JP2009182550A - Camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module which is capable of reducing the focal length of a lens without changing the number of pixels and of preventing the occurrence of chromatic aberration. <P>SOLUTION: An imaging device 1 has at least three regions, and a first region 10 of the imaging device 1 has a filter transmitting only red light, and a second region 11 of the imaging device 1 has a filter transmitting only green light, and a third region 12 of the imaging device 1 has a filter transmitting only blue light, and a lens member 2 has a plurality of lens parts 21 corresponding to respective regions of the imaging device 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera module that obtains image data by receiving light condensed by a lens member with an imaging device, and more particularly to a camera module that divides the imaging device into a plurality of regions and obtains monochromatic data in each region.

  2. Description of the Related Art Conventionally, camera modules are known in which light collected by a lens member having a lens portion is received by an image sensor such as a CCD or CMOS, and the light is converted into an electrical signal to obtain image data. In an image sensor used in such a camera module, the light receiving surface is divided into a large number of pixels, and photoelectric conversion is performed for each pixel. In order to obtain image data in color, one pixel is provided with a color filter of one of the three primary colors of light, and a pixel provided with a filter that passes only red light detects the R signal, and the green light A pixel provided with a filter that only passes blue light detects the G signal, and a pixel provided with a filter that passes only blue light detects the B signal.

These pixels are arranged in a grid pattern as shown in FIG. 3 to constitute color image data. FIG. 3 is an enlarged view of a part of the image sensor, in which pixels of the same type are arranged alternately so as not to be adjacent to each other. As such a conventional camera module, there exists a thing which is mentioned to patent document 1, for example.
JP 2005-109092 A

  Since the camera module is built in a small electronic device such as a mobile phone, it is required to be small and thin. However, regarding the thinning, since the focal length of the lens is required to some extent according to the number of pixels, the distance between the lens member and the image sensor cannot be reduced, and there is a limit to the thinning.

  Further, in order to obtain color image data, light of three types of wavelengths is received for each pixel. However, since the refractive index of the lens is different for each wavelength of light, chromatic aberration occurs. In order to correct chromatic aberration, it is necessary to superimpose a plurality of lenses, which increases the cost of the camera module and hinders thinning.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a camera module that can reduce the focal length of a lens without changing the number of pixels and can prevent chromatic aberration from occurring. And

In order to solve the above-described problems, a camera module according to the present invention is a camera module including an imaging element that converts light into an electrical signal to obtain image data, and a lens member that collects light with respect to the imaging element. ,
The image sensor has at least three regions, the first region of the image sensor has a filter that passes only red light, and the second region of the image sensor has a filter that passes only green light. And the third region of the image sensor has a filter that allows only blue light to pass through,
The lens member includes a plurality of lens portions respectively corresponding to the regions of the image sensor.

  In the camera module according to the present invention, the lens member includes the lens portions arranged in an array.

  Furthermore, in the camera module according to the present invention, the imaging element is formed in a substantially rectangular shape, and is divided into four areas vertically and horizontally, and the lens member includes four lens portions so as to correspond to each area of the imaging element. Are arranged in an array.

  Furthermore, the camera module according to the present invention is characterized in that the region of the image sensor is partitioned by a partition plate.

  And the camera module which concerns on this invention is formed so that each lens part which comprises the said lens member may become a predetermined | prescribed focal distance about the center wavelength of the light which the filter which the area | region of the said said image pick-up element passes has passed, The predetermined focal length is the same in all the image sensor regions.

  According to the camera module of the present invention, the imaging device has at least three regions, the first region has a filter that allows only red light to pass, and the second region has a filter that allows only green light to pass through. And the third region has a filter that allows only blue light to pass therethrough, and the lens member includes a plurality of lens portions respectively corresponding to the respective regions of the image pickup device, whereby each lens portion is formed of the image pickup device. Since it is only necessary to have a focal length for forming an image with respect to one divided region, the focal length can be reduced when the size of the imaging device is constant, and the distance between the imaging device and the lens member can be reduced. Since it can be made smaller, it can be made thinner.

  According to the camera module of the present invention, the lens member can be easily manufactured by arranging the lens portions in an array.

