JP2013007971A - Focus adjustment device, camera module manufacturing apparatus, focus adjustment method, camera module manufacturing method, focus adjustment program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focus adjustment device that has high manufacturing efficiency and can be realized in a compact size.SOLUTION: A focus adjustment device includes a detection unit for detecting a distance y, an arithmetic unit for calculating a distance dz obtained using the following formula (1), and a focus adjustment unit for shortening the relative distance between a focus lens and an image surface by the distance dz.

Description

  The present invention relates to the manufacture of a camera module, and more particularly to position adjustment of a focus lens.

  In recent years, the mounting rate of a camera module for capturing a still image or a moving image in a mobile device such as a mobile phone is increasing, which is a factor in increasing demand for the camera module. In recent years, camera modules mounted on mobile phones and the like have been required to have higher pixels, higher performance, and higher functionality from the viewpoint of improving image quality, etc., and focus adjustment of the focus lens of the camera module should be performed optimally. Is required. In particular, in the case of a camera module mounted on a mobile device, it is usually manufactured assuming that the focus is at least at infinity or a predetermined close-up distance (hereinafter referred to as “optimum object distance”). It is required to adjust the focus well during manufacturing. In the production process of the camera module, the position of the light-receiving image plane of the sensor and the lens are assembled during assembly of a light-receiving sensor (individual imaging device) such as a CCD (charge coupled device) sensor or a CMOS (complementary metal oxide semiconductor) sensor. And a process for adjusting the relative relationship in the optical axis direction.

  In general, the focus is adjusted during the manufacturing process while the operator visually confirms the captured image of the camera module displayed on the display unit of the tester and manually moves the focus lens of the camera module along the optical axis direction. To adjust the focus position. Alternatively, the operator adjusts the focus while confirming the indicator indicating the sharpness of the captured image displayed on the display unit of the tester by manual operation.

  However, when the focus is adjusted manually by an operator, there is a problem that the manufacturing cost is drastically increased due to a high labor cost. Further, there is a problem in that the focus adjustment accuracy differs depending on the worker, that is, the quality of the camera module is affected by the worker, and it is difficult to sufficiently stabilize the quality.

  On the other hand, in Patent Document 1 below, a focus for adjusting the position of the focus lens by obtaining optimum position information that maximizes the focus degree from an approximate curve indicating the relationship between the position information of the focus lens and the focus degree. An adjustment device is disclosed.

JP 2009-3152 A (published January 8, 2009)

  However, since the focus adjustment apparatus disclosed in Patent Document 1 requires several images with different focus adjustment positions to obtain an approximate curve, a great amount of time is required for adjustment. In addition, since the focus adjustment device performs focus adjustment on an object arranged in the device, the position of the object in the device is changed every time the optimum object distance of the camera module to be adjusted is changed. Therefore, a large-scale modification of the device is required. Further, when the optimum object distance of the camera module is relatively long, the size of the focus adjustment device becomes large, resulting in an increase in the production facility of the camera module.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a focus adjustment device and a focus adjustment method that are highly productive and can be realized in a compact manner.

  In order to solve the above-described problem, a focus adjustment device according to the present invention is a focus adjustment device including a position adjustment unit that adjusts a relative position of a camera module with respect to an image plane of a focus lens. Detection means for detecting a distance y between a position where a straight line passing through the center of the focus lens and forming an angle θ with respect to the optical axis of the focus lens intersects the image plane and a position where the optical axis and the image plane intersect And calculating means for calculating a distance dz obtained by the following equation (1), where a is the optimum object distance applied to the camera module, and f is the focal length of the focus lens. The relative distance between the focus lens and the image plane is shortened by a distance dz.

  In order to solve the above-described problem, a focus adjustment method according to the present invention is a focus adjustment method including a position adjustment step of adjusting a relative position of a camera module with respect to an image plane of a focus lens, before the position adjustment step. , The distance y between the position where a straight line passing through the center of the focus lens and forming an angle θ with respect to the optical axis of the focus lens intersects the image plane and the position where the optical axis and the image plane intersect is detected. And a calculation step of calculating a distance dz obtained by the following formula (1), where a is the optimum object distance applied to the camera module, and f is the focal length of the focus lens. In the position adjustment step, the relative distance between the focus lens and the image plane is shortened by a distance dz.

