WO2012169363A1

WO2012169363A1 - Method for producing stereo camera and stereo camera

Info

Publication number: WO2012169363A1
Application number: PCT/JP2012/063294
Authority: WO
Inventors: 水上雅文
Original assignee: コニカミノルタアドバンストレイヤー株式会社
Priority date: 2011-06-10
Filing date: 2012-05-24
Publication date: 2012-12-13

Abstract

Provided are: a method for producing a stereo camera that causes the adjustment of two camera modules to be as simple as possible, is able to reduce the likelihood of deviation or the like of adjusted position resulting from vibration, shock, or changes over time, and can exert stable performance over the long term; and a stereo camera produced by the method for producing a stereo camera. As it is possible to cause the deviation of two black dot images (BPL, BPR) to lie only in the lengthwise direction (or left-right direction) of an observation screen by means of the simple adjustment of rotating the camera modules (20L, 20R), it is possible to reduce the cost of the stereo camera without an increase in steps.

Description

Stereo camera manufacturing method and stereo camera

The present invention relates to a stereo camera manufacturing method and stereo camera for obtaining stereoscopic image data.

In recent years, subject light imaged by solid-state image sensors such as CCD (Charged Coupled Device) type image sensors and CMOS (Complementary Metal Oxide Semiconductor) type image sensors has been converted into digital image data, and storage media such as built-in memory and memory cards Digital cameras that record data are widely used.

As one type of such a digital camera, a so-called stereo camera is known that can capture a stereoscopic image using two imaging units. In this stereo camera, the same subject can be simultaneously imaged by each imaging unit, and two types of images, a right-eye image and a left-eye image, can be acquired.

The acquired two types of images are displayed alternately on the image display device, and glasses that are transparent and non-transparent in synchronization with the display image are put in front of the right eye and the left eye so that stereoscopic viewing is possible. Some display devices are provided with a lenticular lens or the like on the front surface to enable stereoscopic viewing with the naked eye.

By the way, in order to shoot such a stereoscopically visible image, the two acquired images should have parallax by arranging the optical axes of the two cameras in parallel and spaced apart at a predetermined interval. Is required. On the other hand, as shown in Patent Document 1, a technique is known in which a circuit board including a lens and an image pickup element is assembled from the front and back to an integral support member, and the position of the circuit board is moved and rotated in the plane. .

In addition, as shown in Patent Document 2, two circular openings are formed in one plate, a camera module is inserted into each opening, and a flat portion formed in the camera module is brought into contact with the plate surface. Therefore, a technique for making the optical axes of two camera modules parallel is also known.

Japanese Patent Laid-Open No. 2001-242521 International Publication No. 2009/57436 Pamphlet

However, according to the technique of Patent Document 1, adjustment is performed by in-plane displacing the image sensor in the XY direction and the θ direction using a screw or the like as an adjustment unit, which increases man-hours and costs. is there. In addition, when there are a large number of adjustment units, there is a high possibility that the adjustment position of the image sensor that has been adjusted at the folding angle will shift due to vibration, impact, change with time, etc., and the performance cannot be exhibited stably.

On the other hand, the technique of Patent Document 2 is effective for keeping the optical axis parallel, but describes how to deal with the shift in the rotation direction of the two images obtained by the two camera modules. It has not been.

In view of the above problems, the present invention makes the adjustment of the two camera modules extremely simple, can reduce the possibility of deviation of the adjustment position due to vibration, impact, aging, etc., and is stable over a long period of time. It is an object of the present invention to provide a method of manufacturing a stereo camera capable of exhibiting performance and a stereo camera manufactured thereby.

The method for manufacturing a stereo camera according to claim 1 includes a cylindrical lens barrel portion that includes a photographing optical system and an image sensor in order to acquire two images having parallax for stereoscopic viewing. In a method of manufacturing a stereo camera in which two camera modules are arranged on a support member,
The optical axis of the imaging optical system and the imaging surface of the imaging element are orthogonal to each other, and the optical axis of the imaging optical system is positioned on the middle line of two long sides of the outer edge of the effective pixel area of the imaging surface. A camera module manufacturing process for manufacturing a camera module;
An assembling step of inserting and incorporating the lens barrel portions of the two camera modules into two circular openings formed at predetermined intervals in the support member;
An adjustment process to be performed after the assembly process,
The adjusting step is performed only by rotating at least one of the two camera modules around the optical axis within the circular opening.

