JP2009201008A - Compound-eye imaging apparatus - Google Patents

Abstract

の関係を満たすようにした。
【選択図】図１A compound-eye camera module having a wide imaging area and less dust generation is provided.
A compound-eye imaging device 11 includes a lens array 102 composed of a plurality of lenses arranged so that their optical axes are different from each other, and an imaging element 105 in which an imaging region is divided into a plurality of regions corresponding to the plurality of lenses. And at least one light shielding wall 104 provided between the lens array and the imaging device and provided between a plurality of optical paths respectively formed by a plurality of lenses. The length of one side of the divided imaging region is D, the flange back dimension between the lens array and the imaging device is h, the thickness of the light shielding wall is t, and the distance between the imaging device side end surface of the light shielding wall and the imaging device surface is z. If

To meet the relationship.
[Selection] Figure 1

Description

  The present invention relates to a compound-eye imaging apparatus that images a subject by dividing one imaging element into a plurality of imaging regions.

  In recent years, in order to efficiently collect and use various information scattered around us, camera modules as sensing devices such as surveillance cameras and vehicle-mounted cameras have been proposed. The camera module for such applications is required to have a small outer shape, in particular, to be small and thin. However, downsizing an entire device having a complicated configuration such as a conventional video camera has problems such as structural limitations and very high costs. Therefore, by adopting a unique structure of the sensing device camera module, it is considered to reduce the size and cost of the camera module for such applications.

  For example, Patent Document 1 proposes a compound eye type camera module. Hereinafter, this compound-eye camera module will be described with reference to FIG. The camera module shown in FIG. 8 includes a diaphragm member 701, an optical lens array 702, a light shielding block 703, an optical filter 704, and an imaging unit 705.

  The aperture member 701 includes apertures 701a to 701d at positions where the centers of the optical axes of the lenses 702a to 702d of the optical lens array 702 coincide with each other, and a subject image passes through each of the apertures 701a to 701d. Light is condensed by 702a to 702d. The light shielding block 703 is arranged so as to divide the imaging element 705a on the imaging unit 705 into a plurality of imaging areas, and the image of the subject condensed by the lenses 702a to 702d is formed in the divided imaging areas 705a.

  The imaging unit 705 is provided with a parallax calculation circuit 705b that calculates parallax information between images obtained from a plurality of imaging regions. When images obtained from each of the divided imaging regions are compared, a difference (parallax) occurs in the position of the subject on the image due to the difference in the positional relationship between the lenses 702a to 702d and the subject. The parallax calculation circuit 705b detects the amount of parallax and calculates the distance from the camera to the subject.

  According to such a compound-eye camera module, the focal length of the lens can be shortened as compared with a case where an image of a subject is formed in an imaging region with one large optical lens. For this reason, a camera module can be made thin. Also, by dividing the imaging area of one image sensor into a plurality of areas by using a light shielding block without using a plurality of image sensors, the circuit configuration and signal processing can be simplified compared to the case where a plurality of image sensors are used. can do. The circuit configuration can also be simplified by integrally configuring the parallax calculation circuit on the imaging unit. Therefore, a compact compound-eye camera module having a very simple structure can be realized.

In the compound-eye camera module of FIG. 8, the light blocking block 703 is provided to prevent interference due to light leaking from adjacent lens systems and forming an image. Not only the compound-eye camera module disclosed in Patent Document 1, but when an imaging region is divided into a plurality of regions using a single imaging device, the distance between adjacent lenses cannot be increased. For this reason, in order to prevent light leakage from adjacent lens systems and to correctly photograph the subject in each divided imaging region, it is necessary to provide a light shielding wall. In this case, if the space between the lower end surface of the light shielding wall and the image sensor is wide, the effect of preventing light leakage is not sufficient. Patent Documents 2 and 3 disclose that it is desirable to place the image sensor in contact with a light shielding wall and a protective material disposed immediately above the image sensor.
Japanese Patent Laid-Open No. 2003-143459 JP 2002-171429 A JP 2001-061109 A

  However, according to the above-described structure of the conventional compound-eye camera module, the portion of the imaging area of the imaging device that contacts the light shielding wall cannot be used for imaging the subject. Further, if a margin for an alignment error when providing a light shielding wall is not provided, there is a possibility that the imaging region overlaps with the light shielding wall. For this reason, in the imaging area, the area immediately below and around the light shielding wall must be set as an unused area that is not used for imaging.

