JPH05333328A - Image display device - Google Patents

Abstract

PURPOSE:To suppress the increase of areas not to contribute to images, and to improve the quality of images by making the condensed spot shape of a microlens asymmetrical. CONSTITUTION:This device is provided with a liquid crystal panel 1 equipped with a picture element group for which the opening shape of picture elements 6 is rectangular, and microlens array 202 to condense light from a light source to the openings of the picture elements 6 on the liquid crystal panel 1. Then, for the microlens array 202, the curvature of a lens on the end face of a line A-A is made different from the curvature of the lens on the end face of a line B-B. Namely, a focal distance corresponding to the short side direction of the rectangular opening is made different from the focal distance corresponding to the long side direction. By mounting the microlens array 202 using the microlens having such a focal distance on the liquid crystal panel 1, the shape of the condensed spot can be made equal to the opening shape of the liquid crystal panel 1. Thus, the areas not, contributing for images are decreased, and the reduction of picture quality can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device having a microlens array mounted on a liquid crystal display panel for the purpose of increasing the brightness of a projection screen.

[0002]

2. Description of the Related Art A conventional image display device in which a microlens array is mounted on a liquid crystal display panel for the purpose of increasing the brightness of the liquid crystal display panel will be described with reference to FIG. A liquid crystal display panel (hereinafter referred to as a liquid crystal panel) 1 is a TFT
A TFT transparent substrate 3 having a (thin film transistor) 11 formed thereon, a transparent substrate 4 facing the TFT transparent substrate 3, and a liquid crystal 5. The microlens array 2 is loaded on the liquid crystal panel 1. On the TFT transparent substrate 3,
A plurality of electrodes 6 are arranged side by side. This electrode 6
Is transparent to allow the transmission of light,
The electrode 6 is also referred to as an opening of the liquid crystal panel 1. This opening has a substantially rectangular shape corresponding to the shape of the pixel.

The structure of the liquid crystal panel 1 is shown in FIG. 2, FIG. 3, and FIG.
Shown in. A transparent electrode 6, a gate 24, an insulating film 27, a TFT 11, a source 22 and a drain 23 are provided on the TFT transparent substrate 3. Further, an insulating film 29 and a counter electrode 20 are provided on the side of the transparent substrate 4 that faces the liquid crystal 5 in between. FIG. 5 shows the opening 6 and the wiring 7 of the liquid crystal panel 1.
It is a figure when it sees with a microscope. FIG. 6 shows a pattern (white portion) of light transmitted through the opening 6 of the liquid crystal panel 1. Figure 7
Shows an optical system of the liquid crystal projector. The light emitted from the light source 31 is reflected by the reflecting mirror 32, condensed by the condenser lens 33 on the optical axis L, and the light transmitted through the liquid crystal panel 1 having the microlens array 2 mounted thereon is projected onto the screen 38 by the projection lens 37. The image is projected. Polarizing plates 35 and 36 are arranged in front of and behind the liquid crystal panel 1.

Next, image display when the microlens array 2 is not loaded on the liquid crystal panel 1 and when it is loaded will be described with reference to FIGS. 8 and 9. When not loaded, as shown in FIG. 8A, the incident light is incident on the opening 6 of the liquid crystal panel 1.
9A, the projection lens 37 forms an enlarged projection image of the substantially rectangular opening pattern of the liquid crystal panel 1 on the screen 38 by the projection lens 37, as shown in FIG. 9A. On the other hand, when the microlens array 2 is loaded on the liquid crystal panel 1, the incident light is condensed by the microlens array 2 at the position of the opening 6 of the liquid crystal panel 1 as shown in FIG. Then, the light is transmitted through the liquid crystal panel 1, and a projection spot is enlarged and projected on the screen 38 by the projection lens 37 as shown in FIG. 9B. Since the curvature of the microlenses of the microlens array 2 is isotropic, the shape of the focused spot is circular.

