TWI797759B - Test chart, camera manufacturing device, camera manufacturing method, and focus detection program - Google Patents

Abstract

A test chart is provided, which is configured to adjust a camera having an optical system and an imaging element. The test chart is provided with at least one inclined plane, the inclined plane has at least one boundary line, and the boundary line forms a boundary of at least one of color, shade, and brightness. The boundary line extends linearly along an inclination direction of the inclined plane, and the inclined plane is arranged to be inclined with respect to an optical axis of the optical system, and the boundary line is not parallel to an arrangement direction of pixels of the imaging element when the camera captures an image.

Description

Test chart, camera manufacturing device, camera manufacturing method, and focus detection program

The present invention relates to a test chart, a camera manufacturing device, a camera manufacturing method and a focus detection program.

This application claims the right of priority based on the Japanese patent application "Japanese Patent Application No. 2020-168262" filed on October 5, 2020, and incorporates all the contents described in the above-mentioned Japanese patent application.

There is known a device that manufactures a camera by adjusting the position between an optical system and an imaging element using a chart having a predetermined pattern (for example, Patent Document 1).

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2000-165623

According to one aspect of the present invention, a test chart is provided for adjusting a camera having an optical system and a photographing element, the test chart is provided with at least one inclined plane, The slope has at least one boundary line forming a boundary of at least one of color, shading, and brightness and extending linearly along an inclination direction of the slope, and the slope is arranged to be opposite to the The optical axis of the optical system is inclined, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the shooting element.

Another aspect of the present invention provides a test chart for adjusting the camera. The test chart has: an apex set at a specified height; and a plurality of slopes inclined in opposite directions across the apex , each of the plurality of slopes has a plurality of patterns continuously extending from the apex side along different inclination directions.

According to still another aspect of the present invention, a test chart is provided for adjusting the camera, the test chart has an outer block disposed at a position away from the center of the field of view of the camera, and the outer block has : an apex provided at a predetermined height at a position deviated from the central side; and a plurality of slopes inclined in opposite inclination directions across the apex, and the test chart is configured such that, when the camera takes a picture, The apex is located at the center of the outer block.

According to another aspect of the present invention, there is provided a camera manufacturing device, which has: a chart supporting part, which supports a prescribed test chart; a camera supporting part, which supports a camera with an optical system and a At least a part of the camera that captures the component; an image analysis unit that analyzes the image obtained by shooting the test chart and detects the focus position of the camera; and A camera adjustment mechanism, which adjusts the relative position of the optical system and the imaging element according to the focus position of the camera, and the chart supporting part is configured to support the following charts as the test chart, That is: the chart is provided with at least one inclined surface, and the inclined surface has at least one boundary line forming a boundary of at least one of color, shade and brightness, and extending linearly along the inclined direction of the inclined surface, and the inclined surface is opposite to each other. The optical axis of the optical system is inclined, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the imaging element, and the test chart is supported, and the image analysis unit is based on The detection result of the boundary line is used to detect the focus position.

According to another aspect of the present invention, there is provided a camera manufacturing device, which has: a chart supporting part, which supports a prescribed test chart; a camera supporting part, which supports a camera with an optical system and a At least a part of the camera of the imaging element; an image analysis unit that analyzes the image obtained by shooting the test chart to detect the focus position of the camera; and a camera adjustment mechanism that adjusts the , adjusting the relative position of the optical system and the photographing element, the chart supporting part is configured to: support the following chart as the test chart, that is: the chart has a vertex and a clip arranged at a specified height an inclined surface inclined in opposite inclination directions from the apex, the inclined surface has a plurality of patterns continuously extending from the apex side in different inclination directions, and the image analysis unit detects the plurality of patterns based on Correlation of the results to detect the focus position.

According to another aspect of the present invention, a camera manufacturing device is provided, which has: A chart support unit, which supports a prescribed test chart; a camera support unit, which supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; an image analysis unit, which photographs the test chart. Analyzing the image obtained from the test chart to detect the focus position of the camera; and a camera adjustment mechanism, which adjusts the relative position between the optical system and the photographing element according to the focus position of the camera, the The chart support unit is configured to support the following chart as the test chart, that is, the chart has an outer block arranged at a position away from the center of the field of view of the camera, and the outer block has a An apex at a predetermined height and an inclined surface inclined in opposite inclination directions across the apex are provided at a position on the central side, and the apex is supported so that the apex is located at the center of the outer block when the camera takes an image. In the test chart, the video analysis unit detects the focus position based on a detection result of the outer block.

According to still another aspect of the present invention, a method for manufacturing a camera is provided, comprising: a step of preparing a specified test chart; using a camera with an optical system and a photographing element to photograph the test chart; and photographing the test chart. The step of analyzing the image obtained from the test chart to detect the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera. In the steps of the test chart described above, The following chart is prepared as the test chart, that is, the chart is provided with at least one slope, and the slope has a boundary forming at least one of color, shade and brightness, and is linear along the direction of inclination of the slope. The extended at least one boundary line is configured such that the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the imaging element. In the step of analyzing the image, the test chart detects the focus position according to the detection result of the boundary line.

According to still another aspect of the present invention, a method for manufacturing a camera is provided, comprising: a step of preparing a specified test chart; using a camera with an optical system and a photographing element to photograph the test chart; and photographing the test chart. The step of analyzing the image obtained from the test chart to detect the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera. In the step of the test chart, prepare the following chart as the test chart, that is: the chart has a vertex arranged at a specified height and an inclined plane inclined in the opposite direction across the apex, the inclined plane There are a plurality of patterns continuously extending from the apex side in different oblique directions, and in the step of analyzing the image, the focus position is detected based on a correlation of detection results of the plurality of patterns. .

According to another aspect of the present invention, there is provided a method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; using a camera having an optical system and a photographing element to photograph the test chart; Analyzing the image obtained by taking the test chart, detecting the focus position of the camera; and adjusting the relative position of the optical system and the photographing element according to the focus position of the camera , in the step of preparing the test chart, the following chart is prepared as the test chart, that is, the chart is provided with an outer block arranged at a position away from the center of the field of view of the camera, the The outer block has an apex provided at a predetermined height at a position offset from the central side and a slope inclined in an opposite inclination direction across the apex, and the apex is located on the outer block when photographed by the camera. The test chart is configured in the center, and in the step of analyzing the image, the focus position is detected according to the detection result of the outer block.

According to still another aspect of the present invention, a focus detection program is provided, and the focus recording program causes a computer to execute the following procedures: using a camera with an optical system and a photographing element to obtain a prescribed image of a test chart; The image obtained by the test chart is analyzed to detect the focus position of the camera. In the process of obtaining the image, the following chart is used as the test chart, that is, the chart has at least an inclined surface having at least one boundary line forming a boundary of at least one of color, shading, and brightness and extending linearly along the inclined direction of the inclined surface, in a state where the test chart is arranged in the following manner Next, the image of the test chart is obtained, that is, the inclined plane is inclined relative to the optical axis of the optical system, and when the camera performs When shooting, the boundary line is not parallel to the pixel arrangement direction of the imaging element, and the test chart is configured, and in the process of analyzing the image, the detection results of the boundary line are detected. the focus position.

1: Camera manufacturing device

10: Test chart card

20: camera

90:Test chart

110: 3D blocks

110a: central block

110b: outer block

120: apex

122: Center mark

130: Ridge

140: bevel

160: pattern

162: Borderline

162a: Borderline

162b: Borderline

170: 2D blocks

180: 2D pattern

182: Borderline

184: point

190: support plate

220: Optical system

240: Photographing components

260: circuit substrate

262: Adhesive

280: Connector

310: Chart support part

312: Chart card light source

320: relay lens

340: camera support part

360: camera adjustment mechanism

380: camera fixed part

400: control department

410:CPU

420: RAM

430: storage device

440:I/O port

450: input part

460: display part

914: bevel

916: pattern

B ₁ -B ₅₁₂ : focus position

CI: Image

ER: Evaluation Area

L: distance

S100: step

S200: Steps

S300: Steps

S310: step

S320: step

S330: step

S340: step

S350: Steps

S360: Steps

S370: Steps

S400: Steps

S520: step

S540: step

S600: Steps

x: direction

y: direction

z: direction

α : tilt angle

θ _X : tilt angle

θ _Y : tilt angle

θ _Z : tilt angle

FIG. 1 is a perspective view showing a test chart according to the 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 captured by a camera of the test chart card according to the first embodiment of the present invention.

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

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

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

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

Figure 7 is the image when shooting the test chart.

Figure 8A is an enlarged view of a pattern in the test chart.

FIG. 8B is an image showing the evaluation area.

FIG. 9 is a diagram showing a correspondence relationship of luminance to the number of corrected pixels in the first embodiment.

FIG. 10 is a diagram of frequency analysis of interpolation curves in each evaluation area.

FIG. 11 is a graph showing the 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 modified example of the first embodiment of the present invention.

12B is a plan view showing a test chart related to a modified example 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 modified example of the second embodiment of the present invention.

16 is a plan view showing a test chart according to a modified example 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.

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

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

FIG. 22A is a perspective view showing a test chart related to a comparative example.

FIG. 22B is an enlarged view of an image captured by a camera of the test chart related to the comparative example.

