JP2000039503A - Lens array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens array capable of improving sensitivity when this lens array is used for a solid-stage image pickup device and improving the luminance of a screen when the lens array is used for a liquid crystal display element. SOLUTION: Condenser lenses 111 each having a convex lens shape formed within a pixel region are formed in contact with the condenser lenses adjacent in longitudinal and transverse directions. The condenser lens may otherwise be formed over the entire area of the pixel regions. As a result, the area ratio occupied by the condenser lenses in the pixel regions are improved and, therefore, the rays entering the condenser lenses increase. When, therefore, the lens array is used for, for example, a solid-state image pickup element, the sensitivity thereof is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens array used for, for example, a solid-state image sensor or a liquid crystal display.

[0002]

2. Description of the Related Art A solid-state imaging device will be described as an example.

FIG. 15 is a sectional view schematically showing the structure of a general solid-state imaging device.

In general, as shown in FIG. 15, a solid-state imaging device includes an n-type semiconductor substrate 312, a p-well layer 311, a light receiving section 310, a charge transfer section 309, a silicon oxide or nitride film 307, a polysilicon electrode 308, It comprises a metal light shielding layer 306, an element surface protection layer 305, a flat film 304, a color filter layer 303, an intermediate transparent film 302, and a lens array (on-chip lens) 301. Note that the color filter layer 303 is not necessary in the case of a three-plate imaging device or a black-and-white imaging device, or in the case of being color-coded by other wavelength selection means.

[0005] In a general solid-state image pickup device, light is received by a light receiving section 3.
Light received by only 10 and other rays do not contribute to the sensitivity. Therefore, as one of the techniques for increasing the sensitivity, it is known that the lens array 301 is formed on the transparent surface layer on the light receiving section 310 and more light is collected by the light receiving section 310.

Each lens of the lens array 301 is arranged corresponding to each light receiving section 310, and the light incident on the lens is efficiently guided to each light receiving section 310 by using the light condensing action.

FIG. 16 shows the structure of a conventional lens array. FIG. 16A is a plan view of the lens array 301 as viewed from above, and FIG. 16B is a cross-sectional view of the lens array 301 taken along the line XII-XII in FIG. 16A. A region corresponding to one pixel is a region surrounded by a vertical side 355 and a horizontal side 354, and the lens 301 is arranged substantially at the center thereof, thereby contributing to an improvement in sensitivity. Here, between adjacent lenses,
A gap 353 is provided for manufacturing reasons. In addition,
Although only four pixels are shown in FIG. 16 for simplification of the drawing, a predetermined number of pixels shown in FIG. 16A are actually arranged in the vertical and horizontal directions.

[0008]

In the above-mentioned lens array, a gap 353 is provided between adjacent lenses.
Light incident here hardly enters the light receiving element. Also, because the lens shape is substantially circular or substantially elliptical,
In the square pixel region, a gap is also formed at a corner where the lens 301 is not formed, and there is a problem that light incident on this portion hardly enters the light receiving element and does not contribute to sensitivity.

Similarly, in a liquid crystal display element used in a transmission type liquid crystal display device or the like, a lens array having a gap as shown in FIG. 16 is laminated so as to correspond to each pixel. There is a problem that the incident light does not contribute to the brightness of the screen of the liquid crystal display device.

In view of the above problems, the present invention can improve the sensitivity when used in a solid-state imaging device, for example, by enlarging the aperture of a lens, and when used in a liquid crystal display device. It is an object of the present invention to provide a lens array capable of improving the brightness of a screen.

[0011]

In order to achieve the above object, a lens array according to the present invention has the following arrangement.

That is, the lens array according to the first configuration of the present invention has a plurality of condensing lenses arranged in the vertical and horizontal directions, and each of the condensing lenses is one for each pixel arranged in a two-dimensional plane. A lens array installed and used in a one-to-one correspondence, wherein the condenser lens is formed in contact with condenser lenses adjacent in the vertical and horizontal directions.

In a lens array according to a second aspect of the present invention, a plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens is a convex lens and is formed over the entire area corresponding to the pixel.

In the second configuration, the area corresponding to the pixel is rectangular, and when the lengths of the area in the vertical and horizontal directions are X and Y, respectively, the radius of curvature R of the condenser lens is It is preferable to satisfy the following expression (1).

[0015]

(1) (1/2) × (X ² + Y ² ) ^1/2 ≦ R ≦ (2/3) × (X ² + Y ² ) ^1/2 (1)

In the second configuration, the region corresponding to the pixel is rectangular, and the length of the region in the vertical and horizontal directions is X and Y, and the radius of curvature of the condenser lens is R. In this case, it is preferable to satisfy the following expressions (2) and (3).

[0017]

## EQU2 ## 4 μm ≦ (X ² + Y ² ) ^1/2 ≦ 5.7 μm (2) 2 μm ≦ R ≦ 4 μm (3)

A lens array according to a third configuration of the present invention comprises a plurality of condensing lenses arranged in the vertical and horizontal directions, and each of the condensing lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condensing lens is a first lens formed substantially at the center of a region corresponding to the pixel, and the first lens of the region is And second lenses formed in four corner regions where no lens is formed, wherein the first lens is a convex lens, and each of the second lenses formed in the four corners has a common curvature center point. It is characterized by having.

In a lens array according to a fourth aspect of the present invention, a plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is one-to-one for each pixel arranged in a two-dimensional plane. Wherein the condensing lens is a first lens formed substantially at the center of a region corresponding to the pixel, and the first lens of the region is And second lenses formed in four corner regions where no lens is formed, wherein the first lens is a convex lens, and each of the second lenses formed in the four corners has a common curvature center point. Wherein the wall surface of the second lens on the first lens side is not perpendicular to the arrangement surface of the condenser lens.

In a lens array according to a fifth aspect of the present invention, a plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens is a Fresnel lens.

In a lens array according to a sixth aspect of the present invention, a plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens is a Fresnel lens, and the Fresnel lens has at least two or more different groove depths for each region corresponding to the pixel. It is characterized by having.

In the sixth configuration, the Fresnel lens has a groove depth of mλ / (n, where n is the refractive index of the Fresnel lens forming material, and λ is the wavelength or center wavelength of light transmitted through the Fresnel lens. n-1) (m: natural number), preferably a sawtooth shape.

