JP2003309858A - Three-plate type camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-plate type camera with enhanced sensitivity by optimally designing a reflection preventing film in each color for three solid- state imaging devices. <P>SOLUTION: The reflection preventing film proper to respective RGB wavelengths is formed to a lens array surface or/and a light receiving section surface of the each three-solid-stage imaging device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-plate type camera used in, for example, a video camera or a digital still camera.

[0002]

2. Description of the Related Art FIG. 4 shows a structural example of a light receiving portion used in a conventional three-plate video camera.

In FIG. 4, a prism 41 is a three-color separation type prism for separating an input image into RGB colors. The white light 42 incident on the prism is decomposed into red light (R) 43, green light (G) 44, and blue light (B) 45 by this prism 41. Then, each of the decomposed lights is arranged behind the solid-state imaging device 4
It is incident on 6, 47 and 48. This solid-state image sensor 46, 4
Reference numerals 7 and 48 correspond to RGB signals, respectively, and an image for each color can be obtained.

FIG. 5 shows a configuration example of a conventional solid-state image pickup device.
Shown in.

FIG. 5 is a sectional view showing the outline of the configuration of a general solid-state image pickup device.

Generally, a solid-state image pickup device has an n-type semiconductor substrate 51, a p-well layer 52, and a light receiving portion 5 as shown in FIG.
3, a charge transfer portion 54, a polysilicon electrode 55, a metal light shielding layer 56, a flat film 57, and a lens array (on-chip lens) 58.

In a general solid-state image pickup device, light is received by the light receiving section 5.
Rays received by only 3 and other rays do not contribute to sensitivity. Therefore, as one of the techniques for increasing the sensitivity, it is known that the lens array 58 is formed on the flat film layer on the light receiving section 53 to collect more light in the light receiving section 53.

Each lens of the lens array 58 is connected to each light receiving section 5
The light is incident on the lens to each light receiving portion 53 efficiently by using the condensing action.

[0009]

In the above-described three-plate type camera, an air layer enters between the three-color separation type prism and the CCD so that the light is reflected on the surface, resulting in a decrease in sensitivity. Further, even if an antireflection film for preventing this is applied to the CCD, the optimum film thickness for each of R, G, and B differs, so that a multilayer film is required to obtain an optimum configuration for all wavelengths. Precision is required and not realistic. Further, even if the three-color separation type prism and the CCD are bonded to each other to prevent reflection, they are also reflected on the surface due to the lens array.

[0010]

In order to achieve the above object, the three-plate type camera of the present invention has the following configuration.

In a three-plate type camera having three solid-state image pickup devices, the solid-state image pickup device comprises a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each lens array has a lens array that is installed and used so as to correspond to each pixel, and an antireflection film having a different refractive index from the lens array is formed on each lens array. It is assumed that the three-panel type cameras have different thicknesses or configurations of the upper antireflection film.

Further, in a three-plate type camera having three solid-state image pickup devices, the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each pixel has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the light receiving portion is formed on the light receiving portion. It is assumed that the three-plate type camera has different thicknesses or configurations of the antireflection film on the parts.

Further, in a three-plate type camera having three solid-state image pickup devices, the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each pixel has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the lens array is formed on each lens array. And an antireflection film having a different refractive index is formed, and the thickness or the configuration of the antireflection film on the lens arrays of the three solid-state image pickup devices are different,
In addition, a three-plate type camera in which the antireflection films on the light receiving portions of the three solid-state imaging devices have different thicknesses or configurations, respectively.

In a three-plate type camera having three solid-state image pickup devices, the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each lens array has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a different refractive index from the lens array is formed on each lens array. Antireflection films having different rates are formed, and the thickness or configuration of the antireflection films on the lens arrays of the three solid-state imaging devices are low reflection films for blue, green, and red, respectively. In addition, the thickness of the antireflection film on the light receiving portions of the three solid-state image pickup devices or the structure thereof is an antireflection film having a low reflectance for blue, green and red, respectively.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The three-plate type camera of the present invention will be described below more specifically with reference to the drawings.

(First Embodiment) FIG. 1 is a conceptual diagram of a three-plate type camera according to the first embodiment of the present invention.

In FIG. 1, a prism 1 is a three-color separation type prism and separates an input image into RGB colors. The white light 2 incident on the prism is red light (R) 3, green light (G) 4, and blue light (B) 5 at the prism 1.
Is decomposed into. Then, the respective decomposed lights are incident on the solid-state imaging devices 6, 7, and 8 arranged behind them. The solid-state image pickup devices 6, 7, and 8 correspond to RGB signals, respectively, and an image for each color can be obtained.

Enlarged views of these solid-state image pickup devices 6, 7 and 8 are shown in FIGS. 2 (a), 2 (b) and 2 (c).

FIG. 2A shows an R-channel, that is, a red-channel solid-state image pickup device 6, which includes an n-type semiconductor substrate 16, a p-well layer 17, a light receiving portion 13, a charge transfer portion 18, a polysilicon electrode 14, It is composed of a metal light shielding layer 19, a flat film 12, a lens array (on-chip lens) 11, and an antireflection film 15.

Numerical data of the refractive index and the film thickness of the antireflection film 15 of the R channel CCD are as follows.

[0021]

[Table 1]

The light passes through the antireflection film 15 and the on-chip lens 11, the flat film 12, and the light receiving portion 13
To reach. Here, the light is focused on the on-chip lens 11 so as not to reduce the amount of light to the light receiving unit 13 by shining light on the charge transfer unit 18. The antireflection film 15 is optimized so as to minimize the reflectance of red light.