The present inventor mainly aims to give the observer a perspective and stereoscopic effect, so that two images having parallax for stereoscopic viewing are displayed on, for example, a horizontally long display screen. When displaying with parallax in the long side direction (left and right direction), it is necessary that the shooting range in the short side direction (up and down direction) of the display screen is substantially the same, and the long side direction ( We focused on the fact that the amount of deviation between the two images in the left-right direction does not require much accuracy for the purpose of obtaining stereoscopic vision. Therefore, in the adjustment step, by rotating at least one of the camera modules around the optical axis within the circular opening, the shooting range in the short side direction can be substantially matched, and the parallax for stereoscopic viewing only in the long side direction It was found that can be given. On the other hand, as 3D image shooting equipment, it is used in various shooting sites, so it is preferable to have resistance to vibration and impact as much as possible and not change with time. If the lens barrel part is inserted and bonded, the structure can be maintained for a long period of time because it has a resistance to vibration and impact while achieving a simple structure, and can exhibit stable performance. . The “circular opening” is sufficient if at least a part of the opening is circular, and may be any structure that can rotate the camera module around the optical axis of the imaging optical system. “To make the optical axis of the imaging optical system orthogonal to the imaging surface of the imaging element” means to make them orthogonal with an error of ± 0.5 degrees or less, and to “two outer edges of the effective pixel area of the imaging surface” “Locating the optical axis of the imaging optical system on the middle line of the long side” means matching within an error of ± 40 μm.

The method for manufacturing a stereo camera according to claim 2 is the invention according to claim 1, wherein the adjustment step is performed by photographing the same mark on the surface to be photographed by the two camera modules arranged on the left and right. While displaying the mark images obtained by the photographing of the two camera modules on the observation screen, respectively, at least one of the camera modules is set so that the vertical positions of the mark images displayed on the observation screen are equal. Rotating around the optical axis within a circular opening.

As a result, the image shift obtained by the two camera modules can be made to exist only in the long-side direction (left-right direction) of the display screen by simple adjustment, so that man-hours are not required and costs are reduced. Can do. The “mark” includes, but is not limited to, a dot or a crosshair, and may be any mark that can be recognized as a target for adjustment.

The stereo camera according to claim 3 is manufactured by the stereo camera manufacturing method according to claim 1 or 2.

The stereo camera according to claim 4 is the invention according to claim 3, wherein the support member is also used as a component constituting the stereo camera. For example, by using a part of the case of the stereo camera as a support member, the weight can be reduced and the number of parts can be reduced.

According to the present invention, the adjustment of the two camera modules can be made extremely simple, the possibility that the adjustment position shifts due to vibration, impact, change with time, etc. can be reduced, and stable performance over a long period of time. It is possible to provide a method of manufacturing a stereo camera that can be exhibited and a stereo camera manufactured thereby.

It is a perspective view of the stereo camera concerning this Embodiment, (a) is a rear side perspective view, (b) is a front side perspective view, (c) is a perspective view. 1 is a block diagram of a stereo camera 10. FIG. FIG. 4 is a flowchart showing a manufacturing process of the stereo camera 10. It is an assembly drawing of a camera module. It is principal part sectional drawing of a supporting member and a camera module which shows the assembly process to the supporting member 16 of the

camera modules

20L and 20R, (a) is before incorporating a camera module in a supporting member, (b) is after incorporating. Indicates. It is a perspective view which shows the assembly process to the support member 16 of the

camera modules

20L and 20R, (a) shows before incorporating a camera module into a support member, (b) shows after incorporation. It is a front view of the support member 16 assembled | attached with

camera modules

20L and 20R. FIG. 6 is a flowchart showing an adjustment process of the stereo camera 10. It is the schematic of the adjustment apparatus used for an adjustment process. It is a figure explaining adjustment process (a)-(g). (A) is a perspective view which shows the stereo camera concerning the modification manufactured by the manufacturing method of this Embodiment, (b) is the partial cross section figure.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1A and 1B are perspective views of a stereo camera according to the present embodiment. FIG. 1A is a rear perspective view, FIG. 1B is a front perspective view, and FIG. 1C is a perspective view. Only the module is shown, and the internal circuit and the like are not shown.

