CN114788259B

CN114788259B - Test chart card, camera manufacturing apparatus, camera manufacturing method, and computer-readable recording medium

Info

Publication number: CN114788259B
Application number: CN202180004830.XA
Authority: CN
Inventors: 根岸真人
Original assignee: Nagawa Japan Co ltd
Current assignee: Nagawa Japan Co ltd
Priority date: 2020-10-05
Filing date: 2021-08-05
Publication date: 2024-04-23
Anticipated expiration: 2041-08-05
Also published as: JP2023165051A; TWI797759B; JP2022060990A; TW202232933A; CN114788259A; KR20220084137A; JP6974638B1; WO2022074926A1

Abstract

A test chart for adjusting a camera having an optical system and a photographing element, the test chart comprising at least one inclined surface having at least one boundary line which forms a boundary of at least one of color, shade and brightness and extends linearly along an inclined direction of the inclined surface, the inclined surface being arranged so as to be inclined with respect to an optical axis of the optical system, and the boundary line being non-parallel to a pixel arrangement direction of the photographing element when the camera photographs.

Description

Test chart card, camera manufacturing apparatus, camera manufacturing method, and computer-readable recording medium

Technical Field

The invention relates to a test chart card, a camera manufacturing device, a camera manufacturing method and a computer readable recording medium.

The present application requires priority based on japanese patent application "japanese patent application 2020-168862" filed on 5 months 10 in 2020, and the entire contents of the descriptions of the above japanese patent applications are incorporated herein.

Background

A device for manufacturing a camera by adjusting a position between an optical system and an imaging element using a chart (chart) having a predetermined pattern is known (for example, patent literature 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2000-165623

Disclosure of Invention

According to one aspect of the present invention, there is provided a test chart for adjusting a camera having an optical system and a photographing element,

The test card is provided with at least one inclined plane,

The inclined surface has at least one boundary line which forms a boundary of at least one of color, shade and brightness and linearly extends along an inclined direction of the inclined surface,

The inclined surface is configured to be inclined with respect to an optical axis of the optical system, and the boundary line is not parallel to a pixel arrangement direction of the imaging element when the camera performs imaging.

In another aspect of the present invention, a test chart is provided, which adjusts a camera,

The test card has:

a vertex set at a prescribed height; and

A plurality of inclined surfaces inclined in opposite inclined directions across the apex,

The plurality of inclined surfaces have a plurality of patterns extending continuously from the apex side in different inclined directions, respectively.

According to still another aspect of the present invention, there is provided a test chart, which adjusts a camera,

The test card is provided with an outer block which is arranged at a position far from the center of the field of view of the camera,

The outer block has: a vertex provided at a prescribed height at a position offset to the center side; and a plurality of inclined surfaces inclined in opposite inclined directions across the apex,

The test card is configured such that the vertex is located at the center of the outer block when the camera is taking a photograph.

According to still another aspect of the present invention, there is provided a camera manufacturing apparatus including:

A card support section for supporting a predetermined test card;

A camera supporting section that supports at least a part of a camera having an optical system and a photographing element at a position where the test chart can be photographed;

An image analysis unit that analyzes an image obtained by capturing the test card and detects a focal position of the camera; and

A camera adjusting mechanism for adjusting a relative position between the optical system and the imaging element according to the focal position of the camera,

The card support part is configured as follows:

The following cards were supported as the test cards, namely: the graphic card comprises at least one inclined plane having at least one boundary line which forms at least one of color, shade and brightness and extends linearly along the inclined direction of the inclined plane, and

The test chart card is supported in such a manner that the inclined surface is inclined with respect to the optical axis of the optical system, and that the boundary line is not parallel to the pixel arrangement direction of the photographing element when photographing by the camera,

The image analysis unit detects the focal position based on the detection result of the boundary line.

A card support section for supporting a predetermined test card;

The card support part is configured as follows: the following cards were supported as the test cards, namely: the figure card has a vertex provided at a prescribed height and a slope inclined in opposite inclination directions across the vertex, the slope having a plurality of patterns extending continuously from the vertex side in different inclination directions,

The image analysis unit detects the focal position from the correlation of the detection results of the plurality of patterns.

A card support section for supporting a predetermined test card;

The card support part is configured as follows:

The following cards were supported as the test cards, namely: the image card is provided with an outer block arranged at a position far from the center of the field of view of the camera, the outer block having an apex disposed at a prescribed height at a position deviated to the center side and a slope inclined in opposite inclination directions across the apex, and

The test chart card is supported in such a way that the vertex is positioned at the center of the outer side block when the camera shoots,

The image analysis unit detects the focal position from the detection result of the outer block.

According to still another aspect of the present invention, there is provided a method of manufacturing a camera, including:

preparing a predetermined test chart;

a step of photographing the test chart using a camera having an optical system and a photographing element;

analyzing an image obtained by photographing the test chart, and detecting a focal position of the camera; and

Adjusting a relative position between the optical system and the imaging element based on the focal position of the camera,

In the process of preparing the test chart card,

The following cards were prepared as the test cards, namely: the graphic card comprises at least one inclined plane, wherein the inclined plane is provided with at least one boundary line which forms at least one boundary of color, shade and brightness and linearly extends along the inclined direction of the inclined plane,

The test chart card is arranged in such a manner that the inclined surface is inclined with respect to the optical axis of the optical system, and that the boundary line is not parallel to the pixel arrangement direction of the photographing element when the camera performs photographing,

In the step of analyzing the image, the focal position is detected based on the detection result of the boundary line.

preparing a predetermined test chart;

In the step of preparing the test chart card, the following chart cards are prepared as the test chart card, namely: the figure card has a vertex provided at a prescribed height and a slope inclined in opposite inclination directions across the vertex, the slope having a plurality of patterns extending continuously from the vertex side in different inclination directions,

In the step of analyzing the image, the focal position is detected based on correlation of detection results of the plurality of patterns.

preparing a predetermined test chart;

In the process of preparing the test chart card,

The following cards were prepared as the test cards, namely: the image card is provided with an outer block arranged at a position far from the center of the view field of the camera, the outer block is provided with an apex arranged at a prescribed height at a position deviated to the center side and a bevel inclined in opposite inclined directions by sandwiching the apex,

The test chart card is configured in such a way that the vertex is positioned at the center of the outer block when the camera shoots,

In the step of analyzing the image, the focal position is detected based on the detection result of the outer block.

According to still another aspect of the present invention, there is provided a computer-readable recording medium having recorded thereon a focus detection program that causes a computer to execute the steps of:

A step of acquiring an image of a predetermined test chart using a camera having an optical system and a photographing element; and

Analyzing the image obtained by shooting the test chart card, detecting the focus position of the camera,

In the step of taking the image in question,

The following cards were used as the test cards, namely: the graphic card comprises at least one inclined plane, wherein the inclined plane is provided with at least one boundary line which forms at least one boundary of color, shade and brightness and linearly extends along the inclined direction of the inclined plane,

The image of the test chart card is acquired in a state in which the test chart card is arranged in such a manner that: the test chart card is arranged in such a manner that the inclined surface is inclined with respect to the optical axis of the optical system, and that the boundary line is not parallel to the pixel arrangement direction of the photographing element when the camera performs photographing,

In the step of analyzing the image, the focus position is detected based on a detection result of the boundary line.

Drawings

Fig. 1 is a perspective view showing a test chart according to a first embodiment of the present invention.

Fig. 2A is a plan view showing a test chart according to the first embodiment of the present invention.

Fig. 2B is an enlarged view of an image obtained by capturing an image of the test chart according to embodiment 1 of the present invention with a camera.

Fig. 3 is a schematic configuration diagram showing a camera manufacturing apparatus according to embodiment 1 of the present invention.

Fig. 4 is a schematic configuration diagram showing a camera arranged in the camera manufacturing apparatus.

Fig. 5 is a block diagram showing a control unit according to a first embodiment of the present invention.

Fig. 6 is a flowchart showing a method for manufacturing a camera according to embodiment 1 of the present invention.

Fig. 7 is an image at the time of photographing a test chart.

Fig. 8A is a diagram obtained by enlarging one pattern in the test chart.

Fig. 8B is an image showing an evaluation area.

Fig. 9 is a diagram showing a correspondence relationship of luminance with respect to the number of correction pixels in embodiment 1.

Fig. 10 is a diagram of frequency analysis of the interpolation curve in each evaluation region.

Fig. 11 is a diagram showing a correspondence relationship of the peak spatial frequency with respect to the position of the boundary line.

Fig. 12A is a perspective view showing a test chart according to a modification of the first embodiment of the present invention.

Fig. 12B is a plan view showing a test chart according to a modification of the first embodiment of the present invention.

Fig. 13 is a perspective view showing a test chart according to a second embodiment of the present invention.

Fig. 14 is a plan view showing a test chart according to a second embodiment of the present invention.

Fig. 15 is a perspective view showing a test chart according to a modification of the second embodiment of the present invention.

Fig. 16 is a plan view showing a test chart according to a modification of the second embodiment of the present invention.

Fig. 17 is a perspective view showing a test chart according to a third embodiment of the present invention.

Fig. 18 is a plan view showing a test chart according to a third embodiment of the present invention.

Fig. 19 is a perspective view showing a test chart according to a fourth embodiment of the present invention.

Fig. 20 is a perspective view showing a test chart according to modification 4-1 of the fourth embodiment of the present invention.

Fig. 21 is a perspective view showing a test chart according to modification 4-2 of the fourth embodiment of the present invention.

Fig. 22A is a perspective view showing a test chart according to a comparative example.

Fig. 22B is an enlarged view of an image obtained by photographing a test chart card according to a comparative example with a camera.

Fig. 23 is a diagram showing a correspondence relationship of luminance with respect to the number of pixels in the comparative example.