  Furthermore, according to the camera module of the present invention, the imaging element is formed in a substantially rectangular shape and divided into four areas in the vertical and horizontal directions, and the lens member has four lens portions so as to correspond to the respective areas of the imaging element. By arranging in an array, the size of the image to be formed can be halved vertically and horizontally without changing the total number of pixels, and the focal length can be halved. be able to.

  Furthermore, according to the camera module of the present invention, the region of the image sensor is partitioned by the partition plate, so that crosstalk between the regions can be prevented and the image quality can be further improved.

  And according to the camera module concerning the present invention, each lens part which constitutes a lens member is formed so that it may become a predetermined focal length about the central wavelength of the light which the filter which the area of the corresponding image sensor passes through, Since the predetermined focal length is the same in all the image pickup device regions, the focal length can be made uniform in each region of the image pickup device, and chromatic aberration can be prevented from occurring.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an exploded view of the camera module in the present embodiment. As shown in this figure, the camera module of the present embodiment includes an image sensor 1 formed in a square plate shape, a lens member 2 formed in a plate shape facing the image sensor 1, and the image sensor 1. And the partition plate 3 provided between the lens member 2, the light collected by the lens member 2 is received by the image sensor 1, and the image sensor 1 converts the light into an electrical signal to obtain image data. It is something that can be done.

  In the image sensor 1, a large number of photoelectric conversion elements are arranged on the light receiving surface. In addition, since the photoelectric conversion element is very minute, it is not described on the drawing. Each photoelectric conversion element is provided with a filter that allows only one of red, green, and blue light to pass through the surface. The image pickup device 1 is partitioned into a cross shape and divided into four regions, upper, lower, left and right, and a large number of photoelectric conversion elements are arranged in each region.

  In FIG. 1, the photoelectric conversion element arranged in the first region 10 represented by (R) in the drawing is provided with a filter that allows only red light to pass, and is adjacent to the right side of the first region 10. The photoelectric conversion element disposed in the second region 11 represented as middle (G) is provided with a filter that allows only green light to pass, and is adjacent to the lower side of the second region 11 in the drawing (B The photoelectric conversion element arranged in the third region 12 indicated by () is provided with a filter that allows only blue light to pass, and is adjacent to the left side of the third region 12 and indicated by (G) in the drawing. The photoelectric conversion element arranged in the fourth region 13 is provided with a filter that allows only green light to pass through. As described above, only the monochromatic filter is provided in each of the regions 10 to 13 of the image sensor 1.

  The lens member 2 is configured by arranging four lens parts 21 in an array on a flat base 20. The base portion 20 is formed of a glass plate, and each lens portion 21 is formed by molding a resin material on the surface of the base portion 20. The lens member 2 forms a large number of patterns with the four lens portions 21 as one pattern on a large glass plate, and forms individual lens members by cutting the large glass plate. Therefore, it can be manufactured easily.

  The four lens units 21 are arranged corresponding to the respective regions 10 to 13 of the image pickup device 1, and condense light to the respective regions 10 to 13. Thereby, monochromatic image data is obtained in each of the regions 10 to 13 of the image sensor 1. Specifically, red image data is obtained in the first area 10, green image data is obtained in the second area 11 and the fourth area 13, and blue image data is obtained in the third area 12. . By combining these in an image generation unit (not shown) inside or outside the image sensor, color image data can be obtained.

  FIG. 2 is a perspective view of the camera module in a state in which the image sensor 1 and the lens member 2 are assembled. As shown in this figure, the regions 10 to 13 of the image sensor 1 are partitioned by a partition plate 3 formed in a cross shape. The partition plate 3 has a height equivalent to the distance between the light receiving surface of the image sensor 1 and the side surface of the image sensor 1 of the lens member 2, and partitions the image sensor 1 and the lens member 2 for each region. Thereby, each lens part 21 of the lens member 2 and each area | region 10-13 of the image pick-up element 1 respond | correspond one-to-one, and the light from one lens part 21 leaks out of the area | region other than the corresponding image pick-up element 1. So-called crosstalk can be prevented.