In the fifth or sixth configuration, it is preferable that the Fresnel lens is formed in an entire region corresponding to the pixel.

In the first to sixth configurations, it is preferable that the condenser lens is formed in a binary shape whose shape is approximated in a stepwise manner.

The lens array according to the seventh aspect of the present invention comprises a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens is a lens provided with a lens function by a change in refractive index, and the surface of the lens array is substantially flat. And

In the seventh configuration, it is preferable that the lens provided with a lens function by a change in a refractive index is formed in an entire region corresponding to the pixel.

In a lens array according to an eighth aspect of the present invention, a plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens is a gradient index lens, and the surface of the lens array is substantially flat.

In the eighth configuration, it is preferable that the gradient index lens is formed in the entire area corresponding to the pixel.

A lens array according to a ninth aspect of the present invention comprises a plurality of condensing lenses arranged in the vertical and horizontal directions. Each of the condensing lenses has a one-to-one correspondence with each pixel arranged in a two-dimensional plane. Wherein the condenser lens comprises a lens provided with a lens function by a change in refractive index, and a convex lens formed thereon. And

[0030] In the ninth configuration, it is preferable that the lens provided with a lens function by a change in refractive index is formed in an entire region corresponding to the pixel.

The lens array according to the tenth aspect of the present invention comprises a plurality of converging lenses arranged in the vertical and horizontal directions.
Each of the condensing lenses is a lens array that is installed and used so as to correspond to each pixel arranged in a two-dimensional plane on a one-to-one basis, and the condensing lens is provided in an area corresponding to the pixel. A first lens formed in a substantially central portion, and a third lens formed in a region of the region where the first lens is not formed, wherein the first lens is a convex lens; The third lens is a lens provided with a lens function by a change in refractive index.

In the tenth configuration, it is preferable that one of the first lens and the third lens is formed in a region corresponding to the pixel.

The lens array according to the present invention has the above-described first to tenth structures, so that the sensitivity can be improved when used in, for example, a solid-state imaging device, and when the lens array is used in a liquid crystal display device. Can provide a lens array capable of improving the brightness of the screen.

Further, the solid-state imaging device according to the present invention
A solid-state imaging device having a light-receiving unit arranged in a two-dimensional plane and the lens array according to any one of the above, stacked on the light-receiving unit, wherein each condensing lens of the lens array is an individual condensing lens. It is characterized by a one-to-one correspondence to the light receiving units.

Further, the solid-state image pickup device according to the present invention
A light receiving unit arranged in a two-dimensional plane, and a solid-state imaging device having a transparent substrate laminated on the light receiving unit, wherein the transparent substrate is a lens array according to the seventh or eighth configuration, Each of the condensing lenses of the lens array corresponds to each of the light receiving units on a one-to-one basis.

In the above solid-state imaging device, it is preferable that the focal length of the condenser lens is substantially equal to the distance to the light receiving section.

Further, the liquid crystal display device according to the present invention comprises:
A liquid crystal display element having pixels arranged in a two-dimensional plane and the lens array according to any one of the above, stacked on the pixel, wherein individual condenser lenses of the lens array are arranged on individual pixels. It is characterized by a one-to-one correspondence.

In the above liquid crystal display device, it is preferable that the focal length of the condenser lens is substantially equal to the distance to the pixel.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lens array according to the present invention will be described more specifically with reference to the drawings.

(Embodiment 1) FIG. 1 is a conceptual diagram of a lens array according to Embodiment 1 of the present invention.
1A is a plan view, FIG. 1B is a cross-sectional view taken along the line Ib-Ib of FIG. 1A, and FIG. 1C is a sectional view of FIG.
It is sectional drawing seen from the arrow direction in Ic-Ic line. Although only four pixels are shown in FIG. 1 for simplicity, the actual number of pixels shown in FIG. 1A is arranged in a predetermined number in the vertical and horizontal directions.

In the lens array of the present embodiment, a condenser lens 111 having a convex lens shape is arranged in a rectangular pixel region arranged in the vertical and horizontal directions, and one condenser lens corresponds to one pixel region. Have been.

Here, the condenser lens 111 is in contact with condenser lenses adjacent in the vertical and horizontal directions. For example, consider a case in which a lens array is formed on a solid-state imaging device having a light receiving element interval of 5 μm. Assuming that the gap of the conventional condenser lens (the gap 353 in FIG. 16B) is 0.4 μm, the ratio of the area occupied by the condenser lens to the area (pixel region) corresponding to one light receiving element is 66.5. %. On the other hand, when the gap between the condensing lenses adjacent in the vertical and horizontal directions is 0 as in the condensing lens of the present embodiment, the ratio of the area occupied by the condensing lens to the area corresponding to one light receiving element Is 78.5%, and the light rays entering the lens are increased by 18% as compared with the conventional case, so that the sensitivity of the solid-state imaging device is increased accordingly.

As shown in FIG. 15, the p-well layer 311
And a light receiving section 310 having a side length of about 2.5 μm
Next, a silicon oxide film or a nitride film 307 having a thickness of about 0.1 μm is formed, and an element surface protective film 305 having a refractive index of 1.55 and a thickness of about 0.9 μm, and a refractive index of 1.4.
7. A flat film 304 having a thickness of about 1 μm and a color filter layer 303 having a refractive index of 1.52 and a thickness of about 2 μm are formed.
Assume a solid state imaging device that is m square. In the upper part of the pixel region, the change in the light-collecting rate when a light-collecting lens 301 having a refractive index of 1.5 and a radius of curvature of 3 μm is formed by changing the distance between the light-collecting lenses adjacent in the vertical and horizontal directions. Simulated. The results are shown in FIG. In the lens array of the present embodiment, since the condensing lenses adjacent in the vertical and horizontal directions are in contact with each other, the interval between the condensing lenses is 0, and the condensing rate is 75%. On the other hand, the condensing lens gap in the vertical and horizontal directions of a conventional general lens array is about 0.4 μm, so that the condensing rate is 68%, and the condensing rate of the present invention is about 10% as compared with the conventional one. %.