Detailed Description

[ Problem to be solved by the invention ]

The invention aims to provide a technology capable of adjusting the relative position of an optical system and an imaging element with high precision.

[ Effect of the present disclosure ]

According to the present disclosure, the relative position of the optical system and the imaging element can be adjusted with high accuracy.

[ Description of embodiments of the present disclosure ]

< Findings obtained by the inventors >

First, findings obtained by the inventors will be described.

The present inventors studied a graphic card having a three-dimensional structure as a test graphic card in order to adjust a camera with high accuracy. However, it was found that the detection accuracy of the focus position may be lowered depending on the structure of the test chart card or the like.

Here, a test chart 90 of a comparative example will be described with reference to fig. 22A, 22B, and 23.

As a chart for adjusting the camera, for example, a test chart 90 of a comparative example as shown in fig. 22A can be considered. The test chart 90 of the comparative example has, for example, a triangular prism structure, and has 1 inclined surface 914 arranged obliquely with respect to the optical axis of the camera. The slope 914 has a boundary line forming a boundary of white and black, for example, as a pattern 916. By acquiring an image of the test chart card 90 of the comparative example having such a triangular prism structure, the focal position of the camera in the optical axis direction can be easily detected based on the detection result of the pattern 916 in the image.

However, in the test chart card 90 of the comparative example, since only 1 inclined plane 914 is provided, the data obtained as the focal position is only 1 data obtained based on the boundary line extending along the inclined plane 914. Therefore, the detection accuracy of the focal position may be lowered. For example, it is difficult to detect the inclination of the optical axis of the camera with high accuracy.

In addition, in the comparative example, for example, as shown in fig. 22B, the test chart card 90 is arranged such that the boundary line is parallel to the pixel arrangement direction when the camera performs shooting.

However, in the comparative example, for example, as shown in fig. 23, when a change in luminance as an index value is detected in a predetermined evaluation region intersecting with a boundary line, the luminance as an index value of each pixel is plotted at a pixel pitch (per unit pixel). Further, since the index value change in the image is uniform in the extending direction of the boundary line, a plurality of points showing a predetermined index value are superimposed and drawn. Therefore, it is difficult to detect a change in the index value in a range smaller than the pixel pitch. That is, the detection accuracy of the change in the index value is lowered. As a result, the detection accuracy of the focal position may be lowered.

As described above, in the comparative example, since the detection accuracy of the focal position is lowered, there is a possibility that the relative position between the optical system and the imaging element in the camera cannot be adjusted with high accuracy.

The present invention described below is based on the findings of the inventors.

Detailed description of embodiments of the disclosure

Next, an embodiment of the present disclosure is described below with reference to the drawings. Further, the present disclosure is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

< First embodiment of the invention >

(1) Test chart card

The test chart 10 according to the present embodiment will be described with reference to fig. 1 to 2B. In fig. 1, the support plate 190 is shown smaller than the actual one, and the support plate 190 is omitted in fig. 2A.

In the following description, with reference to the camera 20 when the test chart 10 is arranged in the camera manufacturing apparatus 1, the optical axis direction of the optical system 220 may be referred to as "Z direction" (the direction from the test chart 10 to the camera 20 is referred to as +), one of the pixel arrangement directions of the imaging element 240, which is orthogonal to the optical axis of the optical system 220, may be referred to as "X direction", and the other of the pixel arrangement directions of the imaging element 240, which is orthogonal to the optical axis of the optical system 220, may be referred to as "Y direction". In addition, the rotation direction about the Z direction may be referred to as "θ _Z direction", the rotation direction about the X direction may be referred to as "θ _X direction", and the rotation direction about the Y direction may be referred to as "θ _Y direction".

As shown in fig. 1 and 2A, the test chart 10 of the present embodiment has, for example, a three-dimensional structure (three-dimensional structure). The test chart 10 has, for example, a pattern 160 on the inclined surface 140 for adjusting the position between the optical system 220 and the photographing element 240 in the camera 20.

Specifically, the test chart 10 of the present embodiment has, for example, a support plate 190 and a three-dimensional block (3D block) 110.

The support plate 190 is configured as a plate-like member, for example, and is configured to support the 3D block 110. The support plate 190 is made of a blackened aluminum alloy, for example, so as not to allow external light, such as illumination light of a room, to enter. The shape of the support plate 190 in plan view is, for example, a quadrangle (rectangle).

The support plate 190 is supported (fixed) by a card support portion 310 in the camera manufacturing apparatus 1 described later. The support plate 190 may have a fixed portion (not shown) to be fixed at a predetermined position of the card support portion 310, for example. Examples of the fixed portion include a through hole through which a bolt is inserted.

The 3D block 110 is, for example, disposed on the support plate 190, and has a three-dimensional structure. The 3D block 110 of the present embodiment is configured as a cone, for example. Examples of the cone formed by the 3D block 110 include a polygonal pyramid (triangular pyramid, rectangular pyramid, etc.), a cone, and the like. In the present embodiment, the 3D block 110 is configured as, for example, a rectangular pyramid (regular rectangular pyramid).

In the present embodiment, 1 3D block 110 is provided, for example. The 3D block 110 is disposed, for example, at the center of the support plate 190.

The 3D block 110 of the present embodiment has, for example, a bottom surface (not shown), a vertex 120, and a slope 140.

The bottom surface of the 3D block 110 is fixed with respect to the support plate 190, for example, in contact with the upper surface of the support plate 190. In the present embodiment, the shape of the bottom surface is, for example, a square having 4 orthogonal bases.

The apex 120 is disposed at a predetermined height from the support plate 190, for example.

Specifically, the height of the vertex 120 is set in the following order, for example. And determining the target focus position according to the specification of the finished camera module. In this case, the target focal position may be adjusted by replacing the relay lens 320 described later. For example, even in the case of assembling the camera 20 focusing at the first few m, it is not necessary to fabricate the camera manufacturing apparatus 1 as large as more than a few m as long as the relay lens 320 that converts the focal position at the first few m to about 200mm is selected. The distance of about 200mm here is a size that makes it easy to manufacture the camera manufacturing apparatus 1. Then, the target focal position is set to the center of the 3D block 110, that is, half the height of the vertex 120. Next, the height of the vertex 120 is set so that the focal position of the camera 20 before assembly can be measured. Here, the focal position of the camera 20 before assembly may be deviated due to a movement error of the camera support 340 and the camera adjustment mechanism 360. Therefore, if the accuracy of these mechanisms is high, the height of the vertex 120 can be reduced. Conversely, if the height of the vertex 120 is increased, the accuracy of the mechanism described above may be reduced.

In the present embodiment, the vertex 120 is located at the center of the 3D block 110 (support plate 190) in a plan view, for example.

The inclined surface 140 is provided obliquely with respect to the normal direction of the bottom surface, for example, connecting the bottom surface and the apex 120. For example, the test chart 10 is supported by a chart support portion 310 described later so that the inclined surface 140 is inclined with respect to the optical axis of the optical system 220 of the camera 20 to be adjusted.

In the present embodiment, 4 inclined surfaces 140 are provided, for example. The 4 inclined surfaces 140 are inclined in opposite inclined directions with the apex 120 interposed therebetween, for example. In the present embodiment, each of the 4 inclined surfaces 140 has a shape of, for example, an isosceles triangle.

The bevel 140 has, for example, a pattern 160. The "pattern 160" as referred to herein refers to a pattern or design or the like that can be captured by the camera 20.

In the present embodiment, for example, each of the plurality of inclined surfaces 140 has a pattern 160. The plurality of patterns 160 extend continuously from the vertex 120 side in different oblique directions, for example. By continuing the pattern 160 along the inclined surface 140, the focal position (temporary focal position described later) of the camera 20 can be detected on the continuous pattern 160 with high accuracy. In addition, by extending the plurality of patterns 160 in different oblique directions, the best focus position of the camera 20 can be detected from the correlation of the detection results of the plurality of patterns 160.

In the present embodiment, the plurality of patterns 160 are provided, for example, as: when viewed from above (directly above) the vertex 120 in the optical axis direction of the optical system 220 of the camera 20 (when viewed in real space, i.e., in design), the optical system is point-symmetrical about the vertex 120. Thus, the focal position of the camera 20 can be detected uniformly based on the detection results of the patterns 160 point-symmetrical with respect to the vertex 120.

In addition, the plurality of patterns 160 are not necessarily point-symmetrical within the image captured by the camera 20. For example, an influence that the orientation of the optical system 220 of the camera 20 before adjustment is not the front, an influence of distortion aberration of the optical system 220, or the like may be considered.

In the present embodiment, the inclined surface 140 has at least one boundary line 162 as the pattern 160, for example. The boundary line 162 forms, for example, a boundary of at least one of color, shade, and brightness. The boundary line 162 extends linearly along the oblique direction of the oblique surface 140, for example.

In the present embodiment, each of the inclined surfaces 140 has, for example, a plurality of boundary lines 162. Specifically, the inclined surface 140 has a slit (linear opening) formed in the black substrate surface, for example. That is, both sides of the slit constitute boundary lines 162a, 162b.

As shown in fig. 2A, for example, 1 slit is provided for each inclined surface 140. The total of 4 slits are arranged in a cross shape in a plan view, and 4 virtual straight lines obtained by extending the 4 slits intersect at the apex 120. As described above, the point symmetry is achieved around the vertex 120 when looking in real space.

As shown in fig. 1, Z is a coordinate in the Z (height) direction on the support plate 190 at a predetermined point (for example, a temporary focal position described later) on the boundary line 162, and L is a distance from the lower end of the boundary line 162 in the direction of the boundary line 162 in a plan view (image).

(Configuration within an image)

Here, the configuration of the boundary line 162 in the image captured by the camera 20 to be adjusted is described with reference to fig. 2B.