  Each lens portion 21 constituting the lens member 2 is designed so that the focal length is the same for the center wavelength of the light of the color received by the corresponding region of the image sensor 1. Each color of red, green, and blue has a different central wavelength, and the refractive index with respect to the lens member 2 is also slightly different. Correspondingly, by changing the shape of the lens portion 21 for each color, the focal length can be the same for each color. Thus, it is possible to prevent chromatic aberration that cannot be avoided with a single lens in the configuration of the conventional camera module.

  Further, since the light from each lens unit 21 forms an image on one area of the image pickup device 1 divided into four parts, the vertical and horizontal directions are halved as compared with the conventional camera module that forms an image on the entire image pickup device 1. The image is formed on a region having a size. Therefore, the focal length of each lens unit 21 can be halved when the size of the image sensor 1 is the same as the conventional one and the same number of pixels. That is, the interval between the image sensor 1 and the lens member 2 can be reduced. On the other hand, since the number of pixels as the whole image does not change, the image quality is not deteriorated.

  Furthermore, since each lens unit 21 has a focal length that is half that of the conventional lens unit, other aberrations can be reduced in addition to the chromatic aberration described above. Accordingly, since image data with higher image quality can be obtained in the image sensor 1, even if they are combined to generate final image data, the image quality can be prevented from being lowered as compared with the conventional case.

  Although the embodiment of the present invention has been described above, the application of the present invention is not limited to this embodiment, and can be applied in various ways within the scope of its technical idea. For example, in the present embodiment, the lens member 2 is formed by arranging the lens portions 21 on the base portion 20 in an array, but the plurality of lens portions 21 are separate members and are positioned by positioning means. It may be. In this case, it is possible to prevent chromatic aberration from occurring by changing the position in the optical axis direction for each region of the corresponding image sensor 1 while keeping the shape of each lens portion 21 the same.

  In the case where the lens portions 21 are arranged in an array shape, a plurality of through holes may be formed in the base portion 20 and the lens portions 21 may be molded so as to fill the through holes. The shape can be changed, and the chromatic aberration can be prevented from occurring by changing the surface formation position of the lens portion 21.

  In the present embodiment, the image pickup device 1 is divided into four areas, upper, lower, left, and right. However, at least three of the area that receives red, which is the three primary colors of light, the area that receives green, and the area that receives blue. What is necessary is just to be divided | segmented into the area | region. However, by dividing into four regions as in the present embodiment, image data with the same resolution can be obtained when the number of pixels is the same as that of the conventional imaging device 1.

  In the camera module according to the present invention, light is collected by the lens units 21 corresponding to the plurality of regions of the image sensor 1, so that images with slightly different angles are generated for each region. The camera module is assumed to be built in a small electronic device, and since the camera module is small, the difference in angle hardly poses a problem. However, when the difference in angle affects the image quality, such as when performing close-up photography, processing for correcting the difference in angle may be performed when the image is combined in the image generation unit.

It is a disassembled perspective view of the camera module in this embodiment. It is a perspective view of the camera module which assembled the image sensor and the lens member. It is the expanded schematic diagram of the conventional image pick-up element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 Lens member 3 Partition plate 10 1st area | region 11 2nd area | region 12 3rd area | region 13 4th area | region 20 Base 21 Lens part

Claims (5)

In a camera module comprising an image sensor that converts light into an electrical signal to obtain image data, and a lens member that condenses the light to the image sensor,
The image sensor has at least three areas, the first area of the image sensor has a filter that passes only red light, and the second area of the image sensor is a filter that passes only green light. And the third region of the image sensor has a filter that allows only blue light to pass through,
The camera module according to claim 1, wherein the lens member includes a plurality of lens portions respectively corresponding to the regions of the image sensor.   The camera module according to claim 1, wherein the lens member has the lens portions arranged in an array.   The imaging element is formed in a substantially rectangular shape and is divided into four areas in the vertical and horizontal directions, and the lens member is formed by arranging four lens portions in an array so as to correspond to each area of the imaging element. The camera module according to claim 1.   The camera module according to claim 1, wherein a region of the imaging element is partitioned by a partition plate.   Each lens part constituting the lens member is formed to have a predetermined focal length with respect to a center wavelength of light that passes through a filter included in a corresponding region of the image sensor, and the predetermined focal length The camera module according to claim 1, wherein the camera module is the same in a region of the image sensor.

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