  Since there is a limit to thinning the light shielding wall and reducing the alignment error, if the camera module is reduced in size, the proportion of the unused area in the imaging area increases. As a result, the amount of information that can be acquired in one imaging area is reduced, causing problems such as image deterioration and distance measurement accuracy.

  In order to reduce the unused area, it is conceivable to make the light shielding wall thinner. However, in this case, the strength of the light shielding wall is reduced, and chipping of the light shielding wall is likely to occur when the camera module is assembled or used. The dust generated by the chipping adheres to the image sensor or the image sensor protection member and hinders light reception to the image sensor, which causes a large image deterioration.

  SUMMARY OF THE INVENTION An object of the present invention is to solve at least one of the problems of the prior art and to provide a compound eye type camera module having a wide imaging area and less dust generation.

の関係を満たしている。 The compound-eye imaging device of the present invention has a lens array composed of a plurality of lenses arranged so that their optical axes are different from each other, and an imaging region, and the imaging region corresponds to a plurality of lenses of the lens array. An image sensor divided into divided regions, and at least one light-shielding wall provided between the lens array and the image sensor, and provided between a plurality of optical paths respectively formed by the plurality of lenses. And at least one of the plurality of lenses includes an effective opening area of the surface on the image sensor side of the at least one lens and an image sensor area of the image sensor side of the light shielding wall. The projected light shielding from the point farthest from the projected end face region of the light shielding wall of the effective aperture region projected onto the imaging region. The distance from the side of the projected end surface area on the projected effective aperture area side is D, the flange back dimension between the lens array and the image sensor is h, the thickness of the light shielding wall is t, and the light shielding wall When the distance z between the image sensor side end surface and the image sensor surface is,

Meet the relationship.

  In a preferred embodiment, the compound-eye imaging device further includes a barrel that covers the plurality of optical paths formed by the plurality of lenses, and the light shielding wall is formed integrally with the barrel.

  In a preferred embodiment, the compound-eye imaging apparatus further includes a lens barrel that covers the plurality of optical paths formed by the plurality of lenses, and the light shielding wall and the lens barrel are respectively configured by separate members. .

  In a preferred embodiment, the compound-eye imaging device further includes a calculation unit, and images the subject imaged by at least two of the plurality of lenses in at least two corresponding divided regions of the imaging device, The calculation unit detects a parallax amount of an image of a subject obtained from the at least two divided regions, and calculates a distance to the subject based on the detected parallax amount.

  According to the present invention, since the predetermined gap is provided between the imaging element side end face of the light shielding wall and the imaging element surface, it is possible to expand the imaging area to the area below the light shielding wall that could not be used for conventional imaging. Thus, the subject can be imaged in a wide imaging area. When the imaging area is not enlarged, a smaller imaging element can be used, and the compound-eye imaging apparatus can be downsized.

  Further, the light shielding wall can be thickened, and the strength of the light shielding wall can be increased to prevent chipping of the light shielding wall.

(First embodiment)
Hereinafter, a first embodiment of a compound-eye imaging device according to the present invention will be described. FIG. 1 is an exploded perspective view of the compound-eye imaging device 11. The compound eye imaging device 11 includes an upper lens barrel 101, a lens array 102, a lower lens barrel 103, a light shielding wall 104, and an image sensor 105 provided on a substrate 106. These components are arranged in the order of the upper lens barrel 101, the lens array 102, the lower lens barrel 103, the light shielding wall 104, the image sensor 105, and the substrate 106 from the subject side. Hereinafter, for the sake of explanation, coordinate axes X, Y, and Z are set in the compound-eye imaging device 11 as shown in FIG. The XY plane is a plane parallel to the imaging region 105s that is the surface of the imaging element 105, and the Z axis is perpendicular to the imaging region 105s. The compound-eye imaging device 11 of the present embodiment includes four optical systems and is arranged in 2 rows and 2 columns in the XY direction.

  Apertures 101 a to 101 d are formed in the upper lens barrel 101 and have a function of restricting light rays incident on the lens array 102. The upper lens barrel 101 is formed of a material that shields light, and it is preferable that the inner side, that is, the light-side surface incident from the stops 101a to 101d, is subjected to a low reflection treatment.

