JP2012195758A - Imaging module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress component cost and assembling cost by reducing the number of components composing a member for giving a light shielding function.SOLUTION: A positioning part 18 is provided on an outer peripheral part of a lens other than an effective surface of each lens of a lens array 12. The positioning part 18 fits into an opening 17 provided in a light shielding member 13 disposed between an image sensor 11 and the lens array 12. Thereby, the lens array and the light shielding member can be easily and accurately positioned.

Description

  The present invention relates to an imaging module.

  An imaging apparatus such as a digital video camera or a digital camera forms a two-dimensional image of a subject by forming the subject on an imaging element such as a CCD or CMOS through a lens. Such an imaging apparatus uses an optical system such as a lens array in which a plurality of lenses are arranged so as to form a column or matrix extending in a direction substantially orthogonal to the optical axis. Thinning and miniaturization can be achieved. In recent years, a so-called compound-eye imaging module having a plurality of lenses as described above has been used as a distance measuring module for measuring a distance to a subject. In the compound-eye imaging module, the lenses of the lens array are arranged at different positions, so that each image obtained by capturing light from the same subject from each lens and imaged by the imaging device is a parallax image. Then, the parallax amount of each image is calculated, and the distance to the subject can be calculated based on the calculated parallax amount.

  In such a compound-eye imaging module, the light passing through the lens may include unnecessary light called stray light from other than the effective surface of the lens, or crosstalk light may be generated between adjacent lenses. is there. This stray light appears in the image visualized by the image sensor as flare, which is a phenomenon in which the image becomes whitish due to unnecessary light, or in which the light bleeds, or as a ghost, which is a phenomenon in which the same image appears double or triple. . In order to prevent the occurrence of these flares and ghosts, it is necessary to form a light-shielding portion on the outer periphery of each lens. From a light-shielding member in which an opening corresponding to each lens array is provided between the sensor and the lens array. It is necessary to arrange the light shielding wall to be configured. In the assembly of the lens array and the light shielding wall, there is a problem that due to the variation, an error occurs in the parallax calculated by the calculation and the distance measurement accuracy described above is deteriorated. Further, in order to ensure the above assembly accuracy, it is necessary to provide alignment marks on the lens array and the light shielding wall, respectively, and to use a complicated adjustment mechanism for the assembly, resulting in a problem of high production costs.

  An imaging module for solving this problem is proposed in Patent Document 1. The imaging module of Patent Document 1 includes an imaging element, a lens array, a light shielding film, a light shielding wall, and a light shielding block. The imaging device is provided with an imaging region for each light that has passed through each lens, and photoelectrically converts the light that has passed through the lens as described above. The lens array has a plurality of lenses. The light shielding film is a film member that has an opening corresponding to each lens and shields light at a portion other than the opening. The light shielding wall has a predetermined height in the optical axis direction of the lens, and the light path of the incident light is used to prevent the generation of the crosstalk light that forms an image when light passing through the lens enters an imaging region that does not correspond to the lens. Is provided so as to surround. The light shielding block includes a light shielding housing that shields light from the outside, and the light shielding wall is fitted in the concave portion for positioning in the light shielding housing. In Patent Document 1, the light shielding function is improved by assembling a light shielding wall and a light shielding film to the light shielding block. That is, while preventing the incidence of external light by the light shielding housing of the light shielding block, the light that has passed through the lens other than the lens that should originally pass through the light shielding wall forms an image in which the light that has passed through the lens that should pass through is imaged. The incident is prevented. In addition, the light shielding film prevents light that does not need to be imaged due to the incident angle of light from the subject from passing through the lens to form an image in an imaging region corresponding to another lens. The light shielding block is fitted with a reference surface for contacting a reference surface provided on a portion other than the lens of the lens array, and a recess provided in a light shielding film disposed between the lens array and the light shielding block. And a convex part for the purpose. When assembling the lens array and the light shielding film to the light shielding block, the concave portion of the light shielding film is fitted into the convex portion of the light shielding block, the light shielding block and the light shielding film are positioned, and the light shielding film is fitted into the light shielding housing of the light shielding block. Then, the reference surface of the lens array is pressed against the reference surface of the light shielding block to position the light shielding block and the lens array, and the lens array is assembled from above the light shielding film in the light shielding housing of the light shielding block.