FIG. 2B shows a CCD for the G channel, that is, the green channel. The antireflection film 25 at this time is optimized so as to minimize the reflectance of green light.

Numerical data on the refractive index and the film thickness of the antireflection film 25 of the G channel CCD are as follows.

[0025]

[Table 2]

FIG. 2C shows a CCD for the B channel, that is, the blue channel. The antireflection film 35 at this time is optimized so as to minimize the reflectance of blue light.

Numerical data of the refractive index and the film thickness of the antireflection film 35 of the B channel CCD are as follows.

[0028]

[Table 3]

The reflectance of each color CCD is shown in FIG.
This is as shown in (a), (b) and (c).

FIG. 3A shows the reflectance of the lens surface of the CCD 6 of the R channel, and FIG. 3B shows the CC of the G channel.
The reflectance of the lens surface D7 is shown, and FIG. 3C shows the reflectance of the B channel CCD 8 on the lens surface.

As shown in FIGS. 3 (a), 3 (b) and 3 (c), the reflectance for each color is suppressed to be small, and a three-plate type camera with a small loss of sensitivity can be obtained.

[0032]

As described above, according to the present invention,
In the three-plate type camera, the sensitivity can be improved by optimally designing the three solid-state image pickup elements with the antireflection film for each color.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a three-plate camera of the present invention.

FIG. 2A is an enlarged view of an R channel CCD 6 used in the three-plate camera of the present invention. FIG. 2B is an enlarged view of a G channel CCD 7 used in the three-plate camera of the present invention. Enlarged view of B channel CCD8 used for camera

FIG. 3A is a CCD 6 of R channel according to the first embodiment.
(B) shows the reflectance on the lens surface of the G channel CCD 7 of the first embodiment, and (c) shows the reflectance on the lens surface of the B channel CCD 8 of the first embodiment. Diagram showing rate

FIG. 4 is a conceptual diagram showing an example of a conventional three-plate type camera.

FIG. 5 is a conceptual diagram showing a conventional CCD.

[Explanation of symbols]

1 3 color separation type prism 2 white light 3 red light 4 green light 5 blue light Solid-state image sensor for 6 R channel Solid-state image sensor for 7 G channel 8 B-channel solid-state image sensor 11 lens array 12 Flat film 13 Light receiving part 14 Polysilicon electrode 15 Antireflection film (for R channel solid-state image sensor) 16 n-type semiconductor substrate 17 p-well layer 18 Charge transfer unit 19 Metal light shielding layer 25 Anti-reflection film (for G channel solid-state image sensor) 35 Anti-reflection film (for B channel solid-state image sensor) 41 3 color separation type prism 42 white light 43 red light 44 green light 45 blue light 46 R channel solid-state image sensor 47 G-channel solid-state image sensor 48 B channel solid-state image sensor 51 n-type semiconductor substrate 52 p-well layer 53 Light receiving part 54 Charge transfer unit 55 Polysilicon electrode 56 Metal light shielding layer 57 Flat film 58 lens array

Continued front page    (72) Inventor Michihiro Yamagata             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Katsuhiko Hayashi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2H083 AA01 AA11 AA26                 2K009 AA02 AA04 CC03                 5C065 AA01 BB13 CC01 DD02 EE01                       EE12

Claims (7)

[Claims] 1. A three-plate type camera having three solid-state image pickup devices, wherein the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each pixel has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the lens array is formed on each lens array. A three-plate type camera, wherein the antireflection film on the lens array has different thicknesses or configurations. 2. A three-plate type camera having three solid-state image pickup devices, wherein the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each lens has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the light receiving portion (p well layer) is formed on the light receiving portion (p well layer). A three-plate camera in which the thickness or the configuration of the antireflection film on the light receiving portions of the three solid-state image pickup devices are different from each other. 3. A three-plate type camera having three solid-state image pickup devices, wherein the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each pixel has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the lens array is formed on each lens array. An antireflection film having a refractive index different from that of the light receiving portion (p well layer) is formed on the layer).
A three-plate camera in which the thicknesses or configurations of the antireflection films on the lens arrays of the three solid-state imaging devices are different from each other, and the thicknesses or configurations of the antireflection films on the light receiving portions of the three solid-state imaging devices are also different from each other. . 4. A three-plate type camera having three solid-state image pickup devices, wherein the solid-state image pickup device has a plurality of condenser lenses arranged in the vertical and horizontal directions, and each of the condenser lenses is arranged in a two-dimensional plane. Each pixel has a lens array that is installed and used in a one-to-one correspondence, and an antireflection film having a refractive index different from that of the lens array is formed on each lens array. An antireflection film having a refractive index different from that of the light receiving portion (p well layer) is formed on the layer).
The thickness or configuration of the antireflection film on the lens array of the three solid-state image pickup devices is an antireflection film having a low reflectance for blue, green, and red, respectively, and the reflections on the light receiving parts of the three solid-state image pickup devices are The thickness or composition of the barrier film is blue,
A three-plate type camera, which is an antireflection film having a low reflectance for green and red. 5. The antireflection film on the light receiving portion of the solid-state imaging device is made of silicon oxide and / or silicon oxide.
The three-plate type camera according to any one of 4 to 4. 6. A lens array of a solid-state image sensor or /
The three-plate camera according to any one of claims 1 to 4, wherein the antireflection film on the light receiving portion is made of silicon oxide and / or silicon oxide. 7. The solid-state imaging device according to claim 1, wherein the antireflection film on the lens array is made of one layer of silicon oxide, and the RGB solid-state imaging device is different only in thickness. Board camera.