By the way, in order to effectively realize high brightness and high efficiency of the liquid crystal panel, it is necessary to make the shape of the focused spot equal to or smaller than the opening shape (short side length of the opening) of the liquid crystal panel. At this time, the aperture shape is equivalent to the focused spot shape. Therefore, the shape of the aperture pattern (focus spot pattern) projected on the screen becomes smaller than that when the microlens array is not loaded on the liquid crystal panel. Therefore, the area that does not contribute to the image increases, the quality of the image deteriorates, and the image becomes rough. As an example of solving the above problem, it is considered that the shape of the focused spot is made to be the opening shape or more. However, in order to improve the efficiency of the liquid crystal panel, the efficiency decreases because the focused spot vignets on the aperture.

A microlens array is mounted on the light source side of the liquid crystal panel for the purpose of increasing the brightness of the projection screen. Here, the pitch of the microlens array 2 is set equal to the pitch of the liquid crystal panel 1. However, in the conventional configuration in which the pitch of the microlens array 2 and the pitch of the liquid crystal panel 1 are equal, the positions of the microlens and the opening 6 of the liquid crystal panel 1 shift as the distance from the optical axis L of the liquid crystal projector shifts. However, there is a problem that the brightness of the image decreases. FIG. 17 shows the principle of this screen brightness reduction. Since the light condensed by the condenser lens 33 enters the microlens array 2, the light entering the microlens becomes more inclined with respect to the optical axis L of the liquid crystal projector as the distance from the optical axis L of the liquid crystal projector increases. That is, the optical axis of each microlens is directed toward the focal point F of the condenser lens 33. Therefore, the condensing spots of the microlenses are formed on the respective optical axes, so that the light condensed by the microlenses does not pass through the openings 6 of the liquid crystal panel 1 and the brightness of the screen is lowered. is there.

Further, in the image display device as shown in FIG. 1, the microlens array 2 generally has a two-dimensional curvature structure. When mounting such a microlens array 2 on the liquid crystal panel 1, there is a method of bonding and fixing the flat surface of the back surface of the substrate on which the microlens array 2 is formed and the flat surface of the transparent substrate 4 of the liquid crystal panel 1. According to this method, since the flat surfaces are bonded to each other and bonded, it is possible to fill the entire surface with the bonding resin,
It has the advantage of high adhesive strength. On the other hand, the greatest purpose of loading the microlens array 2 on the liquid crystal panel 1 is to improve the efficiency of the liquid crystal panel 1. FIG. 20 shows the principle of increasing the efficiency of the liquid crystal panel 1. 20A shows a conventional example in which the lens forming surface is not close to the opening surface, and FIG. 20B shows an example of the present invention described later in which the lens forming surface is close to the opening surface. In the conventional case of FIG. 1A, the microlens array 2 is used.
Has a thickness of 0.7 μm and the substrate 8 has a thickness of 1.1 mm,
One microlens 102 of the microlens array 2
The light that has passed through is dispersed until it reaches the opening 6 of the liquid crystal panel 1, and the intensity of the light is weakened. The optical distance between the surface on which the microlens array 2 is formed and the opening surface of the liquid crystal panel 1 is distant by the thickness of the substrate on which the microlens array 2 is formed, and the effect of increasing the efficiency of the liquid crystal panel 1 cannot be expected.

In the liquid crystal panel as described above, the TFT transparent substrate 3 and the counter substrate 4 are aligned with each other by detecting the relative positional deviation of the alignment marks formed at the predetermined positions on the respective substrates by using image processing. And, it is done by correcting this gap. The alignment accuracy at this time is about several μm. The alignment marks include
In order to improve the recognition property as an image, an inorganic material such as Cr, which is optically opaque and easy to manufacture in a panel manufacturing process line, is used. FIG. 32 shows a schematic procedure of this alignment, and the adjustment ends when the alignment marks of the two overlap on the image.

FIG. 33 shows a replica structure of the microlens array 2 manufactured by the 2P method. The alignment accuracy between the microlens array 2 and the liquid crystal panel 1 is required to be at the same level (about several μm) as the alignment accuracy between the TFT transparent substrate 3 and the counter substrate 4 of the liquid crystal panel 1 described above. As a method for mounting the microlens array 2 and the liquid crystal panel 1 with high accuracy, the liquid crystal panel 1 using the above-mentioned image processing is provided.
A method similar to the position alignment method of FIG. As a microlens alignment method using this method, FIG.
The following processes are possible as shown in.