  However, in Patent Document 1, in order to provide a light shielding function, three parts including a light shielding wall, a light shielding housing, and a light shielding film constituting the light shielding block are used. Then, the convex part of the light shielding block and the concave part of the light shielding film are fitted, and the reference surface of the light shielding block and the reference surface of the lens array are brought into contact with each other. For this reason, when forming the convex part and the reference surface on the light shielding block, the positional relationship between the concave part of the light shielding film and the reference surface of the lens array is required to be accurate. Furthermore, when the lens array and the light shielding film are individually assembled to the light shielding block, the optical axis of each lens of the lens array must be coincident with the center of the opening of the light shielding film. The positional relationship between the convex portion, the concave portion of the light shielding film, the reference surface of the light shielding block, and the reference surface of the lens array is also required. In addition to the number of parts that constitute the member having the light shielding function, the processing accuracy of each part is also required, which increases the part cost. In addition, the assembly cost is increased because the assembly is performed while performing a plurality of positioning and securing the mutual positional accuracy using a complicated assembly mechanism.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an imaging module capable of reducing the number of parts constituting a member for providing a light shielding function and suppressing the part cost and the assembling cost. It is to be.

To achieve the above object, the invention of claim 1 is directed to a lens array in which a plurality of lenses are arranged on a plane, an imaging device having a plurality of imaging regions corresponding to the respective lenses, and the lens array. An opening that is arranged between the imaging element, has a predetermined thickness in the optical axis direction of the lens, and allows light from each lens to pass to the corresponding imaging region corresponds to each of the lenses. In the imaging module having the formed light shielding member, a positioning portion for positioning the lens array and the light shielding member is provided on an outer peripheral portion that is outside the effective surface of each lens, and the positioning portion is provided as the opening portion. The lens array is assembled to the light-shielding member so as to match the end of the light-shielding member.
According to a second aspect of the present invention, in the imaging module according to the first aspect, the cross-sectional shape of the outer peripheral surface of the positioning portion is a shape that matches the cross-sectional shape of the end portion of the inner wall of the opening. To do.
Further, the invention of claim 3 is the imaging module according to claim 2, wherein the outer peripheral surface of the positioning portion has a cross-sectional shape extending in the optical axis direction of the lens.
According to a fourth aspect of the present invention, in the imaging module according to the second aspect, the outer peripheral surface of the positioning portion is a tapered surface.
Further, the invention of claim 5 is the imaging module according to claim 1, wherein the positioning portion is provided on an outer peripheral portion outside the effective surface where the curved surface of the lens extends.
According to a sixth aspect of the present invention, in the imaging module according to any one of the first to fifth aspects, the cross-sectional shape other than the end of the opening that matches the positioning portion is a taper shape or a step shape. It is characterized by being.

  In the present invention, a positioning portion for positioning the lens array and the light shielding member is provided on the outer peripheral portion outside the effective surface of the plurality of lenses constituting the lens array, and this positioning portion is provided at the end of the opening of the light shielding member. Match. Since the light shielding member has a predetermined thickness in the optical axis direction of the lens, incidence of light from other than the effective surface of the lens can be prevented by a light shielding portion other than the opening of the light shielding member. As a result, the angle of incidence of light from the subject with respect to the optical axis on the optical axis is increased, and image formation in an imaging region corresponding to a lens other than the lens is prevented. That is, the light incident from the lens does not form an image in an imaging area other than the imaging area corresponding to the lens. These light shielding functions are provided only by fitting the lens effective surface into the opening of the light shielding portion by aligning the positioning portion provided on the outer peripheral portion outside the effective surface of the lens with the end of the opening of the light shielding member. Can be made. That is, the light shielding function can be provided only by the light shielding member having each opening provided corresponding to each lens. Therefore, the number of parts constituting the member having the light shielding function is reduced, and the part cost can be suppressed. Further, since the center of the opening of the light shielding member and the optical axis of each lens coincide with each other in one positioning, a complicated assembling mechanism is unnecessary, and the assembling cost can be reduced.

