 may be changed. For example, in FIG. 12A, the microlens array 33 having a radius of curvature r1 is formed at the interface between the lens resin layers 46 and 47 having refractive indexes n1 and n2 (n1 <n2). As described above, when the microlens array 33 has a smaller radius of curvature r2 (<r1), the focal length of the microlens array 33 can be shortened.
[0059]
(Manufacturing method of microlens array substrate)
Next, a method for manufacturing the microlens array substrate 40 will be described with reference to FIGS. 13 and 14A to 16I. This is a method of forming two-layer microlens arrays 33 and 34 between two base glasses 44 and 45 by a so-called 2P (Photo-Polymerization) method using an ultraviolet curable resin that is cured by ultraviolet irradiation. is there.
[0060]
First, as shown in FIG. 13, the base glass 44 is placed on the upper surface of the lower table 52 of the molding machine, and the lower table 52 is exhausted by the suction chuck 53 in the lower table 52 to exhaust the air on the lower surface of the base glass 44. Base glass 44 is adsorbed on the upper surface of 52. Similarly, the stamper 57 is overlapped on the lower surface of the upper table 54 of the molding machine, and the stamper 57 is adsorbed on the lower surface of the upper table 54 by exhausting air on the upper surface of the stamper 57 from the adsorption chuck 55 in the upper table 54. The upper table 54 is moved up and down precisely by a guide mechanism (not shown) so as not to be displaced.
[0061]
Next, as shown in FIG. 14A, a fluid transparent UV curable resin 56 is supplied onto the transparent base glass 44, and then the UV curable resin 56 is directed toward the base glass 44. The stamper 57 is lowered. A reverse pattern 58 that matches the lens pattern of the microlens arrays 33 and 34 is formed on the lower surface of the stamper 57. The stamper 57 is sufficiently pressed against the base glass 44 so that the ultraviolet curable resin 56 is sandwiched between the stamper 57 and the base glass 44, and the ultraviolet curable resin 56 is pushed between the stamper 57 and the base glass 44 to spread the stamper 57. After the UV curable resin 56 is embossed with the reverse pattern 58, the state is maintained as it is, and the UV curable resin 56 is irradiated with ultraviolet rays (UV light) through the base glass 44 by an ultraviolet lamp or the like [FIG. 14B]. ].
[0062]
The ultraviolet curable resin 56 that has been irradiated with ultraviolet rays undergoes a curing reaction and is cured when exposed to ultraviolet rays, so that the reverse pattern 58 of the stamper 57 is transferred and molded onto the ultraviolet curable resin 56. When the stamper 57 is raised and separated from the ultraviolet curable resin 56, the lens resin layer 46 is formed on the base glass 44 by the cured ultraviolet curable resin 56 and the microlens array 33 is formed on the surface of the lens resin layer 46. This pattern is formed [FIG. 14 (c)].
[0063]
Next, a transparent ultraviolet curable resin 59 having a refractive index different from that of the lens resin layer 46 and having fluidity is supplied onto the cured lens resin layer 46, and then the lens resin layer 46 is formed on the ultraviolet curable resin 59. The stamper 57 is lowered again toward [Figure 15 (d)]. The stamper 57 is sufficiently pressed against the lens resin layer 46 so that the ultraviolet curable resin 59 is sandwiched between the stamper 57 and the lens resin layer 46, and the ultraviolet curable resin 59 is embossed by the reversal pattern 58 of the stamper 57. After the mold resin 59 is spread between the stamper 57 and the lens resin layer 46, the state is kept as it is, and ultraviolet rays (UV light) are applied to the ultraviolet curable resin 59 through the base glass 44 and the lens resin layer 46 by an ultraviolet lamp or the like. [FIG. 15 (e)].
[0064]
The ultraviolet curable resin 59 irradiated with ultraviolet rays undergoes a curing reaction and is cured when exposed to ultraviolet rays, so that the reverse pattern 58 of the stamper 57 is transferred and molded onto the ultraviolet curable resin 59. When the stamper 57 is raised and the stamper 57 is separated from the ultraviolet curable resin 59, the lens resin layer 47 is formed on the lens resin layer 46 by the cured ultraviolet curable resin 59. Then, the microlens array 33 is formed at the interface between the lens resin layer 46 and the lens resin layer 47, and the pattern of the microlens array 34 is formed on the surface of the lens resin layer 47 [FIG. 15 (f)].