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

[Problems to be Solved by the Invention]

An object of the present invention is to provide a technique capable of adjusting the relative positions of an optical system and an imaging element with high precision.

[Effect of this disclosure]

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

[Description of Embodiments of the Present Disclosure]

<Invention gained by the inventor>

First, the findings obtained by the inventors will be described.

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

Here, the test chart 90 of a comparative example is demonstrated using FIG.22A, FIG.22B, and FIG.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 one slope 914 arranged obliquely with respect to the optical axis of the camera. The slope 914 has a boundary line forming a boundary between white and black, for example, as a pattern 916 . By acquiring an image of the test chart 90 of the comparative example having such a triangular prism structure, the focus 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 90 of the comparative example, since only one slope 914 is provided, the data obtained as the focus position is only one data obtained based on the boundary line extending along the slope 914 . Therefore, the detection accuracy of the focus position may decrease. For example, it is difficult to detect the inclination of the optical axis of the camera with high precision.

In addition, in the comparative example, for example, as shown in FIG. 22B , the test chart 90 is arranged such that the boundary line is parallel to the pixel arrangement direction when the camera is 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 area intersecting a boundary line, the luminance as each pixel is plotted at a pixel pitch (per unit pixel). The brightness of the indicator value. In addition, since the change of the index value in the image is uniform in the extending direction of the boundary line, a plurality of points showing predetermined index values are drawn superimposedly. because Therefore, it is difficult to detect changes in index values within a range smaller than the pixel pitch. That is, the detection accuracy of the change in the index value decreases. As a result, the detection accuracy of the focus position may be lowered.

As described above, in the comparative example, since the detection accuracy of the focus 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 precision.

The present invention below is based on the above-mentioned new subject discovered by the inventors.

[Details of Embodiments of the Present Disclosure]

Next, one embodiment of the present disclosure will be described below with reference to the drawings. In addition, this indication is not limited to these illustrations, It shows by the claim, It is intended that all changes within the meaning and range equivalent to a claim are included.

<First Embodiment of the Present Invention>

(1) Test chart

The test chart 10 related to this embodiment will be described using FIGS. 1 to 2B . In addition, in FIG. 1 , the support plate 190 is shown smaller than it actually is, and the support plate 190 is omitted in FIG. 2A .

In addition, hereinafter, with the camera 20 when the test chart 10 is arranged in the camera manufacturing apparatus 1 as a reference, the optical axis direction of the optical system 220 is sometimes referred to as "Z direction" (assuming that the direction from the test chart 10 to the camera 20 is +), the direction perpendicular to the optical axis of the optical system 220 and one of the pixel arrangement directions of the imaging element 240 is called "X direction", and the pixel of the imaging element 240 perpendicular to the optical axis of the optical system 220 The other direction perpendicular to the X direction among the arrangement directions is called "Y direction". In addition, the rotational direction around the Z direction may be referred to as "θ _Z direction", the rotational direction around the X direction as "θ _X direction", and the rotational direction around the Y direction as "θ X direction". θ _Y direction".

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

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

The support plate 190 is configured as a plate-shaped member, for example, and configured to support the 3D block 110 . The support plate 190 is made of black-coated aluminum alloy, for example, so that light from the outside, such as room lighting, does not enter. The shape of the support plate 190 in plan view is, for example, a quadrilateral (rectangular).

The support plate 190 is configured to be supported (fixed) on the card support portion 310 in the camera manufacturing apparatus 1 described later. The support plate 190 may have, for example, a fixed portion (not shown) to be fixed at a predetermined position of the chart support portion 310 . As a fixed part, the through-hole etc. which are penetrated by a bolt etc. are mentioned, for example.

The 3D block 110 is, for example, disposed on a support plate 190 and has a three-dimensional structure. The 3D block 110 of this embodiment is configured as a pyramid, for example. Examples of pyramids constituted by the 3D blocks 110 include polygonal pyramids (triangular pyramids, quadrangular pyramids, etc.), circular cones, and the like. In this embodiment, the 3D block 110 is configured as, for example, a quadrangular pyramid (regular quadrangular pyramid).

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

The 3D block 110 of this embodiment has, for example, a bottom surface (not shown), an apex 120 , and a slope 140 .

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

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

Specifically, for example, the height of the apex 120 is set in the following order. Determine the target focus position according to the specifications of the finished camera module. At this time, the target focus position can also be adjusted by replacing the relay lens 320 described later. For example, even in the case of a camera 20 assembled to focus at the first few m Next, as long as the relay lens 320 that converts the focal position at the first few meters to about 200 mm is selected, there is no need to manufacture a camera manufacturing device 1 that is larger than several meters. The distance of about 200 mm mentioned here is a size that makes it easy to manufacture the camera manufacturing apparatus 1 . Next, the target focus 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 apex 120 is set so that the focus position of the camera 20 before assembly can be measured. Here, the focus position of the camera 20 before assembly may deviate due to motion errors of the camera support 340 and the camera adjustment mechanism 360 . Therefore, if the precision of these mechanisms is high, the height of the apex 120 can be reduced. Conversely, if the height of the apex 120 is increased, the accuracy of the mechanism described above can be reduced.

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

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

In this embodiment, for example, four slopes 140 are provided. For example, the four inclined surfaces 140 are inclined in opposite inclination directions across the apex 120 . In this embodiment, the shape of each of the four slopes 140 is, for example, an isosceles triangle.

The slope 140 has, for example, a pattern 160 . The “pattern 160 ” referred to here refers to a design, pattern, or the like that can be photographed by the camera 20 .

In this embodiment, for example, each of the plurality of slopes 140 has a pattern 160 . The plurality of patterns 160 continuously extend in different oblique directions, for example, from the apex 120 side. By making the pattern 160 continuous along the slope 140 , the focus position of the camera 20 (temporary focus position described later) can be detected with high precision on the continuous pattern 160 . In addition, by extending the plurality of patterns 160 along different oblique directions, the best focus position of the camera 20 can be detected according to 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, when viewed from above (directly above) the vertex 120 in the direction of the optical axis of the optical system 220 of the camera 20 (when viewed visually in real space, that is, in terms of design). It is point-symmetric about the vertex 120 . Accordingly, the focus position of the camera 20 can be detected in a balanced manner based on the detection results of the respective patterns 160 that are point-symmetrical to the vertex 12 .

In addition, in the image captured by the camera 20 , the patterns 160 are not necessarily point-symmetrical. For example, the effect that the orientation of the optical system 220 of the camera 20 before adjustment is not facing the front, or the effect of the distortion of the optical system 220 may be considered.

In this embodiment, the slope 140 has at least one boundary line 162 as a pattern 160 , for example. The boundary line 162 forms, for example, a boundary of at least one of color, shade, and brightness. In addition, the boundary line 162 extends, for example, linearly along the inclination direction of the slope 140 .

In this embodiment, each slope 140 has a plurality of boundary lines 162 , for example. Specifically, the slope 140 has, for example, slits (linear openings) formed on the black base surface. That is, both sides of the slit constitute boundary lines 162a, 162b.

In addition, as shown in FIG. 2A , for example, one slit is provided for each slope 140 . A total of four slits are arranged in a cross shape in plan view, and four imaginary straight lines obtained by extending the four slits intersect at a vertex 120 . Accordingly, as described above, when viewed visually in real space, point symmetry is formed around the apex 120 .

In addition, as shown in FIG. 1 , for a predetermined point on the boundary line 162 (for example, a tentative focus position described later), Z is the coordinate in the Z (height) direction on the support plate 190, and L is the distance from the boundary in plan view (video). The distance of the lower end of the line 162 along the direction of the boundary line 162 .

(configuration in video)

Here, the arrangement of the boundary line 162 in the image captured by the camera 20 to be adjusted will be described using FIG. 2B .

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

Further, in this embodiment, the test chart 10 is arranged such that the boundary line 162 is linearly inclined with respect to the pixel arrangement direction of the imaging element 240 when the camera 20 takes pictures.

The inclination angle α of the boundary line 162 relative to the pixel arrangement direction is greater than 0.02 rad, for example. Thereby, data of pixels in 50 rows can be interpolated, and an index value corresponding to one pixel can be evaluated. However, actually, if the number of rows of evaluation regions ER described later is increased, the resolution in the horizontal direction of the image, that is, the resolution in the Z direction of the focus position tends to deteriorate. That is, there is a tendency that the resolution in the horizontal direction of the image deteriorates as the interpolation accuracy increases. Therefore, in practice, the number of rows of the evaluation region ER is set to 10 or more and 30 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 0.79 rad (45°) or less. Thereby, it is possible to grasp the change of the index value finer than one pixel with high precision.

Here, it is considered that the camera 20 is affected by the distortion aberration of the optical system 220 when taking pictures.

However, in the present embodiment, the test chart 10 is configured so that when the camera 20 takes pictures, the deviation of the boundary line 162 relative to the pixel arrangement direction of the picture element 240 is larger than that caused only by the distortion aberration of the optical system 220. offset. That is, the deviation of the boundary line 162 with respect to the pixel arrangement direction when the camera 20 takes an image has, for example, a component caused by the distortion aberration of the optical system 220 and a component inclined linearly with respect to the pixel arrangement direction of the imaging element 240 (also referred to as Straight line slope component).