  According to the above configuration, the distance dz is calculated from the angle θ, the distance y, the optimum object distance a, and the focal distance f, and the relative distance between the focus lens and the image plane is shortened by the distance dz. Can be adjusted to the best image plane position. That is, since the focus adjustment amount can be calculated by a single calculation, the focus adjustment with respect to an arbitrary optimum object distance can be performed in a short time.

  For the distance y, for example, a chart having a predetermined shape (light shielding means) or a laser light source (light emitting means) that emits laser light incident at an angle θ with respect to the optical axis of the focus lens is provided. It is detected based on the map reflected in At this time, since the chart and the laser light source can be installed closer than the optimum object distance of the camera module, the apparatus can be easily downsized.

  Therefore, it is possible to provide a focus adjustment device and a focus adjustment method that have high production efficiency and can be realized in a compact manner.

  In the focus adjustment apparatus according to the present invention, a light shielding unit that is spaced apart from the focus lens in the direction of the optical axis is provided, and a straight line connecting a specific edge of the light shielding unit and the center of the focus lens is the optical axis. And the detection means detects a distance between a position corresponding to the specific edge of the mapping of the light shielding means reflected on the image plane and the optical axis as a distance y. preferable.

  According to the above configuration, the light shielding means can be installed at a distance shorter than the optimum object distance of the camera module, so that the focus adjustment device can be easily downsized.

  In the focus adjustment apparatus according to the present invention, the focus adjustment apparatus includes a light emitting unit that emits light that passes through the center of the focus lens at an angle θ with respect to the optical axis, and the detection unit reaches the image plane. The distance between the position and the position where the optical axis of the focus lens and the image plane intersect is preferably detected as the distance y.

  According to the above configuration, the light emitting means can be installed at a distance shorter than the optimum object distance of the camera module, so that the focus adjustment device can be easily downsized.

  In the focus adjustment device according to the present invention, it is preferable that the focus adjustment device includes an aperture diameter reducing unit that makes an aperture diameter of the focus lens smaller than a design aperture diameter of the camera module.

  According to the above configuration, by reducing the aperture diameter of the focus lens during focus adjustment, the depth of field increases, so the amount of blurring of the mapping decreases. Therefore, it is possible to improve the detection accuracy of the distance y and reduce the focus adjustment amount error.

  A camera module manufacturing apparatus according to the present invention includes the above-described focus adjustment apparatus.

  According to the above configuration, the focus adjustment device is compact with a short focus adjustment time, and therefore it is possible to easily improve the production efficiency and downsize the camera module manufacturing apparatus.

  A manufacturing method of a camera module according to the present invention is a manufacturing method of a camera module including an assembly process of assembling a focus lens and an individual image sensor provided on an image plane of the focus lens, and the assembly process includes the focus described above. The method includes the detection step, the calculation step, and the position adjustment step of the adjustment method.

  According to said structure, manufacture of a camera module can be implement | achieved compactly with high efficiency.

  The focus adjustment apparatus may be realized by a computer. In this case, focus adjustment for causing the computer to function as the detection means, the calculation means, and the position adjustment means of the focus adjustment apparatus is performed. The present invention includes a program and a computer-readable recording medium on which the focus adjustment program is recorded.

  As described above, the focus adjustment device according to the present invention is a focus adjustment device including a position adjustment unit that adjusts the relative position of the focus lens of the camera module with respect to the image plane, and the center of the focus lens before the position adjustment. Detecting means for detecting a distance y between a position where a straight line forming an angle θ with respect to the optical axis of the focus lens intersects the image plane and a position where the optical axis and the image plane intersect, and the camera And calculating means for calculating a distance dz obtained by the following equation (1), where a is the optimum object distance applied to the module, and f is the focal length of the focus lens, and the position adjusting means includes the focus lens And the relative distance between the image plane and the image plane are shortened by a distance dz.