[0065]
Further, a transparent UV curable resin 60 having a refractive index different from that of the lens resin layer 47 and having fluidity is supplied onto the cured lens resin layer 47, and then the base glass 45 is adsorbed on the lower surface of the upper table 54. Then, the base glass 45 is lowered straight from the ultraviolet curable resin 60 toward the lens resin layer 47 [FIG. 16 (g)]. The base glass 45 is sufficiently pressed against the lens resin layer 47 so that the ultraviolet curable resin 60 is sandwiched between the base glass 45 and the lens resin layer 47, and the surface of the ultraviolet curable resin 60 is leveled by the base glass 45. After the ultraviolet curable resin 60 is spread between the base glass 45 and the lens resin layer 47, the state is kept as it is, and the ultraviolet curable resin 60 is passed through the base glass 44 and the lens resin layers 46 and 47 by an ultraviolet lamp or the like. Irradiation with ultraviolet rays (UV light) [FIG. 16 (h)].
[0066]
The ultraviolet curable resin 60 irradiated with ultraviolet rays undergoes a curing reaction and cures when exposed to ultraviolet rays. As a result, the lens resin layer 48 is molded between the lens resin layer 47 and the base glass 45 by the ultraviolet curable resin 60 and the microlens array 34 is molded at the interface between the lens resin layer 47 and the lens resin layer 48.
[0067]
In this way, the microlens array substrate 40 having the structure as shown in FIG. Since the scanning electrode 43 and the like for driving the liquid crystal layer 41 are formed on the inner surface of the microlens array substrate 40 (the surface of the base glass 45), a high level of flatness is required here. Therefore, when the undulation of the base glass 45 is increased to the extent that the flatness required for the liquid crystal substrate is impaired by pressing the base glass 45 with the upper table 54 in the step of FIG. A polishing step for the glass 45 may be added. In the case of polishing, a base cover 45 that is thick enough to be polished in advance is used.
[0068]
Further, in this manufacturing process, positioning of the stamper 57 and the base glass 45 attracted to the lower surface of the upper table 54 and the base glass 44 attracted to the upper surface of the lower table 52 may be performed with a certain degree of accuracy. Until the stamper 57 adsorbed on the lower surface of the upper table 54 is replaced with the base glass 45, the relative positions of the stamper 57 and the base glass 44 do not change, and the pattern of the microlens array 33 and the pattern of the microlens array 34 are the same. Therefore, even if the positioning of the stamper 57 and the base glasses 44 and 45 has a certain degree of accuracy, the microlens array 33 and the microlens array 34 are exactly coincident with each other.
[0069]
The reason for positioning the stamper 57 and the base glass 44 to a certain degree of accuracy is that when the microlens array substrate 40 is manufactured, the substrate is not manufactured one by one, and in many cases, the microlens array is formed as described above. After the substrate 40 is manufactured roughly, the outer shape of the microlens array substrate 40 is cut based on the markers previously formed in the stamper 57, and further, the microlens array substrate 40 is cut into a predetermined number as necessary. It is because it uses it. However, in this case, the focal length of the microlens arrays 33 and 34 is adjusted by the refractive index of each lens resin layer.
[0070]
When adjusting the focal length of the microlens arrays 33 and 34 according to the curvature radius of each lens pattern, it is necessary to use two types of stampers. In this case, positioning means is provided on the upper table 54. Only the stamper needs to be positioned precisely. The resin material for molding the lens resin layers 46, 47, 48 may be a photo-curing resin other than the ultraviolet curable resin, an electron beam curable resin, a thermosetting resin, or the like. However, the UV curable type is currently superior in terms of ease of handling and productivity.
[0071]
(Stamper manufacturing method)
Next, a method for manufacturing the stamper 57 is shown in FIG. First, a flat glass plate 61 as shown in FIG. 17A is prepared. As shown in FIG. 18, the surface of the glass plate 61 is irradiated with laser light condensed by an imaging lens 62, and laser The glass plate 61 is evaporated and removed to a depth indicated by a two-dot chain line by processing (laser lithography), and the surface of the glass plate 61 has a desired uneven pattern 63 (that is, the same shape as the lens pattern of the microlens arrays 33 and 34). And stored in advance in a computer that controls the laser processing apparatus [FIG. 17B]. After a desired lens pattern 63 is formed on the surface of the glass plate 61 to produce a master 64 made of the glass plate 61, nickel is deposited on the master 64, and a nickel master that is an inverted version of the master by nickel electroforming. 65 is manufactured [FIG. 17C], and the nickel master 65 is peeled from the master 64 [FIG. 17D]. When preparing the nickel master 65 by the nickel electroforming method, the master 64 is made conductive by, for example, vapor deposition or electroless plating as a preparation, and the surface of the conductive master 64 is used as a cathode, for example, sulfamic acid. A nickel master 65 is produced by electroplating in a nickel bath.