At this time, the convergence rate is the number of light rays incident on the light receiving element out of the number of light rays passing through the pixel region corresponding to one light receiving element when the ray tracing is arbitrarily performed. However, in this simulation, the angle of the incident light beam on the pixel area is arbitrary within a range of 0 to 15 degrees.

FIG. 3 is a conceptual diagram of a lens array according to a second embodiment of the present invention.
3 (a) is a plan view, FIG. 3 (b) is a cross-sectional view taken along the line IIb-IIb in FIG. 3 (a), and FIG. 3 (c) is FIG. 3 (a).
FIG. 2 is a sectional view taken along the line IIc-IIc in FIG. Although only four pixels are shown in FIG. 3 for simplification of the drawing, a predetermined number of the pixels shown in FIG. 3A are actually arranged in the vertical and horizontal directions.

In the lens array according to the present embodiment, a condenser lens 121 having a convex lens shape is arranged in a rectangular pixel area arranged in the vertical and horizontal directions, and one condenser lens corresponds to one pixel area. Have been.

Here, the condenser lens 121 covers the entire area of the pixel area, and there is no area in the pixel area where the condenser lens is not formed. For example, the light receiving element interval is 5 μm
Consider a case in which a lens array is formed on the solid-state imaging device of FIG. The gap of the conventional condenser lens (the gap 35 in FIG. 16B)
If 3) is 0.4 μm, the ratio of the area occupied by the condenser lens to the area (pixel region) corresponding to one light receiving element is 66.5%. On the other hand, in the lens array according to the present embodiment, the ratio occupied by the condenser lens in the area corresponding to one light receiving element is 100%. Therefore, the lens array according to the present embodiment improves the effective light receiving area by 50.7%. Accordingly, the light receiving sensitivity of the solid-state imaging device is also improved.

The radius of curvature of the lens, for example, must be at least half the diagonal length of the pixel in order for the lens to cover the entire pixel area. Also, if the radius of curvature is too large, the light-gathering power is weakened, causing a reduction in sensitivity.
Therefore, assuming that the vertical length of the pixel is X and the horizontal length is Y, it is preferable that the radius of curvature R of the condenser lens satisfies the following expression (1). When Expression (1) is satisfied, the lens can cover the entire pixel region, and can obtain a sufficient light-collecting power. If the value falls below the lower limit of the expression (1), the lens cannot cover the entire pixel region. On the other hand, when the value exceeds the upper limit of Expression (1), a sufficient light-collecting power cannot be obtained.

[0049]

(3) (1/2) × (X ² + Y ² ) ^1/2 ≦ R ≦ (2/3) × (X ² + Y ² ) ^1/2 (1)

It is preferable that the following expressions (2) and (3) are satisfied, since a sufficient sensitivity can be obtained and a sufficient resolution can be obtained.

[0051]

4 μm ≦ (X ² + Y ² ) ^1/2 ≦ 5.7 μm (2) 2 μm ≦ R ≦ 4 μm (3)

Here, in order to perform a simulation,
The shape of the solid-state imaging device was as follows. As shown in FIG. 15, there is a p-well layer 311 having a thickness of about 3 μm,
About 1 μm on one side and about 2.5 μm on the other side
, And then a silicon oxide film or a nitride film 307 having a thickness of about 0.1 μm. Further, an element surface protective film 30 having a refractive index of 1.55 and a thickness of about 0.9 μm.
5, a flat film 3 having a refractive index of 1.47 and a thickness of about 1 μm.
It is assumed that the solid-state imaging device has a color filter layer 303 having a refractive index of 1.52, a refractive index of 1.52, and a thickness of about 2 μm, and a pixel region corresponding to the light receiving element is a square of about 4.5 μm in length and width. A refractive index of 1.5 at the top of the pixel area
FIG. 4 shows the relationship between the radius of curvature and the light collection rate when the light collection lens described above is formed. When the radius of curvature is 3.4 μm, the light-collecting rate becomes maximum, and the light-collecting rate at that time is 94%, which is 38% higher than the conventional light-collecting rate of 68%.

(Embodiment 3) FIG. 5 is a conceptual diagram of a lens array according to Embodiment 3 of the present invention.
5 (a) is a plan view, and FIG. 5 (b) is IIIb-IIIb in FIG. 5 (a).
FIG. 5C is a cross-sectional view as viewed from the direction of the arrow in FIG.
FIG. 3A is a cross-sectional view taken along the line IIIc-IIIc of FIG. Although only four pixels are shown in FIG. 5 for simplification of the drawing, a predetermined number of pixels shown in FIG. 5A are actually arranged in the vertical and horizontal directions.

In the lens array of the present embodiment, a first lens 131 having a convex lens shape formed at a substantially central portion of each rectangular pixel region arranged in the vertical and horizontal directions, and a first lens 131 are provided. Second lens 132 formed in the remaining area of the pixel area including the four corner areas not formed
Is a unit, and one condenser lens is arranged so as to correspond to one pixel region. Here, the second lenses 132 formed at the four corners of the pixel region have a common center of curvature.

Generally, when a convex lens is to be formed in a rectangular pixel region, a region in which a lens is not formed at least in a diagonal direction is formed unless the configuration as in the second embodiment is adopted. In the present embodiment, by forming another second lens 132 in this region, a large effective light receiving area can be obtained. Furthermore, this second
The curvature of the lens 132 of the first lens 13 at the center is
Since it is not necessary to make the curvature equal to one, it is possible to secure a larger amount of received light by optimizing the combination of the curvatures of the two lenses by, for example, simulation or the like.

Further, according to the present embodiment, by making the radius of curvature of the second lens 132 at least half the length of the diagonal line of the pixel region, it is possible to form the lens without gaps over the entire pixel region. it can. For example, the light receiving element interval is 5 μm
Consider a case in which a lens array is formed on the solid-state imaging device of FIG. The gap of the conventional condenser lens (the gap 35 in FIG. 16B)
If 3) is 0.4 μm, the ratio of the area occupied by the condenser lens to the area (pixel region) corresponding to one light receiving element is 66.5%. On the other hand, in the lens array according to the present embodiment, the ratio occupied by the condenser lens in the area corresponding to one light receiving element can be set to almost 100%. Therefore, the lens array according to the present embodiment improves the effective light receiving area by 50.7%. with this,
The light receiving sensitivity of the solid-state imaging device is also improved.