  Further, the focus adjustment method according to the present invention is a focus adjustment method including a position adjustment step of adjusting a relative position of the camera module with respect to the image plane of the focus lens, and before the position adjustment step, the center of the focus lens A detecting step for detecting a distance y between a position where a straight line forming an angle θ with respect to the optical axis of the focus lens intersects the image plane and a position where the optical axis intersects the image plane, and the camera And calculating the distance dz obtained by the following equation (1), where a is the optimum object distance applied to the module, and f is the focal length of the focus lens. In this configuration, the relative distance between the lens and the image plane is shortened by a distance dz.

  Therefore, it is possible to provide a focus adjustment device and a focus adjustment method that are high in production efficiency and can be realized in a compact manner.

It is a figure which shows the one part schematic structure of the camera module manufacturing apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the chart provided in the said camera module manufacturing apparatus. 1 is a block diagram showing a schematic configuration of a focus adjustment apparatus according to an embodiment of the present invention. It is sectional drawing which shows the positional relationship of a camera module and a chart. It is a figure which shows the captured image data of the chart shown in FIG. It is a figure which shows the other example of a chart. It is a figure which shows the captured image data of the chart shown in FIG. It is a figure which shows the other example of a chart, (a) has shown the circular chart, (b) has shown the rectangular chart. It is sectional drawing which shows the structural example which reduces the aperture diameter of a focus lens.

  One embodiment of the present invention will be described below with reference to FIGS.

(Configuration of camera module manufacturing equipment)
FIG. 1 is a diagram showing a schematic configuration of a part of a camera module manufacturing apparatus 1 according to the present embodiment. The camera module manufacturing apparatus 1 is an apparatus for manufacturing the camera module 2. In FIG. 1, among the members constituting the camera module manufacturing apparatus 1, a socket board 3, a personal computer 4, a transport device 5 and a chart 6 are shown. Has been.

  The socket board 3 transfers captured image data captured by the individual image sensor of the camera module 2 to the personal computer 4.

  The personal computer 4 calculates an adjustment amount of the relative distance with respect to the image plane of the focus lens in accordance with the captured image data and the optimum object distance applied to the camera module 2. Here, the optimum object distance is a distance set in advance as a distance of an object in which the in-focus state of the camera module 2 is maximized, and the optimum object distance is different for each type of the camera module 2.

  Based on the adjustment amount of the relative distance with respect to the image plane of the focus lens calculated in the personal computer 4, the focus lens driving device of the camera module 2 described later moves the focus lens. Thereby, the position of the focus lens according to the optimum object distance is adjusted.

  The socket board 3 is installed in the vicinity of the transport device 5 that transports the camera module 2. Each camera module 2 is transported in an assembled state with a focus lens and an individual image sensor provided on the image plane of the focus lens, and sequentially adjusts focus at a position closest to the socket board 3 (referred to as a focus adjustment position). Is done. Further, a chart 6 that is spaced apart in the optical axis direction of the focus lens of the camera module 2 is provided at the focus adjustment position.

  The chart 6 corresponds to the light shielding means described in the claims, and is, for example, a black plate having a circular opening 61 in the center as shown in FIG. As shown in FIG. 1, the chart 6 is provided so that the opening 61 and the focus lens of the camera module 2 at the focus adjustment position face each other. As a result, mainly the light that has passed through the opening 61 enters the focus lens of the camera module 2.

  Among the members constituting the camera module manufacturing apparatus 1 shown in FIG. 1, the socket board 3, the personal computer 4 and the chart 6 are included in the focus adjusting apparatus according to the present invention.

  FIG. 3 is a block diagram showing a schematic configuration of the focus adjustment apparatus. The focus adjustment device includes a socket board 3, a personal computer 4, a chart 6, and a focus lens driving device 7.

  The personal computer 4 includes a detection unit 41, a calculation unit 42, and a focus adjustment unit 43. These functional blocks formed in the personal computer 4 are formed by executing a focus adjustment program in the personal computer 4.