As shown in FIG. 34A, first, similarly to the case of the liquid crystal panel 1, the alignment mark 73 is formed on the transparent substrate 8 using Cr or the like. Next, FIG.
As shown in (b), the alignment mark 73 on the transparent substrate 8 and the alignment mark on the stamper 71 are aligned. Next, a photocurable resin is applied onto the transparent substrate 8 to cure and form a lens pattern. Next, FIG.
As shown in FIG. 4C, alignment with the liquid crystal panel 1 is performed using the alignment mark 73 on the transparent substrate 8.

However, the alignment process as shown in FIG. 34 has the following three problems. In order to make the alignment accuracy of the microlens array 2 and the liquid crystal panel 1 about several μm, the stamper 71 is used.
It is necessary to make the alignment accuracy between the glass substrate 8 and the glass substrate 8 about submicron, which is not feasible. The stamper 71 material is mainly made of Ni which is optically opaque and has a light reflection intensity similar to that of Cr. Therefore, the contrast of the image cannot be obtained, and it is very difficult to align the stamper 71 and the glass substrate 8. New glass substrate 8
Since the step of aligning the stamper 71 is added, the total cost of the liquid crystal panel 1 increases.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and a first object thereof is to provide an image display device using a liquid crystal panel and a microlens array. The asymmetrical shape of the condensing spot of the microlens can reduce the increase of the area not contributing to the image and improve the quality of the image. Second
The purpose of is to align the optical axis of the microlens and the optical axis of the liquid crystal panel aperture over the entire liquid crystal panel, so that the light condensed by the microlens will pass through the aperture of the liquid crystal panel and the brightness of the screen will be reduced. It is to prevent it from dropping. The third purpose is to mount the microlens array forming surface toward the liquid crystal panel side,
It is intended to improve the efficiency of the liquid crystal panel by efficiently collecting the light on the pixels of the liquid crystal panel. A fourth object is to eliminate the positioning process of the stamper and the glass substrate in the positioning process of the microlens array and the liquid crystal panel, thereby reducing the positioning accuracy and reducing the cost. ..

[0013]

In order to achieve the above object, the invention of claim 1 is a light source, a liquid crystal panel having a pixel group in which the opening shape of each pixel is substantially rectangular, and light from the light source. In an image display device including a microlens array for condensing the above into the aperture of each pixel of the liquid crystal panel,
The microlens array is configured such that the focal length corresponding to the short side direction and the focal length corresponding to the long side direction of the substantially rectangular opening are different. According to a second aspect of the present invention, the microlens array is configured to form a condensing pattern that is short in the short side direction and long in the long side direction at the opening position of the substantially rectangular shape. In the invention of claim 3, the distance between the position of the condensing point by the condensing optical system and the pixel of the liquid crystal panel on the optical axis of the condensing optical system is L1, and the distance on the optical axis of the condensing optical system is L1. When the distance between the position of the condensing point by the condensing optical system and the microlens array is L2, the pixel pitch of the liquid crystal panel is Λ1, and the microlens array pitch is Λ2, Λ2 / Λ1 = L2 / It satisfies the relationship of L1. According to a fourth aspect of the invention, the microlens array is arranged such that the lens constituting surface faces the liquid crystal panel. According to a fifth aspect of the present invention, a spacer is formed in the peripheral portion of the microlens array, and the microlens array is arranged on the liquid crystal panel via the spacer. According to the invention of claim 6, a material having a refractive index smaller than that of the material forming the lens array is filled between the microlens array and the liquid crystal panel. The invention of claim 7 is
An optical path conversion pattern for converting the optical path of incident light for alignment is formed on the peripheral portion of the lens array of the microlens array.

[0014]

According to the above structure, the condensed spot of the microlens array can pass through the opening of the liquid crystal panel, so that high brightness of the liquid crystal panel can be realized. further,
The alignment accuracy can be suppressed, the alignment process can be simplified, and the cost of the liquid crystal panel can be reduced.