The stereo camera 10 has two

openings

11L and 11R for taking in subject light on the front side of the housing 11 as shown in FIG. As shown in FIG. 1A, the stereo camera 10 has a display unit 12 such as a display on the back side of the casing 111, and

function buttons

13 and 14 are provided on the side of the display unit 12. Further, a release button 15 is provided on the upper portion of the housing 11.

Further, as shown in FIG. 1C, the stereo camera 10 is provided with two

camera modules

20L and 20R supported by the support member 16 so as to face the

openings

11L and 11R, respectively.

FIG. 2 is a block diagram showing the relationship between the main parts of the stereo camera 10. In FIG. 2, the control unit 17 supplied with power from the power supply unit 19 inputs image signals from the left-eye camera module 20 </ b> L and the right-eye camera module 20 </ b> R in response to the release signal from the release button 15. Image data obtained by performing various image processing is input to the display unit 12, and a 3D image is displayed. Such image data is stored in a storage unit 18 such as a memory. As examples of the

function buttons

13 and 14, in FIG. 2, a stereo shooting / non-stereo shooting switching switch and a moving image / still image switching switch are provided. When stereo shooting is selected with the stereo shooting / non-stereo shooting switch, shooting and recording are performed using both the

camera modules

20L and 20R, and when non-stereo shooting is selected, Shooting / recording is performed by only one of the

camera modules

20L and 20R.

FIG. 3 is a flowchart showing the manufacturing process of the stereo camera 10 according to the present embodiment. FIG. 4 is an assembly diagram of the camera module.

The manufacturing process of the stereo camera 10 will be described with reference to the drawings. In step S101 of FIG. 3, as shown in FIG. 4, a substrate 21 on which a circuit (not shown) is printed is set, and in step S102, a sensor package SP including an image sensor (sensor) 22 is mounted on the substrate 21. . Further, in step S103, a lens 23 as a photographing optical system is inserted and bonded to the hollow lens barrel portion 24 to form a lens unit LU, and then the center of the image sensor 22 and the optical axis of the lens 23 coincide with each other. In addition, the lens unit LU is attached to and adhered to the sensor package SP so that the imaging surface of the imaging element 22 is orthogonal to the optical axis of the lens 23. It is assumed that the optical axis of the lens 23 included in the lens barrel portion 24 is parallel to the cylindrical outer peripheral surface 24 a of the lens barrel portion 24 and is orthogonal to the lower end of the lens barrel portion 24.

As a method for attaching the lens unit LU to the sensor package SP with high accuracy, there are the following examples.
(A) Light required as the center of the outer periphery of the lens barrel portion 24 on the assumption that the center coordinates of the imaging surface (effective pixel area) of the imaging device 22 are accurately positioned with respect to the outer shape of the sensor package SP. By moving the axis to the center coordinates depending on the outer shape of the sensor package SP, the center of the image sensor 22 and the optical axis of the lens 23 can be matched with high accuracy. Or
(B) The imaging device 22 is photographed with a camera from the imaging surface side, the center of the effective pixel region is obtained from its outer shape, the lens 23 is photographed with the camera from the image surface side, and the center of the lens 23 is obtained from its outer diameter, The center of the image sensor 22 and the optical axis of the lens 23 are accurately matched by moving and superimposing the center of the lens 23 and the center of the image pickup surface (effective pixel area) of the image sensor 22 so as to substantially match. Can be made.
In the present embodiment, it is sufficient to position the optical axis of the imaging optical system on the middle line of the two long sides of the outer edge of the effective pixel area on the imaging surface.

Furthermore, on the assumption that the lower end of the lens barrel portion 24 is accurately orthogonal to the optical axis of the lens 23, the lower end of the lens barrel portion 24 is placed on the upper surface of the sensor package SP, so that the imaging device The 22 imaging surfaces are perpendicular to the optical axis of the lens 23 with high accuracy.

After attaching the lens unit LU to the sensor package SP with high accuracy through the above camera module manufacturing process, the

camera modules

20L and 20R are completed through the inspection process of step S104 in FIG. 3 (step S105). Next, the

camera modules

20L and 20R are assembled to the support member 16 in step S106 (assembly process).