[0072]
A stamper 57 is obtained by further replicating the nickel master 65 by a nickel electroforming method. When replicating the nickel master 65, an oxide film is formed on the surface of the nickel master 65 with, for example, a potassium dichromate solution, and then a stamper 57 (replica of the master disk) with the projections and recesses inverted again by nickel electroforming. [FIG. 17 (e)].
[0073]
Further, in order to produce the stamper 57, as shown in FIGS. 19A to 19E, the master 64 may be produced by laser processing the resist 68 applied to the surface of the glass plate 61. When the resist 68 is used, as an adhesive between the glass plate 61 and the resist 68, for example, a silane coupling agent is applied to the surface of the glass plate 61, and after laser processing, exposure, development, and washing steps are performed. As a result, a concavo-convex pattern 63 of the resist 68 is formed on the surface of the glass plate 61 [FIGS. 19A and 19B]. The subsequent processing is performed in the same manner as in FIG. 17C and thereafter [FIGS. 19C to 19E].
[0074]
In the present embodiment, since the microlens array substrate 40 is manufactured as described above, the following effects (1) to (4) can be obtained.
(1) Positioning is not required and highly accurate lens positioning is possible.
As can be seen from the above-described embodiment, the base glass serving as a substrate on which the stamper for molding the microlens array and the lens resin layer are laminated is adsorbed to the upper table and the lower table of the molding machine and does not move. That is, even if a plurality of microlens arrays are stacked, the positions of the microlens arrays in the plurality of layers do not shift. Therefore, even without special positioning, it is possible to position the lens with high precision that is not compared with a microlens array substrate manufactured by a conventional bonding method.
[0075]
(2) Mass production, which was virtually impossible by pasting, becomes possible.
As described above, since high-precision lens positioning can be performed without performing high-precision positioning, mass production of microlens arrays becomes possible.
(3) The occurrence rate of defective products is reduced and the yield is improved.
In the conventional microlens array substrate by the bonding method, if foreign matter or air bubbles are inserted, the characteristics as a microlens array cannot be satisfied, and the microlens array substrate itself becomes a defective product. On the other hand, in the microlens array substrate of the present invention, if it is a size that can be accommodated between the base glasses (strictly, the size between the base glass and the stamper), foreign substances and bubbles are mixed in between the lens resin layers. Even if the lens itself becomes a defective part, the entire microlens array substrate does not become a defective product. This is because a lens resin layer (such as an ultraviolet curable resin) pressed by a stamper has good fluidity before curing, and it is assumed that foreign matter or air bubbles are sandwiched between the lens resin layer or between the lens resin layer and the base glass. This is because only foreign matters and bubbles are mixed in the portion and the other portions are not affected (that is, the entire microlens substrate is not warped, tilted, or swollen).
[0076]
Of course, there is a limit to the size of foreign matter and bubbles allowed. Since the microlens array substrate is an optical component, what is recognized as a defect when it becomes a final product such as a projection color liquid crystal display device is also a defective product as a microlens array substrate. This depends on individual product specifications, but at least as small as a few microns of foreign matter and bubbles are not allowed, as in the conventional manufacturing method.
[0077]
▲ 4 ▼ Production man-hours are small
According to the method for manufacturing a microlens array substrate according to the present invention, high accuracy is not required for lens positioning, and therefore, there is no process with a great number of steps in the manufacturing process. Further, even when compared with a method of manufacturing a single-layer microlens array substrate using a stamper, it is only necessary to repeat the process of pressing and curing the resin with the stamper, and the manufacturing man-hours are almost the same. In addition, if the manufacturing equipment for the microlens array substrate is an apparatus that can manufacture a single-layer microlens array substrate, it is only necessary to supply resins having different refractive indexes. A lens array can be made. Therefore, there is no need for a bonding apparatus as in the conventional method, and the equipment cost is reduced.