As shown in fig. 2B, in the present embodiment, the test chart 10 is arranged such that the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 is imaging. In other words, the test chart 10 is arranged in such a manner that the boundary line 162 intersects the pixel arrangement direction of the imaging element 240 when the camera 20 is imaging. This makes it possible to detect a change in the index value of the pixel at a finer pitch than the pixel pitch.

Further, in the present embodiment, the test chart 10 is arranged so that the boundary line 162 is inclined linearly with respect to the pixel arrangement direction of the imaging element 240 at the time of imaging by the camera 20.

The inclination angle α of the boundary line 162 with respect to the pixel arrangement direction is, for example, greater than 0.02rad. This allows interpolation of data of 50 columns of pixels and evaluation of an index value corresponding to 1 pixel. However, in practice, if the number of columns of the evaluation region ER to be described later is increased, the resolution in the image lateral direction, that is, the resolution in the Z direction of the focal position tends to be deteriorated. That is, the resolution in the image lateral direction tends to be deteriorated as the interpolation accuracy is improved. Therefore, the number of columns of the evaluation region ER is actually 10 columns or more and 30 columns or less.

On the other hand, the inclination angle α of the boundary line 162 with respect to the pixel arrangement direction is, for example, about 0.79rad (45 °) or less. This makes it possible to accurately grasp the change in the index value finer than 1 pixel.

Here, when the camera 20 performs shooting, it is considered that the influence of distortion aberration of the optical system 220 is received.

However, in the present embodiment, the test chart 10 is configured such that the deviation of the boundary line 162 from the pixel arrangement direction of the imaging element 240 is larger than the deviation caused by only the distortion aberration of the optical system 220 when the camera 20 performs imaging. That is, the offset of the boundary line 162 with respect to the pixel arrangement direction when the camera 20 performs shooting includes, for example, a component due to distortion aberration of the optical system 220 and a component (also referred to as a straight-line inclination component) that is inclined linearly with respect to the pixel arrangement direction of the shooting element 240.

In addition, when the camera 20 performs photographing, the width of the slit on the side close to the camera 20 is wider than the width of the slit on the bottom side due to the difference in imaging magnification. Therefore, in one slit, the boundary line 162a on the one hand and the boundary line 162b on the other hand are not parallel to each other. However, even in consideration of the influence caused by the difference in imaging magnification, it is preferable that the boundary lines 162a, 162b intersect the pixel arrangement direction within the image CI, respectively.

As a configuration of the test chart 10 in a real space in which such a configuration within the image CI can be obtained, for example, the 4 bottom sides of the 3D block 110 are respectively parallel to one of the 4 sides (corresponding to the orthogonal pixel arrangement direction of the photographing element 240) of the support plate 190. In contrast, the boundary line 162 in each inclined surface 140 is inclined at a predetermined angle α with respect to the extending direction of one of the 4 bottom edges in plan view.

(2) Camera manufacturing apparatus

Next, a camera manufacturing apparatus 1 according to the present embodiment will be described with reference to fig. 1 to 5.

As shown in fig. 3, the camera manufacturing apparatus 1 of the present embodiment is configured to adjust the relative position between the optical system 220 and the imaging element 240 in the camera 20 based on the detection result of the test chart 10, for example. Specifically, the camera manufacturing apparatus 1 includes, for example, a card support 310, a relay lens 320, a camera support 340, a camera adjustment mechanism 360, a camera fixing unit 380, and a control unit 400.

(Camera)

Here, the camera 20 adjusted by the camera manufacturing apparatus 1 will be described with reference to fig. 4. As shown in fig. 4, the camera 20 includes, for example, an optical system 220, an auto-focus mechanism (not shown), an imaging element 240, a circuit board 260, and a connector 280.

The optical system 220 has, for example, a lens group (not shown) including at least one lens and a lens barrel (not shown). The lens barrel integrally supports the lens group.

The auto-focus mechanism is configured to be capable of moving a lens barrel supporting a lens group along an optical axis, for example. Examples of the autofocus mechanism include an actuator such as a voice coil motor.

The imaging element 240 is configured as a solid-state image sensor, for example. Examples of the imaging element 240 include CCD (Charge Coupled Device) and CMOS (Complementary Metal to Oxide Semiconductor).

The imaging element 240 is disposed, for example, at a position orthogonal to the optical axis of the optical system 220 and imaging via the optical system 220. The relative position between the imaging element 240 and the optical system 220 is adjusted by the camera manufacturing apparatus 1.

The circuit board 260 is configured to mount the imaging element 240, and to drive the imaging element 240 and the autofocus mechanism, for example. An adhesive 262 for fixing the optical system 220 is applied to the periphery of the imaging element 240 on the circuit board 260. The adhesive 262 is, for example, an ultraviolet curable resin.

The connector 280 is configured to be connectable to a mobile phone or the like on which the camera 20 is mounted. In the camera manufacturing apparatus 1, the camera 20 is also connected via the connector 280.

(Card support)

The card support 310 is configured to support the test card 10, for example.

The test chart support 310 of the present embodiment is configured to support the test chart 10 such that the inclined surface 140 is inclined with respect to the optical axis of the optical system 220 and the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 at the time of imaging by the camera 20, for example.

Specifically, in the card support portion 310, for example, the test card 10 is arranged such that the support plate 190 of the test card 10 is orthogonal to the optical axis of the optical system 220 and the center of the support plate 190 is coincident with the optical axis of the optical system 220. In the card support 310, for example, the test card 10 is disposed so that the boundary line 162 on each inclined surface 140 of the 3D block 110 is inclined at a predetermined angle α with respect to the pixel arrangement direction of the imaging element 240.

In this state, a bolt is inserted into the through hole of the test chart 10 as the fixed portion, and the bolt is screwed into the screw hole of the test chart support portion 310. In this way, the test card 10 is fixed to the card support 310.

The card support 310 may be configured to be able to adjust the position of the test card 10 in the optical axis direction, for example. Specifically, for example, the test chart 10 may be moved by about ±50mm in the optical axis direction by a feed screw.

The card support 310 has, for example, a card light source 312. The card light source 312 may be disposed on the back side of the test card 10, for example, and irradiates light from the inside of the 3D block 110, so that the light is transmitted through the slit of the inclined surface 140.

The side surface of the camera manufacturing apparatus 1 is preferably covered with an opaque acrylic sheet or curtain to shield light.

(Relay lens)

The relay lens 320 is configured to form an image of the test chart 10 at the position of the imaging element 240, for example. The relay lens 320 is configured as a convex lens, for example. With this configuration, the inter-object distance in the camera manufacturing apparatus 1 can be shortened. For example, in the case of adjusting the camera 20 designed with a focal length of 10m, the object-to-image distance can be shortened to 200mm. The relay lens 320 is configured such that the optical axis of the relay lens 320 overlaps with the center normal line of the test chart 10 and the optical axis of the optical system 220 of the camera 20.

(Camera support portion)

The camera supporting section 340 is configured to support at least a part of the camera 20 having the optical system 220 and the imaging element 240 at a position where the test card 10 can be imaged, for example. In the present embodiment, the camera supporting portion 340 is configured to support the imaging element 240, the circuit board 260, and the connector 280, for example.

The connector 280 of the camera 20 is connected to the camera support 340. In this way, in the camera manufacturing apparatus 1, the test chart 10 can be photographed by the photographing element 240.

(Camera adjusting mechanism)

The camera adjustment mechanism 360 is configured to adjust the relative position between the optical system 220 and the imaging element 240 according to the focal position of the camera 20, for example.

Specifically, the camera adjustment mechanism 360 is configured to be able to adjust the optical system 220 in the Z direction, the X direction, the Y direction, the θ _Z direction, the θ _X direction, and the θ _Y direction, for example. Further, the camera adjustment mechanism 360 may be configured to be able to adjust the camera support 340 that supports the imaging element 240 in the X-direction and the Y-direction, for example.

(Camera fixing part)

The camera fixing unit 380 is configured to fix the optical system 220 and the imaging element 240, for example. Specifically, the camera fixing unit 380 is configured to be a light source that emits ultraviolet light, for example. For example, the optical system 220 and the imaging element 240 can be fixed by irradiating ultraviolet rays from the camera fixing portion 380 to the adhesive 262 on the circuit board 260 to cure the adhesive 262.

(Control part)

The control unit 400 is configured to control each unit of the camera manufacturing apparatus 1, for example, and adjust the camera 20 based on the image of the test card 10 captured by the camera 20.

Specifically, as shown in fig. 5, the control unit 400 is configured as a computer, and includes CPU (Central Processing Unit), RAM (Random Access Memory), 420, a storage device 430, an I/O port 440, an input unit 450, and a display unit 460.RAM 420, storage device 430, and I/O port 440 are configured to enable data exchange with CPU 410.

The I/O port 440 is connected to, for example, the card light source 312, the camera support 340, the camera adjustment mechanism 360, and the camera fixing portion 380. The I/O port 440 is connected to the imaging element 240 of the camera 20 via the camera support 340.

The storage device 430 is configured to store, for example, a program related to focus detection of the camera 20, a program for controlling the camera adjustment mechanism 360, an image of the test chart 10, and the like. The storage device 430 is HDD (Hard disk drive) or SSD (Solid STATE DRIVE), for example.

RAM 420 is configured to temporarily store programs, information, and the like read from storage device 430 by CPU 410.

CPU 410 is configured to function as an image analysis unit and a camera adjustment control unit by executing a predetermined program stored in storage device 430.

The image analysis unit is configured to analyze an image obtained by capturing the test card 10, for example, and detect the focal position of the camera 20.

The camera adjustment control unit is configured to control the camera adjustment mechanism 360 to adjust the relative position between the optical system 220 and the imaging element 240 according to the focal position of the camera 20, for example.

Regarding the camera manufacturing method based on the above-described portions, details will be described later.

The predetermined program for realizing the above-described respective units is installed and used in, for example, a computer configured by the control unit 400. The program may be provided, for example, by being stored in a computer-readable storage medium before it is installed. Or the program may be supplied to the computer via a communication line (optical fiber or the like) connected to the control unit 400, for example.