FIGS. 5 and 6 are diagrams showing an assembling process of the

camera modules

20L and 20R into the support member 16. FIG. FIG. 7 is a front view of the support member 16 in which the

camera modules

20L and 20R are incorporated.

The support member 16 is, for example, a rectangular plate material, and

circular openings

16L and 16R are formed at predetermined intervals as shown in FIGS. 5 (a) and 6 (a). As shown in FIGS. 5B and 6B, the

camera modules

20L and 20R are inserted into the

circular openings

16L and 16R from the same side, and the cylindrical outer peripheral surface 24a of the lens barrel portion 24 is fitted. I am letting. At this time, since the

circular openings

16L and 16R and the cylindrical outer peripheral surface 24a in FIG. 7 are clearance fitting, they can be rotated relative to each other, and bonding is not performed at this point.

Thereafter, an adjustment process is performed in step S107 of FIG. Hereinafter, the adjustment process will be described in detail. FIG. 8 is a flowchart showing the adjustment process of the stereo camera 10 and shows the contents of step S107. FIG. 9 is a schematic diagram of an adjustment device used in the adjustment process, and FIG. 10 is a diagram illustrating the adjustment process.

First, in step S107a in FIG. 8, the support member 16 to which the

camera modules

20L and 20R are attached is set in the adjusting device. More specifically, as shown in FIG. 9, the support member 16 is horizontally attached to the base BS, the optical axes of the

camera modules

20L and 20R are directed to the screen SC, and the outputs of the

camera modules

20L and 20R are further displayed on the display DP. The wirings WL and WR are connected so that they can be output. Note that a black dot (mark) BP is formed at the center of the screen SC.

Next, in step S107b, the black spot image BP photographed by the

camera modules

20L and 20R is displayed on the observation screen of the display DP. At this time, as shown in FIG. 10A, the horizontal positions of the

camera modules

20L and 20R are shifted. As a result, as shown in FIG. 10B, the black spots BP on the imaging surfaces of the

camera modules

20L and 20R. Are assumed to be shifted from the center of the imaging surface in the x and y directions. Here, the horizontal base line (long side middle line) of the imaging surface is HL, and the vertical base line (short side center line) is VL.

Further, when the outputs of the two

camera modules

20L and 20R are combined so that the horizontal base line HL and the vertical base line VL overlap each other, as shown in FIG. 10C, two black dot images BPL and BPR are displayed on the observation screen. Displayed at different positions on the top. In such a state, an appropriate parallax suitable for 3D display cannot be given to the stereo camera.

Therefore, in step S107c, as shown in FIG. 10D, the camera module 20R is rotated, for example, counterclockwise within the circular opening 16R. Then, since the position of the center of the imaging surface does not change and the imaging surface is tilted, the horizontal base line HL is also tilted. Therefore, the black dot image BPR on the observation screen is relatively displaced as indicated by the arrow. (See the right figure in FIG. 10E).

Further, in step S107d, as shown in FIG. 10D, the camera module 20L is rotated, for example, counterclockwise within the circular opening 16L. Then, since the position of the center of the imaging surface does not change and the imaging surface is tilted, the horizontal base line HL is also tilted. Therefore, the black dot image BPL on the observation screen is relatively displaced as indicated by the arrow. (Refer to the left figure of FIG. 10 (e)).

As described above, when the

camera modules

20L and 20R are rotated, the imaging surface is inclined with respect to the horizontal. However, the images themselves output from the

camera modules

20L and 20R are as shown in FIG. Then, when the outputs of the two

camera modules

20L and 20R are combined so that the horizontal base line HL and the vertical base line VL overlap, the black dot image BPL is horizontal on the observation screen as shown in FIG. Displayed in a state shifted only in the direction.

In other words, in this state, when viewed from the optical axis direction of the imaging optical system of the

camera modules

20L and 20R, the outer edge of the effective pixel region parallel to the horizontal base line of each imaging element is substantially parallel to the line connecting the respective optical axes. This state can be achieved only by rotating the camera module around the optical axis.

That is, when the center positions of the

circular openings

16L and 16R formed in the support member 16 are shifted from the predetermined positions on the support member 16, or the diameters of the

circular openings

16L and 16R and the

camera modules

20L and 20R. Even when the diameter of the cylindrical outer peripheral surface 24a is larger than the fitted state, the adjustment can be performed only by rotating the camera module around the optical axis.