In addition, when the camera 20 is shooting, due to the difference in imaging magnification, 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. Therefore, in a slit, one side The boundary line 162a of one side and the boundary line 162b of the other side are not parallel to each other. However, even after considering the influence of the above-mentioned difference in imaging magnification, it is preferable that in the image CI, the boundary lines 162a and 162b respectively intersect with the pixel arrangement direction.

As the configuration of the test chart 10 in real space that can obtain such a configuration in the image CI, for example, the four bottom sides of the 3D block 110 are respectively connected to the four sides of the support plate 190 (corresponding to the positive side of the imaging element 240). One of the intersecting pixel arrangement directions) is parallel. On the other hand, the boundary line 162 of each slope 140 is inclined at a predetermined angle α with respect to the extending direction of any one of the four bases in plan view.

(2) Camera manufacturing device

Next, the camera manufacturing apparatus 1 according to this embodiment will be described using FIGS. 1 to 5 .

As shown in FIG. 3 , the camera manufacturing apparatus 1 of the present embodiment is configured, for example, 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 . Specifically, the camera manufacturing apparatus 1 includes, for example, a chart support unit 310 , a relay lens 320 , a camera support unit 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 using FIG. 4 . As shown in FIG. 4 , the camera 20 includes, for example, an optical system 220 , an autofocus 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 autofocus mechanism is configured to be able to move, for example, a lens barrel supporting the lens group along the optical axis. As an autofocus mechanism, actuators, such as a voice coil motor, etc. are mentioned, for example.

The imaging element 240 is configured as a solid-state image sensor, for example. As the imaging element 240, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor), etc. are mentioned, for example.

The imaging element 240 is arranged, for example, at a position perpendicular to the optical axis of the optical system 220 and forms an image through the optical system 220 . The relative position between the imaging element 240 and the optical system 220 is adjusted through the camera manufacturing device 1 .

The circuit board 260 is configured, for example, to mount the imaging element 240 and to drive the imaging element 240 and an autofocus mechanism. An adhesive 262 for fixing the optical system 220 is coated on the periphery of the imaging element 240 on the circuit board 260 . Examples of the adhesive 262 include 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 addition, in the camera manufacturing apparatus 1 , the camera 20 is also connected via the connector 280 .

(chart support part)

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

The test chart support unit 310 of this embodiment is configured, for example, to support the test chart so that the slope 140 is inclined relative 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 takes pictures. Chart 10.

Specifically, on the chart support portion 310, for example, the test chart is arranged in such a way that the support plate 190 of the test chart 10 is perpendicular to the optical axis of the optical system 220 and the center of the support plate 190 coincides with the optical axis of the optical system 220. Card 10. Also, on the chart support portion 310 , for example, the test chart 10 is arranged such that the boundary line 162 on each slope 140 of the 3D block 110 is inclined at a predetermined angle α with respect to the pixel array direction of the imaging device 240 .

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

In addition, the chart support part 310 may be configured so that the position of the test chart 10 can be adjusted in the optical axis direction, for example. Specifically, for example, the test chart 10 may be able to move about ±50 mm in the optical axis direction through a feed screw.

The chart support 310 has, for example, a chart light source 312 . The chart light source 312 can be arranged, for example, on the back side of the test chart 10 , irradiates light from the inside of the 3D block 110 , and transmits the light through the slit of the slope 140 .

In addition, the side of the camera manufacturing device 1 is preferably covered with an opaque acrylic plate or curtain to block light.

(relay lens)

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

(Camera support part)

The camera support unit 340 is configured, for example, to support at least a part of the camera 20 including the optical system 220 and the imaging element 240 at a position capable of imaging the test chart 10 . In the present embodiment, the camera support unit 340 is configured to support, for example, the imaging element 240 , the circuit board 260 , and the connector 280 .

The connector 280 of the camera 20 is connected to the camera support 340 . Accordingly, in the camera manufacturing apparatus 1 , the test chart 10 can be photographed through the imaging element 240 .

(camera adjustment mechanism)

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

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. Furthermore, the camera adjustment mechanism 360 may be configured to be able to adjust the camera support portion 340 supporting the imaging element 240 in the X direction and the Y direction, for example.

(camera mount)

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

(control department)

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

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

The I/O port 440 is connected to the chart light source 312 , the camera supporting part 340 , the camera adjusting mechanism 360 and the camera fixing part 380 , for example. In addition, the I/O port 440 is connected to the imaging element 240 of the camera 20 via the camera support portion 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 , images of the test chart 10 , and the like. The storage device 430 is, for example, HDD (Hard Disk Drive) or SSD (Solid State Drive).

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

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

The video analysis unit is configured, for example, to analyze the video imaged by the test chart 10 and detect the focus position of the camera 20 .

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

The details of the camera manufacturing method based on the above-mentioned components will be described later.

Predetermined programs for realizing the above-mentioned respective units are installed and used in, for example, a computer constituted by the control unit 400 . The program may be provided, for example, stored in a computer-readable storage medium before its installation. Alternatively, the program may be provided to the computer via a communication line (such as an optical fiber) 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 corrected pixels to be described later, a graph obtained by performing frequency analysis on the interpolation curve in each evaluation area, and a graph showing the relative A graph of the peak spatial frequency at the position of the boundary line, etc. 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, for example, to be able to input information that the user performs a predetermined operation into the control unit 400 . The input unit 450 is, for example, a mouse, a keyboard, or the like.

In addition, the display unit 460 and the input unit 450 may also be configured such that a touch panel or the like functions as both.

(3) Manufacturing method of camera

Next, a method of manufacturing the camera of the present embodiment will be described with reference to FIGS. 1 , 4 to 11 .

As shown in FIG. 6 , the camera manufacturing method of this embodiment includes, for example, a preparation step S100 , a shooting 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. Each step after the preparatory step S100 is processed or controlled by the control unit 400 .

(S100: preparation step)

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

At this time, for example, the test chart 10 is supported by the chart supporting portion 310 so that the inclined surface 140 is inclined relative to the optical axis of the optical system 220, and when the camera 20 is photographed, the boundary line 162 is not aligned with the pixel arrangement direction of the photographing element 240. parallel. After the test chart 10 is configured, the chart light source 312 is activated to illuminate the test chart 10 with light.

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 at a position where the test chart 10 can be imaged through the camera support portion 340 . 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 arranged in the camera adjustment mechanism 360 so that the relative positions of the optical system 220 and the imaging element 240 can be adjusted.

(S200: photographing step)

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

At this time, for example, through the configuration of the above-mentioned test chart 10 , in the image CI, the boundary line 162 of the test chart 10 is not parallel to the pixel arrangement direction.

(S300: image analysis step)

Next, the image CI obtained by shooting the test chart 10 is analyzed to detect the focus position of the camera 20 .

In this embodiment, for example, in the image CI obtained by shooting the test chart 10 , the focus position of the camera 20 is detected according to the detection result of the boundary line 162 .

Specifically, the video analysis step S300 includes, for example, an evaluation area selection step S310, an index value acquisition step S320, an interpolation step S330, a frequency analysis step S340, a step for determining the end of all evaluation areas S350, a tentative focus position detection step S360, and all boundaries. Line end decision step S370.

(S310: evaluation area selection step)

As shown in FIG. 8A , within 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 four slits as the pattern 160 in the test chart 10 of the present embodiment. Next, a plurality of evaluation regions ER are selected along the boundary line 162 a constituting one side of the slit of the pattern 160 . In addition, for example, a plurality of evaluation regions ER are selected at predetermined equal intervals along the boundary line 162a.

In addition, at this time, as shown in FIG. 8B , for example, a plurality of pixel columns intersecting the boundary line 162 are selected as the evaluation region ER. In addition, the shape of the evaluation region ER is, for example, a rectangle having two sides parallel to the two orthogonal pixel arrangement directions. In addition, as described above, the number of columns of the evaluation region ER is set according to the resolution in the horizontal direction of the image, and is set to, for example, 10 or more and 30 or less.

(S320: Index value acquisition step)

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

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

d’=d+ntan α‧‧‧(1)

Wherein, d is the number of pixels (the number of pixel rows) in the evaluation area ER along the pixel arrangement direction (the long side direction of the evaluation area ER, the vertical direction of the figure) intersecting with the boundary line 162 in the evaluation area ER from one end of the evaluation area ER (the number of pixel rows) (unit pixel) . n is the number of pixel columns in the evaluation region ER.

Based on these results, as shown in FIG. 9 , for each pixel in the evaluation region ER, the correspondence relationship of the index value of the pixel with respect to the number of corrected pixels d' is obtained. In addition, the vertical axis of FIG. 9 is, for example, luminance (brightness) as an index value.

At this time, for example, if the horizontal axis is set to the number d of pixels along the pixel arrangement direction, the index value of each pixel is plotted at a pixel pitch (per unit pixel). Therefore, there is a possibility that the same problems as those of the above-mentioned comparative example may arise.