In the present embodiment, the first lens 1
The second lens 132 is configured around the
Another lens having a different curvature may be formed around the lens 132.

Here, in order to perform a simulation,
The shape of the solid-state imaging device was as follows. As shown in FIG. 15, there is a p-well layer 311 having a thickness of about 3 μm,
About 1 μm on one side and about 2.5 μm on the other side
, And then a silicon oxide film or a nitride film 307 having a thickness of about 0.1 μm. Further, an element surface protective film 30 having a refractive index of 1.55 and a thickness of about 0.9 μm.
5, a flat film 3 having a refractive index of 1.47 and a thickness of about 1 μm.
It is assumed that the solid-state imaging device has a color filter layer 303 having a refractive index of 1.52, a refractive index of 1.52, and a thickness of about 2 μm, and a pixel region corresponding to the light receiving element is a square of about 4.5 μm in length and width. In the case where a convex lens (first lens) having a refractive index of 1.5 and a conventional lens having a refractive index of 1.5 and a second lens having a radius of curvature of 4 μm are formed therearound at a substantially central portion above the pixel region, light is condensed. The light-collecting rate is 78%, which is 15% higher than the light-collecting rate of 68% in the case of only the conventional central lens.
improves.

(Embodiment 4) FIG. 6 is a conceptual diagram of a lens array according to Embodiment 4 of the present invention.
6 (a) is a plan view, FIG. 6 (b) is a cross-sectional view taken along the line IVb-IVb in FIG. 6 (a), and FIG. 6 (c) is FIG. 6 (a).
FIG. 4 is a sectional view taken along the line IVc-IVc in FIG. In FIG. 6, only four pixels are shown in order to simplify the drawing. However, actually, a predetermined number of pixels shown in FIG. 6A are arranged in the vertical and horizontal directions.

In the lens array of the present embodiment, a first lens 141 having a convex lens shape formed at a substantially central portion of each rectangular pixel region arranged in the vertical and horizontal directions, and a first lens 141 are provided. Second lens 142 formed in the remaining area of the pixel area including the four corner areas not formed
Is a unit, and one condenser lens is arranged so as to correspond to one pixel region. Here, the second lenses 142 formed at the four corners of the pixel region have a common center of curvature.

In general, if a convex lens is to be formed in a rectangular pixel area, an area in which no lens is formed at least in the diagonal direction will be formed unless the configuration as in the second embodiment is adopted. In the present embodiment, by forming another second lens 142 in this region, a large effective light receiving area can be obtained. Furthermore, this second
The curvature of the lens 142 of the first lens 14
Since it is not necessary to make the curvature equal to one, it is possible to secure a larger amount of received light by optimizing the combination of the curvatures of the two lenses by, for example, simulation or the like.

Further, the outer second lens 142 is provided so that the inner wall 143 is located at the center 145 of the first lens 141 in order to prevent light rays having a relatively small incident angle from being totally reflected by the inner wall 143 and scattered. It is inclined outward by an angle θ.

Further, according to the present embodiment, by making the radius of curvature of the second lens 142 equal to or more than half the length of the diagonal line of the pixel area, it is possible to form the lens without gaps over the entire area of the pixel area. it can. For example, the light receiving element interval is 5 μm
Consider a case in which a lens array is formed on the solid-state imaging device of FIG. The gap of the conventional condenser lens (the gap 35 in FIG. 16B)
If 3) is 0.4 μm, the ratio of the area occupied by the condenser lens to the area (pixel region) corresponding to one light receiving element is 66.5%. On the other hand, in the lens array according to the present embodiment, the ratio occupied by the condenser lens in the area corresponding to one light receiving element can be set to almost 100%. Therefore, the lens array according to the present embodiment improves the effective light receiving area by 50.7%. with this,
The light receiving sensitivity of the solid-state imaging device is also improved.

In the present embodiment, the first lens 1
The second lens 142 is configured around
Another lens having a different curvature may be formed around the lens 142.

Here, in order to perform a simulation,
The shape of the solid-state imaging device was as follows. As shown in FIG. 15, there is a p-well layer 311 having a thickness of about 3 μm,
About 1 μm on one side and about 2.5 μm on the other side
, And then a silicon oxide film or a nitride film 307 having a thickness of about 0.1 μm. Further, an element surface protective film 30 having a refractive index of 1.55 and a thickness of about 0.9 μm.
5, a flat film 3 having a refractive index of 1.47 and a thickness of about 1 μm.
It is assumed that the solid-state imaging device has a color filter layer 303 having a refractive index of 1.52, a refractive index of 1.52, and a thickness of about 2 μm, and a pixel region corresponding to the light receiving element is a square of about 4.5 μm in length and width. A conventional convex lens (first lens) having a refractive index of 1.5 is formed substantially at the center of the upper part of the pixel region, and a second lens having an inner wall surface inclined outward is formed around the convex lens (first lens). did. Here, Table 1 shows how the light collection ratio changes when the radius of curvature of the second lens and the inclination angle θ of the inner wall of the second lens are changed.

[0066]

[Table 1] The radius of curvature of the second lens is 4 μm, and the inclination angle θ is 10 deg.
Then, the light collection rate is about 81%, which is about 3% higher than the light collection rate of about 78% when the inclination radius θ is 0 deg. At the same radius of curvature. Also, the condensing rate of the conventional lens is 68%.
It is about 19% higher than that of.

(Embodiment 5) FIG. 7 is a conceptual diagram of a lens array according to Embodiment 5 of the present invention.
FIG. 7A is a plan view, and FIG. 7B is a cross-sectional view taken along the line VV in FIG. Although only four pixels are shown in FIG. 7 to simplify the drawing, a predetermined number of pixels shown in FIG. 7A are actually arranged in the vertical and horizontal directions.

The lens array of the present embodiment is composed of Fresnel lenses 151 having a light-condensing action formed in rectangular individual pixel regions arranged in the vertical and horizontal directions. The Fresnel lens 151 is formed by forming an uneven portion corresponding to the phase modulation amount of the lens on the lens surface. Thus, for example, in a solid-state imaging device, the distance between the light receiving element and the lens is reduced, which contributes to improvement in sensitivity. Also,
By forming the Fresnel lens over the entire pixel region corresponding to one light receiving element, the effective light receiving area can be increased and the sensitivity can be improved.