  Captured image data captured by the individual image sensor of the camera module 2 is transferred from the socket board 3 to the detection unit 41 of the personal computer 4. The detection unit 41 corresponds to detection means described in the claims, and detects a “distance y” to be described later from the captured image data. The calculation unit 42 corresponds to the calculation means described in the claims, and calculates a “distance dz” that is a focus adjustment amount from the detected distance y. The focus adjustment unit 43 corresponds to the position adjustment means described in the claims, and the focus adjustment unit 43 changes the relative position between the focus lens of the camera module 2 and the image plane by the calculated distance dz. Instruct the lens driving device 7.

(Calculation for focus adjustment)
Subsequently, calculation for focus adjustment of the focus lens in the present embodiment will be specifically described.

  FIG. 4 is a cross-sectional view showing the positional relationship between the camera module 2 and the chart 6. The left-right direction in FIG. 4 corresponds to the up-down direction in FIG.

  As shown in FIG. 4, the focus lens 21 of the camera module 2 and the opening 61 of the chart 6 face each other, and the center of the opening 61 is located on the optical axis of the focus lens 21.

  On the image plane 22 of the focus lens 21, an individual image sensor such as a CCD sensor or a CMOS sensor is disposed. The mapping of the opening 61 of the chart 6 is projected on the image plane 22 and is photoelectrically converted by the individual imaging device. Thereby, captured image data as shown in FIG. 5 is generated. This captured image data is sent from the socket board 3 to the personal computer 4.

  Here, as shown in FIG. 4, the intersection of the optical axis of the focus lens 21 and the image plane 22 is defined as a position Y1. The distance between the focus lens 21 and the chart 6 and the size of the opening 61 are such that a straight line connecting the edge of the opening 61 and the center of the focus lens 21 forms an angle θ with respect to the optical axis of the focus lens 21. Is set. The intersection point between the straight line and the image plane 22 before the focus position adjustment is defined as a position Y2. At this time, the distance between the position Y1 and the position Y2 is y.

Further, the optimum object distance set at the time of manufacturing the camera module 2 is a, the distance between the best image plane position F1 of the focus lens 21 and the main plane of the focus lens 21 at the optimum object distance a is b, and the image before the focus position adjustment. If the distance between the surface 22 and the best image plane position is dz,
y = (b + dz) × tan θ
It becomes. Further, when the focal length of the focus lens 21 is f, from the mapping formula,
(1 / a) + (1 / b) = 1 / f
It becomes.

  From these equations,

Holds.

  In the focus adjustment process according to the present embodiment, the distance y is detected by the detection unit 41 of the personal computer 4 shown in FIG. 3 based on the captured image data shown in FIG. 5 (detection process). Further, the optimum object distance a, the focal distance f, and the angle θ are stored in advance in the personal computer 4. As a result, the calculation unit 42 of the personal computer calculates the distance dz from the equation (1) (calculation step), and the focus adjustment unit 43 shortens the relative distance between the focus lens 21 and the image plane 22 by the distance dz. Next, the focus lens driving device 7 is controlled (position adjustment step). In other words, when the distance dz is a positive value, the focus lens 21 and the image plane 22 are adjusted to be close to each other by the distance dz. When the distance dz is a negative value, the focus lens 21 and the image plane 22 are It is adjusted to be separated by an absolute distance. In this adjustment, the focus lens 21 may be moved, or the image plane 22 may be moved. Thereby, the position of the focus lens 21 is adjusted to be the best image plane position F1 at the optimum object distance a of the camera module 2.

  As described above, in the present embodiment, before focus adjustment, the position Y2 that passes through the center of the focus lens 21 and forms an angle θ with the optical axis of the focus lens 21 intersects the image plane 22, and the optical axis. By detecting the distance y between the position Y2 where the image surface 22 and the image plane 22 intersect, calculating the distance dz obtained by the equation (1), and reducing the relative distance between the focus lens 21 and the image plane 22 by the distance dz, Adjust the focus. That is, since the focus adjustment distance can be calculated by a single calculation, the focus adjustment for an arbitrary optimum object distance can be performed in a short time.