Although rare, in some cases, it may be possible to adjust by rotating only one of the

camera modules

20L and 20R.

Here, if the positions of the two black dot images BPL and BPR displayed on the observation screen of the display DP after adjustment are equal to the vertical distance Δ with respect to the horizontal base line HL (the y coordinate is equal on the imaging surface). Therefore, a stereo camera capable of capturing an image having a parallax only in the horizontal base line HL direction suitable for 3D display on the observation screen of the display DP can be obtained. However, the relative distance between the two black dot images BPL and BPR in the horizontal base line HL direction may be ignored. Therefore, in step S107e, it is determined whether or not the positions of the two black dot images BPL and BPR have the same vertical distance with respect to the horizontal base line HL. If not, the process returns to step S107b and the same steps are repeated. On the other hand, if the positions of the two black dot images BPL and BPR are equal to the horizontal base line HL, the lens barrel 24 of the

camera modules

20L and 20R is bonded to the support member 16 in step S107f. The adjustment process is completed.

Thereafter, in step S108 of FIG. 3, the performance of the stereo camera is checked. If the target optical performance is satisfied, the stereo camera is completed.

According to the present embodiment, with the simple adjustment of rotating the

camera modules

20L and 20R, the deviation between the two black dot images BPL and BPR is present only in the long side direction (or left and right direction) of the observation screen. Therefore, man-hours are not required and the cost of the stereo camera can be reduced.

FIG. 11A is a perspective view of a portable terminal having a stereo camera according to a modification manufactured by the manufacturing method of the present embodiment, and FIG. 11B is a partial cross-sectional view thereof. . The portable terminal MV has a case CA on the back side, but the stereo camera of this modification also uses the case CA as a support member. That is, as shown in FIG. 11B, the case CA has circular openings CAL and CAR, into which the lens barrel portions 24 of the

camera modules

20L and 20R are fitted. Other than that, it is the same as that of embodiment mentioned above also including an adjustment process.

The present invention is not limited to the embodiments described in the specification, and it is apparent to those skilled in the art from the examples and ideas described in the present specification that other embodiments and modifications are included. It is. The description and the embodiments are for illustrative purposes only, and the scope of the present invention is indicated by the following claims.

DESCRIPTION OF SYMBOLS 10 Stereo camera 11 Housing | casing 11L, 11R Opening 12

Display part

13,14 Function button 15 Release button 16 Support member 16L Circular opening 16R Circular opening 17 Control part 18 Memory | storage part 19 Power supply part

20L Camera module

20R Camera module 21 Board | substrate 22 Imaging element 23 Lens 24 Lens barrel portion 24a Cylindrical outer peripheral surface BP Black point BPL Black point image BPR Black point image BS Pedestal CA Case CAL, CAR Circular aperture DP Display HL Horizontal base line WR Wiring WL Wiring LU Lens unit MV Mobile terminal SC Screen SP Sensor package VL Vertical baseline

Claims

In order to acquire two images having parallax for stereoscopic viewing, a stereo in which two camera modules each having a cylindrical lens barrel portion including an imaging optical system and an image sensor are arranged on a support member In the manufacturing method of the camera,
The optical axis of the imaging optical system and the imaging surface of the imaging element are orthogonal to each other, and the optical axis of the imaging optical system is positioned on the middle line of two long sides of the outer edge of the effective pixel area of the imaging surface. A camera module manufacturing process for manufacturing a camera module;
An assembling step of inserting and incorporating the lens barrel portions of the two camera modules into two circular openings formed at predetermined intervals in the support member;
An adjustment step performed after the assembly step,
The method of manufacturing a stereo camera, wherein the adjusting step is performed only by rotating at least one of the two camera modules around the optical axis within the circular opening.
The adjustment step is to shoot the same mark on the surface to be imaged by the two camera modules arranged on the left and right, while displaying the mark images obtained by the imaging of the two camera modules on the observation screen, The at least one camera module is rotated around the optical axis in the circular opening so that the vertical positions of the mark images displayed on the observation screen are equal. Stereo camera manufacturing method.
A stereo camera manufactured by the method for manufacturing a stereo camera according to claim 1 or 2.
4. The stereo camera according to claim 3, wherein the supporting member is also used as a part constituting the stereo camera.