[0015]

FIG. 10 shows an optical system in which a microlens array 202 having an asymmetry of curvature is loaded on a liquid crystal panel 1 according to the first embodiment of the present invention. In the present embodiment, claim 1,
This corresponds to the second invention. The figure (b) shows the AA line cross section of the same figure (a), and the (c) shows the BB line cross section of the same figure (a). As shown, the microlens array 20
In No. 2, the lens curvature in the AA line cross section and the lens curvature in the BB line cross section are different. A design example of the microlens array 2 will be described with reference to FIG.
Now, the combined focal length l'of the condenser lens 33 and the microlens is obtained. Assuming that the focal length of the condenser lens 33 is Fc, the focal length of the microlens is f, and the principal plane distance between the condenser lens 33 and the microlens is l, the combined focal length l ′ of the condenser lens 33 and the microlens is Required by.

[0016]

[Equation 1]

From the above, it is understood that the combined focal length l'of the condenser lens 33 and the microlens should be treated as approximately equal to the focal length f of the microlens. As an example actually used, Fc = 160 m
m, l = 10 mm, f = 0, 5 mm are raised.

FIG. 12 shows the image forming diameter of the light source by the microlens. The image of the light source 31 formed by the light source and the microlens is connected in a collimated form via the reflecting mirror 32 and the microlens. Light source 31 diameter is D, light source 3
Fr is the distance from 1 to the main plane of the reflecting mirror 32 along the optical axis L, f is the combined focal length of the condenser lens 33 and the microlens, and the aperture diameter of the liquid crystal panel is a × b (a: short side, b : Long side), and the aperture diameter of the microlens is c × d. When the curvature of the microlens is isotropic, the focused spot diameter W is W = D × f / Fr.

First, the focal length of the microlens in the case of W> a will be described with reference to FIGS. 13, 15 and 16. Here, la is the optical distance from the main plane of the microlens to the opening 6 of the liquid crystal panel 1, fx, f
y represents the focal length in the x direction and the y direction when the coordinate axes are made to correspond to the microlenses having biaxial symmetry. The increase amount ΔWx of the focused spot diameter in the x direction at the focus position in the y direction is ΔWx = d / fx × (fx−f
y). At this time, in order to make the focused spot diameter in the x direction equal to the length b of the opening 6 in the x direction, ΔWx = b
-W is sufficient. Therefore, the focal length fx of the microlens is fx = d / (d−b + W) × fy fy = la.

Next, the focal length of the microlens in the case of W <a will be shown with reference to FIGS. 14, 15 and 16. The increase amount ΔWy of the focused spot diameter when the focal length fy ′ (≠ la) in the y direction is ΔWy = c / fy ′ ×
(Fy'-la). At this time, in order to make the focused spot diameter in the y direction equal to the length a in the y direction of the opening 6, ΔWy = a−W. Therefore, the focal length f
y ′ is fy ′ = c × la / (c−a + W). At this time, in order to make the focused spot diameter in the x direction equal to the aperture diameter in the x direction, ΔWx = d / fx ′ × (fx
′ −fy ′) and ΔWx = b−a, the focal length fy ′ of the microlens is fy ′ = c × la / (c−a + W) fx ′ = d / (d + a−b) × fy ′ Becomes In this embodiment, calculation is performed assuming that the pixel shape of the liquid crystal panel 1 and the aperture shape of the microlens array 2 are the same.

By loading the microlens array 202 using the microlenses having the above-mentioned focal lengths on the liquid crystal panel 1, the shape of the focused spot of the microlens array 202 is almost the same as the aperture shape of the liquid crystal panel 1. The microlens array 202 can be
The opening pattern of the liquid crystal panel 1 projected onto the screen when the liquid crystal panel 1 is loaded can be made to have the same shape as the opening pattern when the microlens array 202 is not loaded on the liquid crystal panel 1. As a result, the area that does not contribute to the image is reduced, and the deterioration of the image quality can be suppressed. The aperture of the microlens may be rectangular, circular, elliptical, or the like, and the focal length may be different depending on the long side direction and the short side direction. It is conceivable that the aperture of the lens itself is elliptical and the light spot is condensed as it is. Further, the microlens array 2 may be loaded on the liquid crystal panel 1 in either direction.