(Embodiment 6) FIG. 8 is a conceptual diagram of a lens array according to Embodiment 6 of the present invention.
8A is a plan view, and FIG. 8B is a cross-sectional view taken along the line VI-VI in FIG. 8A. Although only four pixels are shown in FIG. 8 for simplification of the drawing, a predetermined number of pixels shown in FIG. 8A are actually arranged in the vertical and horizontal directions.

The lens array according to the present embodiment is composed of Fresnel lenses 161, 162, and 163 having a light-condensing action formed in individual rectangular pixel regions arranged in the vertical and horizontal directions. Each Fresnel lens has a sawtooth shape with a groove depth of mλ / (n−1) (m: natural number), where n is the refractive index of the Fresnel lens forming material, and λ is the wavelength or center wavelength of the transmitted light. . Each Fresnel lens of the lens array in the present embodiment has an optimal shape for each wavelength so as to correspond to three different wavelengths. Therefore, for example, when used in a solid-state imaging device, it is useful to improve the sensitivity to a light beam of a specific wavelength.

In FIG. 8, the lens array is composed of three types of Fresnel lenses corresponding to three types of wavelengths, but may be composed of two types of Fresnel lenses, or four or more types of Fresnel lenses. It may be constituted by a lens.

Since each Fresnel lens has wavelength selectivity, a wavelength filter can be omitted.

Further, by forming a Fresnel lens over the entire pixel region corresponding to one light receiving element, the effective light receiving area can be increased and the sensitivity can be improved.

(Embodiment 7) FIG. 9 is a conceptual diagram of a lens array according to Embodiment 7 of the present invention.
FIG. 9A is a plan view, and FIG. 9B is a cross-sectional view taken along the line VII-VII in FIG. 9A. In FIG. 9,
Although only four pixels are shown in order to simplify the drawing, in practice, a predetermined number of the pixels shown in FIG. 9A are arranged in the vertical and horizontal directions.

The lens array of the present embodiment is a lens of a type in which a whole pixel area is covered with a convex lens in a rectangular pixel area arranged in the vertical and horizontal directions as shown in the second embodiment (FIG. 3). This is an array, which is a binary lens whose lens shape is approximated in a stepwise manner.

A step shape 171 is formed so as to approach the original lens shape 172. In this case, as the number of steps on the stairs increases, the performance of the original lens shape approaches. By using such a binary lens shape, options in manufacturing a lens array can be expanded.

FIG. 9 shows an example in which the lens array shown in the second embodiment (FIG. 3) is a binary lens.
The lens array shown in the other embodiments described above can also be a binary lens.

(Eighth Embodiment) FIG. 10 is a conceptual diagram of a lens array according to an eighth embodiment of the present invention.
10A is a plan view, and FIG. 10B is VIIIb of FIG.
FIG. 10C is a cross-sectional view as viewed from the direction of the arrow along the line VIIIb.
FIG. 10 is a cross-sectional view taken along the line VIIIc-VIIIc in FIG. Although only four pixels are shown in FIG. 10 for simplicity, the actual number of pixels shown in FIG. 10A is arranged in a predetermined number in the vertical and horizontal directions.

In the lens array of this embodiment, a condensing lens in which a rectangular pixel region arranged in the vertical and horizontal directions is given a lens function by a change in refractive index is provided with one condensing lens in one pixel region. Are arranged to correspond.

That is, the lens material layer 183 is composed of a high refractive index portion 181 and a low refractive index portion 182, and the interface between them has a predetermined curvature. As a result, the light beam is refracted when passing through the interface between the two, and the high refractive index portion 181 functions as a condenser lens. Therefore, for example, when the present invention is applied to a solid-state imaging device, the lens portion is closer to the light receiving device, and works effectively for a light beam having a relatively large incident angle with respect to the lens. Therefore, the light receiving sensitivity is improved.

In this embodiment, the condensing lens due to the change in the refractive index is formed in the entire pixel region, but may be formed in a part. By forming a condensing lens over the entire pixel region, the effective light receiving area can be increased and the sensitivity can be improved.

A lens based on a change in the refractive index is shown in FIG.
Instead of newly providing the lens material layer 183 and forming it inside as described above, a condensing lens may be formed by directly changing the refractive index inside a solid-state imaging device or a liquid crystal display device.

(Embodiment 9) FIG. 11 is a conceptual diagram of a lens array according to Embodiment 9 of the present invention.
11 (a) is a plan view, and FIG. 11 (b) is IX-XI in FIG. 11 (a).
It is sectional drawing seen from the arrow direction in a line. Although only four pixels are shown in FIG. 11 for simplification of the drawing, in practice, a predetermined number of the pixels shown in FIG. 11A are arranged in the vertical and horizontal directions.

In the lens array of this embodiment, a gradient index lens functioning as a condenser lens corresponds to a rectangular pixel region arranged in the vertical and horizontal directions, and one condenser lens corresponds to one pixel region. Are arranged as follows.

That is, the lens material layer 193 in each of the rectangular pixel regions is located at the intersection (center portion) of the diagonal line of the pixel region.
, The center portion 191 has the highest refractive index, and the peripheral portion 19 has the highest refractive index.
2, the refractive index decreases in order. The gradient index lens formed as described above functions as a condensing lens as a whole. Therefore, for example, when the present invention is applied to a solid-state imaging device, the lens portion is closer to the light receiving device, and works effectively for a light beam having a relatively large incident angle with respect to the lens. Therefore, the light receiving sensitivity is improved.

In this embodiment, the gradient index lens is formed over the entire pixel region, but may be formed partially. By forming it over the entire pixel region, the effective light receiving area can be enlarged and the sensitivity can be improved.

Further, the refractive index distribution type lens is not formed inside the lens material layer 193 newly as shown in FIG. 11, but is directly formed inside the solid-state image pickup device or the liquid crystal display device. May be formed to form a condenser lens.