  The lens array 102 includes, for example, four lenses 102a to 102d having the same optical characteristics, and is integrally molded using a material such as plastic or glass. The upper lens barrel 101 and the lens array 102 are supported by the lower lens barrel 103 so that the centers of the diaphragms 101a to 101d are positioned on the optical axes of the lenses 102a to 102d. The optical axes of the lenses 102a to 102d are parallel to the Z axis. These optical axes do not coincide with each other, and the lenses 102a to 102d are also arranged in 2 rows and 2 columns in the XY direction so that the four optical systems are arranged in 2 rows and 2 columns in the XY direction as described above. Yes.

  The lower lens barrel 103 is attached to the substrate 16 so as to cover the optical paths of the lenses 102 a to 102 d and the image sensor 105 provided on the substrate 106. The lens array 102 has a lower mirror so that the optical axes of the lenses 102a to 102d are perpendicular to the imaging region 105s, and the distance between the imaging region 105s and the lens array 102 matches the focal length of the lenses 102a to 102d. It is held by the cylinder 103.

  A plurality of light shielding walls 104 are provided in the lower barrel 103 by integral molding or assembly. The light shielding wall 104 is located between the optical paths formed by the lenses 102a to 102d. In the present embodiment, four optical paths arranged in two rows and two columns in the X direction and the Y direction are formed in the lower barrel 103 by the lenses 102a to 102d. For this reason, the light shielding wall 104 also extends in the Z direction and is positioned so as to divide the two optical paths in the X direction and the Y direction, respectively.

  The imaging element 105 is an image sensor such as a CCD, for example, and has an imaging area 105s. The imaging region 105s includes a large number of pixels arranged two-dimensionally in the X direction and the Y direction. In the present embodiment, the imaging region 105s is divided into two rows and two columns in the X direction and the Y direction, and includes four divided imaging regions (hereinafter referred to as divided imaging regions) 105a to 105d. In the imaging area 105s, the divided imaging areas 105a to 105d may be physically divided, or the imaging area 105s is a continuous area, and the light beams applied to the divided imaging areas 105a to 105d are respectively One region may be divided by signal processing as being different regions.

  The image of the subject imaged by the compound-eye imaging device 11 passes through the apertures 101a to 101d and is condensed by the lenses 102a to 102d, respectively, and in the divided imaging regions 105a to 105d of the image sensor 105, the image of the independent subject is obtained. Tie. Each pixel constituting the divided imaging regions 105a to 105d photoelectrically converts the incident light and outputs an electrical signal corresponding to the intensity of the light. The output electric signal is subjected to various signal processing by an arithmetic circuit 107 formed on the substrate 106 to generate an image signal. The generated image signal is processed according to the application of the compound eye imaging device 11 and the function of the compound eye imaging device 11.

  For example, when calculating the distance from the compound-eye imaging device 11 to the subject, the arithmetic circuit 107 calculates the parallax amount of the subject image by performing correlation processing on image signals obtained from a plurality of divided imaging regions. The distance from the subject to the compound-eye imaging device 11 can be obtained from the parallax amount using the principle of triangulation. Further, a high-definition subject image can be obtained by combining image signals obtained from a plurality of divided imaging regions in consideration of the amount of parallax.

  2A is a perspective view seen from the opening 103u on the lens array 102 side of the lower barrel 103, and FIG. 2B is a perspective view seen from the opening 103d on the image sensor 105 side. As shown in FIG. 2A, a lens contact surface 201 that supports the lens array 102 and a reference surface 202 that contacts the upper lens barrel are provided on the inner surface of the lower lens barrel 103 on the opening 103u side. Yes. As shown in FIG. 2B, the opening 103 d of the lower barrel 103 is provided with a substrate contact surface 204 that contacts the substrate 106.

  In order to ensure parallelism of the lens array 102 with respect to the XY plane, in other words, the optical axes of the lenses 102 a to 102 d of the lens array 102 are perpendicular to the imaging region 105 s of the imaging device 105 within the range of the design error. In addition, between the lens contact surface 201 and the substrate contact surface 204 so that the flange focal length of the lens array 102 and the image sensor 105 matches the design value within a predetermined accuracy. The distance and parallelism are formed with particularly high accuracy.

  The lower lens barrel 103 and the light shielding wall 104 are preferably molded integrally from the viewpoint of ease of assembly and assembly accuracy. The lower lens barrel 103 and the light shielding wall 104 are made of a material that does not transmit light, and are preferably subjected to various surface treatments such as roughening treatment, plating, and blackening treatment for low reflection.