Next, a second embodiment will be described with reference to FIG. In this embodiment, the optical axis of the microlens is aligned with the optical axis of the liquid crystal aperture over the entire liquid crystal panel. The focus F of the condenser lens 33 from the position of the opening 6 of the liquid crystal panel 1 and the surface on which the microlens array 52 is formed.
The optical distances up to are L1 and L2, respectively. Further, assuming that the pitch of the liquid crystal panel 1 and the pitch of the microlens array 52 are Λ1 and Λ2, respectively, by configuring so that the relationship of Λ2 / Λ1 = L2 / L1 is satisfied, all condensed spots of the microlens are The light can be effectively transmitted through the opening 6 of the liquid crystal panel 1. This makes it possible to realize high brightness over the entire projection screen. In addition,
The aperture of the lens and the focused spot can be any shape,
The microlens array 52 may be loaded on the liquid crystal panel 1 in either direction.

Next, a third embodiment of the present invention will be described.
FIG. 19 shows the image forming optical system of the liquid crystal projector, and FIG. 20 shows the principle of increasing the efficiency of the liquid crystal panel. In this embodiment, the lens forming surface of the microlens array 2 is close to the opening surface, as shown in FIG. This FIG.
In the case of (b), the light passing through the microlens 102 is not dispersed and the intensity of the light is not weakened as compared with the conventional configuration of FIG. 20 (a). Therefore, when the surface of the microlens array 2 formed on the support substrate 8 is closer to the opening surface of the liquid crystal panel 1, the focused spot diameter becomes smaller, which is advantageous for higher efficiency. I understand.
Therefore, as shown in FIG. 21, the microlens array 2
By arranging the lens so that the lens constituting surface faces the liquid crystal panel 1, the efficiency of the liquid crystal panel 1 can be improved. The lens aperture and the focused spot may be of any shape.

Here, the focused spot diameter in the case of the conventional configuration of FIG. 20A will be described with reference to FIG. 12 described above. The light source diameter is D = 2 mm, and the focal length of the reflecting mirror is Fr.
= 13 mm, the glass substrate thickness of the liquid crystal panel 1 is dp =
1.1 mm, the substrate thickness of the microlens array 2 is dm
= 1.1 mm. In addition, the refractive index of the substrate is n = 1.5
Then, the focused spot diameter W on the opening surface of the liquid crystal panel 1
Is W = D × (dp + dm) / (Fr × n) = 225 μm. Aperture shape of liquid crystal panel 1 a × b = 120 × 94
If it is μm ² , the efficiency is not improved because the aperture diameter is larger than the focused spot diameter W = 225 μm. Although the thickness of the glass substrate of the liquid crystal panel 1 tends to be thin in recent years, the flatness of the substrate is lowered due to the difficulty of polishing, and the handling of the liquid crystal panel 1 in the manufacturing process and the deflection of the substrate during transportation are caused. It is difficult to realize a thin substrate due to uneven cleaning that occurs. Similarly, it is difficult to make the substrate of the microlens array 2 into a thin substrate in view of flatness, difficulty of cleaning, and strength. From the above, it can be seen that it is difficult to increase the efficiency of the liquid crystal panel with the conventional configuration.

On the other hand, the present invention solves the above problem by providing the microlens array 2 with the lens component surface facing the liquid crystal panel 1 as described above. Hereinafter, as this mounting example, a configuration example of the spacer member when the spacer member is used will be described. Figure 2
2 shows an example in which a spacer member 61 is provided between the liquid crystal panel 1 and the microlens array 2. The spacer member 61 has a flat plate and frame structure, the inner diameter of the frame is larger than the area where the microlens array 2 is formed, and the outer diameter of the frame is larger than the outer diameter of the glass substrate of the liquid crystal panel 1 to be mounted. Is also small. By doing so, since the flat surface of the glass substrate of the liquid crystal panel 1 and the flat surface of the microlens array 2 can be fixed by adhesion, the adhesive strength can be increased.
23 and 24 show a spacer member 61 fixed to the surface of the substrate 8 of the microlens array 2.