  Regardless of the optimum object distance of the camera module 2, the position of the chart 6 is set so that the off-axis ray path passing through the edge of the opening 61 forms an angle θ with respect to the optical axis of the focus lens 21. do it. That is, it is not necessary to install the chart 6 at the optimal object distance of the camera module 2, and the chart 6 can be installed at a relatively short distance (for example, 10 to 50 cm) from the camera module 2 at the focus adjustment position.

  Therefore, it is possible to achieve a compact focus adjustment device with high production efficiency.

  The value of the angle θ is not particularly limited as long as it satisfies 0 deg <θ <90 deg. As the angle θ is larger, the accuracy of focus position adjustment is improved, but aberration due to manufacturing errors is increased. If the distance between the chart 6 and the camera module 2 is too short, aberrations such as distortion increase. The accuracy of focus position adjustment will be described later.

(Modification)
In the above, before the focus adjustment, the position Y2 passing through the center of the focus lens 21 and the angle θ with respect to the optical axis of the focus lens 21 intersects the image plane 22, and the optical axis and the image plane 22 intersect. In order to detect the distance y to the position Y2, the chart 6 having the circular opening 61 is used, but the method for detecting the distance y is not limited to this. The shape of the opening of the chart is not particularly limited. For example, as shown in FIG. 6, a chart 6a having a rectangular opening 62 may be used.

  In this case, as shown in FIG. 7, since the mapping of the aperture 62 projected on the image plane 22 is also rectangular, the distance between the position Y1 where the optical axis of the focus lens 21 and the image plane 22 intersect and the outer edge of the mapping is It is not constant. Therefore, when using the chart 6a, for example, the distance between the position Y2a corresponding to the specific edge 62a of the opening 62 and the position Y1 in the mapping of the opening 62 may be used as the distance y used in the calculation. . At this time, an angle formed by a straight line connecting the edge 62a and the center of the focus lens 21 and the optical axis of the focus lens 21 is an angle θ used in the above calculation. Thereby, the distance dz is calculated from the above equation (1).

  Alternatively, the distance dz may be calculated for the plurality of edges of the opening 62 using the above formula (1), and a value obtained by averaging the calculated distances dz may be used for focus adjustment.

  In the above description, the distance y is detected based on the mapping of the opening of the chart, but the shape of the chart is not limited to this. For example, a black disk-shaped chart 6b shown in FIG. 8A or a black rectangular chart 6c shown in FIG. 8B may be used. Even when these charts 6b and 6c are used, the distance y can be detected based on the map projected on the image plane 22. The shape of the chart is not limited to a circle and a rectangle.

  Furthermore, the distance dz can be obtained by using a laser light source (light emitting means) instead of the chart. In this case, a laser light is emitted from the laser light source through the center of the focus lens 21 at an angle θ with respect to the optical axis of the focus lens 21, and the distance between the position where the laser light reaches the image plane 22 and the position Y1. Is detected as a distance y. Further, since the laser beam has directivity, there is an advantage that an error in a focus adjustment amount described later is small. Also in this configuration, the position of the laser light source is not particularly limited, and may be closer than the optimum object distance of the camera module 2. Therefore, it is possible to reduce the size of the focus adjustment device.

  The light used for detecting the distance y is not limited to laser light as long as it has directivity.

  Thus, in the present embodiment, before focus adjustment, the position Y2 that passes through the center of the focus lens 21 and forms an angle θ with the optical axis of the focus lens 21 intersects the image plane 22, and the optical axis. If the distance y to the position Y2 where the image plane 22 intersects can be detected, the focus lens 21 can be adjusted to the best image plane position at the optimum object distance a, and the method for detecting the distance y is not particularly limited.

(Accuracy of focus adjustment)
As shown in FIG. 2, the light that has passed through the edge of the opening 61 of the chart 6 and passed through the focus lens 21 converges at the imaging position F2. Unless the position of the image plane 22 before the focus adjustment coincides with the image formation position F2, the image formation position F2 and the position of the image plane 22 do not usually coincide with each other. Therefore, the map shown in FIG. 5 is in a state where the outer edge is blurred, and an error occurs in the detection of the distance y.