  As described above, according to the present invention, there is an excellent effect that the number of parts constituting the member for providing the light shielding function can be reduced, and the member cost and the assembling cost can be suppressed.

It is a schematic sectional drawing which shows the structure of the imaging module of this embodiment. It is the elements on larger scale of another structure of the imaging module of this embodiment. It is a schematic sectional drawing which shows the modification of a structure of the imaging module of this embodiment. It is a schematic sectional drawing which shows the modification of a structure of the imaging module of this embodiment.

Hereinafter, an embodiment of an imaging module to which the present invention is applied will be described.
FIG. 1 is a schematic cross-sectional view showing the configuration of the imaging module of the present embodiment. FIG. 1A is an exploded schematic sectional view, and FIG. 1B is an assembled schematic sectional view. In FIG. 1A, the imaging module 10 according to the present embodiment includes an imaging element 11, a lens array 12, and a light shielding member 13. The image sensor 11 is an image sensor such as a CCD, and includes a plurality of pixels that are two-dimensionally arranged in the vertical and horizontal directions (not shown). And the imaging region of the image sensor 11 is each equally divided. Light from the subject that has passed through each lens forms an image on each imaging region of the image sensor 11, and each pixel in each imaging region photoelectrically converts the light from the subject that has entered the electrical signal in accordance with the intensity of the light. Are output respectively. The output electrical signal is subjected to various signal processings and visualized. Each lens 14 constituting the lens array 12 is configured by forming convex lenses 15 and 16 on both sides in the optical axis direction. Further, the light shielding member 13 is disposed between the imaging element 11 and the lens array 12 and has a plurality of openings 17 corresponding to the plurality of lenses 14. Further, the light shielding member 13 has a focal length for forming an image on the corresponding imaging area of the light passing through the lens 14, and the imaging area corresponding to the light passing through the lens other than the corresponding lens. In order to prevent intrusion into the lens, the lens has a predetermined thickness in the optical axis direction of the lens. An effective surface positioning portion 18 is formed on the outer peripheral portion of the convex lens 16. The positioning portion 18 is a portion that is continuous with the lens curved surface of the convex lens 16 and is formed in a region outside the lens effective surface as described above. The positioning portion 18 is formed so that the optical axis direction of the lens is determined in a predetermined direction when the lens array 12 is assembled to the light shielding member 13. On the other hand, the shape of the opening 17 of the light shielding member 13 is formed to match the shape of the positioning portion 18 of the convex lens 16. When the lens array 12 and the light shielding member 13 are assembled, as can be seen from FIG. 1C, which is an enlarged view of the portion surrounded by the dotted line in FIG. 1B and FIG. The positioning portion 18 provided on the outer periphery of the convex lens 16 and the opening portion 17 of the light shielding member 13 coincide with each other. Thereby, the lens array 12 and the light shielding member 13 are positioned.

  As shown in FIG. 2 which is a partially enlarged view, the sectional shape of the positioning portion 18 provided on the outer periphery of the convex lens 16 of the lens array 12 and the sectional shape of the opening portion 17 of the light shielding member 13 are tapered. That is, the outer peripheral surface of the positioning portion 18 and the inner wall surface at the end of the opening 17 are tapered surfaces. Thereby, since both become taper alignment, the positioning operation | work can be implemented easily and correctly further.

  In the embodiment shown in FIGS. 1 and 2, the shape of the positioning portion 18 provided on the outer periphery of the convex lens 16 of the lens array 12 extends in a direction orthogonal to the flat portion of the lens array 12 where the convex lens 16 is not provided. However, the present invention is not limited to this. For example, as shown in FIG. 3, the positioning portion 18 may be formed on an extension line of the lens shape of the convex lens 16. A part of the light shielding member 13 is formed on a curved surface that matches the curved surface of the positioning portion 18 so that the opening shape of the opening 17 of the light shielding member 13 also matches the shape of the positioning portion 18 of the convex lens 15. . In this case, there is no step in the lens shape of the lens array 12, so that the lens can be easily processed.