  As shown in FIG. 2A, in this embodiment, the end surface 203 of the light shielding wall 104 on the opening 103 u side of the lower lens barrel 103 is located behind the lens contact surface 201. The end surface 203 of the light shielding wall 104 may be positioned in the same plane as the lens contact surface 201 so that the end surface 203 also contacts the lens array 102 and supports the lens array 102. In this case, it is preferable that the accuracy of the position of the end surface 203 and the finishing of the surface is as high as that of the lens contact surface 201.

  On the other hand, as shown in FIG. 2B, the end surface 205 of the light shielding wall 104 on the opening 103d side of the lower barrel 103 is in a position recessed from the substrate contact surface 204 by a predetermined distance z0. This distance z0 is longer than the height of the imaging element 105 provided on the substrate 106, and is set so that a predetermined gap is generated between the end face 205 of the light shielding wall 104 and the imaging area 105s of the imaging element 105. Yes. Thereby, while suppressing light leakage to the adjacent optical system, the ratio of the unused area generated on the imaging area by the light shielding wall can be reduced, and the area that can be used for imaging in the imaging area can be increased. . Further, the light shielding wall can be made thick to suppress chipping of the light shielding wall and accompanying dust. Hereinafter, a method for setting the distance z0 will be described in detail.

  FIGS. 3A and 3B are XZ sectional views of the compound-eye imaging device 11, and two of the four optical systems including the lenses 102a and 102b are shown.

  As shown in FIG. 3A, the effective aperture region 102 e on the image sensor 105 side of the lens 102 b and the end surface 205 of the light shielding wall 104 are projected perpendicularly to the image region 105 s of the image sensor 105. A point farthest from the projected end face area (referred to as a projected end face area) 205 ′ in the projected effective aperture area (referred to as a projected effective aperture area) 102 e ′ and a projection in the projected end face area 205 ′. Let D be the distance from the side of the effective opening region 102e ′ side.

  Further, the flange back dimension between the lens array 102 and the image sensor 105 is h, the thickness of the light shielding wall 104 is t, and the distance between the end face 205 of the light shielding wall 104 and the surface of the imaging region 105s of the image sensor 105 is z. .

If the width of the region of light incident from the optical system of the lens 102b to the optical system of the adjacent lens 102a is x with reference to the side of the projection effective aperture region 102e ′ side of the projection end surface region 205 ′, D, The following formula (1) is established from the geometric relationship between figures formed by x, z, and h.

  At this time, among the light rays incident on the effective aperture region 102e on the image sensor 105 side of the lens 102b, the light beam passing through the position farthest from the light shielding wall 104 is the optical system of the lens 102a adjacent to the center of the projection end surface region 205 ′. If the lens does not enter the side, interference with the optical system of the lens 102a does not occur, and an image can be formed up to the center of the projection end face region 205 ′. Since the projection end face area 205 ′ is an area that cannot be used for imaging when the light shielding wall 104 is in contact with the image sensor 105, the projection facet area 205 ′ is thus separated from the image sensor 105 by separating the end face 205 of the light shielding wall 104. The divided imaging area can be enlarged.

  That is, as shown in FIG. 3B, when x is ½ or less of the thickness t of the light shielding wall 104, the light shielding in the imaging region 105s is prevented while preventing the incidence of light from the adjacent optical system. An area located directly below the wall 104, that is, the projection end face area 205 ′ can be used for imaging, and the divided imaging area can be enlarged.

The condition under which the subject can be imaged below the light shielding wall without the light shielding wall 104 being in contact with the surface of the image sensor 105 is expressed by the following equation (2).

  From equation (2), if t is set large, z can be increased. Conversely, if t is decreased, z is also decreased. In order to reduce the distance z between the light shielding wall 204 and the image sensor 105, it is necessary to reduce t. For example, as shown by a broken line in FIG. 3B, when a light shielding wall 104 ′ having a thickness t ′ larger than t is provided, the distance z ′ between the end surface end surface 205 ′ of the light shielding wall and the surface of the imaging element 105 is a distance. It becomes larger than z.

  Therefore, by determining t and z within a range satisfying Expression (2), a distance z between the end face 205 of the light shielding wall 104 and the surface of the image sensor 105 is provided, and an object is imaged below the light shielding wall 104. In addition, a sufficient thickness t of the light shielding wall 104 can be ensured. Similarly, in the lenses 102a, 102c, and 102d, the thickness t of the light shielding wall 104 and the distance z between the end face 205 of the light shielding wall and the surface of the image sensor 105 can be set.