(Embodiment 10) FIG. 12 is a conceptual diagram of a lens array according to Embodiment 10 of the present invention. FIG. 12 (a) is a plan view, and FIG. 12 (b) is FIG. 12 (a). X
It is sectional drawing seen from the arrow direction in -X-ray. FIG.
In FIG. 2, only four pixels are shown in order to simplify the drawing, but in actuality, a predetermined number of pixels shown in FIG. 12A are arranged in the vertical and horizontal directions.

The lens array according to the present embodiment includes a lens in which a rectangular pixel region is provided with a lens function by a change in refractive index as described in the eighth embodiment, and a convex lens formed thereon. A condensing lens is arranged in the vertical and horizontal directions so that one condensing lens corresponds to one pixel region.

That is, on the upper surface of the lens material layer 204, the convex lens 201 is formed substantially at the center of the pixel area. The lens material layer 204 includes a high refractive index portion 202 and a low refractive index portion 203, and the interface between the two has a predetermined curvature. As a result, the light beam is refracted when passing through the interface between the two, and the high refractive index portion 202 functions as a condenser lens.

As described above, the central part of the pixel area has two lens functions, that is, the convex lens 201 and the lens 202 due to the change in the refractive index, thereby increasing the light condensing power. Also, for example,
When applied to a solid-state imaging device, the presence of the lens 202 due to a change in the refractive index causes the lens portion to be closer to the light receiving device, and works effectively for a light beam having a relatively large incident angle with respect to the lens. Therefore, the light receiving sensitivity is improved.

Further, by forming the lens 202 due to the change in the refractive index over the entire pixel region as shown in FIG. 12, the ratio of the lens to the area corresponding to one light receiving element becomes almost 100%, and the effective light receiving area Can be enlarged and the sensitivity can be improved.

The lens 202 caused by the change in the refractive index is
It is not always necessary that the area is larger than the convex lens 201 and is formed in all the pixel regions corresponding to the light receiving elements, and a part thereof may be used. However, by forming the lens 202 by a change in the refractive index over the entire pixel region, the effective light receiving area can be increased, and the sensitivity can be improved.

The convex lens 201 does not necessarily need to be formed in a part of the pixel region corresponding to the light receiving element, but may be formed in the entire pixel region. By forming the convex lens 201 over the entire pixel region, the effective light receiving area can be enlarged and the sensitivity can be improved.

The lens 202 due to the change in the refractive index is
Instead of newly providing a lens material layer 204 and forming it inside as shown in FIG. 12, a condensing lens may be formed by directly changing the refractive index inside a solid-state imaging device or a liquid crystal display device. good.

(Embodiment 11) FIG. 13 is a conceptual diagram of a lens array according to Embodiment 11 of the present invention. FIG. 13 (a) is a plan view and FIG. 13 (b) is FIG. 13 (a). XI
It is sectional drawing seen from the arrow direction in -XI line. FIG.
In FIG. 3, only four pixels are shown in order to simplify the drawing. However, in actuality, a predetermined number of the pixels shown in FIG.

The lens array according to the present embodiment has a convex lens (first lens) formed substantially in the center of a rectangular pixel region and a refractive index formed in a region of the pixel region where no convex lens is formed. And a condensing lens including a lens (third lens) to which a lens function is given by the change in the vertical and horizontal directions so that one condensing lens corresponds to one pixel region.

That is, on the upper surface of the lens material layer 214, the convex lens 211 is formed substantially at the center of the pixel area. Further, the lens material layer 214 includes a high refractive index portion 213 and a low refractive index portion 212. As a result, FIG.
3 (b), a low refractive index portion 2
Reference numeral 12 functions as a diverging lens.

As described above, when the present invention is applied to, for example, a solid-state imaging device, light is condensed by the convex lens 211 at the center of the pixel region, and the light is condensed by the lens 212 at the peripheral portion where the convex lens 211 is not formed. Is guided to each light receiving element. Therefore, the entire pixel region can be used effectively, which can contribute to improvement in sensitivity.

Note that the lens 212 based on the change in the refractive index may be formed over the entire pixel region, or may be overlapped with the convex lens 211. Thereby, the effective light receiving area is enlarged, and the sensitivity can be improved.

The lens 212 due to the change in the refractive index is
Instead of newly providing a lens material layer 214 and forming it inside as shown in FIG. 13, a condensing lens may be formed by directly changing the refractive index inside a solid-state imaging device or a liquid crystal display device. good.

When the lens array described in each of the above embodiments is used for a solid-state imaging device, the focal length of the condensing lens constituting the lens array is substantially equal to the distance to the light receiving section of the solid-state imaging device. It is preferable to form so that it becomes. When used for a liquid crystal display element, it is preferable that the focal length of the condenser lens forming the lens array be formed so as to be substantially equal to the distance to the pixel of the liquid crystal display element. In any case, with such a configuration, a clear image can be obtained.

(Embodiment 12) An example of a method for manufacturing a lens array according to the present invention will be described below.

For example, a case where a lens array is formed on a flat film of a solid-state imaging device will be described with reference to FIG.

First, a synthetic resin layer 421 as a lens material is formed on the flat film 402 by spin coating (FIG. 14).
(A)). As a material used for the synthetic resin layer 421, for example, a phenol-based resin, a styrene-based resin, and an acrylic resin can be used, but other conventionally used materials can also be used. As a material of the synthetic resin layer 421, specifically, a photosensitive resin obtained by adding naphthoquinonediazide to a polyparavinylphenol-based resin is preferable.
This resin can be used as a positive resist,
When heat-treated, the material is liquefied by thermoplasticity and deformed into a hemispherical shape, and then the shape is fixed and solidified by thermosetting, and a hardened lens shape is realized. Further, the photosensitive resin can improve the visible light transmittance to 90% or more by ultraviolet irradiation in a process immediately after the development, and can be transformed into a lens shape in the transparent state.

Next, the applied synthetic resin layer 421
Is selectively exposed. When a positive resist such as the above polyparavinylphenol resin is used, only portions to be removed are irradiated with ultraviolet light 423 and developed. By patterning using such an ultraviolet stepper, the synthetic resin layer 421 is divided into one-to-one correspondence with each light receiving section (FIG. 14B).

Further, the divided synthetic resin portions 422 are bleached. That is, the opaque material is made transparent by irradiation with ultraviolet light. Thereafter, the synthetic resin portion 422 having a rectangular cross section is covered with the overcoat layer 425 by a method such as spin coating (FIG. 14C).