FIG. 25 shows an example in which at least one region of the frame structure of the spacer member 62 is cut. In this figure, the liquid crystal panel is omitted. In the structure in which the microlens array 2 is mounted on the liquid crystal panel 1, an air layer is formed between the liquid crystal panel 1 and the surface on which the microlens array 2 is formed. However, as described above, the gap is partially provided in the spacer member 62. As a result, this air layer becomes equal to the atmospheric pressure, so warping of the substrate of the microlens array 2 due to changes in external pressure can be eliminated.

FIG. 26 shows a method for producing a duplicate of the microlens array 2 provided with the spacer member 61 using a stamper. In this manufacturing method, the microlens array 2 provided with the spacer member 61 is used as a master (a), a stamper 71 material is deposited from above (b), and the stamper 71 is manufactured (c). The stamper 71 is turned upside down, the molten resin 72 is injected from above, and the supporting substrate 8 is further placed (d). A replica is manufactured by the above method (e). By doing so, since the microlens array 2 in which the spacer member 61 is integrally formed on the substrate 8 can be manufactured,
Labor saving of the alignment process at the time of mounting and cost reduction by reducing the number of parts can be achieved.

FIG. 27 shows an example in which at least two frames of the spacer member 61 are provided in the plane of the substrate 8. This makes it possible to effectively prevent the resin from squeezing out of the substrate when the replication is performed using the 2-P method.
That is, when the molten resin 72 is filled between the stamper 71 and the supporting substrate 8 with the microlens surface facing upward, as shown in FIG.
2 may protrude, but as shown in FIG. 28 (b),
When the molten resin 72 is filled with the microlens surface facing downward, since there are two or more grooves, it is possible to prevent the molten resin 72 from protruding.

Next, a mounting process using the spacer member as described above will be described. As shown in FIG. 24 and the like described above, the flat surface of the glass substrate of the liquid crystal panel 1 and the flat surface of the substrate 8 of the microlens array 2 are bonded to each other with the spacer member 61 interposed therebetween and separated by the thickness of the spacer member 61. In the above configuration, the gap formed between the two is filled with the curable resin. By doing so, since the flat surfaces can be bonded to each other, the bonding strength can be increased. At this time, the spacer member 61 prevents the curable resin from penetrating into the lens forming surface, and can be mounted with high yield.

In the mounting structure shown in FIG. 29, the photo-curable resin 74 is used for temporary fixing of the mounting, and the epoxy-based curable resin 7 is used for main fixing so as to cover the upper surface of the photo-curing resin 74.
5, the liquid crystal panel 1 and the microlens array 2 are bonded. Although the photocurable resin 74 has a short curing time, its adhesive strength is relatively weak as compared with other curable resins. on the other hand,
The epoxy-based curable resin 75 has a long curing time, but has a high adhesive strength. Therefore, by using the photo-curable resin 74 for temporary fixation and the epoxy-based curable resin 75 for main fixation, the advantages of both can be positively used, so that the curing time is short and the strength is stable. Adhesive mounting can be realized.

Next, with reference to FIGS. 30 and 31, the operation when the filling material is filled between the liquid crystal panel 1 and the microlens array 2 will be described. A material 74 having a refractive index smaller than that of the material forming the microlens array 2 is filled between the liquid crystal panel 1 and the microlens array 2. In this case, the spacer member 61 may be provided (in the case of FIG. 31) between the liquid crystal panel 1 and the microlens array 2 (in the case of FIG. 30). As described above, the spacer member 61 is not always necessary, and when the filler is filled as described above, the spacer member 61 functions as an adhesive resin at the time of mounting. Therefore, it is better to spray the adhesive as an adhesive than to apply it around. Easy and strong. Further, by filling with a resin, it is possible to prevent warpage of the lens and the liquid crystal substrate due to a pressure difference. The reason why the material 74 having a low refractive index is filled is that when the lens shape is convex, the light collecting function is not provided unless the surrounding refractive index is smaller than the lens refractive index.

A fourth embodiment of the present invention will be described. FIG. 35 shows the configuration of the microlens array 2. An optical path conversion element 80 having a function of changing the traveling direction of light is formed on the glass substrate 8 at a position corresponding to the alignment mark of the liquid crystal panel 1 when the master is manufactured. Optical path changing element 80
As shown in FIG. 36, is manufactured using a semiconductor manufacturing process as in the case of manufacturing the microlens array 2 described above. Therefore, as the relative position between the optical path conversion element 80 and the microlens array 2 has a precision of submicron or less,
Be accurate.