  Thereby, the area which can be imaged in the imaging region 105s can be increased. FIG. 4A is a plan view showing divided imaging regions 105a to 105d in the imaging region 105s of the imaging element in the conventional compound-eye imaging device. As shown in FIG. 4A, according to the prior art, since the light shielding wall is in contact with the surface of the image sensor, the projection end face region 205 ′ on the imaging region 105s of the light shielding wall is a contact region with the light shielding wall. But there is. For this reason, the projection end face area 205 ′ is not irradiated with light, and the divided imaging areas 105a to 105d cannot be set so as to extend into the projection end face area 205 ′, and the divided imaging areas 105a to 105d Adjacent to the projection end face region 205 ′.

  On the other hand, according to the present embodiment, as shown in FIG. 4B, for the reason described above, the subject can be imaged also in the projection end face region 205 ′, and the imaging regions 105a to 105d are formed. It can be set so as to extend into the projection end face region 205 ′. Therefore, when the image sensor 105 having the same size of the imaging area 105s is used, the number of pixels in the divided imaging areas 105a to 105d for imaging the subject can be increased, so that shooting with a wider angle of view is possible. become. On the other hand, when imaging with the same angle of view, higher resolution images can be taken by increasing the resolution of the lens. Further, when calculating the distance to the subject using the amount of parallax of the subject photographed by a plurality of optical systems, the resolution for detecting the amount of parallax is increased, so that the distance can be calculated more accurately.

  On the other hand, when imaging a subject with the same number of pixels as before, it is possible to reduce the area that cannot be used for imaging, so it is possible to capture an image with the same resolution as the conventional image sensor. It becomes. Therefore, the compound eye imaging device 11 can be made smaller.

  Further, since the light shielding wall 104 can be made thicker, the strength of the light shielding wall 104 can be increased compared to the conventional case, and the generation of dust due to chipping of the light shielding wall 104 can be suppressed. Since the end face 205 of the light shielding wall 104 and the surface of the imaging element 105 are separated from each other by a distance z, the light shielding wall 104 and the imaging element 105 do not come into contact with each other when the compound-eye imaging device is manufactured. The possibility of chipping can be reduced.

  In order to provide the distance z with high accuracy, it is preferable to integrally mold the light shielding wall 104 and the lower lens barrel 103. In this case, the distance z0 from the substrate contact surface 204 of the lower barrel 103 to the end surface 205 of the light shielding wall 104 may be set to a value obtained by adding the distance z to the height z1 from the substrate surface to the imaging device surface. That is, z0 = z1 + z. Accordingly, the distance z can be set with high accuracy by bringing the substrate contact surface 204 of the lower lens barrel 103 into contact with the surface of the substrate 06 on which the imaging element 105 is provided.

  If the light shielding wall 104 and the lower lens barrel 103 are integrally molded in this way, even in a compound eye type imaging apparatus having two or more optical systems, the imaging of the end face 205 of the light shielding wall and the imaging is relatively simple and accurate. A distance z to the surface of the element 105 can be set.

  Hereinafter, a method for manufacturing the compound-eye imaging device 11 will be described with reference to FIGS.

  First, as shown in FIG. 5A, the upper lens barrel 101 and the lens array 102 are fitted. The upper lens barrel 101 is provided with a recess 101r that receives the lens array 102, and diaphragms 101a to 101d are provided at the bottom of the recess 101r. By bringing the side surface of the lens array 102 into contact with the side surface 401 of the recess 101r, the centers of the stops 101a to 101d and the centers of the lenses 102a to 102d are made to coincide. The lens array 102 is kept in contact with the upper lens barrel 101 with a jig or the like, and fixed with a UV curing adhesive or the like. Hereinafter, the upper lens barrel 101 in which the lens array 102 is incorporated is referred to as a lens unit 108.

  Next, as shown in FIG. 5B, the lens unit 108 is fixed to the lower barrel 103 formed integrally with the light shielding wall 104. At this time, while the lens contact surface 201 is in contact with the surface 402 of the lens array 102, the side surface of the upper barrel is pressed against the reference surface 202 and fixed. By assembling in this procedure, the position of the lens array 102 and the image sensor 105, in particular the inclination and distance (flange back dimension), with the lower lens barrel 103 as a reference, can be set to the design values with relative ease and accuracy. Can be matched. Hereinafter, the lower barrel 103 to which the lens unit 108 is attached is referred to as a barrel portion 109.