1、即α

0.79rad(45°)，能夠以比像素間距短的間距繪製各像素的指標值。即，能夠假想地縮短採樣間距。其結果是，能夠在與邊界線162相交的方向上高精度地掌握比1個像素更細的指標值的變化。 On the other hand, in the present embodiment, by setting the horizontal axis as the number of corrected pixels d' calculated from the reference line passing through the corner of the evaluation area ER and parallel to the boundary line 162, it is possible to obtain for each column of the evaluation area ER The index value after correcting the number of pixels d' shifted by tan α. by making tanα

1, namely α

0.79rad (45°), the index value of each pixel can be plotted at a pitch shorter than the pixel pitch. That is, the sampling pitch can be virtually shortened. As a result, changes in index values finer than one pixel can be grasped with high precision in the direction intersecting the boundary line 162 .

(S330: interpolation step)

Next, as shown in FIG. 9 , an interpolation curve (interpolation function) IC is obtained by interpolating discrete data which is the correspondence relationship between the number of corrected pixels d' and the index value of pixels in the evaluation region ER.

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

(S340: frequency analysis step)

Next, 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 in one of the curves in FIG. 10 , a frequency response (SFR: Spatial Frequency Response) curve with respect to the spatial frequency is obtained. In addition, the curve of the frequency response with respect to the spatial frequency is also referred to as a "frequency response curve" below.

As described above, in a plurality of evaluation regions ER whose positions are different 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. step.

(S350: All evaluation areas 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 have been completed for all the evaluation regions ER selected on one boundary line 162 .

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

(S360: tentative focus position detection step)

When the steps from the evaluation region selection step S310 to the frequency analysis step S340 are completed for all the evaluation regions ER ("Yes" in S350), as shown in FIG. Get the frequency response curve.

At this time, in this embodiment, for example, among the plurality of evaluation regions ER, the position within the evaluation region ER where the change in the index value with respect to the number of corrected pixels d' is the steepest is detected as the tentative focus position. The “tentative focus position” referred to here refers to a candidate position of a tentative focus detected based on the detection results of a plurality of evaluation regions ER within one boundary line 162 .

Specifically, as shown in FIG. 10 , in each evaluation region ER, the maximum value of spatial frequencies having a frequency response equal to or greater than a predetermined criterion (Criteria) is obtained as "best spatial frequency (Best Frequency)".

Next, as shown in FIG. 11 , the correspondence relation of the optimum spatial frequency with respect to the center position (L) of each evaluation region FR in the direction along the boundary line 162 is obtained. After obtaining the corresponding relationship, the corresponding relationship is fitted through a prescribed approximation function.

After obtaining the approximate function, find the highest spatial frequency in the approximate function as the peak spatial frequency. In this case, the position where the peak spatial frequency is obtained corresponds to the case where the change in the index value is the steepest. Therefore, the position where this peak spatial frequency is obtained is determined as the tentative focus position in the boundary line 162 .

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

(S370: All boundary lines end determination step)

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

When the steps from the evaluation area selection step S310 to the tentative focus position detection step S360 have not been 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 steps from the evaluation area selection step S310 to the tentative focus position detection step S360 are completed for all the boundary lines 162 ("Yes" in S370), as shown in FIG. 2A , all the boundary lines 162 The provisional focus positions (coordinates B ₁₁₁ -B ₁₄₂ ) are respectively obtained.

At this time, in the present embodiment, for example, the best focus position of the camera 20 is detected based on 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 provisional focus position on the boundary lines 162a and 162b in one slit. The coordinates B _mn of the average focus position are obtained, for example, by the following formula (2).

B _mn =(B _mn1 +B _mn2 )/2‧‧‧(2)

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

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

B _m =(B _m1 +B _m2 +B _m3 +B _m4 )/4‧‧‧(3)

In addition, when abnormal coordinates are detected in the coordinates B _mn1 and B _mn of the tentative focus position and the coordinate B _mn of the average focus position, the image analysis step S300 may be re-performed at least for the boundary line 162 where the abnormal coordinates are detected. .

As described above, after obtaining the coordinates B _m of the best focus position of the camera 20, the inclination angles θ _X , θ _Y of the focal plane of the camera 20 and the coordinates (C _x , C _y , C _z ).

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

z=ax+by+c‧‧‧(4)

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

In the present embodiment, since the coordinates B _ijk of more than three tentative focus positions are obtained, the constants a, b, and c are optimized, for example, by the method of least squares. This calculation method is sometimes called curve fitting.

In addition, the constants a, b, and c may be optimized based on the coordinates _Bij of the average focus position in the pair of boundary lines 162a, 162b obtained above or the coordinates Bi of the best focus position in each 3D block 110. .

Next, C _x and _Cy in the coordinates of the center position of the focal plane are obtained. Specifically, first, the intersection point obtained by extending the center line of the slit is obtained. If there are n slits, n×(n-1) intersection points can be calculated. By averaging these intersection points, the best intersection point is found. As a result, C _x and _Cy are obtained from the coordinates of the optimum intersection point.

Next, from the coordinates C _x and C _y of the center position of the focal plane, C _z is obtained through the expression (4).

In addition, from the constants in the above formula (4), the inclination angles θ _X and θ _Y are obtained from the following formulas.

θ _X = -b

θ _Y =-a

After obtaining the inclination angles θ _X , θ _Y of the focal plane of the camera 20 and the coordinates (C _x , _Cy , C _z ) of the center position of the focal plane in this way, the error between each value and the target value is calculated. In addition, the target value is 0, for example. The error obtained in this way will also be referred to as "focus error" hereinafter. The focus error corresponds to the error in the position and attitude of the optical system 220 of the camera 20 .

(S520: focus position determination step)

After finding the focus error, it is determined whether the focus position of the camera 20 is good or not.

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

(S540: camera position adjustment step)

In the case where the focus position of the camera 20 is not good (that is, the focus error is greater than the allowable value, "No" in S520), based on the focus position of the camera 20, the optical system 220 and the imaging element are adjusted through the camera adjustment mechanism 360 240 relative position.

Specifically, for example, 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 so that the focus error described above becomes 0 (zero).

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

(S600: Camera fixing procedure)

On the other hand, when the focus position of the camera 20 is good (that is, when the focus error is not more than the preset allowable value, “Yes” in S520), the optical system 220 and the imaging element 240 are connected through the camera fixing unit 380 fixed.

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

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

(4) Effects related to this embodiment

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

1、即α

0.79rad(45°)，能夠以比像素間距短的間距繪製各 像素的指標值。即，能夠假想地縮短採樣間距。其結果是，能夠在與邊界線162相交的方向上，高精度地掌握比1個像素更細的指標值的變化。 (a) In this embodiment, the test chart 10 is arranged such that the slope 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 takes pictures. For example, in the image CI of the test chart 10, select the evaluation region ER that intersects with the boundary line 162, and for each pixel in the evaluation region ER, obtain the index value relative to the corner that passes through the evaluation region ER and crosses the boundary line 162. The corresponding relationship of the number of corrected pixels d' calculated from the parallel reference line. In this way, for each column of the evaluation region ER, an index value obtained by shifting the number of corrected pixels d' by tan α can be obtained. by making tanα

1, namely α

0.79rad (45°), the index value of each pixel can be plotted at a pitch shorter than the pixel pitch. That is, the sampling pitch can be virtually shortened. As a result, changes in the index value finer than one pixel can be grasped with high precision in the direction intersecting the boundary line 162 .

In this way, by accurately grasping the change in the index value in the direction intersecting the boundary line 162 , it is possible to accurately detect the focus position on the boundary line 162 (the tentative focus position described above). 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 precision.

(b) In this embodiment, the test chart 10 is configured so that when the camera 20 takes pictures, the deviation of the boundary line 162 relative to the pixel arrangement direction of the imaging element 240 is larger than that caused only by the distortion aberration of the optical system 220 offset. Thus, even if a part of the offset component (linear inclination component) in which the boundary line 162 is linearly inclined with respect to the pixel array direction of the imaging element 240 cancels out the component caused by the distortion aberration of the optical system 220, it is possible to sufficiently ensure The other part (remainder) of the rectilinear slanted composition. 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 slope 140 of the test chart 10 has a plurality of boundary lines 162 . Thereby, the average focus position can be detected from the tentative focus positions of a plurality of close locations within the same slope 140 . As a result, the focus position accuracy within the same slope 140 can be improved.

(d) In the present embodiment, the inclined surface 140 of the test chart 10 is inclined in opposite inclined directions across the apex 120 . The plurality of patterns 160 on the slope 140 continuously extend from the apex 120 side along different inclination directions. By making the pattern 160 continuous along the slope 140 , the tentative focus position of the camera 20 can be detected with high precision on the continuous pattern 160 . In addition, by extending the plurality of patterns 160 along different oblique directions, the best focus position of the camera 20 can be detected according to 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 four or more slopes 140 . The best focus position is detected based on the correlation between the detection results of the pattern 160 on each of the four slopes 140 .

Here, if there are three measurement data, the three-dimensional coordinates of the best focus position can be calculated. However, there is a possibility that at least one of the three measurement data has a measurement error. As the cause of the measurement error, for example, various causes such as image quality degradation caused by foreign matter adhering to the imaging element of the camera, and manufacturing error of the optical system can be considered. When such a measurement error occurs, the accuracy of the best focus position may decrease.