The display unit 460 is configured to display, for example, an image of the test chart 10, a graph of an index value with respect to the number of correction pixels, which will be described later, a graph obtained by frequency-analyzing an interpolation curve in each evaluation region, a graph showing a peak spatial frequency with respect to the position of a boundary line, and the like. The display unit 460 is, for example, a liquid crystal display, an organic EL (OLED) display, or the like.

The input unit 450 is configured to be able to input information for a predetermined operation by a user to the control unit 400, for example. The input unit 450 is, for example, a mouse, a keyboard, or the like.

The display unit 460 and the input unit 450 may be configured by a touch panel or the like to serve as both.

(3) Method for manufacturing camera

Next, a method for manufacturing a camera according to the present embodiment will be described with reference to fig. 1 and 4 to 11.

As shown in fig. 6, the method for manufacturing a camera according to the present embodiment includes, for example, a preparation step S100, an imaging step S200, an image analysis step S300, a focus error calculation step S400, a focus position determination step S520, a camera position adjustment step S540, and a camera fixing step S600. The respective steps subsequent to the preparation step S100 are processed or controlled by the control unit 400.

(S100: preparation step)

First, the test chart 10 of the present embodiment is prepared.

At this time, for example, the test chart 10 is supported by the chart support portion 310 such that the inclined surface 140 is inclined with respect to the optical axis of the optical system 220, and the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 performs imaging. After the test chart 10 is arranged, the chart light source 312 is activated to irradiate light onto the test chart 10.

In addition, the camera 20 to be adjusted is arranged in the camera manufacturing apparatus 1.

At this time, for example, at least a part of the camera 20 is supported by the camera support 340 at a position where the test chart 10 can be photographed. When the camera 20 is supported by the camera support 340, the connector 280 of the camera 20 is connected to the camera support 340. In addition, at least a part of the optical system 220 and the imaging element 240 is disposed in the camera adjusting mechanism 360 so that the relative positions of the optical system 220 and the imaging element 240 can be adjusted.

(S200: shooting Process)

Next, as shown in fig. 7, the image CI of the test chart 10 is obtained by photographing the test chart 10 using the camera 20.

At this time, for example, by the arrangement of the above-described test chart card 10, the boundary line 162 of the test chart card 10 is not parallel to the pixel arrangement direction within the image CI.

(S300: image analysis step)

Next, the image CI obtained by capturing the test chart 10 is analyzed, and the focal position of the camera 20 is detected.

In the present embodiment, for example, in an image CI obtained by photographing the test chart 10, the focal position of the camera 20 is detected based on the detection result of the boundary line 162.

Specifically, the image analysis step S300 includes, for example, an evaluation region selection step S310, an index value acquisition step S320, an interpolation step S330, a frequency analysis step S340, an all-evaluation region end determination step S350, a provisional focal point position detection step S360, and an all-boundary-line end determination step S370.

(S310: evaluation region selection step)

As shown in fig. 8A, in the image CI of the test chart 10, an evaluation region ER including a plurality of pixels intersecting the boundary line 162 is selected.

At this time, as shown in fig. 8A, for example, a plurality of evaluation regions ER having different positions along the extending direction of the boundary line 162 are selected. Specifically, for example, one slit is selected from 4 slits that are patterns 160 in the test chart 10 of the present embodiment. Next, a plurality of evaluation regions ER are selected along the boundary line 162a constituting one side of the slit as the pattern 160. For example, a plurality of evaluation regions ER are selected at predetermined equal intervals along the boundary line 162 a.

In this case, as shown in fig. 8B, for example, a plurality of pixel rows intersecting the boundary line 162 are selected as the evaluation region ER. The evaluation region ER is, for example, rectangular in shape having two sides parallel to the two orthogonal pixel arrangement directions. As described above, the number of columns of the evaluation region ER is set according to the resolution in the image lateral direction, and is, for example, 10 columns or more and 30 columns or less.

(S320: index value obtaining step)

Next, at least one index value (pixel value) of the color, shade, and brightness of the pixel is acquired for each pixel in the evaluation region ER.

In addition, the number of correction pixels d' from the reference line passing through the corner of the evaluation region ER and parallel to the boundary line 162 is obtained in each pixel in the evaluation region ER in fig. 8B. Since the boundary line 162 is inclined at the angle α with respect to the pixel arrangement direction, the correction pixel number d' is obtained by the following expression (1).

d’＝d+ntanα···(1)

Here, d is the number of pixels (the number of pixel rows) (unit pixel) in the pixel arrangement direction (the longitudinal direction of the evaluation region ER, the vertical direction of the drawing) intersecting the boundary line 162 in the evaluation region ER from one end of the evaluation region ER. n is the number of pixel columns of the evaluation area ER.

Based on these results, as shown in fig. 9, for each pixel in the evaluation region ER, a correspondence relationship between the index value of the pixel and the correction pixel number d' is obtained. The vertical axis of fig. 9 is, for example, brightness (luminance) as an index value.

At this time, for example, if the horizontal axis is set to the number d of pixels in the pixel arrangement direction, the index value of each pixel is plotted at the pixel pitch (per unit pixel). Therefore, the same problems as those of the comparative example described above may occur.

In contrast, in the present embodiment, the horizontal axis is set to the corrected pixel number d 'from the reference line that passes through the corner of the evaluation region ER and is parallel to the boundary line 162, and thus the index value obtained by shifting the corrected pixel number d' by tan α can be obtained for each column of the evaluation region ER. By making tan α 1 or less, that is, α 0.79rad or less (45 °), the index value of each pixel can be plotted at a shorter pitch than the pixel pitch. That is, the sampling interval can be virtually shortened. As a result, the change in the index value finer than 1 pixel can be grasped with high accuracy in the direction intersecting the boundary line 162.

(S330: interpolation Process)

Next, as shown in fig. 9, discrete data, which is a correspondence relationship between the corrected pixel number d' and the index value of the pixel in the evaluation region ER, is interpolated to obtain an interpolation curve (interpolation function) IC.

The specific interpolation method is not particularly limited, and examples thereof include a linear interpolation method and a spline interpolation method.

(S340: frequency analysis step)

Next, the frequency analysis (fourier transform) is performed on the interpolation curve IC showing the change in luminance obtained in the interpolation step S330. Thus, as shown by one curve in FIG. 10, a curve of the frequency response (SFR: spatial Frequency Response) with respect to the spatial frequency was obtained. In the following, the frequency response curve with respect to the spatial frequency is also referred to as a "frequency response curve".

As described above, in the plurality of evaluation regions ER having different positions along the extending direction of the boundary line 162, a series of steps including the evaluation region selection step S310, the index value acquisition step S320, the interpolation step S330, and the frequency analysis step S340 are performed.

(S350: all evaluation area end determination step)

Next, it is determined whether or not the steps from the evaluation region selection step S310 to the frequency analysis step S340 are completed for all the evaluation regions ER selected in one boundary line 162.

When the steps from the evaluation region selection step S310 to the frequency analysis step S340 are not completed for all the evaluation regions ER (no in S350), these steps are performed for the remaining evaluation regions ER.

(S360: temporary focal position detecting step)

When the process from the evaluation region selection process S310 to the frequency analysis process S340 ends for all the evaluation regions ER (yes in S350), as shown in fig. 10, frequency response curves are obtained for all the evaluation regions ER.

In this case, in the present embodiment, for example, among the plurality of evaluation regions ER, the position in the evaluation region ER in which the change of the index value with respect to the correction pixel number d' is steepest is detected as the provisional focal position. The "tentative focus position" referred to herein is a candidate position of the tentative focus detected based on the detection results of the plurality of evaluation regions ER in one boundary line 162.

Specifically, as shown in fig. 10, in each evaluation region ER, the maximum value of the spatial Frequency having a Frequency response equal to or higher than a predetermined reference (criterion) is obtained as "Best spatial Frequency".

Next, as shown in fig. 11, a correspondence relationship of the optimal spatial frequency with respect to the center position (L) of each evaluation region ER in the direction along the boundary line 162 is obtained. After the correspondence is obtained, the correspondence is fitted by a predetermined approximation function.

After the approximation function is obtained, the highest spatial frequency is obtained as the peak spatial frequency in the approximation function. At this time, the position where the peak spatial frequency is obtained corresponds to the case where the change in the index value is steepest. Therefore, the position at which the peak spatial frequency is obtained is determined as the provisional focal point position in the boundary line 162.

After the provisional focal position is determined, coordinates (three-dimensional coordinates) B _mn1 (X, Y, Z) of the provisional focal position in the real space are obtained from the distance L from the lower end of the boundary line 162 to the provisional focal position in the direction along the boundary line 162 in the image CI. The coordinates of the center point of the support plate 190 of the test chart 10 are (0, 0).

(S370: all boundary line end determination step)

Next, after the provisional focal position is obtained on the predetermined boundary line 162, it is determined whether or not the process from the evaluation area selection process S310 to the provisional focal position detection process S360 is completed for all the boundary lines 162 included in the test chart 10.

When the steps from the evaluation region selection step S310 to the provisional focal position detection step S360 are not completed for all the boundary lines 162 (no in S370), these steps are performed for the remaining boundary lines 162.

(S400: focus error calculation step)

When the process from the evaluation region selection process S310 to the provisional focal position detection process S360 ends for all the boundary lines 162 (yes in S370), provisional focal positions (coordinates B ₁₁₁～B₁₄₂) are obtained for all the boundary lines 162, as shown in fig. 2A.

At this time, in the present embodiment, for example, the best focus position of the camera 20 is detected from the correlation of the detection results of the plurality of boundary lines 162.

Specifically, first, the coordinates of the average focus position are obtained from the coordinates of the tentative focus position in the boundary lines 162a, 162b among the 1 slits. The coordinate B _mn of the average focal position is obtained by, for example, the following equation (2).