Each of the synthetic resin portions 422 covered by the overcoat layer 425 is softened by being heated,
It is transformed into a dome-shaped lens shape 401 whose cross section is formed by the upwardly convex curve (FIG. 14D). In this deformation, since the overcoat layer 425 is formed, adjacent synthetic resin portions are less likely to contact each other. In other words, the overcoat layer 425 exerts a buffering action so that the synthetic resin portion does not approach quickly. The material of the overcoat layer 425 can be used without any particular limitation as long as it can exert the above-described buffering action. On the other hand, the overcoat layer 425 includes the synthetic resin portion 42 at a temperature at which the synthetic resin portion 422 is heated.
It is required that the deformation of item 2 is not completely restricted.

By leaving the overcoat layer 425 as it is, it is possible to form a lens array formed by mutually contacting converging lenses adjacent in the vertical and horizontal directions. Further, when a lens is formed in the entire region corresponding to the pixel, the lens can be formed in the same manner as described above.

When the overcoat layer 425 is extremely thin, as shown in FIG. 14E, even if the overcoat layer is removed, a lens array in which the adjacent condenser lenses 401 are almost in contact with each other can be obtained. it can.

[0111]

As described above, according to the present invention,
For example, by using the pixel region effectively by covering the entire pixel region with a convex lens, for example, the sensitivity can be improved when used in a solid-state imaging device, and when used in a liquid crystal display element. A lens array capable of improving the brightness of a screen can be provided.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a lens array according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, and FIG. 1B is an arrow along a line Ib-Ib in FIG. FIG. 1C is a cross-sectional view as seen from the direction of the arrow along the line Ic-Ic in FIG. 1A.

FIG. 2 is a diagram showing the relationship between the interval between convex lenses adjacent in the vertical and horizontal directions and the light collection rate.

3A and 3B are conceptual diagrams of a lens array according to a second embodiment of the present invention. FIG. 3A is a plan view, and FIG. 3B is an arrow along line IIb-IIb in FIG. Sectional view seen from the direction,
FIG. 3C is a cross-sectional view taken along the line IIc-IIc in FIG.

FIG. 4 is a diagram showing a relationship between a radius of curvature of a convex lens and a light collection rate.

5A and 5B are conceptual diagrams of a lens array according to a third embodiment of the present invention, where FIG. 5A is a plan view and FIG. 5B is an arrow along line IIIb-IIIb in FIG. FIG. 5C is a cross-sectional view taken along the line IIIc-IIIc in FIG. 5A.

6A and 6B are conceptual diagrams of a lens array according to a fourth embodiment of the present invention. FIG. 6A is a plan view, and FIG. 6B is an arrow along line IVb-IVb in FIG. Sectional view seen from the direction,
FIG. 6C is a cross-sectional view taken along the line IVc-IVc in FIG.

7A and 7B are conceptual diagrams of a lens array according to a fifth embodiment of the present invention, where FIG. 7A is a plan view and FIG. 7B is an arrow along line VV in FIG. It is sectional drawing seen from the direction.

8A and 8B are conceptual diagrams of a lens array according to a sixth embodiment of the present invention. FIG. 8A is a plan view, and FIG. 8B is an arrow along line VI-VI in FIG. It is sectional drawing seen from the direction.

9A and 9B are conceptual diagrams of a lens array according to a seventh embodiment of the present invention. FIG. 9A is a plan view, and FIG. 9B is an arrow along line VII-VII in FIG. It is sectional drawing seen from the direction.

10A and 10B are conceptual diagrams of a lens array according to an eighth embodiment of the present invention, where FIG. 10A is a plan view and FIG.
10B is a cross-sectional view taken along the line VIIIb-VIIIb in FIG. 10A, and FIG. 10C is VIIIc-V in FIG.
FIG. 3 is a cross-sectional view as seen from the direction of the arrow along the line IIIc.

11A and 11B are conceptual diagrams of a lens array according to a ninth embodiment of the present invention, where FIG. 11A is a plan view and FIG.
FIG. 12B is a cross-sectional view taken along the line IX-XI in FIG.

FIG. 12A is a conceptual diagram of a lens array according to a tenth embodiment of the present invention, where FIG. 12A is a plan view and FIG.
FIG. 12B is a cross-sectional view taken along the line XX of FIG.

13A and 13B are conceptual diagrams of a lens array according to Embodiment 11 of the present invention. FIG.
FIG. 13B is a cross-sectional view taken along the line XI-XI in FIG.

FIG. 14 is a sectional view schematically showing a method of manufacturing a lens array according to a twelfth embodiment of the present invention in the order of steps.

FIG. 15 is a cross-sectional view schematically illustrating a configuration of a general solid-state imaging device.

16 (a) is a plan view schematically showing a conventional lens array, FIG. 16 (b) is a plan view thereof, and FIG.
It is sectional drawing seen from the arrow direction in XII-XII line of (a).

[Explanation of symbols]

 111 Condensing lens (lens array) 121 Condensing lens (lens array) 131 First lens 132 Second lens 141 First lens 142 Second lens 143 Inner wall of second lens 151 Fresnel lens 161, 162 163 Fresnel lens 171 Step shape (binary lens) 172 Original lens shape 181 High refractive index portion (condensing lens portion) 182 Low refractive index portion 183 Lens material layer 191 Central portion (high refractive index portion) 192 Peripheral portion (low) 193 lens material layer 201 convex lens 202 high refractive index portion (condensing lens portion) 203 low refractive index portion 204 lens material layer 211 convex lens 212 low refractive index portion (divergent lens portion) 213 high refractive index portion 214 lens material Layer 301 Lens array (on-chip lens) 302 Intermediate transparent film 303 Color filter Luster layer 304 Flat film 305 Device surface protective layer 306 Metal light shielding film 307 Silicon oxide film or nitride film 308 Polysilicon electrode 309 Charge transfer unit 310 Light receiving unit 311 P well layer 312 N-type semiconductor substrate 401 Condensing lens 402 Flat film 421 Synthesis Resin layer 422 Synthetic resin part 423 Ultraviolet light 425 Overcoat layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/66 102 H01L 31/02 D (72) Inventor Michihiro Yamagata 1006 Odakadoma, Kazuma, Osaka Matsushita Electric Inside Sangyo Co., Ltd. Person Michiyo Ichikawa 1006 Kadoma, Kazuma, Kazuma, Osaka, Japan Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiromitsu Aoki 1006 Kazuma, Kazuma, Kadoma, Osaka Pref. 1006 Kadoma Matsushita Electric Industrial Co., Ltd. F-term (reference) 4M118 AA01 AB01 BA10 CA04 CA32 CA40 FA06 GB11 GC07 GD02 GD04 GD06 GD07 GD09 GD10 5C024 AA00 CA31 EA04 FA01 FA11 5C058 AA06 AB05 AB06 5C094 AA10 AA48 BA43 CA18 ED01 JA08 5F088 AA20 BA01 BB03 DA20