[0078]
(5) There are few coupling surfaces on the microlens array substrate, and the design burden is reduced.
The most important points in the multi-layer structure design in the microlens array substrate are the refractive index ratio between the lens resin layers and the lens curvature of each microlens array. In this structural design, the more the coupling surfaces (boundary surfaces of materials having different refractive indexes), the more complicated the design and simulation. Specifically, in the conventional microlens array substrate having the structure shown in FIG. 4, a high refractive index resin, a glass substrate, and a lens substrate (glass) are provided between the first and second microlens arrays (patterns). In contrast, the microlens array substrate of this embodiment has a simple structure with only one lens resin layer between the microlens arrays.
[0079]
In the above embodiment, the method for forming a two-layer microlens array has been described. However, the method of the present invention can also be applied to a case of forming a three-layer or more microlens array.
[0080]
(Second Embodiment)
Next, implementation using a well-known twisted nematic mode (TN) active matrix type liquid crystal display element that is dynamically displayed through an amorphous silicon semiconductor thin film transistor that switches rectangular picture elements arranged in a matrix. A form is demonstrated.
[0081]
In the liquid crystal display element of this embodiment, as shown in FIG. 20 (a), the pixel arrangement is a delta arrangement, and the pixel electrodes 71R, 71G, 71B corresponding to each picture element have a delta arrangement, The portions not showing the pixel electrodes 71R, 71G, 71B are light shielding layers.
[0082]
When the pixel array is the delta array as described above, it is inappropriate to use a lenticular lens as the microlens array. That is, in this case, as shown in FIG. 20 (a), the microlens array in which square-shaped microlenses 72 are arranged in a brick shape, or the shape of each microlens is not necessarily that of the corresponding picture element. Since it is not necessary to be similar to the shape of the set, as shown in FIGS. 5B and 5C, a honeycomb in which hexagonal microlenses 73 in which outer peripheral portions of spherical lenses are fused with each other are arranged in a dense manner A microlens array is used.
[0083]
In the case shown in FIGS. 20A and 20C, the three primary color condensing spots collected by one micro lens 72 (or 73) are arranged in a horizontal row, and one micro lens 72 (or 73) is in a horizontal row. The relative positional relationship between the picture element array and the microlens array is set so as to correspond to the three picture element electrodes 71R, 71G, 71B arranged in a row. On the other hand, in the case shown in FIG. 5B, the three primary color condensing spots condensed by one microlens 73 are arranged so as to form the apex of a triangle, and one microlens 73 is a triangle. The relative positional relationship between the picture element array and the microlens array is set so that the three picture element electrodes 71R, 71G, 71B arranged so as to be at the vertices correspond to each other.
[0084]
Thus, when a set of condensing spots is irradiated in a triangular shape, the dichroic mirror is arranged so that the direction of the normal line is inclined. As a result, the angle between the optical axis of the microlens and the incident light of each color is reduced, so that the aberration of the microlens array is reduced.
[0085]
As the two-layer microlens array or the microlens array substrate used in such a liquid crystal display element, the one having the structure described in the first embodiment can be used. The microlens array substrate can also be manufactured in the same manner as the manufacturing method described in the first embodiment.
[0086]
(Third embodiment)
Next, still another embodiment of the present invention will be described. FIG. 21 is a cross-sectional view of a reflective liquid crystal display element 81 with a microlens array used in a reflective color liquid crystal display device. FIG. 22 is a diagram showing the lens portion and the arrangement of pixels. The reflective liquid crystal display element 81 is formed with transparent scanning electrodes 83 and reflective electrodes 84R, 84G, and 84B on opposite surfaces of the microlens array substrate 40 and the glass substrate 82, respectively, and a liquid crystal layer 85 is filled therebetween to surround the periphery. Sealed with a sealing material 86.
[0087]
The microlens array substrate 40 is obtained by sandwiching three lens resin layers 46, 47, 48, which are transparent and have different refractive indexes, between base glasses 44, 45, and has an interface between the lens resin layers 46, 47, 48. Microlens arrays 33 and 34 are formed on the surface. Since the microlens array substrate 40 is the same as that described in the first embodiment, the detailed structure and manufacturing method will not be described.