B_mn＝(B_mn1+B_mn2)/2···(2)

Where m is a natural number identifying the 3D block 110 and n is a natural number identifying the bevel 140. B _mn1 is the coordinates of the tentative focus position of the boundary line 162a of one slit, and B _mn2 is the coordinates of the tentative focus position of the boundary line 162B of the other slit.

Next, after the coordinates B _mn of the average focal position of each of the plurality of slits are obtained, the coordinates B _m of the optimal focal position of the camera 20 are obtained from the coordinates B _mn of the average focal position. The coordinates B _m of the best focus position are obtained by, for example, the following equation (3).

B_m＝(B_m1+B_m2+B_m3+B_m4)/4···(3)

In addition, when an abnormal coordinate is detected in the coordinates B _mn1、B_mn of the provisional focal position and the coordinates B _mn of the average focal position, at least the boundary line 162 or the like where the abnormal coordinate is detected may be subjected to the image analysis step S300 again.

As described above, after the coordinates B _m of the optimal focal position of the camera 20 are obtained, the inclination angle θ _X、θ_Y of the focal plane of the camera 20 and the coordinates of the center position of the focal plane are obtained according to the following procedure (C _x,C_y,C_z).

Specifically, for example, the equation of the focal plane is obtained by the following equation (4) based on the coordinates B _ijk of the provisional focal point positions in all the boundary lines 162.

z＝ax+by+c···(4)

Where i is a natural number (1 in this embodiment) identifying the 3D block 110, j is a natural number identifying the bevel 140, and k is a natural number identifying the boundary line 162 on the same bevel 140. a. b and c are constants.

In the present embodiment, since the coordinates B _ijk of the tentative focal point position exceeding 3 points are obtained, the constants a, B, and c are optimized by, for example, the least square method. This method of calculation is sometimes referred to as curve fitting.

The constants a, B, and c may be optimized based on the coordinates B _ij of the average focus position in the pair of boundary lines 162a and 162B or the coordinates B _i of the optimal focus position in each 3D block 110.

Next, C _x、C_y in the coordinates of the center position of the focal plane is obtained. Specifically, first, an intersection point obtained by extending the center line of the slit is obtained. If n slits are present, n× (n-1) intersections can be calculated. The optimal intersection point is obtained by averaging these intersection points. As a result, C _x、C_y is obtained from the coordinates of the optimal intersection point.

Next, C _z is obtained by equation (4) based on the coordinates C _x、C_y of the center position of the focal plane.

The inclination angle θ _X、θ_Y is obtained from the constant in the above formula (4) according to the following formula.

θ_X＝-b

θ_Y＝-a

After the inclination angle θ _X、θ_Y of the focal plane of the camera 20 and the coordinates (C _x、C_y、C_z) of the center position of the focal plane are obtained in this way, the errors between the respective values and the target values are calculated. The target value is, for example, 0. The error thus obtained is also referred to as "focus error" hereinafter. The focus error corresponds to an error in the position and posture of the optical system 220 of the camera 20.

(S520: focal position determination step)

After the focus error is obtained, it is determined whether the focus position of the camera 20 is good.

Specifically, for example, it is determined whether or not the focus error is equal to or smaller than a preset allowable value.

(S540: camera position adjustment step)

In the case where the focal position of the camera 20 is not good (i.e., the case where the focal error is greater than the allowable value, no in S520), the relative position of the optical system 220 and the imaging element 240 is adjusted by the camera adjustment mechanism 360 based on the focal position of the camera 20.

Specifically, the optical system 220 is adjusted in the Z direction, the X direction, the Y direction, the θ _Z direction, the θ _X direction, and the θ _Y direction, for example, so that the focus error becomes 0 (zero).

After the adjustment of the camera 20, the steps after the photographing step S200 are performed again.

(S600: camera fixing Process)

On the other hand, when the focal position of the camera 20 is good (that is, when the focal error is equal to or less than the allowable value set in advance, "yes" in S520), the optical system 220 and the imaging element 240 are fixed by the camera fixing unit 380.

Specifically, for example, ultraviolet rays from the camera fixing portion 380 are irradiated to the adhesive 262 on the circuit board 260, and the adhesive 262 is cured. Thereby, the optical system 220 is fixed to the imaging element 240.

As described above, the camera manufacturing process of the present embodiment ends.

(4) Effects of the present embodiment

According to the present embodiment, one or more effects shown below are exhibited.

(A) In the present embodiment, the test chart 10 is arranged such that the inclined surface 140 is inclined with respect to the optical axis of the optical system 220 and the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 performs imaging. For example, in the image CI of the test chart 10, an evaluation region ER intersecting the boundary line 162 is selected, and a correspondence relationship of the index value with respect to the number d' of correction pixels from a reference line passing through the corner of the evaluation region ER and parallel to the boundary line 162 is obtained for each pixel in the evaluation region ER. Thus, the index value obtained by shifting the correction pixel number d' by tan α can be obtained for each column of the evaluation region ER. By making tan α 1 or less, that is, α 0.79rad or less (45 °), the index value of each pixel can be plotted at a shorter pitch than the pixel pitch. That is, the sampling interval can be virtually shortened. As a result, the change in the index value finer than 1 pixel can be grasped with high accuracy in the direction intersecting the boundary line 162.

By thus grasping the change in the index value in the direction intersecting the boundary line 162 with high accuracy, the focal position (the provisional focal position described above) on the boundary line 162 can be detected with high accuracy. As a result, the relative position between the optical system 220 and the imaging element 240 in the camera 20 can be adjusted with high accuracy.

(B) In the present embodiment, the test chart 10 is configured such that the boundary line 162 is shifted from the pixel arrangement direction of the imaging element 240 by more than the shift caused by only the distortion aberration of the optical system 220 when the camera 20 performs imaging. Thus, even if some of the offset components (linear tilt components) in which the boundary line 162 is linearly tilted with respect to the pixel arrangement direction of the imaging element 240 cancel out components due to distortion aberration of the optical system 220, other portions (remaining portions) of the linear tilt components can be sufficiently ensured. That is, the inclination angle α of the boundary line 162 with respect to the pixel arrangement direction can be sufficiently ensured.

(C) In the present embodiment, the inclined surface 140 of the test chart 10 has a plurality of boundary lines 162. This allows the average focal position to be detected from the temporary focal positions of a plurality of adjacent portions located in the same slope 140. As a result, the focal position accuracy in the same inclined plane 140 can be improved.

(D) In the present embodiment, the inclined surface 140 of the test chart 10 is inclined in the opposite inclined direction with the apex 120 interposed therebetween. The plurality of patterns 160 in the inclined surface 140 continuously extend from the vertex 120 side along different inclination directions. By continuing the pattern 160 along the inclined plane 140, the tentative focal position of the camera 20 can be detected with high accuracy on the continued pattern 160. In addition, by extending the plurality of patterns 160 in different oblique directions, the best focus position of the camera 20 can be detected from the correlation of the detection results of the plurality of patterns 160. As a result, the adjustment accuracy of the camera 20 can be improved.

(E) In the present embodiment, the test chart 10 has 4 or more inclined surfaces 140. The best focus position is detected based on correlation between the detection results of the patterns 160 on the respective 4 slopes 140.

Here, if there are 3 pieces of measurement data, three-dimensional coordinates of the best focus position can be calculated. However, it is possible that at least one of the 3 measurement data has a measurement error. As a cause of the measurement error, various causes such as degradation of image quality due to foreign matter adhering to an imaging element of a camera, and manufacturing errors of an optical system can be considered. If such a measurement error occurs, the accuracy of the optimal focal position may be lowered.

In contrast, in the present embodiment, by detecting the optimal focal position from the correlation of the detection results of the patterns 160 on the 4 inclined surfaces 140, the number of measurement data can be increased, and redundancy can be ensured. Thus, even if a measurement error occurs in any one of the measurement data of each of the 4 inclined surfaces 140, a decrease in the detection accuracy of the optimal focal position can be suppressed.

(F) In the present embodiment, the image analysis step is performed in a plurality of evaluation regions ER having different positions along the extending direction of the boundary line 162. Then, among the plurality of evaluation regions ER, the position in the evaluation region ER in which the change of the index value with respect to the correction pixel number d' is steepest is detected as the provisional focus position.

Here, as another comparative example, for example, a method of disposing a plurality of plane cards at predetermined intervals in the optical axis direction of an optical system and detecting the focal position of a camera based on the detection results of the plane cards at the respective positions may be considered. However, in this method, since the number of data obtained is limited by the number of planographic cards, there is a possibility that the detection accuracy of the focal position is lowered. In addition, in order to arrange a plurality of planogram cards so as not to interfere with each other, it is difficult to increase the number of planogram cards. In addition, a plurality of plan view cards must be arranged parallel to each other, and the structure of the device becomes complicated. For this reason, it is also difficult to increase the number of the plan view cards. Further, since the position of the planographic card must be changed to take the planographic card a plurality of times, the manufacturing process of the camera is complicated and the manufacturing time may become long.

In contrast, in the present embodiment, by selecting a plurality of evaluation regions ER in the image CI obtained by capturing the test chart 10 having the three-dimensional structure, the positions of the respective evaluation regions ER can be set to arbitrary positions along the boundary line 162. In addition, the intervals between the evaluation regions ER can be selected at intervals narrower than those in the actual space in the case of using the above-described plan view card. The number of evaluation areas ER can be set to an arbitrary number, and can be more easily increased than in the case of using the above-described plan view card. In addition, the size of the evaluation regions ER can be set to an arbitrary size, and the sizes of the evaluation regions ER can be easily equalized to each other. As a result, the detection accuracy of the provisional focal point position on the boundary line 162 can be improved.