Here, assuming that the pixel pitch (distance between the individual imaging elements) is ε (μm) and the blur width of the mapping is ε or less, the detection error of the distance y is ε. That is, if the maximum value of the detected distance y is y ′ and the minimum value of the detected distance y is y ″,
ε = y′−y ″ (2)
It becomes. Here, from the above equation (1),

It becomes. Therefore, if the distance dz calculated based on the distance y ′ is the distance dz ′ and the distance dz calculated based on the distance y ″ is the distance dz ″,
y′−y ″ = (dz′−dz ″) × tan θ
From equation (2),
dz′−dz ″ = ε / tan θ (3)
Holds.

  dz′−dz ″ is an error in the focus adjustment amount of the focus lens 21 and ε is constant, and it can be seen that the greater the angle θ, the higher the accuracy of focus adjustment. For example, the pixel pitch of the camera module 2 When ε = 1.4 μm, the relationship between the angle θ and the focus adjustment amount error is as shown in Table 1 below.

  For example, if the angle θ is 15 degrees or more, the focus adjustment can be performed with an accuracy of about 5 μm or less. Regarding a focus lens manufacturing error, in a focus lens for a mobile device, an angle-of-view error due to a manufacturing error is generally ± 2 deg or less. Therefore, an error of an angle θ that is a half angle of view is ± 1 deg or less.

  Further, in the case of θ = 25 deg, even if θ = 26 (25 + 1) deg due to a manufacturing error, the error of the focus adjustment amount is about 0.1 μm, and high-precision focus adjustment can be realized.

(Accuracy improvement by narrowing the aperture)
As described above, since the mapping of the chart 6 is a defocused image that is projected on the image plane 22 in a blurred state, an error occurs in the focus adjustment amount. Therefore, it is desirable that the aperture diameter of the focus lens 21 be made pseudo-narrower than the aperture diameter set in the camera module 2 as described below. Thereby, since the depth of field is increased, it is possible to reduce the blur amount of the mapping and reduce the error of the focus adjustment amount.

  FIG. 9 is a cross-sectional view showing a configuration example in which the aperture diameter of the focus lens 21 is reduced. The design opening diameter A 1 of the camera module 2 is defined by the frame 23. Here, the frame 8 having an opening diameter of A2 smaller than A1 is overlapped with the frame 23 at the time of focus adjustment. The frame 8 is a jig corresponding to the aperture diameter reducing means described in the claims, and shields light rays relatively outside the designed aperture diameter from the light toward the focus lens 21 by the frame 8. .

  Thereby, since the depth of field is increased, the blur amount of the mapping of the chart 6 can be reduced, and the detection accuracy of the above-described distance y can be improved. Therefore, the error of the focus adjustment amount (the above-mentioned dz′−dz ″) can be reduced.

  Note that since the amount of light incident on the focus lens 21 is reduced when the aperture diameter is reduced, the aperture amount of the aperture diameter is appropriately set according to the sensitivity of the individual image sensor.

(Example by software)
Each block of the personal computer 4 of the camera module manufacturing apparatus 1, that is, the detection unit 41, the calculation unit 42, and the focus adjustment unit 43 may be realized in hardware by a logic circuit formed on an integrated circuit (IC chip). However, it may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the personal computer 4 includes a CPU that executes instructions of a program that realizes each function, a ROM (Read Only Memory) that stores the program, a RAM (Random Access Memory) that expands the program, the program, and various data. A storage device (recording medium) such as a memory for storing the. An object of the present invention is that a recording medium in which a program code (execution format program, intermediate code program, source program) of a focus adjustment program, which is software that realizes the above-described functions, is recorded on a personal computer 4 in a computer-readable manner. This can also be achieved by supplying and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. IC cards (including memory cards) / optical cards, semiconductor memories such as mask ROM / EPROM / EEPROM / flash ROM, or PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array) Logic circuits can be used.