37 and 38 show the principle of the alignment process. A camera 90 that measures the amount of light is provided above the microlens array 2. Optical path changing element 80
The direction of travel of the light illuminated by the light changes. As a result, the amount of light taken into the camera 90 is reduced by the optical path conversion element 80.
Since the contrast as an image is obtained unlike in the surroundings, it is possible to easily align the image of the optical path conversion element 80 and the image of the alignment mark of the liquid crystal panel 1.

By providing the optical path conversion element 80 in this way, the alignment accuracy between the optical path conversion element 80 (alignment mark) and the microlens array 2 can be realized in submicron or less, so that the liquid crystal panel 1 and the microlens array 2 are provided. It can be implemented without lowering the alignment accuracy with. Further, since the optical path conversion element 80 (alignment mark) and the microlens array 2 are manufactured at the same time, the alignment process is simplified and the liquid crystal panel 1 can be manufactured at low cost and the yield can be improved.

[0035]

As described above, according to the first and second aspects of the present invention, since the shape of the condensing spot of the microlens array can be made substantially equal to the shape of the aperture of the liquid crystal panel, it is possible to reduce the increase of the area not contributing to the image. As a result, it is possible to prevent deterioration of the image quality such as graininess of the image. Therefore, higher brightness and higher efficiency of the liquid crystal panel can be more effectively realized.
According to the third aspect of the present invention, since all the converging spots of the microlens array can pass through the openings of the liquid crystal panel, it is possible to realize high brightness over the entire screen. According to the invention of claims 4 to 6, since the microlens array forming surface is close to the opening surface of the liquid crystal panel, it is possible to efficiently collect light on the pixels of the liquid crystal panel, and to improve the efficiency of the liquid crystal panel. You can According to the invention of claim 7, since the alignment process is simplified without lowering the alignment accuracy, the cost of the liquid crystal panel and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a conventional liquid crystal panel and a microlens array.

FIG. 2 is a plan view of a transparent substrate of a liquid crystal panel.

FIG. 3 is a plan view of a transparent electrode.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a view showing an opening and wiring of a liquid crystal panel as viewed with a microscope.

FIG. 6 is a diagram showing a pattern of light transmitted through an aperture of a liquid crystal panel.

FIG. 7 is a diagram showing an optical system of a liquid crystal projector.

8A and 8B are diagrams showing an optical system, where FIG. 8A shows a case where a microlens array is not loaded on a liquid crystal panel, and FIG. 8B shows a case where a microlens array is loaded on a liquid crystal panel.

FIG. 9 is a diagram showing an opening expansion pattern on the screen,
(A) shows the case where the microlens array is not loaded on the liquid crystal panel, and (b) shows the case where the microlens array is loaded on the liquid crystal panel.

FIG. 10 is a diagram showing a liquid crystal panel and a microlens array according to the first embodiment of the present invention, in which (a) is a perspective view,
(B) is a sectional view taken along the line AA, and (c) is a sectional view taken along the line BB.

FIG. 11 is a diagram for deriving a combined focal length of a condenser lens and a microlens.

FIG. 12 is a diagram for deriving a light source diameter by a microlens.

FIG. 13 is a diagram showing a relationship between a focused spot and an aperture diameter of a liquid crystal panel.

FIG. 14 is a diagram showing a relationship between a focused spot and an aperture diameter of a liquid crystal panel.

FIG. 15 is a diagram showing a light condensing characteristic when the focal length has asymmetry.

FIG. 16 is a diagram showing a light collecting characteristic when the focal length has asymmetry, wherein (a) shows a light collecting state in the x direction, and (b) shows a light collecting state in the y direction.

FIG. 17 is a diagram illustrating a conventional principle of screen brightness reduction.

FIG. 18 is a diagram showing a liquid crystal panel and a microlens array according to a second embodiment of the present invention.

FIG. 19 is a diagram showing an image forming optical system of a liquid crystal projector.