In the present embodiment, a plurality of evaluation areas ER can be selected by photographing the test chart 10 only once. This can simplify the manufacturing process of the camera 20 and shorten the manufacturing time.

(5) Modification of the first embodiment of the present invention

In the above embodiment, the case where the inclined surface 140 of the test chart 10 has the plurality of boundary lines 162 has been described, but may be modified as needed as in the modification shown below.

Only elements different from those described in the above embodiment will be described below, and elements substantially identical to those described in the above embodiment will be denoted by the same reference numerals, and description thereof will be omitted. Note that, the second embodiment, the third embodiment, and the like described below are also omitted in the same manner as in the present modification.

The test chart 10 according to the modification of the present embodiment will be described with reference to fig. 12A and 12B. In fig. 12A and 12B, the support plate 190 is omitted.

In the test chart 10 of the present modification, for example, the 4 inclined surfaces 140 each have one boundary line 162. Specifically, each of the inclined surfaces 140 has, for example, a non-light-transmitting region and a light-transmitting region as the pattern 160. The boundary line 162 forms, for example, a boundary between the non-light-transmitting region and the light-transmitting region.

(Effect)

According to the present modification, as described above, the inclined surface 140 of the test chart 10 may have only one boundary line 162. Thereby, the pattern 160 of the test chart 10 can be simplified. By simplifying the pattern 160, the test chart card 10 can be easily manufactured. As a result, the cost of the test card 10 can be reduced.

< Second embodiment of the invention >

Next, a second embodiment of the present invention will be described.

(1) Test chart card

The test chart 10 according to the present embodiment will be described with reference to fig. 13 and 14.

As shown in fig. 13 and 14, the test chart 10 of the present embodiment has, for example, a support plate 190 and a plurality of 3D blocks 110.

The plurality of 3D blocks 110 have, for example, a center block 110a and 4 outer blocks 110b.

The center block 110a is configured as a regular rectangular pyramid, for example, in the same manner as the 3D block 110 of the first embodiment. The center block 110a is disposed, for example, at the center of the field of view of the camera 20, i.e., at the center of the support plate 190.

The outer block 110b is disposed, for example, at a position away from the center of the field of view of the camera 20, that is, at a position away from the center of the support plate 190. In the present embodiment, the 4 outer blocks 110b are disposed near the 4 corners of the support plate 190, respectively.

In the present embodiment, the outer block 110b is formed as a rectangular pyramid, for example, but has a shape deformed from a regular rectangular pyramid.

Specifically, as shown in fig. 13, the apex 120 of the outer block 110b is disposed at a position offset to the center side of the support plate 190.

On the other hand, as shown in fig. 14, the test chart 10 is configured such that the vertex 120 is located at the center of the outer block 110b when the camera 20 performs shooting. That is, the test chart 10 is configured such that even if distortion aberration occurs in the optical system 220 of the camera 20, since the vertex 120 of the outer block 110b is disposed at a position biased toward the center side of the support plate 190 in real space, the vertex 120 is located at the center of the outer block 110 b.

In addition, with the outer block 110b of the present embodiment, the test chart 10 is also arranged so that the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 performs imaging.

(2) Method for manufacturing camera

Next, a method for manufacturing the camera according to the present embodiment will be described.

(S100: preparation step)

In the preparation step S100 of the present embodiment, for example, as described above, the test chart 10 is supported by the chart support portion 310 such that the apex 120 of the outer block 110b is located at the center of the outer block 110b when the camera 20 performs shooting.

(S310-S370: image analysis step)

In the image analysis step S300 of the present embodiment, for example, the provisional focal point position (coordinate B ₁₁₁～B₅₄₂) is detected in all boundary lines 162 of the center block 110a and the 4 outer blocks 110B.

(S400: focus error calculation step)

In the focus error calculation step S400 of the present embodiment, the focal plane of the camera 20 is detected based on the correlation of the detection results of all the boundary lines 162 of the center block 110a and the 4 outer blocks 110b, for example.

Specifically, for example, the equation of the focal plane is obtained by the above equation (4) based on the coordinates B _ijk of the provisional focal point positions in all the boundary lines 162.

In the present embodiment, since the coordinates B _ijk of the tentative focal point position exceeding 3 points are obtained, the constants a, B, and c are optimized by, for example, the least square method.

The constants a, B, and c may be optimized based on the coordinate B _ij of the average focal position in the pair of boundary lines 162a and 162B obtained in the above embodiment 1 or the coordinate B _i of the optimal focal position in each 3D block 110.

(S540: camera position adjustment step)

In the camera position adjustment step S540 of the present embodiment, the relative position between the optical system 220 and the imaging element 240 is adjusted by the camera adjustment mechanism 360 according to the equation of the focal plane of the camera 20.

The subsequent steps are the same as those of the first embodiment.

(3) Effects of the present embodiment

According to the present embodiment, the test chart 10 is configured such that even if distortion aberration is generated in the optical system 220 of the camera 20, since the vertex 120 of the outside block 110b is disposed at a position biased toward the center side of the support plate 190 in real space, the vertex 120 is located at the center of the outside block 110b within the image CI of the test chart 10. Thus, even if the outer block 110b is disposed at a position away from the center of the field of view of the camera 20, the plurality of patterns 160 can be uniformly disposed around the vertex 120 in the outer block 110b within the image CI of the test chart 10. For example, the length of the boundary line 162, which is the pattern 160, can be equalized in each of the inclined surfaces 140 in the image CI of the test chart 10. Thus, even at a position distant from the center of the image CI of the test chart 10, the detection accuracy of the tentative focal point positions in the plurality of patterns 160 can be equalized. That is, the tentative focus position can be detected uniformly throughout the field of view. As a result, the detection accuracy of the focal plane can be improved.

(4) Modification of the second embodiment of the present invention

In the above embodiment, the case where the inclined surface 140 of each 3D block 110 has the plurality of boundary lines 162 has been described, but may be modified as needed as in the modification shown below.

The test chart 10 according to the modification of the present embodiment will be described with reference to fig. 15 and 16.

In the test chart 10 of the present modification, for example, the 4 inclined surfaces 140 in each 3D block 110 each have one boundary line 162. The boundary line 162 of the pattern 160 according to the present modification is, for example, the same as that of the modification of the first embodiment.

(Effect)

According to the present modification, the inclined surface 140 of the test chart 10 has only one boundary line 162, so that the pattern 160 of the test chart 10 can be simplified. Thus, even if the outer block 110b has a complicated shape due to the displacement of the apex 120 and the arrangement of the boundary line 162, the outer block 110b can be easily manufactured. As a result, the cost of the test chart card 10 having the outside block 110b can be reduced.

Third embodiment of the invention

Next, a third embodiment of the present invention will be described.

(1) Test chart card

The test chart 10 according to the present embodiment will be described with reference to fig. 17 and 18.

As shown in fig. 17 and 18, the test chart 10 of the present embodiment has, for example, a support plate 190, a plurality of 3D blocks 110, and a plurality of two-dimensional blocks (2D blocks) 170.

The plurality of 3D blocks 110 have, for example, a center block 110a and 4 outer blocks 110b. The arrangement and shape of the center block 110a and the 4 outer blocks 110b of the present embodiment are the same as those of the second embodiment.

As shown in fig. 18, the center block 110a may have a center mark 122, for example. The center mark 122 is configured as a camera-recognizable mark, for example. The center mark 122 is disposed, for example, at a position overlapping with the optical axis of the camera 20. That is, the center mark 122 is provided, for example, on the vertex 120 overlapping with the center normal line of the support plate 190. Thus, for example, the centers in the X direction and the Y direction can be easily detected from the detection result of the center mark 122.

The plurality of 2D blocks 170 each have, for example, a two-dimensional pattern (2D pattern) 180. The 2D pattern 180 is disposed, for example, orthogonal to the optical axis of the camera 20.

The 2D pattern 180 is provided on a flat upper surface of the 2D block 170, for example. The height of the 2D pattern 180 from the support plate 190 is, for example, lower than the height of the vertices 120 of the 3D block 110. Specifically, the height of the 2D pattern 180 is, for example, 1/2 times the height of the vertices 120 of the 3D block 110.

Further, the 2D block 170 has, for example, at least one boundary line 182 as the 2D pattern 180. The boundary line 182 forms, for example, a boundary of at least one of color, shade, and brightness. The boundary line 182 extends linearly from the center (central axis) side of the 2D block 170 toward the outside, for example.

The 2D block 170 has, for example, 4 slits as the 2D pattern 180, and two sides of the 4 slits constitute a pair of boundary lines 182.

The 4 slits of the 2D pattern 180 are provided so as to be point-symmetrical with respect to the center of the 2D block 170 when viewed from above the 2D block 170 (when viewed from the actual space).

In the present embodiment, the test chart 10 is configured such that the boundary line 182 of the 2D pattern 180 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 performs imaging. Thus, the change in the index value in the direction intersecting the boundary line 182 can be grasped with high accuracy according to the same principle as that of the boundary line 162 in the 3D block 110.

The 2D blocks 170 are provided with 4, for example. The 4 2D blocks 170 are arranged symmetrically with respect to the center block 110a, for example. In addition, the 2D block 170 is provided, for example, in the center between the pair of outer blocks 110 b. With such a configuration, the centers in the X direction and the Y direction can be easily detected from (the correlation of) the detection result of the 2D block 170.

(2) Method for manufacturing camera

Next, a method for manufacturing the camera according to the present embodiment will be described. The method of manufacturing a camera according to the present embodiment differs from embodiment 1 and embodiment 2 described above in that, for example, a camera origin adjustment step S150 is provided between the preparation step S100 and the evaluation region selection step S310.

(S150: camera origin adjustment Process)

In the image CI obtained by tentatively photographing the test chart 10, a portion of the 2D block 170 is analyzed, and the position of the optical system 220 is adjusted to the origin position by the optical adjustment mechanism of the camera 20. The "origin position" referred to herein refers to, for example, the center of the movable region of the optical system 220 in the optical axis direction.