  Next, as illustrated in FIG. 5C, the image sensor 105 is positioned with respect to the substrate 106, and the image sensor 105 is fixed to the substrate 106. The image sensor 105 is electrically connected to the substrate 106 by wire bonding or by a conductive print pattern formed on the substrate 106. An electronic component that processes an electrical signal from the image sensor 105 is fixed to the substrate 106 and is electrically connected to the image sensor 105. The surface of the substrate 106 on which the image sensor 105 is provided is used as a reference surface during assembly. Hereinafter, for the sake of explanation, the substrate 106 on which the imaging element 105 is fixed is referred to as an imaging unit 110.

  Finally, the lens barrel unit 109 and the imaging unit 110 are assembled. The substrate 106, the imaging unit 110, and the lens barrel unit 109 are fixed by a jig or the like so that the surface of the imaging device 105 and the optical axes of the lenses 102a to 102d of the lens array 102 are perpendicular to each other. In this state, the image sensor 105 is driven while collimator light is incident parallel to the lens optical axis. Thereby, it is possible to perform alignment in the XY directions while confirming the optical axis positions of the respective lenses 102a to 102d. After alignment in the XY directions, the lens barrel 109 is brought into contact with the substrate 106 of the imaging unit 110 to perform positioning in the Z direction.

  Thereby, it is possible to easily assemble the compound-eye imaging device 11 without using an expensive assembly device, and to set the accuracy of the distance z.

  Hereinafter, a specific example of the compound eye imaging device of the present embodiment will be described.

  The upper barrel 101, the lower barrel 103, the light shielding wall 104, and the lens array 102 of the compound-eye imaging device 11 are manufactured by injection molding. The lower lens barrel 103 and the light shielding wall 104 are integrally formed. A CCD was used for the image sensor 105, and after being fixed to the substrate 106, it was electrically connected by wire bonding.

As shown in FIGS. 3A and 3B, the distance is D, the flange back dimension h, and the light shielding wall thickness t is as follows. The lens diameter is set to 2.65 mm.
D = 3.15mm
h = 4.841mm
t = 0.20mm

  In this case, the distance z between the end face 205 of the light shielding wall 104 and the surface 105 of the imaging element 105 can be set in the range of 0 <z <0.148 (mm) from Equation (2). These numerical values are practical values from the viewpoint of molding accuracy and assembly accuracy of each part.

  A component mounting error at a distance z between the end face 205 of the light shielding wall 104 and the surface of the imaging region 105s of the imaging element 105 is assumed to be ± 0.01 mm, and the light shielding wall 104 is installed at a position where z = 0.138 mm. Under this condition, the length of one side on the divided imaging region can be increased by 0.0271 mm to 0.0315 mm compared to the conventional structure in which the light shielding wall 104 is in contact with the imaging element 105, and cannot be used for conventional imaging. The region can be reduced by 13.5% to 15.7% in the thickness direction of the light shielding wall.

  The number of pixels of the image sensor used in this example is 7M (3096 pixels × 2328 pixels), and the image sensor 105 in which one pixel is 1.85 μm is divided into two in the longitudinal direction of the image sensor 105 by the light shielding wall 104. In this case, the divided imaging region can be increased by 14 to 17 pixels in the thickness direction of the light-shielding wall 104 (longitudinal direction of the imaging device), and for the entire imaging device 105, 32592 to 39576 pixels.

  Further, the value of the distance z is first determined. At this time, when the thickness t of the light shielding wall satisfying the expression (2) is betted by 0.353 mm, the light shielding wall having a thickness t = 0.2 mm is brought into contact with the image sensor. It is possible to secure a divided photographing area having the same size as that of the case where the image is taken. Therefore, it is possible to increase the strength of the light shielding wall by increasing the thickness of the light shielding wall without reducing the divided imaging region.

(Second Embodiment)
Hereinafter, a second embodiment of the compound-eye imaging device according to the present invention will be described. FIG. 6 is an exploded perspective view of the compound-eye imaging device 12.

  In the case where a plurality of optical systems are separated by the light shielding wall, if the light of the optical system is reflected by the surface of the light shielding wall and becomes stray light, the influence on the image is particularly large. For this reason, the surface of the light shielding wall may be preferably subjected to special surface treatment (texture processing, formation of a reflection-reducing fine structure, etc.) so that the reflectance is particularly small. However, if the light shielding wall and the lower lens barrel subjected to such surface treatment are to be molded integrally, it is necessary to move the mold for molding the light shielding wall in a direction perpendicular to the light shielding wall at the time of mold release. Yes, mold release becomes very difficult. In addition, since the light shielding wall is extremely thinner than other members, it may be possible to increase the molding accuracy of the light shielding wall itself and the dimensional accuracy of the lens barrel reference surface if manufactured separately from the lower lens barrel.