In contrast, in this embodiment, by detecting the best focus position based on the correlation of the detection results of the patterns 160 on the four slopes 140 , the amount of measurement data can be increased to ensure repeatability. Accordingly, even if a measurement error occurs in any of the measurement data on each of the four slopes 140 , it is possible to suppress a decrease in the detection accuracy of the best focus position.

(f) In the present embodiment, the video analysis step is performed in a plurality of evaluation regions ER whose positions are different along the extending direction of the boundary line 162 . Then, among the plurality of evaluation regions ER, a position within the evaluation region ER at which the change in the index value with respect to the number of corrected pixels d' is the steepest is detected as a tentative focus position.

Here, as another comparative example, for example, a method of arranging a plurality of plan view cards at predetermined intervals in the direction of the optical axis of the optical system and detecting the focus position of the camera based on the detection results of the plan view cards at each position can be considered. However, in this method, since the amount of obtained data is limited by the number of floor plan cards, the detection accuracy of the focus position may decrease. In addition, in order to arrange a plurality of floor plan cards so as not to interfere with each other, it is difficult to increase the number of floor plan cards. In addition, it is necessary to arrange a plurality of floor plan cards in parallel to each other, which complicates the structure of the device. For this reason, it is also difficult to increase the number of floor plan cards. Further, since the plan card must be photographed many times while changing the position of the plan card, the manufacturing steps of the camera are complicated and the manufacturing time may become longer.

In contrast, in this embodiment, by selecting a plurality of evaluation regions ER in the image CI obtained by photographing the test chart 10 having a three-dimensional structure, the position of each evaluation region ER can be set to be along the boundary line 162. any position. In addition, the interval between the evaluation regions ER can be selected at an interval narrower than the interval in the real space when the above-mentioned plan view card is used. In addition, the number of evaluation regions ER can be set to an arbitrary number, and it is easier to increase the number than the case of using the above-mentioned floor plan 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 made equal to each other. As a result, the detection accuracy of the tentative focus position on the boundary line 162 can be improved.

In addition, in the present embodiment, a plurality of evaluation regions ER can be selected by imaging the test chart 10 only once. Thereby, the manufacturing steps of the camera 20 can be simplified and the manufacturing time can be shortened.

(5) Modified example of the first embodiment of the present invention

In the above-mentioned embodiment, the case where the slope 140 of the test chart 10 has a plurality of boundary lines 162 has been described, but it can be changed as a modified example shown below as necessary.

Hereinafter, only elements different from those of the above-mentioned embodiment will be described, and elements that are substantially the same as those described in the above-mentioned embodiment will be assigned the same reference numerals and their description will be omitted. In addition, descriptions of the following second embodiment, third embodiment, etc. are omitted in the same manner as the present modified example.

A test chart 10 related to a modified example of the present embodiment will be described using FIGS. 12A and 12B . In FIGS. 12A and 12B , the support plate 190 is omitted.

In the test chart 10 of this modified example, for example, each of the four slopes 140 has one boundary line 162 . Specifically, each slope 140 has, for example, a non-translucent region and a translucent region as the pattern 160 . The boundary line 162 forms, for example, the boundary between the non-translucent region and the translucent region.

(Effect)

According to this modified example, as described above, the slope 140 of the test chart 10 may have only one boundary line 162 . Thus, the pattern 160 of the test chart 10 can be simplified. Through the simplified pattern 160, the test chart 10 can be easily manufactured. As a result, the cost of the test chart 10 can be reduced.

<Second Embodiment of the Present Invention>

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

(1) Test chart

The test chart 10 related to this embodiment will be described using FIG. 13 and FIG. 14 .

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

The plurality of 3D blocks 110 includes, for example, a central block 110a and four outer blocks 110b.

The central block 110a is configured as a regular quadrangular pyramid, for example, similarly to the 3D block 110 of the first embodiment. The central block 110 a is arranged, for example, at the center of the field of view of the camera 20 , that is, at the center of the support plate 190 .

The outer block 110 b is arranged, 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 four outer blocks 110b are arranged near the four corners of the support plate 190, respectively.

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

Specifically, as shown in FIG. 13 , the apex 120 of the outer block 110 b is provided at a position deviated from the center side of the support plate 190 .

On the other hand, as shown in FIG. 14 , the test chart 10 is arranged such that the apex 120 is positioned at the center of the outer block 110 b when the camera 20 takes an image. 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 apex 120 of the outer block 110b is set at a position deviated from the central side of the support plate 190 in real space, The apex 120 is located at the center of the outer block 110b.

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

(2) Manufacturing method of camera

Next, a method of manufacturing the camera of this embodiment will be described.

(S100: preparation step)

In the preparation process S100 of this embodiment, for example, as described above, the test chart 10 is supported by the chart supporting part 310 so that when the camera 20 takes pictures, the apex 120 of the outer block 110b is located at the center of the outer block 110b.

(S310~S370: image analysis step)

In the video analysis step S300 of the present embodiment, for example, provisional focus positions (coordinates B ₁₁₁ to B ₅₄₂ ) are detected on all boundary lines 162 of the central block 110a and the four outer blocks 110b.

(S400: focus error calculation step)

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

Specifically, for example, the equation of the focal plane is obtained from the above-mentioned equation (4) based on the coordinates B _ijk of the tentative focus positions in all the boundary lines 162 .

In the present embodiment, since the coordinates B _ijk of more than three tentative focus positions are obtained, the constants a, b, and c are optimized, for example, by the method of least squares.

In addition, a constant may be set based on the coordinates B _ij of the average focus position in the pair of boundary lines 162a and 162b obtained in the first embodiment or the coordinates B _i of the best focus position in each 3D block 110 . a, b and c are optimized.

(S540: camera position adjustment step)

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

Subsequent steps are the same as in the first embodiment described above.

(3) Effects of this embodiment

According to the present embodiment, the test chart 10 is configured such that even if distortion aberration occurs in the optical system 220 of the camera 20, since the apex 120 of the outer block 110b is set at a position deviated from the central side of the supporting plate 190 in real space, Therefore, in the image CI of the test chart 10, the vertex 120 is located at the center of the outer block 110b. As a result, even if the outer block 110 b is arranged far from the center of the field of view of the camera 20 , in the outer block 110 b in the image CI of the test chart 10 , a plurality of patterns 160 can be arranged in a balanced manner around the vertex 120 . For example, in each slope 140 in the image CI of the test chart 10 , the length of the boundary line 162 as the pattern 160 can be made equal. Thereby, even at a position away from the center of the image CI of the test chart 10 , the detection accuracy of the provisional focus position among the plurality of patterns 160 can be made equal. That is, provisional focus positions can be detected evenly throughout the entire field of view. As a result, the detection accuracy of the focal plane can be improved.

(4) Modified example of the second embodiment of the present invention

In the above-mentioned embodiment, the case where the slope 140 of each 3D block 110 has a plurality of boundary lines 162 has been described, but it may be changed as in the modified example shown below as necessary.

A test chart 10 related to a modified example of the present embodiment will be described using FIGS. 15 and 16 .

In the test chart 10 of this modified example, for example, each of the four slopes 140 in each 3D block 110 has one boundary line 162 . The form of the boundary line 162 of the pattern 160 in this modification is, for example, the same as that of the modification of the first embodiment described above.

(Effect)

According to this modified example, the slope 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 shift of the vertices 120 and the arrangement of the boundary lines 162, the outer block 110b can be easily manufactured. As a result, the cost of the test chart 10 having the outer block 110b can be reduced.

<Third Embodiment of the Present Invention>

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

(1) Test chart

The test chart 10 related to this embodiment will be described using FIGS. 17 and 18 .

As shown in FIGS. 17 and 18 , the test chart 10 of this 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 includes, for example, a central block 110a and four outer blocks 110b. The arrangement and shape of each of the central block 110a and the four outer blocks 110b in this embodiment are the same as those of the above-mentioned second embodiment.

Moreover, as shown in FIG. 18, the center block 110a may have the center mark 122, for example. The central marker 122 is designed, for example, as a marker recognizable by a camera. The center mark 122 is arranged, for example, at a position overlapping the optical axis of the camera 20 . That is, the center mark 122 is provided, for example, on the vertex 120 that overlaps with the central normal of the support plate 190 . Thereby, for example, the center in the X direction and the Y direction can be easily detected based on the detection result of the center mark 122 .

Each of the plurality of 2D blocks 170 has, for example, a two-dimensional pattern (2D pattern) 180 . The 2D pattern 180 is arranged to be orthogonal to the optical axis of the camera 20 , for example.

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

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

In addition, the 2D block 170 has, for example, four slits as the 2D pattern 180 , and both sides of the four slits form a pair of boundary lines 182 .

In addition, the four slits as the 2D pattern 180 are provided so as to be point-symmetrical about the center of the 2D block 170 when viewed from above the 2D block 170 (when viewed in real space), for example.

In the present embodiment, the test chart 10 is configured so that when the camera 20 takes pictures, the boundary line 182 of the 2D pattern 180 is not parallel to the pixel arrangement direction of the imaging element 240 . Thus, based on the same principle as that of the boundary line 162 in the 3D block 110 , it is possible to accurately grasp the change in the index value in the direction intersecting the boundary line 182 .