20A and 20B are diagrams for explaining the principle of increasing the efficiency of a liquid crystal panel, FIG. 20A shows a conventional example, and FIG. 20B shows a third embodiment of the present invention.

21A and 21B are views showing the arrangement of the microlens array in the third embodiment, where FIG. 21A is a perspective view and FIG.
FIG. 6 is a sectional view taken along line BB of FIG.

FIG. 22 is a perspective view of a liquid crystal panel and a microlens array when a spacer is used in the third embodiment.

FIG. 23 is a perspective view of a microlens array when a spacer is used.

FIG. 24 is a perspective view of a liquid crystal panel and a microlens array when a spacer is used.

FIG. 25 is a perspective view of a microlens array according to a modified example.

FIG. 26 is a diagram illustrating a method for manufacturing a microlens array.

FIG. 27 is a perspective view showing a modified example of a microlens array.

FIG. 28 is a diagram showing a molten resin filling method.

FIG. 29 is a diagram showing another example of a bonding configuration of a microlens array and a liquid crystal panel.

FIG. 30 is a side sectional view showing a state where a filler is filled between the liquid crystal panel and the microlens array.

FIG. 31 is a side sectional view showing a state in which a filler is filled between the liquid crystal panel and the microlens array using a spacer.

FIG. 32 is a flowchart showing a process of aligning each glass substrate of a conventional liquid crystal panel.

FIG. 33 is a perspective view of a microlens array.

FIG. 34 is a diagram illustrating alignment of microlens arrays.

FIG. 35 is a perspective view of a microlens array according to a fourth embodiment of the present invention.

FIG. 36 is a diagram illustrating a manufacturing process of a microlens array.

FIG. 37 is a perspective view for explaining alignment of the microlens array in the above-described embodiment.

FIG. 38 is a side sectional view for explaining alignment of the microlens array in the example.

[Description of Reference Signs] 1 liquid crystal panel 2, 52, 202 microlens array 6 pixel electrode (aperture) 31 light source 61, 62 spacer member 74 member with low refractive index 80 optical path conversion element

Claims (7)

[Claims] 1. A light source, a liquid crystal panel having a pixel group in which the opening shape of each pixel is substantially rectangular, and a microlens array for condensing light from the light source into the opening of each pixel of the liquid crystal panel. In the provided image display device, the microlens array is configured such that a focal length corresponding to a short side direction of the substantially rectangular opening is different from a focal length corresponding to a long side direction. Image display device. 2. A light source, a liquid crystal panel having a pixel group in which the opening shape of each pixel is substantially rectangular, and a microlens array for condensing light from the light source into the opening of each pixel of the liquid crystal panel. In the image display device provided, the microlens array is configured to form a condensing pattern that is short in the short side direction of the opening and long in the long side direction at the substantially rectangular opening position. Image display device. 3. A light source, a liquid crystal panel having a pixel group,
An image display device comprising: a condensing optical system that condenses light from the light source; and a microlens array that condenses the light condensed by the condensing optical system into each pixel of the liquid crystal panel. The distance between the position of the condensing point by the condensing optical system on the optical axis of the condensing optical system and the pixel of the liquid crystal panel is L1, and the condensing optical system condenses on the optical axis of the condensing optical system. When the distance between the point position and the microlens array is L2, the pixel pitch of the liquid crystal panel is Λ1, and the microlens array pitch is Λ2, Λ
An image display device characterized by satisfying a relationship of 2 / Λ1 = L2 / L1. 4. A light source, a liquid crystal panel having a pixel group,
In an image display device including a microlens array that condenses light from the light source onto each pixel of the liquid crystal panel, the lens forming surface of the microlens array is arranged toward the liquid crystal panel. Characterized image display device. 5. The image display device according to claim 4, wherein a spacer is formed in a peripheral portion of the microlens array, and the microlens array is arranged on the liquid crystal panel via the spacer. 6. The material having a refractive index smaller than that of the material forming the lens array is filled between the microlens array and the liquid crystal panel. 5. The image display device according to item 5. 7. The optical path conversion pattern for converting the optical path of incident light for alignment is formed in the peripheral portion of the lens array of the microlens array. The image display device according to 3, 4, or 5.