  As shown in FIG. 6, the compound-eye imaging device 12 is different from the first embodiment in that the compound-eye imaging device 12 includes light shielding walls 501 and 502 and a lower lens barrel 103 that are separately formed. The light shielding walls 501 and 502 are configured as parts separated from the lower lens barrel 103.

  FIG. 7 is a perspective view of the light shielding wall 502. The light shielding wall 502 includes a flat plate portion 605 and fitting portions 601 provided at both ends thereof. The flat plate portion 605 has a thin plate shape that separates a plurality of optical paths, and a low reflection structure such as a textured process or a reflection reducing microstructure is provided on the surface. The fitting portion 601 has, for example, a rod shape, and fixes the light shielding wall 502 to the lower lens barrel 103 by fitting with the inner surface of the lower lens barrel 103. Since the flat plate portion 605 has a thin plate shape, the fitting portion 601 is used as a grip portion during assembly. A substrate contact surface 603 that contacts the substrate 106 is provided at one end of the fitting portion 601. The distance between the end surface 604 of the flat plate portion 605 and the substrate contact surface 603 is z0. In addition, a slit 602 is provided on a surface facing the end surface 604 of the flat plate portion 605 in order to fit with the light shielding wall 501.

  The light shielding wall 501 has the same structure as the light shielding wall 502 except that the slit 602 is provided on the end surface 604 side.

  A manufacturing method of the compound eye type imaging device 12 will be described with reference to FIG. First, as described in the first embodiment, the upper lens barrel 101 and the lens array 102 are assembled to complete the lens unit.

  Next, assembly of the light shielding walls 501 and 502 and the lower barrel 103 will be described. The substrate contact surface 204 (FIG. 2B) of the lower lens barrel 103 is fixed on a flat plate with a jig or the like, a light shielding wall 502 is inserted into the inner space of the lower lens barrel 103, and the inner surface of the lower lens barrel 103 is inserted. The fitting portion 601 of the light shielding wall 502 is fitted into the provided receiving portion 503. At this time, while applying pressure so that the substrate contact surface 204 (FIG. 2B) of the lower lens barrel 103 and the contact surface 603 of the light shielding wall 502 are in contact with the flat plate at the same time, the lower lens barrel 103 and the light shielding wall 502 are moved. Glue. As a result, the contact surface 603 of the light shielding wall 502 and the substrate contact surface 204 of the lower lens barrel 103 are positioned on the same plane. As a result, the distance from the substrate contact surface 204 of the lower barrel 103 to the end surfaces 204 of the light shielding walls 501 and 502 can be accurately set to z0.

  Next, the light shielding wall 501 is inserted into the inner space of the lower lens barrel 103, and the fitting portion 601 of the light shielding wall 501 is fitted to the receiving portion 503 of the lower lens barrel 103 while aligning the slit 602 of the light shielding wall 501 with the slit 602 of the light shielding wall 502. To fit. Similar to the light shielding wall 502, the substrate contact surface 204 of the lower lens barrel 103 and the substrate contact surface 603 of the light shielding wall 501 are bonded so as to contact the flat plate. Thereafter, it is preferable to fix the periphery of the slit 602 so that the light shielding walls 51 and 502 do not slide in the slit 602. In this way, the lower lens barrel 103 to which the light shielding walls 501 and 502 are fixed is referred to as a lower lens barrel unit.

  Thereafter, as described in the first embodiment, the lower barrel unit and the lens unit are assembled to complete the barrel unit. Furthermore, after fixing the imaging device 105 to the substrate 106 and assembling the imaging unit, the lens barrel unit and the imaging unit are assembled while performing alignment as described in the first embodiment, and the compound-eye imaging device 12 is assembled. To complete.

  As described above, according to this embodiment, even when the lower lens barrel and the light shielding wall are configured separately, the distance z from the surface of the image sensor to the end surface of the light shielding wall can be accurately determined without using an expensive assembly device. I can decide well. Therefore, it is possible to provide a low reflection structure on the surface of the light shielding wall, suppress the influence of stray light of the optical system, and reduce interference with the adjacent optical system. Further, as in the first embodiment, the imaging region can be enlarged and the light shielding wall can be thickened.