For example, four 2D blocks 170 are provided. The four 2D blocks 170 are symmetrically arranged around the center block 110a, for example. In addition, the 2D block 170 is provided, for example, at the center between the pair of outer blocks 110b. With such an arrangement, it is possible to easily detect the center of the X direction and the Y direction based on (correlation of) the detection result of the 2D block 170 .

(2) Manufacturing method of camera

Next, a method of manufacturing the camera of this embodiment will be described. The camera manufacturing method of this embodiment differs from the above-mentioned first and second embodiments in that, for example, a camera origin adjustment step S150 is included between the preparation step S100 and the evaluation region selection step S310 .

(S150: camera origin adjustment step)

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

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

In addition, the position of the optical system 220 may be adjusted to the origin position according to the detection result of the center mark 122 of the center block 110a.

(S540: camera position adjustment step)

In the camera position adjustment step S540 of this embodiment, in addition to the adjustments performed in the above embodiments, the adjusted focus position and the X The optical system 220 is adjusted in such a way that the centers of the Y direction and the Y direction overlap.

(3) Effects of this embodiment

According to the present embodiment, the 2D block 170 has the 2D pattern 180 orthogonal to the optical axis of the camera 20 . Accordingly, the position of the optical system 220 can be adjusted to the origin position through the optical adjustment mechanism of the camera 20 according to the detection result of the 2D pattern 180 of the 2D block 170 .

Here, as in the above-mentioned first and second embodiments, when the test chart 10 has only the 3D block 110, it is difficult to adjust the position of the optical system 220 to origin position. If the relative position of the optical system 220 and the imaging element 240 is fixed in a state where the position of the optical system 220 is not arranged at the origin position on the optical axis, in the camera 20 after manufacture, the optical system in the direction of the optical axis The movable area of 220 may be offset.

In contrast, in this 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 position of the optical system 220 can be arranged at the origin on the optical axis. In the state of the position, the relative positions of the optical system 220 and the imaging element 240 are optimized and fixed. Accordingly, in the manufactured camera 20 , it is possible to suppress shifting of the movable region of the optical system 220 in the optical axis direction.

<Fourth embodiment of the present invention>

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

(1) Test chart

The test chart 10 related to this embodiment will be described using FIG. 19 .

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

In this embodiment, the 3D block 110 has, for example, a plurality of ridges 130 and a plurality of slopes 140 .

The plurality of ridgelines 130 are provided, for example, at predetermined heights from the support plate 190 . In addition, the ridgeline 130 can also be considered to be formed by a collection of vertices 120 in the above-mentioned embodiment. Preferably, the heights of the plurality of ridgelines 130 from the support plate 190 are equal to each other.

For example, a plurality of slopes 140 are provided so as to incline in opposite inclination directions across each of the plurality of ridgelines 130 .

In the present embodiment, each slope 140 has a plurality of slits as the pattern 160 , for example. Each of the plurality of slits has a pair of boundary lines 162 (162a, 162b). For example, among 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 addition, in the present embodiment, similar to the above-mentioned embodiment, the test chart 10 is arranged so that when the camera 20 takes an image, the plurality of boundary lines 162 on each slope 140 are not parallel to the direction in which the pixels of the imaging element 240 are arranged. .

In addition, in this embodiment, the plurality of ridgelines 130 are arranged radially around, for example, the optical axis of the optical system 220 of the camera 20 (that is, the center of the support plate 190 ). That is, in the present embodiment, the 3D block 110 has, for example, a shape in which a plurality of triangular prisms are joined at the center of the support plate 190 .

In addition, in this embodiment, preferably, the plurality of ridgelines 130 are axisymmetric with respect to the optical axis of the optical system 220 of the camera 20 , for example.

(2) Effects of this embodiment

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

Here, in order to increase the number of measurement points in the pyramid-shaped 3D blocks 110 as in the above-mentioned embodiment, it is conceivable to increase the number of 3D blocks 110 while reducing the size of the pyramid-shaped 3D blocks 110 . However, if the 3D block 110 becomes smaller, measurement accuracy may decrease. In addition, increasing the number of 3D blocks 110 may result in increased manufacturing costs. On the other hand, as another method, adding a slit on one slope 140 of the pyramid-shaped 3D block 110 may be considered. In this case, however, the height of the slope 140 gradually decreases from the apex 120 with respect to the creepage direction of the support plate 190 . Therefore, it is difficult to process a large number of slits on one slope 140 .

On the other hand, in this embodiment, by providing a plurality of slits on one inclined surface 140 constituting the triangular prism, the number of slits can be easily increased on the wide inclined surface 140 . In addition, even if the number of slits is increased, the slits can be easily processed. In addition, an increase in manufacturing cost can also 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 measurement accuracy of the focal point can be improved.

(b) In the present embodiment, the plurality of ridgelines 130 are radially arranged around the optical axis of the optical system 220 of the camera 20 . Thus, the distribution of the slits can be spatially uniformed. 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) Modified example of the fourth embodiment of the present invention

[Modification 4-1]

The test chart card 10 related to Modification 4-1 of this embodiment will be described using 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 configuration described in the fourth embodiment. The 2D block 170 of this modified example is the same as the 2D block 170 of the third embodiment.

(Effect)

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

[Modification 4-2]

The test chart card 10 related to Modification 4-2 of this embodiment will be described using FIG. 21 .

In the test chart card 10 of Modification 4-2, the 2D block 170 is different from that of 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 . In addition, the dot 184 is, for example, a dot-shaped opening.

According to Modification 4-2, by making the 2D pattern 180 in the 2D block 170 the dots 184, the 2D pattern 180 can have a simple configuration and can be processed easily. In addition, using the point 184, the center of the 2D pattern 180 can be clearly and easily detected.

<Other embodiments of the present invention>

As mentioned above, although embodiment of this invention was concretely demonstrated, this invention is not limited to the said embodiment, Various changes are possible in the range which does not deviate from the summary. Hereinafter, "the above-mentioned embodiment" means 1st Embodiment, 2nd Embodiment, and 3rd Embodiment and these modification examples.

In the above-mentioned first embodiment, the case where the following (a) and (b) are satisfied is described, and in the above-mentioned second and third embodiments, it is described that the following (a), (b) and (c) are satisfied. circumstances, but not limited to these circumstances. 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 precision. However, the more configurations satisfying (a), (b) and (c), the more the adjustment position accuracy of the camera 20 can be improved.

(a) The test chart 10 is configured such that the slope 140 is inclined relative to the optical axis of the optical system 220 , and when the camera 20 is shooting, the boundary line 162 is not parallel to the pixel arrangement direction of the shooting element 240 .

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

(c) The apex 120 of the outer block 110 b is provided at a position deviated from the center side of the field of view of the camera 20 . In addition, the test chart 10 is arranged such that the apex 120 of the outer block 110b is located at the center of the outer block 110b when the camera 20 takes an image.

In the above-mentioned embodiment, the case where the 3D block 110 has a plurality of slopes 140 has been described, but the present invention is not limited to this case. The 3D block 110 may have only one slope 140 as long as the test chart 10 is arranged so that the boundary line 162 is not parallel to the pixel arrangement direction of the imaging element 240 when the camera 20 takes an image. Accordingly, the focus position can be detected from the detection result of the boundary line 162 on the one slope 140 . However, as in the above-described embodiment, when the 3D block 110 has a plurality of slopes 140 , the detection accuracy of the focus position can be further improved, which is preferable.

In the above embodiment, the case where one boundary line 162a of one slit is not parallel to the other boundary line 162b due to a difference in imaging magnification when the camera 20 captures images has been described, but the present invention is not limited to this case. For example, the test chart card 10 may be arranged such that one of the boundary lines 162a of one slit is parallel to the other boundary line 162b when the camera 20 takes an image. That is, the difference in imaging magnification may be considered in advance, and the width of the slit on the side closer to the camera 20 may be made narrower than the width of the slit on the bottom side. Thereby, the boundary lines 162a and 162b can be inclined at the same angle with respect to the pixel array direction within 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-mentioned embodiment, it has been explained that the four bases of the 3D block 110 are respectively parallel to one of the four sides of the supporting plate 190, and the boundary lines 162 in each of the slopes 140 are opposite to one of the four bases in plan view. A case where one of the extending directions is inclined at a predetermined angle α , but not limited to this case.

For example, with respect to the case where each of the four ridgelines of the 3D block 110 is parallel to one of the four sides of the support plate 190 (that is, the case where the 3D block 110 is arranged in a rhombus shape when viewed from above), the inclined surface 140 may be Each of the boundary lines 162 is inclined at a predetermined angle α with respect to the extending direction of any one of the four ridgelines in plan view.

Or, for example, the test chart 10 may also have a 3D block 110 whose boundary line 162 in each of the inclined surfaces 140 is parallel to the extension direction of one of the 4 bottom edges when viewed from above, and the 3D block 110 is parallel to the normal direction of the bottom surface. It is installed on the support plate 190 in a state where the shaft is rotated at an angle α .

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

In the above-mentioned embodiment, the case where the provisional focus position at which the change in the index value is the steepest is detected based on the peak spatial frequency when frequency analysis is performed on the interpolation curve IC of the index value with respect to the number of corrected pixels d′ is described. The position at which the maximum value of the slope of the index value with respect to the number of corrected pixels d' is obtained can be detected as a tentative focus position.