  The personal computer 4 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited as long as it can transmit the program code. For example, the Internet, an intranet, an extranet, a LAN, an ISDN, a VAN, a CATV communication network, a virtual private network, a telephone line network, a mobile communication network, a satellite communication network, and the like can be used. The transmission medium constituting the communication network may be any medium that can transmit the program code, and is not limited to a specific configuration or type. For example, even with wired lines such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL (Asymmetric Digital Subscriber Line) line, etc., infrared rays such as IrDA and remote control, Bluetooth (registered trademark), IEEE 802.11 wireless, HDR ( It can also be used by radio such as High Data Rate (NFC), Near Field Communication (NFC), Digital Living Network Alliance (DLNA), a mobile phone network, a satellite line, and a digital terrestrial network. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

(Additional notes)
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention is particularly suitable for manufacturing a camera module having a relatively long optimum object distance.

DESCRIPTION OF SYMBOLS 1 Camera module manufacturing apparatus 2 Camera module 3 Socket board 4 Personal computer 5 Conveyance apparatus 6 Chart (light shielding means)
6a chart (light shielding means)
6b Chart (light shielding means)
6c chart (light shielding means)
7 Focus lens drive 8 Frame (Aperture diameter reduction means)
21 Focus lens 22 Image surface 23 Frame 41 Detection unit (detection means)
42 Calculation unit (calculation means)
43 Focus adjustment unit (position adjustment means)
61 Aperture 62 Aperture A1 Aperture diameter A2 Aperture diameter F1 Best image plane position F2 Imaging position Y1 Position Y2 Position Y2a Position

Claims (9)

A focus adjustment device comprising a position adjustment means for adjusting the relative position of the focus lens of the camera module to the image plane,
Before the position adjustment, a distance between a position where a straight line passing through the center of the focus lens and forming an angle θ with respect to the optical axis of the focus lens intersects the image plane and a position where the optical axis and the image plane intersect detecting means for detecting y;
Calculating means for calculating a distance dz obtained by the following equation (1), where a is the optimum object distance applied to the camera module, and f is the focal length of the focus lens;
The focus adjusting apparatus, wherein the position adjusting means shortens a relative distance between the focus lens and the image plane by a distance dz.

A light shielding means spaced apart from the focus lens in the direction of the optical axis,
A straight line connecting a specific edge of the light shielding means and the center of the focus lens forms an angle θ with respect to the optical axis,
The said detection means detects the distance of the position corresponding to the said specific edge of the mapping of the said light shielding means reflected on the said image surface, and the said optical axis as the distance y, The feature of Claim 1 characterized by the above-mentioned. Focus adjustment device. A light emitting means for emitting light passing through the center of the focus lens at an angle θ with respect to the optical axis;
2. The detection unit according to claim 1, wherein the detection unit detects a distance y between a position where the light reaches the image plane and a position where an optical axis of the focus lens and the image plane intersect. Focus adjustment device.   4. The focus adjusting apparatus according to claim 2, further comprising an aperture diameter reducing unit that makes an aperture diameter of the focus lens smaller than a design aperture diameter of the camera module.   A camera module manufacturing apparatus provided with the focus adjustment apparatus of any one of Claims 1-4. A focus adjustment method including a position adjustment step of adjusting a relative position of an image plane of a focus lens of a camera module,
Before the position adjusting step, a position where a straight line passing through the center of the focus lens and forming an angle θ with respect to the optical axis of the focus lens intersects the image plane, and a position where the optical axis and the image plane intersect A detection step of detecting a distance y from
A calculation step of calculating a distance dz obtained by the following equation (1), where a is the optimum object distance applied to the camera module, and f is the focal length of the focus lens.
In the position adjustment step, the relative distance between the focus lens and the image plane is shortened by a distance dz.

A camera module manufacturing method including an assembly step of assembling a focus lens and a solid-state image sensor provided on an image plane of the focus lens,
7. The method of manufacturing a camera module according to claim 6, wherein the assembly step includes the detection step, the calculation step, and the position adjustment step of the focus adjustment method according to claim 6.   A focus adjustment program for causing a computer to function as the detection unit, the calculation unit, and the position adjustment unit of the focus adjustment apparatus according to claim 1.   A computer-readable recording medium on which the focus adjustment program according to claim 8 is recorded.

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