  The compound-eye imaging device of the present invention can capture a subject in a wide imaging area, and thus can be designed to obtain a high-definition image, and the amount of parallax of the subject image obtained from a plurality of optical systems The distance can be accurately calculated based on the above. In addition, since an area that cannot be used for imaging can be reduced, it is possible to capture an image with a smaller imaging element. Therefore, it becomes possible to make the compound-eye imaging device smaller.

  For this reason, the compound-eye imaging device of the present invention is suitably used for a network camera, a vehicle-mounted camera, a portable camera, and the like.

1 is an exploded perspective view showing a first embodiment of a compound eye imaging device of the present invention. (A) And (b) is the perspective view which looked at the lower barrel of the compound eye type imaging device of FIG. 1 from the opening on the lens array side and the perspective view seen from the opening on the imaging element side, respectively. (A) And (b) is sectional drawing of the compound eye type imaging device shown in FIG. 1, Comprising: It is a figure explaining the space | interval of a light-shielding wall and an image pick-up element. (A) is a top view which shows the imaging region divided | segmented by the conventional image pick-up element, (b) is a top view which shows the imaging region divided | segmented by the image pick-up element by this embodiment. (A)-(c) is a perspective view explaining the manufacturing method of the compound eye type imaging device of FIG. It is a disassembled perspective view which shows 2nd Embodiment of the compound-eye imaging device of this invention. It is a perspective view which shows the light-shielding wall of the compound eye type imaging device of FIG. It is a disassembled perspective view of the conventional compound eye system camera module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 12 Compound eye type imaging device 101 Upper lens barrel 101a-101d Aperture 101r Concave part 102 which receives lens array 102 Lens array 102a-102d Lens 102e Effective opening area 102e 'on the image sensor 105 side of lens 102b Tube 104, 501, 502 Light-shielding wall 105 having thickness t ′ larger than light-shielding wall 104 ′ t Image sensor 105a to 105d Divisional imaging region 105s Imaging region 106 Substrate 107 Arithmetic circuit 201 Lens contact surface 202 Reference surface 203 Side end surface 204 Substrate contact surface 205 End surface 205 ′ Projected end surface region 401 Side surface 402 Surface 503 Receiving portion 601 Fitting portion 602 Slit 603 Substrate contact surface 604 End surface 605 Flat plate portion 701 Diaphragm members 701a to 701d Diaphragm 702 Optical lens arrays 702a to 702d Lens 70 Light shielding block 704 optical filter 705 imaging unit 705a imaging device 705b parallax calculating circuit

Claims (4)

A lens array composed of a plurality of lenses arranged so that their optical axes are different from each other;
An imaging device having an imaging region, wherein the imaging region is divided into a plurality of divided regions corresponding to a plurality of lenses of the lens array;
At least one light-shielding wall provided between the lens array and the imaging device, and provided between a plurality of optical paths respectively formed by the plurality of lenses;
With
At least one of the plurality of lenses is
When the effective aperture region of the surface on the image sensor side of the at least one lens and the end surface on the image sensor side of the light shielding wall are respectively projected onto the image sensor region of the image sensor, it is projected onto the image sensor region The distance between the point of the effective opening area farthest from the projected end face area of the light shielding wall and the side of the projected end face area of the light shielding wall on the projected effective opening area side is D,
The flange back dimension between the lens array and the image sensor is h,
The thickness of the light shielding wall is t,
When the distance z between the image sensor side end surface of the light shielding wall and the image sensor surface,

A compound-eye imaging device that satisfies the above relationship. Further comprising a lens barrel covering the plurality of optical paths respectively formed by the plurality of lenses;
The compound-eye imaging device according to claim 1, wherein the light shielding wall is formed integrally with the lens barrel. Further comprising a lens barrel covering the plurality of optical paths respectively formed by the plurality of lenses;
The compound eye imaging apparatus according to claim 1, wherein the light shielding wall and the lens barrel are respectively configured by different members. It further includes an arithmetic unit,
The subjects respectively imaged by at least two of the plurality of lenses are imaged in at least two corresponding divided regions of the image sensor,
The said calculating part detects the amount of parallax of the image | photograph of the to-be-photographed object obtained from the said at least 2 division area, The distance to the to-be-photographed object is calculated based on the detected amount of parallax. Compound eye imaging device.

Images