  Furthermore, as for the shape of the opening 17 of the light shielding member 13, it is only necessary that at least the portion to be positioned with the positioning portion 18 of the convex lens 16 fits with the positioning portion 18, for example, FIG. As shown in FIG. 4, the opening wall 19 of the opening portion 17 other than the portion to be positioned is tapered, or a stepped portion 20 is provided as shown by a dotted line shown in FIG. It is good also as a shape which extended the opening part by the side of the image pick-up element 11 of the opening part 17. As shown in FIG. The wider the opening of the light shielding member 13 on the image sensor 11 side, the greater the number of pixels of the image sensor 11 corresponding to one lens, and the better the resolution. In particular, when the imaging module in the present embodiment is used as a ranging imaging module, the distance accuracy can be improved.

  As described above, according to the embodiment, as shown in FIG. 1, the positioning portion 18 is provided on the outer peripheral portion of the lens other than the effective surface of each lens of the lens array 12. The positioning portion 18 is matched with the end portion of the opening portion 17 provided in the light shielding member 13 disposed between the lens array 12 and the image sensor 11. As a result, the lens array 12 and the light shielding member 13 are positioned. In this way, adjustment of the lens surface and adjustment of coincidence between the optical axis of each lens 15 and the center of the opening 17 of the light shielding member 13 are completed by only one positioning. Further, a complicated assembly mechanism is not required. Therefore, the number of parts can be reduced, and the part cost and assembly cost can be suppressed.

  Further, according to the embodiment, as shown in FIG. 1, the cross-sectional shape of the positioning portion 18 is a linear shape that matches the end cross-section of the opening 17. The cross-sectional shape of the positioning portion 18 is a linear shape extending in the optical axis direction of the lens 14. Moreover, as shown in FIG. 2, the cross-sectional shape of the positioning part 18 is a taper shape. Therefore, the positioning operation can be performed easily and accurately.

  Furthermore, according to the embodiment, as shown in FIG. 3, since the cross-sectional shape of the positioning portion 18 is an extended shape of the curved surface shape of the convex lens 16, the lens can be easily processed.

  Further, according to the embodiment, as shown in FIG. 4, the cross-sectional shape other than the end of the opening 17 with which the positioning portion 18 matches is a tapered shape or a step shape. Therefore, the number of pixels of the image sensor corresponding to one lens increases, and the resolution of the image sensor improves. When such an imaging module is used as a ranging imaging module, the distance accuracy is improved.

DESCRIPTION OF SYMBOLS 10 Image pick-up module 11 Image pick-up element 12 Lens array 13 Light-shielding member 14 Lens 15, 16 Convex lens 17 Opening part 18 Positioning part 19 Opening wall 20 Step part

JP 2009-164654 A

Claims (6)

A lens array in which a plurality of lenses are arranged on one plane, an imaging device having a plurality of imaging regions corresponding to each of the lenses, and an optical axis direction of the lens arranged between the lens array and the imaging device In the imaging module having a predetermined thickness and a light-shielding member formed corresponding to each of the lenses, an opening that allows light from each lens to pass to the corresponding imaging region,
A positioning portion for positioning the lens array and the light shielding member is provided on an outer peripheral portion that is outside the effective surface of each lens, and the lens array is shielded from light by aligning the positioning portion with an end of the opening. An imaging module that is assembled to a member. The imaging module according to claim 1,
The cross-sectional shape of the outer peripheral surface in the said positioning part is a shape matched with the cross-sectional shape of the edge part of the inner wall in the said opening part, The imaging module characterized by the above-mentioned. The imaging module according to claim 2, wherein
The imaging module according to claim 1, wherein a cross-sectional shape of an outer peripheral surface of the positioning portion is a shape extending in an optical axis direction of the lens. The imaging module according to claim 2, wherein
An imaging module, wherein an outer peripheral surface of the positioning portion is a tapered surface. The imaging module according to claim 1,
The imaging module according to claim 1, wherein the positioning portion is provided on an outer peripheral portion outside an effective surface where a curved surface of the lens extends. The imaging module according to any one of claims 1 to 5,
The cross-sectional shape other than the end of the opening with which the positioning portion matches is a taper shape or a step shape.

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