In Modification 4-2 of the fourth embodiment described above, the case where the 2D pattern 180 is the dots 184 has been described, but the 2D pattern 180 of the third embodiment may also be the dots 184 .

<Preferred Mode of the Invention>

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

(Note 1)

A test chart for adjusting a camera having an optical system and a photographing element, the test chart having at least one slope, the slope having at least one boundary line forming at least one of color, shade and brightness and extending linearly along the inclination direction of the slope, the slope is configured to be inclined with respect to the optical axis of the optical system, and when the camera is shooting, the boundary line and the shooting The pixel arrangement direction of the device is not parallel.

(Note 2)

According to the test chart card described in appendix 1, wherein, The test chart is configured such that when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the imaging element is larger than the deviation caused only by the distortion aberration of the optical system.

(Note 3)

The test chart according to Supplementary Note 1 or 2, wherein, when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction has a component caused by the distortion aberration of the optical system and relative to A component in which the pixel arrangement direction of the imaging element is linearly inclined.

(Note 4)

The test chart according to any one of Supplements 1 to 3, wherein the slope has a plurality of boundary lines.

(Note 5)

The test chart according to any one of Supplements 1 to 4, wherein the vertex is provided at a predetermined height, and the inclined surfaces are inclined in opposite inclination directions across the vertex.

(Note 6)

The test chart according to any one of Supplementary Notes 1 to 5, wherein a plurality of ridgelines are provided at a predetermined height, and the slopes are inclined toward opposite inclination directions across each of the plurality of ridgelines. There are a plurality of ways, and the plurality of ridges are radially arranged around the optical axis of the optical system.

(Note 7)

A test chart for adjusting a camera, the test chart having: an apex set at a prescribed height; and a plurality of slopes inclined in opposite inclination directions across the apex, The plurality of slopes each have a plurality of patterns continuously extending from the apex side in different inclination directions.

(Note 8)

The test chart according to supplementary note 7, wherein the plurality of patterns are arranged to be point-symmetrical about the apex when viewed from above the apex.

(Note 9)

The test chart according to Supplementary Note 7 or 8, wherein the test chart has an outer block, which is arranged at a position away from the center of the field of view of the camera, has the vertex and the slope, and the outer block is The apex of the block is arranged at a position deviated from the central side, and the test chart is configured so that the apex is located at the center of the outer block when the camera takes an image.

(Additional Note 10)

A test chart for adjusting a camera, the test chart having an outer block arranged at a position away from the center of the field of view of the camera, the outer block having: a position deviated from the central side an apex provided at a prescribed height; and a plurality of slopes inclined in opposite inclination directions across the apex, the test chart being configured such that the apex is positioned at the center of the outer block when the camera is photographed .

(Additional Note 11)

The test chart according to any one of Supplements 1 to 10, wherein the test chart has: a three-dimensional block having the slope; and a two-dimensional block having an angle perpendicular to the optical axis of the camera. Two-dimensional pattern of ground configuration.

(Additional Note 12)

The test chart according to any one of Supplements 1 to 11, wherein a center mark is arranged at a position overlapping with the optical axis of the camera, and the camera can recognize the center mark.

(Additional Note 13)

A camera manufacturing device comprising: a chart support unit that supports a predetermined test chart; a camera support unit that supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; image analysis a part, which analyzes the image obtained by shooting the test chart, and detects the focus position of the camera; and a camera adjustment mechanism, which adjusts the optical system and the shooting position according to the focus position of the camera The relative position of the elements, the chart supporting part is configured to: support the following chart as the test chart, that is: the chart has at least one slope, and the slope has at least one of color, shade and brightness and at least one boundary line extending linearly along the inclination direction of the slope, and the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line and The test chart is supported in such a manner that the pixel arrangement directions of the imaging element are not parallel, and the image analysis unit detects the focus position based on the detection result of the boundary line.

(Additional Note 14)

A camera manufacturing device, comprising: a chart support portion supporting a prescribed test chart; a camera supporting unit, which supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; an image analysis unit, which analyzes the image obtained by photographing the test chart, and detects the The focus position of the camera; and a camera adjustment mechanism, which adjusts the relative position between the optical system and the photographing element according to the focus position of the camera, and the chart support part is configured to: support the test chart as the test chart A card having an apex arranged at a predetermined height and a slope inclined in opposite inclination directions across the apex, the slope having different inclination directions from the side of the apex A plurality of patterns extending continuously, the image analysis unit detects the focus position according to the correlation of the detection results of the plurality of patterns.

(Additional Note 15)

A camera manufacturing device comprising: a chart support unit that supports a predetermined test chart; a camera support unit that supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; image analysis a part, which analyzes the image obtained by shooting the test chart, and detects the focus position of the camera; and a camera adjustment mechanism, which adjusts the optical system and the shooting position according to the focus position of the camera The relative position of the components, the chart support part is configured to: support the following chart as the test chart, that is: the chart has an outer block arranged at a position away from the center of the field of view of the camera, so The outer block has a position biased toward the central side An apex at a predetermined height and an inclined surface inclined in opposite inclination directions across the apex are provided at a predetermined height, and the test chart is supported in such a manner that the apex is located at the center of the outer block when the camera takes an image. The video analysis unit detects the focus position based on the detection result of the outer block.

(Additional Note 16)

A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, The step of detecting the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, and in the step of preparing the test chart, supporting as The following chart of the test chart, that is: the chart has at least one slope, the slope has a boundary forming at least one of color, shade and brightness, and extends linearly along the slope of the slope. At least one boundary line is configured such that the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the imaging element. In the test chart, in the step of analyzing the image, the focus position is detected according to the detection result of the boundary line.

(Additional Note 17)

The method for manufacturing a camera according to appendix 16, wherein, The step of analyzing the image includes: performing a series of steps including the steps of: A step of selecting an evaluation area including a plurality of pixels that intersects with the boundary line; and obtaining an index value of at least one of the color, shade, and brightness of the pixel relative to each pixel in the evaluation area. In the step of correcting the correspondence relationship of the number of pixels, wherein, the number of corrected pixels is the number of corrected pixels counted from the reference line passing through the corner of the evaluation area and parallel to the boundary line, and in the plurality of evaluation areas In the step of detecting, as the focus position, a position within the evaluation region where the change of the index value with respect to the number of corrected pixels is the steepest.

(Note 18)

A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, The step of detecting the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, in the step of preparing the test chart, prepare as The following chart of the test chart, that is: the chart has a vertex arranged at a specified height and a slope inclined to the opposite inclination direction across the apex, and the slope has a direction from the apex side along each different direction. a plurality of patterns continuously extending in the same oblique direction, In the step of analyzing the image, the focus position is detected based on the correlation of the detection results of the plurality of patterns.

(Additional Note 19)

A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, The step of detecting the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, in the step of preparing the test chart, prepare as The following chart of the test chart, that is, the chart has an outer block arranged at a position away from the center of the field of view of the camera, and the outer block has a The test chart is arranged so that the apex is located at the center of the outer block when the camera captures images of the apex with a predetermined height and the slope inclined in the opposite inclination direction across the apex. In the step of analyzing the image, the focus position is detected based on the detection result of the outer block.

(Additional Note 20)

A focus detection program and a computer-readable recording medium recorded with a focus recording program, the focus recording program causes a computer to execute the following process: a process of obtaining an image of a prescribed test chart using a camera having an optical system and a photographing element; and The process of analyzing the image obtained by shooting the test chart and detecting the focus position of the camera, in the process of obtaining the image, using the following chart as the test chart, namely: the chart At least one inclined surface is provided, and the inclined surface has at least one boundary line forming a boundary of at least one of color, shade and brightness, and extending linearly along the inclined direction of the inclined surface, and the test chart is arranged in the following manner In the state, the image of the test chart is obtained, that is, the inclined plane is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line and the photographing element The test chart is arranged in such a way that the arrangement directions of the pixels are not parallel, and in the process of analyzing the image, the focus position is detected according to the detection result of the boundary line.

(Additional Note 21)

The focus detection program and the computer-readable recording medium recorded with the focus recording program according to Supplementary Note 20, wherein, in the process of analyzing the image, the computer is made to execute the following process: performing a series of processes including the process of selecting an evaluation area including a plurality of pixels intersecting the boundary line in the image of the test chart in a plurality of evaluation areas with different directions and positions; And, in each pixel in the evaluation area, the process of obtaining the corresponding relationship between the index value of at least one of the color, shade and brightness of the pixel relative to the number of corrected pixels, wherein the number of corrected pixels is obtained from the number of corrected pixels from the reference line passing through the corner of the evaluation area and parallel to the boundary line, A flow of detecting, among the plurality of evaluation areas, a position within the evaluation area at which the change in the index value with respect to the number of corrected pixels is the steepest, as the focus position.