[0088]
In such a microlens array substrate 40, as shown in FIG. 25, the first microlens array 33 condenses the light beams of the respective colors, and the second microlens array 34 has the first microlens array 33. Is refracted so that the principal ray of each light beam transmitted through the light beam enters the corresponding reflecting electrode 84R, 84G, 84B perpendicularly. By irradiating the reflective electrodes 84R, 84G, and 84B with a light beam perpendicularly, the light beam reflected by the reflective electrodes 84R, 84G, and 84B is emitted from the front surface of the reflective liquid crystal display element 81 through the original lens portion. .
[0089]
In addition, in the individual lens portions constituting the microlens arrays 33 and 34, the centers of the reflective electrodes 84R, 84G, and 84B are evenly arranged at the apex positions of the triangles. In this arrangement, red (R), blue (B), and green (G) pixels (reflecting electrodes 84R, 84G, and 84B) are linearly formed over a plurality of lens portions as indicated by dotted lines in FIG. It is arranged.
[0090]
As for the arrangement of the lens portion and the reflection electrodes 84R, 84G, and 84B, as shown in FIG. 23, each pixel of red (R), blue (B), and green (G) is arranged linearly and You may make it fit in a lens part. Alternatively, as shown in FIG. 24, the contour shape of the lens portion may be a quadrangle instead of a hexagon.
[0091]
Thus, as shown in FIG. 21, the luminous flux separated into the three primary colors by the dichroic mirror is incident on the microlens array substrate 40 at different angles, and is narrowed down by the first microlens array 33, and then the second microlens array. The light beam which is refracted at 34 and vertically incident on the reflective electrodes 84R, 84G and 84B and reflected by the reflective electrodes 84R, 84G and 84B follows the same optical path as the incident light and is emitted in the original direction. Thus, if each light beam enters from the center of each lens portion of the microlens arrays 33 and 34, a reflected light beam corresponding to this incident light beam is also emitted from the center of the lens portion, thereby reducing the diameter of the projection lens. The irradiation light can be effectively used.
[0092]
(Fourth embodiment)
FIG. 26 is a schematic view showing the configuration of a reflective display apparatus 101 according to still another embodiment of the present invention. This uses a fine optical element called DMD (digital micromirror device) 102, and is used for a projector, for example.
[0093]
First, the DMD 102 will be described. This is an optical element in which a large number of fine micromirrors 105 are arranged on a Si substrate 103 by using a micromachining technique. The structure of one pixel of this DMD is shown in FIG. A pair of support portions 106 are provided on the upper surface of the Si substrate 103, and both ends of the torsion hinge 107 are supported by the support portions 106 on the surface of the Si substrate 103. A central portion of a yoke 108 is attached to the torsion hinge 107, and a micro mirror 105 is formed at the upper end of a column portion 109 standing at the center of the yoke 108. On the upper surface of the Si substrate 103, the angle of the micro mirror 105 is controlled by adjusting the inclination of the yoke 108 while twisting the torsion hinge 107 by applying a driving force to the yoke by an electromagnetic force such as static electricity. Mirror drive means (not shown) is provided. By tilting the yoke 108 in this manner, the angle of the micromirror 105 can be changed, and when the micromirror 105 is irradiated with light, the direction of reflected light can be freely controlled.
[0094]
As shown in FIG. 26, the reflective display element 101 using the DMD 102 has a microlens array substrate 40 disposed so as to face the DMD 102, and white light emitted from the light source 110 is red, green, and blue by the dichroic mirror 111. The light beams of the respective colors are transmitted through the microlens array substrate 40 to irradiate the three micromirrors 105 constituting one picture element. In each picture element, a light beam that does not need to be displayed on the screen 114 is reflected in the horizontal direction by the micromirror 105 and absorbed by the light absorber 112. When displaying on the screen, the direction of the projection lens 113 is displayed by the micromirror 105. And is imaged on the screen 114 by the projection lens 113 to become one pixel of the display image. In order to display gradation, the mirror is controlled so that light is projected onto the screen for a time divided according to the gradation level during one frame period. For example, in 256 gradations, the mirror is controlled at intervals of 1/256 divided by 1 frame time (1/60 seconds for 60 frames).
[0095]
When the microlens array substrate 40 having a two-layer structure is used in such a reflective display device 101 using the DMD 102, the principal rays of the light beams of the respective colors are emitted in parallel between the microlens array substrate 40 and the DMD 102. Therefore, the pitch between the micromirrors 105 can be reduced, and the pixels of the reflective display device 101 can be refined. In addition, if the microlens array substrate 40 is formed by molding the microlens arrays 33 and 34 by the interface of the lens resin layer, the optical characteristics can be improved, so that the quality of the reflective display device is improved and the cost is low. Can be.