Claims (24)

[Claims] 1. A plurality of condensing lenses are arranged in the vertical and horizontal directions, and each of the condensing lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens is formed in contact with condenser lenses adjacent in the vertical and horizontal directions. 2. A plurality of condensing lenses are arranged in the vertical and horizontal directions, and each of the condensing lenses is installed and used so as to correspond to each pixel arranged in a two-dimensional plane on a one-to-one basis. A lens array, wherein the condenser lens is a convex lens, and is formed over the entire area corresponding to the pixel. 3. A region corresponding to the pixel has a rectangular shape. When the lengths of the region in the vertical and horizontal directions are X and Y, respectively, the radius of curvature R of the condenser lens is expressed by the following formula (1). )
The lens array according to claim 2, satisfying the following. (1/2) × (X ² + Y ² ) ^1/2 ≦ R ≦ (2/3) × (X ² + Y ² ) ^1/2 (1) 4. A region corresponding to the pixel has a rectangular shape, and the length of the region in the vertical and horizontal directions is X, Y,
The lens array according to claim 2, wherein when the radius of curvature of the condenser lens is R, the following expressions (2) and (3) are satisfied. 4 μm ≦ (X ² + Y ² ) ^1/2 ≦ 5.7 μm (2) 2 μm ≦ R ≦ 4 μm (3) 5. A plurality of condensing lenses are arranged in the vertical and horizontal directions, and each of the condensing lenses is installed and used so as to correspond to each pixel arranged in a two-dimensional plane on a one-to-one basis. A lens array, wherein the condenser lens is a first lens formed at a substantially central portion of a region corresponding to the pixel;
A second lens formed in four corner areas where the first lens is not formed in the area,
Wherein each of the second lenses formed at the four corners has a common curvature center point. 6. A plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is installed and used so as to correspond to each pixel arranged in a two-dimensional plane on a one-to-one basis. A lens array, wherein the condenser lens is a first lens formed at a substantially central portion of a region corresponding to the pixel;
A second lens formed in four corner areas where the first lens is not formed in the area,
Are convex lenses, each of the second lenses formed at the four corners has a common curvature center point, and the wall surface of the second lens on the first lens side is an arrangement surface of the condenser lens. A lens array that is not perpendicular to the lens array. 7. A plurality of condensing lenses are arranged in the vertical and horizontal directions, and each of the condensing lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens is a Fresnel lens. 8. A plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens is a Fresnel lens, and the Fresnel lens has at least two or more different groove depths for each region corresponding to the pixel. 9. The groove depth of the Fresnel lens is mλ, where n is the refractive index of the Fresnel lens forming material, and λ is the wavelength or center wavelength of light transmitted through the Fresnel lens.
The lens array according to claim 8, wherein the lens array has a sawtooth shape of / (n-1) (m: natural number). 10. The lens array according to claim 7, wherein the Fresnel lens is formed in an entire region corresponding to the pixel. 11. The condensing lens is formed in a binary shape whose shape is approximated in a stepwise manner.
11. The lens array according to any one of items 10. 12. A plurality of condensing lenses are arranged in the vertical and horizontal directions, and each of the condensing lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens is a lens provided with a lens function by a change in refractive index, and a surface of the lens array is substantially flat. 13. The lens array according to claim 12, wherein the lens provided with a lens function by a change in a refractive index is formed in an entire region corresponding to the pixel. 14. A plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens is a gradient index lens, and the surface of the lens array is substantially flat. 15. The lens array according to claim 14, wherein the gradient index lens is formed in an entire region corresponding to the pixel. 16. A plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. A lens array, wherein the condenser lens comprises a lens provided with a lens function by a change in refractive index, and a convex lens formed thereon. 17. The lens array according to claim 16, wherein the lens provided with a lens function by a change in a refractive index is formed in an entire region corresponding to the pixel. 18. A plurality of condenser lenses are arranged in the vertical and horizontal directions, and each of the condenser lenses is installed and used so as to correspond one-to-one to each pixel arranged in a two-dimensional plane. In a lens array, the condensing lens is formed in a first lens formed at a substantially central portion of a region corresponding to the pixel, and in a region of the region where the first lens is not formed. A third lens, wherein the first lens is a convex lens, and the third lens is a lens provided with a lens function by a change in refractive index. 19. The lens array according to claim 18, wherein one of the first lens and the third lens is formed in a region corresponding to the pixel. 20. A solid-state imaging device comprising: a light receiving portion arranged on a two-dimensional plane; and the lens array according to claim 1 stacked on the light receiving portion, wherein the lens array Wherein the individual condenser lenses correspond one-to-one to the individual light receiving units. 21. A solid-state imaging device having a light receiving portion arranged in a two-dimensional plane and a transparent substrate laminated on the light receiving portion, wherein the transparent substrate is any one of claims 12 to 15. The solid-state imaging device according to claim 1, wherein the individual condensing lenses of the lens array correspond to the individual light receiving units on a one-to-one basis. 22. The solid-state imaging device according to claim 20, wherein a focal length of the condenser lens is substantially equal to a distance to the light receiving unit. 23. A liquid crystal display device having pixels arranged in a two-dimensional plane and the lens array according to claim 1 stacked on the pixels, wherein each of the lens arrays is Wherein the condensing lens corresponds to each of the pixels in a one-to-one manner. 24. The liquid crystal display device according to claim 23, wherein a focal length of the condenser lens is substantially equal to a distance to the pixel.