Specifically, the initial focus position of the camera 20 is detected from the detection result of the 2D pattern 180 in the 2D block 170. Next, the position of the optical system 220 is adjusted to the origin position by the optical adjustment mechanism of the camera 20 according to the initial focus position of the camera 20.

The position of the optical system 220 may be adjusted to the origin position based on the detection result of the center mark 122 of the center block 110 a.

(S540: camera position adjustment step)

In the camera position adjustment step S540 of the present embodiment, the optical system 220 may be adjusted so that the adjusted focal position overlaps with the centers in the X-direction and the Y-direction based on the detection result of the center mark 122 of the 2D block 170 or the center block 110a, in addition to the adjustment performed in the above embodiment.

(3) Effects of the present embodiment

According to the present embodiment, the 2D block 170 has a 2D pattern 180 orthogonal to the optical axis of the camera 20. Thereby, the position of the optical system 220 can be adjusted to the origin position by the optical adjustment mechanism of the camera 20 based on the detection result of the 2D pattern 180 of the 2D block 170.

Here, as in the first and second embodiments described above, when the test chart 10 has only the 3D block 110, it is difficult to adjust the position of the optical system 220 to the origin position based on the detection result of the pattern 160 of the 3D block 110. If the relative position between the optical system 220 and the imaging element 240 is fixed in a state where the position of the optical system 220 is not disposed at the origin position on the optical axis, the movable region of the optical system 220 in the optical axis direction may be shifted in the manufactured camera 20.

In contrast, in the present embodiment, by adjusting the position of the optical system 220 to the origin position based on the detection result of the 2D pattern 180 of the 2D block 170, the relative positions of the optical system 220 and the imaging element 240 can be optimized and fixed in a state where the position of the optical system 220 is arranged at the origin position on the optical axis. In this way, in the camera 20 after manufacturing, the movable region of the optical system 220 in the optical axis direction can be suppressed from being shifted.

< Fourth embodiment of the invention >

Next, a fourth embodiment of the present invention will be described.

(1) Test chart card

The test chart 10 according to the present embodiment will be described with reference to fig. 19.

As shown in fig. 19, the test chart 10 of the present embodiment has, for example, a support plate 190 and a 3D block 110.

In the present embodiment, the 3D block 110 has, for example, a plurality of ridge lines 130 and a plurality of inclined surfaces 140.

The plurality of ridge lines 130 are provided at a predetermined height from the support plate 190, for example. The ridge 130 may be formed by the collection of the vertices 120 in the above embodiment. Preferably, the plurality of ridges 130 are each equal in height from the support plate 190.

The inclined surface 140 is provided in plurality so as to be inclined in opposite inclination directions, for example, with each of the plurality of ridge lines 130 interposed therebetween.

In the present embodiment, each of the inclined surfaces 140 has a plurality of slits as the pattern 160, for example. The plurality of slits each have a pair of boundary lines 162 (162 a, 162 b). For example, in the plurality of slits, the height difference (the length of the Z component) from the upper end to the lower end of the boundary line 162 is equal to each other.

In the present embodiment, as in the above-described embodiment, the test chart 10 is arranged such that the plurality of boundary lines 162 in each inclined plane 140 are not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 performs imaging.

In the present embodiment, the plurality of ridge lines 130 are arranged radially around the optical axis of the optical system 220 of the camera 20 (i.e., the center of the support plate 190), for example. That is, in the present embodiment, the 3D block 110 has a shape in which a plurality of triangular prisms are coupled to the center of the support plate 190, for example.

In the present embodiment, the plurality of ridge lines 130 are preferably axisymmetric with respect to the optical axis of the optical system 220 of the camera 20, for example.

(2) Effects of the present embodiment

(A) In the present embodiment, the 3D block 110 has a plurality of inclined surfaces 140 constituting a triangular prism. A plurality of slits are provided for one inclined surface 140.

Here, in order to increase the number of measurement points in the pyramid-shaped 3D blocks 110 as in the above-described embodiment, it is considered to increase the number of 3D blocks 110 while decreasing the number of pyramid-shaped 3D blocks 110. However, if the 3D block 110 becomes small, the measurement accuracy may be degraded. In addition, increasing the number of 3D blocks 110 may result in an increase in manufacturing costs. On the other hand, as another method, it is considered to add a slit on one slope 140 of the pyramid-shaped 3D block 110. In this case, however, the height of the inclined surface 140 gradually decreases in the in-plane direction with respect to the support plate 190 from the apex 120. Therefore, it is difficult to process a large number of slits on one inclined surface 140.

In contrast, in the present embodiment, by providing a plurality of slits to one inclined surface 140 constituting the triangular prism, the number of slits can be easily increased in the inclined surface 140 having a wide width. In addition, even if the number of slits is increased, the slits can be easily processed. In addition, an increase in manufacturing cost can be suppressed.

By increasing the number of slits in this way, a large number of evaluation regions ER can be set, and SFR can be measured at a large number of points. As a result, the accuracy of measuring the focal point can be improved.

(B) In the present embodiment, the plurality of ridge lines 130 are arranged radially around the optical axis of the optical system 220 of the camera 20. This makes it possible to spatially uniformly distribute the slits. By making the distribution of the slits uniform, the SFR can be measured uniformly over the entire field of view of the camera 20.

(3) Modification of the fourth embodiment of the present invention

Modification 4-1

The test chart 10 according to modification 4-1 of the present embodiment will be described with reference to fig. 20.

The test chart 10 of modification 4-1 has, for example, a support plate 190, a 3D block 110, and a plurality of 2D blocks 170. The 3D block 110 has the constitution described in the fourth embodiment. The 2D block 170 of the present modification is the same as the 2D block 170 of the third embodiment.

(Effect)

According to modification 4-1, the effects of both the third and fourth embodiments can be obtained.

Modification 4-2

The test chart 10 according to modification 4-2 of the present embodiment will be described with reference to fig. 21.

In the test chart 10 of modification 4-2, the 2D block 170 is different from the test chart 10 of modification 4-1. The 2D pattern 180 in the 2D block 170 of modification 4-2 is configured as dots 184. The point 184 is, for example, a dot-shaped opening.

According to modification 4-2, by setting the 2D pattern 180 in the 2D block 170 to the point 184, the 2D pattern 180 can be made simple in structure, and processing can be performed easily. In addition, the center of the 2D pattern 180 can be clearly and easily detected by the dot 184.

< Other embodiments of the invention >

The embodiments of the present invention have been described above specifically, but the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist thereof. Hereinafter, "the above-described embodiments" refer to the first, second, and third embodiments and their modifications.

In the above-described first embodiment, the case where (a) and (b) below are satisfied is described, and in the above-described second embodiment and third embodiment, the case where (a), (b) and (c) are satisfied is described, but the case is not limited to these cases. As long as at least one of (a), (b), and (c) is satisfied, the relative position of the optical system 220 and the imaging element 240 can be adjusted with high accuracy. However, the more the configurations (a), (b), and (c) are satisfied, the more the positional accuracy of the camera 20 can be improved.

(A) The test chart 10 is configured such that the inclined surface 140 is inclined with respect to the optical axis of the optical system 220, and the boundary line 162 is not parallel to the pixel arrangement direction of the photographing element 240 when the camera 20 performs photographing.

(B) The inclined surface 140 of the test chart 10 has a plurality of patterns 160 extending continuously in different inclined directions from the apex 120 side.

(C) The vertex 120 of the outer block 110b is disposed at a position biased toward the center side of the field of view of the camera 20. In addition, the test chart 10 is configured such that the vertex 120 of the outer block 110b is located at the center of the outer block 110b when the camera 20 performs shooting.

In the above embodiment, the case where the 3D block 110 has the plurality of inclined planes 140 is described, but is not limited to this case. The 3D block 110 may have only one inclined surface 140 as long as the test chart 10 is arranged such that the boundary line 162 is not parallel to the pixel arrangement direction of the photographing element 240 when the camera 20 performs photographing. Thereby, the focal position can be detected based on the detection result of the boundary line 162 on the one inclined surface 140. However, as in the above embodiment, when the 3D block 110 has a plurality of inclined surfaces 140, it is preferable to further improve the accuracy of detecting the focal position.

In the above embodiment, the case where the boundary line 162a of one slit is not parallel to the boundary line 162b of the other slit due to the difference in imaging magnification at the time of photographing by the camera 20 has been described, but the present invention is not limited to this case. For example, the test chart 10 may be arranged so that one boundary line 162a of one slit is parallel to the other boundary line 162b when the camera 20 performs shooting. That is, the width of the slit on the side closer to the camera 20 may be narrower than the width of the slit on the bottom side in consideration of the difference in imaging magnification. This makes it possible to incline the boundary lines 162a and 162b at the same angle with respect to the pixel arrangement direction in the image CI. As a result, the detection accuracy of the change in the index value in the boundary lines 162a and 162b can be equalized.

In the above embodiment, the case where the 4 bottom edges of the 3D block 110 are parallel to any one of the 4 sides of the support plate 190, and the boundary line 162 in each of the inclined surfaces 140 is inclined at the predetermined angle α with respect to the extending direction of any one of the 4 bottom edges in a plan view has been described, but the present invention is not limited to this case.

For example, the boundary line 162 in each of the inclined surfaces 140 may be inclined at a predetermined angle α with respect to the extending direction of one of the 4 ridge lines in a plan view with respect to the case where each of the 4 ridge lines of the 3D block 110 is parallel to one of the 4 sides of the support plate 190 (that is, with respect to the case where the 3D block 110 is arranged in a diamond shape in a plan view).

Alternatively, for example, the test chart 10 may have 3D blocks 110 in which the boundary lines 162 in the inclined surfaces 140 are parallel to the extending direction of one of the 4 bottom edges in a plan view, and the 3D blocks 110 may be provided on the support plate 190 in a state rotated by an angle α about the normal direction of the bottom surface.