[0096]
Furthermore, the microlens array substrate of the present invention is used as a projection type projector, a rear projection type projector TV (rear pro TV), a head mounted display (HMD; recently a partial amusement, etc.) as an application field of an image display device. It can also be used for glasses-type display monitors.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a conventional projection type color liquid crystal display device.
FIG. 2 is a diagram showing a configuration of a dichroic mirror used in the apparatus.
FIG. 3 is a cross-sectional view showing a liquid crystal display element and a microlens array used in the apparatus.
FIG. 4 is a cross-sectional view showing a liquid crystal display element and a microlens array substrate used in another conventional projection type color liquid crystal display device.
FIG. 5 is a diagram for explaining the operation of the microlens array according to the first embodiment.
FIGS. 6A, 6B, 6C, 6D, and 6E are cross-sectional views for explaining a manufacturing method of the microlens array.
FIG. 7 is a diagram for explaining a method of manufacturing a microlens array substrate from the same microlens array or glass substrate.
FIG. 8 is a cross-sectional view showing a configuration of a projection type color liquid crystal display device according to an embodiment of the present invention.
FIG. 9 is a sectional view showing a liquid crystal display element and a microlens array used in the apparatus.
FIG. 10 is a diagram for explaining the operation of a microlens array substrate used in the apparatus described above.
FIGS. 11A and 11B are diagrams illustrating a method for adjusting the focal length of the microlens array according to the embodiment.
FIGS. 12A and 12B are diagrams for explaining another method of adjusting the focal length of the microlens array according to the embodiment.
FIG. 13 is a schematic cross-sectional view showing an upper table and a lower table of a molding machine for manufacturing the microlens array substrate same as above.
FIGS. 14A, 14B, and 14C are diagrams illustrating a manufacturing process of the microlens array substrate according to the embodiment.
15 (d) (e) (f) is a continuation of FIG.
16 (g) (h) (i) is a continuation of FIG.
FIGS. 17A to 17E are views for explaining a stamper manufacturing method for forming a microlens array pattern; FIGS.
FIG. 18 is a diagram showing how a glass plate is laser processed.
FIGS. 19A to 19E are views for explaining another method of manufacturing a stamper for forming a pattern of a microlens array. FIGS.
20A, 20B, and 20C are views showing the shape of a microlens array used in a projection type color liquid crystal display device in another embodiment of the present invention.
FIG. 21 is a cross-sectional view showing the structure of a reflective liquid crystal display device according to still another embodiment of the present invention.
FIG. 22 is a diagram showing an arrangement of lens portions and pixels in the element.
FIG. 23 is a diagram showing another arrangement of lens portions and pixels in the element.
FIG. 24 is a diagram showing still another arrangement of lens portions and pixels in the element.
FIG. 25 is a diagram showing optical paths of irradiated light and reflected light in the element described above.
FIG. 26 is a schematic view showing a configuration of a reflective display device according to still another embodiment of the present invention.
FIG. 27 is a perspective view showing the structure of a DMD used in the above display device.
[Explanation of symbols]
32 Liquid crystal display elements
33, 34 Micro lens array
38R, 38G, 38B Dichroic mirror
40 Microlens array substrate
41 Liquid crystal layer
44, 45 Base glass
46, 47, 48 Lens resin layer
56, 59, 60 UV curable resin
57 Stamper
102 DMD
105 Micromirror

Claims (2)

A method of manufacturing a lens array substrate having a lens array of a plurality of layers,
Curing the resin material in a state in which the first stamper is pressed against an uncured resin material, and molding the first translucent resin layer;
An uncured resin material having a refractive index different from that of the translucent resin layer is supplied onto the first translucent resin layer, and the second stamper is pressed against the translucent resin layer. Forming a second translucent resin layer and forming a lens array on the boundary surface between the first and second translucent resin layers;
An uncured resin material having a refractive index different from that of the translucent resin layer is supplied and cured on the second translucent resin layer to form a third translucent resin layer. Forming another lens array on the boundary surface of the translucent resin layer,
Of manufacturing a lens array substrate. The method for manufacturing a lens array substrate according to claim 1 , wherein the first stamper and the second stamper are the same stamper.

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