10: Test chart card

110: 3D blocks

120: apex

140: bevel

160: pattern

162: Borderline

162a: Borderline

162b: Borderline

190: support plate

B ₁₁₁ : Focus position

L: distance

x: direction

y: direction

z: direction

Claims (16)

A test chart for adjusting a camera having an optical system and a photographing element, the test chart having at least one slope, the slope having at least one boundary line forming at least one of color, shade and brightness and extending linearly along the inclination direction of the slope, the slope is configured to be inclined with respect to the optical axis of the optical system, and when the camera is shooting, the boundary line and the shooting The pixel arrangement directions of the elements are not parallel, and the test chart is configured such that when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the photographing element is greater than that caused only by the distortion of the optical system Aberration-induced offset. The test chart card according to claim 1, wherein the slope has a plurality of boundary lines. The test chart card according to claim 1, further comprising an apex provided at a predetermined height, and a plurality of slopes are provided so as to incline in opposite inclination directions across the apex. The test chart card according to Claim 1, wherein it has a plurality of ridgelines arranged at a predetermined height, and the inclined surface is provided with a plurality of ridgelines inclined toward opposite inclination directions across each of the plurality of ridgelines. , the plurality of ridgelines are radially arranged around the optical axis of the optical system. A test chart for adjusting a camera, the test chart having: an apex set at a prescribed height; and a plurality of slopes inclined in opposite inclination directions across the apex, Each of the plurality of slopes has a plurality of patterns continuously extending from the apex side in different inclination directions, and the test chart includes an outer block disposed at a position away from the center of the field of view of the camera. , having the vertex and the slope, the vertex of the outer block is arranged at a position deviated from the central side, and the test chart is configured such that when the camera is photographed, the vertex is located on the outer side the center of the block. A test chart for adjusting a camera, the test chart having an outer block arranged at a position away from the center of the field of view of the camera, the outer block having: a position deviated from the central side an apex provided at a prescribed height; and a plurality of slopes inclined in opposite inclination directions across the apex, the test chart being configured such that the apex is positioned at the center of the outer block when the camera is photographed , the slope has at least one boundary line, the boundary line forms a boundary of at least one of color, shade and brightness, and extends linearly along the slope direction of the slope, and the test chart is configured to, When the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the imaging element is greater than the deviation caused only by the distortion of the optical system. The test chart as claimed in any one of claims 1-6, wherein the test chart is provided with: a three-dimensional block, which has the slope; and a two-dimensional block, which has an optical axis perpendicular to the camera A 2D pattern of cross-ground configurations. A camera manufacturing device, comprising: a chart support portion supporting a prescribed test chart; a camera supporting unit, which supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; an image analysis unit, which analyzes the image obtained by photographing the test chart, and detects the The focus position of the camera; and a camera adjustment mechanism, which adjusts the relative position between the optical system and the photographing element according to the focus position of the camera, and the chart support part is configured to: support the test chart as the test chart A card having at least one inclined plane having at least one boundary line forming a boundary of at least one of color, shade, and brightness and extending linearly along the inclined direction of the inclined plane, And the test chart is supported in such a way that the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the shooting element, The test chart is configured such that when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the imaging element is greater than the deviation caused only by the distortion aberration of the optical system, so The video analysis unit detects the focus position based on the detection result of the boundary line. A camera manufacturing device comprising: a chart support unit that supports a predetermined test chart; a camera support unit that supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; image analysis a part, which analyzes the image obtained by shooting the test chart, and detects the focus position of the camera; and A camera adjustment mechanism, which adjusts the relative position of the optical system and the imaging element according to the focus position of the camera, and the chart supporting part is configured to support the following charts as the test chart, That is, the card has an apex arranged at a predetermined height and a slope inclined in opposite inclination directions across the apex, and the slope has a plurality of patterns continuously extending from the apex side in different inclination directions. , the test chart card has an outer block, which is arranged at a position away from the center of the field of view of the camera, has the apex and the slope, and the apex of the outer block is arranged at a position that is biased to the central side position, the test chart card is configured such that when the camera is shooting, the vertex is located at the center of the outer block, and the image analysis unit detects the focal point according to the correlation of the detection results of the plurality of patterns Location. A camera manufacturing device comprising: a chart support unit that supports a predetermined test chart; a camera support unit that supports at least a part of a camera having an optical system and an imaging element at a position where the test chart can be photographed; image analysis a part, which analyzes the image obtained by shooting the test chart, and detects the focus position of the camera; and a camera adjustment mechanism, which adjusts the optical system and the shooting position according to the focus position of the camera The relative position of the components, the chart support part is configured to: support the following chart as the test chart, that is: the chart has an outer block arranged at a position away from the center of the field of view of the camera, so The outer block has an apex provided at a predetermined height at a position deviated from the central side, and a slope inclined in an opposite inclination direction across the apex, The slope has at least one boundary line forming a boundary of at least one of color, shading, and brightness and extending linearly along an inclination direction of the slope, and the test chart is configured such that, at the When shooting with the above-mentioned camera, the deviation of the boundary line relative to the pixel arrangement direction of the shooting element is greater than the deviation caused only by the distortion aberration of the optical system, and when shooting with the camera, the The test chart is supported such that the vertex is located at the center of the outer block, and the video analysis unit detects the focus position based on the detection result of the outer block. A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, The step of detecting the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, in the step of preparing the test chart, prepare as The following chart of the test chart, that is: the chart has at least one slope, the slope has a boundary forming at least one of color, shade and brightness, and extends linearly along the slope of the slope. At least one boundary line, the test chart is configured such that when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the imaging element is greater than that caused only by the distortion aberration of the optical system offset of The test chart is configured in such a way that the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the shooting element, and In the step of analyzing the image, the focus position is detected based on the detection result of the boundary line. The method for manufacturing a camera according to claim 11, wherein the step of analyzing the image includes: performing a series of steps including The step of step, that is: the step of selecting an evaluation area including a plurality of pixels intersecting with the boundary line in the image of the test chart; a step of corresponding relationship between index value of at least one of color, shading and brightness with respect to corrected pixel count, wherein the corrected pixel count is measured from a reference point that passes through the corner of the evaluation area and is parallel to the boundary line The number of correction pixels counted from a line, and in the plurality of evaluation regions, a position within the evaluation region where the change of the index value with respect to the number of correction pixels is the steepest is detected as the focus position. A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, a step of detecting the focus position of the camera; and a step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, In the step of preparing the test chart, the following chart is prepared as the test chart, that is, the chart has an apex arranged at a predetermined height and a slope inclined in an opposite direction across the apex, The slope has a plurality of patterns continuously extending from the apex side in different inclination directions, and the test chart has an outer block arranged at a position away from the center of the field of view of the camera, and has the The apex and the slope, the apex of the outer block is set at a position biased to the central side, and the test chart is configured such that when the camera takes pictures, the apex is located at the center of the outer block , in the step of analyzing the image, the focus position is detected according to the correlation of the detection results of the plurality of patterns. A method for manufacturing a camera, comprising: a step of preparing a prescribed test chart; a step of photographing the test chart using a camera having an optical system and a photographing element; analyzing the image obtained by photographing the test chart, The step of detecting the focus position of the camera; and the step of adjusting the relative position of the optical system and the photographing element according to the focus position of the camera, in the step of preparing the test chart, prepare as The following chart of the test chart, that is, the chart has an outer block arranged at a position away from the center of the field of view of the camera, and the outer block has a An apex of a predetermined height and a slope inclined in opposite inclination directions across the apex, the slope having at least one boundary line forming a boundary of at least one of color, shade, and brightness along the The inclined direction of the slope extends linearly, The test chart is configured such that when the camera is shooting, the deviation of the boundary line relative to the pixel arrangement direction of the imaging element is greater than the deviation caused only by the distortion aberration of the optical system, so that When the camera is shooting, the test chart is arranged such that the apex is located at the center of the outer block, and in the step of analyzing the image, the focal point is detected according to the detection result of the outer block Location. A focus detection program, the focus recording program causes a computer to execute the following procedures: using a camera with an optical system and a photographing element to obtain an image of a prescribed test chart; Analysis, the process of detecting the focus position of the camera, in the process of obtaining the image, use the following chart as the test chart, that is: the chart has at least one inclined plane, and the inclined plane has a forming color, The boundary of at least one of shading and brightness, and at least one boundary line extending linearly along the inclined direction of the slope, the test chart is configured such that when the camera is shooting, the boundary line is relatively The displacement of the pixel arrangement direction of the imaging element is larger than the displacement caused only by the distortion aberration of the optical system, and the test chart is obtained in the state where the test chart is arranged in the following manner: Image, namely: configure the test in such a way that the slope is inclined relative to the optical axis of the optical system, and when the camera is shooting, the boundary line is not parallel to the pixel arrangement direction of the imaging element Tuka, In the process of analyzing the image, the focus position is detected according to the detection result of the boundary line. The focus detection program according to claim 15, wherein, in the process of analyzing the image, the computer is caused to execute the process of: performing evaluation in a plurality of evaluation areas at different positions along the extending direction of the boundary line A flow of a series of steps including a flow of selecting an evaluation area including a plurality of pixels intersecting the boundary line within the image of the test chart; , a process of obtaining the corresponding relationship between the index value of at least one of the color, shade, and brightness of the pixel relative to the number of corrected pixels, wherein the number of corrected pixels is obtained from the corner of the evaluation area and is related to the corrected pixel number. The number of correction pixels counted from the reference line parallel to the boundary line, in the plurality of evaluation areas, the position in the evaluation area where the change of the index value relative to the number of correction pixels is the steepest is detected as the focus position process.

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