In the above embodiment, the case where the test chart 10 is fixed to the chart support portion 310 by fastening the bolts has been described, but this is not a limitation. The method of fixing the test card 10 to the card support 310 may be other than the bolt fastening method.

In the above embodiment, the case where the provisional focal position where the change of the index value is steepest is detected based on the peak spatial frequency when the interpolation curve IC of the index value with respect to the correction pixel number d 'is frequency-resolved has been described, but the position where the maximum value of the slope of the index value with respect to the correction pixel number d' is obtained may be detected as the provisional focal position.

In modification 4-2 of the fourth embodiment, the case where the 2D pattern 180 is the dot 184 is described, but the 2D pattern 180 of the third embodiment may be the dot 184.

< Preferred embodiment of the invention >

Hereinafter, preferred embodiments of the present invention will be described.

(Additionally, 1)

A test chart for adjusting a camera having an optical system and a photographing element,

The test card is provided with at least one inclined plane,

The inclined surface is arranged to be inclined with respect to an optical axis of the optical system, and the boundary line is not parallel to a pixel arrangement direction of the imaging element when the camera performs imaging.

(Additionally remembered 2)

The test chart card according to supplementary note 1, wherein,

The test chart is configured such that, when the camera performs photographing, the boundary line is shifted from the pixel arrangement direction of the photographing element more than a shift caused by only distortion aberration of the optical system.

(Additionally, the recording 3)

The test chart according to supplementary note 1 or 2, wherein,

The offset of the boundary line with respect to the pixel arrangement direction when the camera performs photographing has a component due to distortion aberration of the optical system and a component that is linearly inclined with respect to the pixel arrangement direction of the photographing element.

(Additionally remembered 4)

The test chart card according to any one of supplementary notes 1 to 3, wherein,

The bevel has a plurality of boundary lines.

(Additionally noted 5)

The test chart card according to any one of supplementary notes 1 to 4, wherein,

Comprises a vertex arranged at a prescribed height,

The inclined surface is inclined in the opposite inclined direction across the apex.

(Additionally described 6)

The test chart according to any one of supplementary notes 1 to 5, wherein,

Comprising a plurality of ridge lines arranged at a prescribed height,

The inclined surface is provided with a plurality of inclined surfaces in such a manner as to sandwich each of the plurality of ridge lines and to incline in opposite inclined directions,

The plurality of ridge lines are arranged radially about an optical axis of the optical system.

(Additionally noted 7)

A test chart card for adjusting a camera, the test chart card having:

a vertex set at a prescribed height; and

(Additionally noted 8)

The test chart card according to supplementary note 7, wherein,

The plurality of patterns are arranged so as to be point-symmetrical about the vertex when viewed from above the vertex.

(Additionally, the mark 9)

The test chart according to supplementary note 7 or 8, wherein,

The test card has an outer block disposed at a position away from the center of the field of view of the camera, having the apex and the inclined surface,

The apex of the outer block is disposed at a position offset toward the center side,

The test card is configured such that the vertex is located at the center of the outside block when the camera is taking a photograph.

(Additionally noted 10)

A test chart card for adjusting a camera,

(Additionally noted 11)

The test chart card according to any one of supplementary notes 1 to 10, wherein the test chart card includes:

a three-dimensional block having the inclined surface; and

A two-dimensional block having a two-dimensional pattern arranged orthogonal to an optical axis of the camera.

(Additional recording 12)

The test chart card according to any one of supplementary notes 1 to 11, wherein,

There is a center mark that is arranged at a position overlapping with the optical axis of the camera, and the camera is capable of recognizing the center mark.

(Additional recording 13)

A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

The card support part is configured as follows:

(Additional recording 14)

A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

(Additional recording 15)

A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

The card support part is configured as follows:

(Additionally remembered 16)

A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

In the process of preparing the test chart card,

The following cards were supported as the test cards, namely: the graphic card comprises at least one inclined plane, wherein the inclined plane is provided with at least one boundary line which forms at least one boundary of color, shade and brightness and linearly extends along the inclined direction of the inclined plane,

(Additionally noted 17)

The method of manufacturing a camera according to supplementary note 16, wherein,

The step of analyzing the image includes:

In a plurality of evaluation areas having different positions along the extending direction of the boundary line, a series of steps including:

a step of selecting an evaluation area including a plurality of pixels intersecting the boundary line in the image of the test chart; and

A step of obtaining, in each pixel in the evaluation region, a correspondence relationship between an index value of at least one of a color, a shade, and a brightness of the pixel and a correction pixel number calculated from a reference line passing through a corner of the evaluation region and parallel to the boundary line,

And detecting, as the focal position, a position in an evaluation region in which the index value changes most steeply with respect to the correction pixel number among the plurality of evaluation regions.

(Additional notes 18)

A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

(Additionally, a mark 19)

A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

In the process of preparing the test chart card,

(Additionally noted 20)

A focus detection program and a computer-readable recording medium having recorded thereon a focus recording program that causes a computer to execute the steps of:

Analyzing an image obtained by photographing the test chart card, detecting a focus position of the camera, and in the step of obtaining the image,

(Additionally, the recording 21)

The focus detection program according to supplementary note 20, and a computer-readable recording medium having the focus recording program recorded thereon, wherein,

In the step of analyzing the image, causing a computer to execute the steps of:

A step of performing a series of steps including the steps of:

a step of selecting an evaluation area including a plurality of pixels intersecting the boundary line within an image of the test chart; and

And detecting, as the focal position, a position in an evaluation region in which the index value changes steepest with respect to the correction pixel number among the plurality of evaluation regions.

Symbol description

1. Camera manufacturing apparatus

10. Test chart card

20. Camera with camera body

90. Test chart card

110 3D block

110A central block

110B outer side block

120. Vertex point

122. Center mark

130. Edge line

140. Inclined plane

160. Pattern and method for producing the same

162. 162A, 162b boundary line

170 2D block

180 2D pattern

182. Boundary line

184. Point(s)

190. Support plate

220. Optical system

240. Imaging element

260. Circuit substrate

262. Adhesive agent

280. Connector with a plurality of connectors

310. Card support

312. Light source for graphic card

320. Relay lens

340. Camera support

360. Camera adjusting mechanism

380. Camera fixing part

400. Control unit

410 CPU

420 RAM

430. Storage device

440 I/O port

450. Input unit

460. And a display unit.

Claims

1. A test chart for adjusting a camera having an optical system and a photographing element,

The test card is provided with at least one inclined plane,

The inclined surface is configured to be inclined with respect to an optical axis of the optical system, and the boundary line is not parallel to a pixel arrangement direction of the photographing element when the camera performs photographing,

2. The test card of claim 1, wherein,

The bevel has a plurality of boundary lines.

3. The test card of claim 1, wherein,

Comprises a vertex arranged at a prescribed height,

The inclined surfaces are provided in a plurality so as to be inclined in opposite inclination directions across the apex.

4. The test card of claim 1, wherein,

Comprising a plurality of ridge lines arranged at a prescribed height,

5. A test chart card for adjusting a camera, the test chart card having:

a vertex set at a prescribed height; and

The plurality of inclined planes have a plurality of patterns extending continuously from the vertex side in different inclination directions,

6. A test chart card for adjusting a camera,

7. The test chart according to any one of claims 1 to 6, wherein the test chart includes:

a three-dimensional block having the inclined surface; and

8. A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

The card support part is configured as follows:

The test chart is configured such that, at the time of photographing by the camera, the boundary line is shifted from the pixel arrangement direction of the photographing element more than that caused by only distortion aberration of the optical system,

9. A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

The card support part is configured as follows: the following cards were supported as the test cards, namely: the test chart card has a vertex provided at a predetermined height and a slope inclined in opposite inclination directions across the vertex, the slope having a plurality of patterns extending continuously in different inclination directions from the vertex side, the test chart card has an outer block disposed at a position away from the center of the field of view of the camera, the vertex and the slope are provided, the vertex of the outer block is disposed at a position biased to the center side, the test chart card is configured such that, when the camera performs photographing, the vertex is located at the center of the outer block,

10. A camera manufacturing apparatus includes:

A card support section for supporting a predetermined test card;

The card support part is configured as follows:

11. A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

In the process of preparing the test chart card,

12. The method for manufacturing a camera according to claim 11, wherein,

The step of analyzing the image includes:

13. A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

In the step of preparing the test chart card, the following chart cards are prepared as the test chart card, namely: the test chart card has a vertex provided at a predetermined height and a slope inclined in opposite inclination directions across the vertex, the slope having a plurality of patterns extending continuously in different inclination directions from the vertex side, the test chart card has an outer block disposed at a position away from the center of the field of view of the camera, the vertex and the slope are provided, the vertex of the outer block is disposed at a position biased to the center side, the test chart card is configured such that, when the camera performs photographing, the vertex is located at the center of the outer block,

14. A method of manufacturing a camera, comprising:

preparing a predetermined test chart;

In the process of preparing the test chart card,

15. A computer-readable recording medium having a focus detection program recorded thereon, the focus detection program causing a computer to execute the steps of:

In the step of taking the image in question,

The image of the test chart card is acquired in a state in which the test chart card is arranged in such a manner that: the test chart card is arranged in such a manner that the inclined plane is inclined with respect to the optical axis of the optical system and the boundary line is not parallel to the pixel arrangement direction of the photographing element when the camera performs photographing, the test chart card being arranged such that, when the camera performs photographing, the boundary line is offset from the pixel arrangement direction of the photographing element more than that caused by distortion aberration of the optical system alone,

16. The computer-readable recording medium recorded with the focus detection program according to claim 15, wherein,

In the step of analyzing the image, causing a computer to execute the steps of:

A step of performing a series of steps including the steps of: