JPH0394110A - Testing method for distance measurement module - Google Patents

Abstract

PURPOSE:To miniaturize the device, and also, to execute a distance measurement test in various distances by providing optical members whose focal distances are different so as to be changeable in an optical path for connecting a light emitting part, a body whose distance is to e measured and a light receiving part. CONSTITUTION:A distance plate 13 is provided so as to be movable in a desired distance in front of a distance measurement module 3, and a rotary plate 15 in which a concave lens 17 whose focal distance is different is integrated in the periphery is provided so as to be freely rotatable in front of a light receiving part 7 so that the center line of the concave lens 17 coincides with the center of the light receiving part 7. Supposing that the distance plate 13 and the concave lens 17 do not exist, and a distance plate 21 exists in an actual distance whose distance is to be measured, a spot image by the distance plate 21 of a projected infrared beam is brought to image formation in the light receiving part 7. An angle made by the projecting direction A and the photodetecting direction B in this case is denoted as theta1. Subsequently, when an angle theta2 made by the projecting direction and the photodetecting direction B' in the case the distance plate 13 and the concave lens 17 are provided is set to the same as the angle theta1, a distance measurement can be executed as a spot beam image from the distance plate 21 which as if it is in an actual distance by the light receiving part 7. Also, by changing the concave lens 17, the distance measurement test can be executed in various distances.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a distance measurement test method for a distance measurement module used in cameras, videos, etc.
More specifically, the present invention relates to a distance measurement test method for an active distance measurement module.

(Prior art) An active distance measuring module projects a beam from a light emitting unit to a subject, and forms a spot beam image projected onto the subject using this beam on a light receiving unit. This method measures the distance from the direction in which the beam is received or the direction in which the beam is projected from the light emitting unit to the subject.

1M, in a distance measuring module that measures the distance from the direction in which the light receiving part receives a spot beam image to the subject, the beam projection direction in the light emitting part is constant, and In a distance measuring module that measures the distance to an object, the direction in which the spot beam image is received in the light receiving section is fixed.

The distance measurement principle of these distance measurement modules is to measure the distance to the subject based on the angle between the beam projection direction at the light emitting section and the direction in which the spot beam image is received at the light receiving section using triangulation. be.

? It is necessary to test whether an active ranging module such as the above actually performs a correct ranging operation, and a ranging test is performed before or after being incorporated into a camera, video camera, or the like.

FIG. 6 shows a schematic diagram of a conventional distance measurement test method for a distance measurement module.

In FIG. 6, 3l is a distance measurement test device, 2 is a camera, and the distance measurement module 3 is built into the camera 1.

The distance measuring module 3 includes a light emitting section 5 consisting of an infrared light emitting element and a light projecting lens, and a light receiving section 7 consisting of a condensing lens and a light receiving element. The light emitting section 5 and the light receiving section 7 are separated by a distance Xo (baseline length).

This distance measuring module 3 is of a type that measures the distance to the subject from a direction B in which a spot beam image is received in a light receiving section 7, and an infrared beam is projected in a fixed direction A from a light emitting section 5.

The distance measurement test device 31 has predetermined distances D1D2. D
．． . . respectively distance plates 33. ．． 33 ■. 33. ．． ...
are arranged so that they can be taken in and out.

In the test method, first, the camera 1 is installed at a predetermined position of the distance measurement test device 3l.

Next, when obtaining the measured distance data of the distance measuring module 3 for the distance D1, for example, the distance plate 33.
is set on the projection optical path of the light emitting unit 5.

Here, when the infrared beam is projected from the light emitting section 5 toward the distance plate 33, a spot beam image is projected onto the distance plate 33, and this spot beam image is formed on the light receiving element of the light receiving section 7.

The light receiving section 7 detects on which part of the light receiving element the spot light image is formed, and this detection signal is taken into a calculation section (not shown) to measure the distance to the distance plate 33.

Then, from the angle 01 between the beam projection direction A and the direction B in which the spot beam image is received in the light receiving section 7,
That is, since the projection direction A of the infrared beam is constant, the distance to the subject is measured based on the triangulation method from the angle θ1 at which the spot beam image is received in the light receiving unit 7.

Next, by comparing the measurement data calculated by the distance measurement module 3 and the distance D1 to the distance plate 33 using a target table prepared in advance, it is checked whether the distance measurement module 3 is measuring the distance correctly. do.

Furthermore, each distance plate 33. ．． 333. ... distance D2
．． A distance measurement test for D3, . . . - is performed in the same manner as above.

This test method is similar to the distance measurement Joule test, which measures the distance to the object by reflecting the beam from the light emitting part and makes effective use of space.

(Problem to be solved by the invention) Therefore, in the conventional method, when conducting a test, a distance plate is installed at the actual distance to be measured, which requires a large space, and the test equipment becomes large. there were.

In particular, distance measurement modules for cameras equipped with a zoom mechanism require a distance of 10 meters or more, so the test equipment is even larger. There was a problem that was extremely disadvantageous when incorporating it.

The present invention has been devised in view of the above-mentioned circumstances, and an object of the present invention is to miniaturize and save space of a distance measurement test device, and further, to measure various distances using a small and simple device. An object of the present invention is to provide a distance measurement test method for a distance measurement module that can perform a distance test.

(Means for Solving the Problems) In order to achieve the above object, the present invention arranges a distance measuring object at a desired distance from a distance measuring module, and provides a plurality of distance measuring objects each having a different degree of bending the beam path. At least one of the optical members is prepared in an optical path connecting the light emitting part, the object to be measured, and the light receiving part, and a distance measurement test is performed while replacing the optical member. It is characterized by what it did.

The present invention also provides an optical member that arranges a distance measurement object at a desired distance from the distance measurement module, and bends the course of the beam in an optical path connecting the light emitting section, the distance measurement object, and the light receiving section. is arranged, and the distance measurement test is performed while moving the object to be measured in a direction toward and away from the distance measurement module.

(Function) The light receiving unit regards the spot beam image as if it were from an object to be measured at the actual distance, and uses this to measure the distance.

Therefore, a distance measurement test can be performed without requiring an actual distance measurement as in the conventional method, and the test apparatus can be made smaller and space-saving.

Moreover, distance measurement tests can be performed for various distances by replacing the optical member or by moving the object to be measured in a direction toward and away from the distance measurement module.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram of a distance measurement test method in which a distance measurement test is performed while replacing optical members.

First, to explain from test device l1, ■ is test device 1l.
The distance measuring module 3 incorporated in the camera 1 is equipped with a light emitting section 5 and a light receiving section 7 spaced apart by a predetermined distance (baseline length X), as in the conventional case.

13 is a distance plate, 15 is a rotary plate, and the distance plate l3 is disposed movably in the direction of approaching and separating from the camera (arrow E) at a desired distance (for example, lm) in front of the distance measuring module 3. In the example, this distance plate 13 corresponds to the object to be measured.

The rotary plate l5 is rotatably disposed in front of the light receiving section 7. As shown in FIG. 2, a plurality of concave lenses 17 having different focal lengths are installed around the rotating plate 15 at predetermined intervals.

The center of rotation 15A of the rotating plate 15 is shifted outward from the center of the light receiving section 7, and the center 17A of each concave lens 17 is positioned on an extension of the center of the light receiving section 7 when the rotating plate 15 is rotated appropriately. It is arranged.

Next, the test method will be explained.

When an infrared beam is projected from the light emitting unit 5, a spot beam image is projected onto the distance plate 13 by this beam, and the course of the spot beam image is bent by the concave lens 17.
An image is formed on the light receiving section 7.

At this time, the projection direction (constant) of the infrared beam in the light emitting unit 5 is defined as A, the direction in which the spot beam image is received in the light receiving unit 7 is defined as B°, and the angle formed by the direction A and the direction B° is 02
shall be. Note that this angle θ2 corresponds to the projection direction A of the infrared beam.
Since this is constant, it is also the angle at which the spot beam image is received in the light receiving section 7.

In FIG. 1, 2l indicates a distance plate that is assumed to be placed at an actual distance for distance measurement.

If the distance plate l3 and the concave lens l7 are not provided, and an infrared beam is projected from the light emitting section 5 onto the distance plate 2l, a spot beam image of this beam on the distance plate 21 will be formed on the light receiving section 7. The direction in which the spot beam image is received in the light receiving section 7 at this time is designated as B, and the angle between direction 8 and direction B is designated as θl. Since the projection direction A of the infrared beam is constant, this angle θl is also the angle at which the spot beam image is received in the light receiving section 7.

Therefore, if the concave lens 17 makes the angle θl and the angle θ2 the same, that is, if the concave lens 17 makes the direction B° in which the spot beam image is received in the light receiving section 7 the same as the direction B, then the light receiving section 7 The distance is measured as if it were a spot beam image from the distance plate 21 at the actual distance.

Here, when the rotating plate l5 is rotated and the concave lens 17 is replaced with another one, the angle θ2 changes discontinuously, and the actual distance to be measured changes discontinuously for each concave lens 17. Become.

Therefore, distance measurement tests can be performed for various distances by replacing the concave lens l7.

Furthermore, when the distance plate l3 is moved in the direction of arrow E within a predetermined range, the angle θ2 changes continuously, and the actual distance to be measured follows the movement of the distance plate 13 and remains within the predetermined range. It will change continuously.

Therefore, even if the distance to be measured is long, the distance plate 1
By combining the movement of 3 and the plurality of concave lenses 17, it is possible to conduct distance measurement tests by continuously changing long distances in order to measure distances within a narrow space.

Next, this principle will be explained with reference to FIG.

In FIG. 3, 23 indicates a location where a virtual image is formed, where the focal length of the concave lens 17 is f, and the distance plate l from the concave lens 17 is
3 is L, and the distance from the light receiving part 7 to the concave lens 17 is 2, then the distance from the light receiving part to the distance plate l3 seen through the concave lens l7 is optically equivalent to D, which is derived from the following formula. , D is optically the same as when the distance plate 13' is placed at a distance of D.

D=L {fL-12 (L-f)}/fL (however, f
<0) Also, the moving range of the 1k separating plate 13 is set to L. Assuming that L2 is from , the measurable distance range is D, to D
The range is 2.

D,=L,{PI-,-β(L,-f) l/r
L. D2=L2{fL2-12(L2-f)}/fL2
Therefore, if the test distance is in the range D, to D2, the distance measurement test can be performed with a single concave lens 17, and the test distance is D,
When the distance is out of the range of D2 from 12, a distance measurement test can be performed by replacing 12 with another concave lens 17, and it is convenient to perform a test if the distances that can be measured by each concave lens 17 overlap. in this case,
The same concept can be applied even if the concave lens l7 is positioned in front of the light emitting section 5 by shifting its center outward.

Therefore, according to this embodiment, the actual distance to be tested is not required, and by replacing the concave lens 17 by rotating the rotary plate 15, distance measurement tests can be performed for various distances, for example, at a distance of about 1 m, and the testing device Aim to downsize and save space.
The test device can be easily integrated into the camera assembly line.

Furthermore, if the concave lens l7 is replaced and the distance plate l3 is moved as in the embodiment, it becomes possible to continuously perform distance measurement tests for various distances.

Furthermore, since the concave lens 17 is used to bend the optical path, great accuracy is not required in the position of the concave lens 17, and therefore, the distance measurement test apparatus can be constructed simply and at low cost.

In the embodiment, a case was explained in which the concave lens l7 was used, but it is also possible to arrange a convex lens in front of the light emitting part 5, or to shift its core inward and arrange it in front of the light receiving part 7. are similar.

Further, the method for replacing the concave lenses 17 is arbitrary; for example, a plurality of concave lenses 17 may be assembled in an elongated plate, and the concave lenses 17 may be replaced by sliding this plate.

Further, the optical member is not limited to the concave lens l7 or the convex lens, and may be any member as long as it bends the course of the beam, and other optical members such as mirrors and prisms may be used.

Furthermore, if a zoom lens is used as the optical member based on the same concept, by changing its magnification, it is possible to perform a distance measurement test by continuously changing the distance without moving the distance plate.

Further, in the embodiment, a distance measurement module 3 that performs distance measurement based on the direction in which the spot beam image is received in the light receiving unit 7
Although the case has been described, the present invention is similarly applicable to a distance measuring module that measures distance based on the projection direction of the beam in the light emitting section 5.

Furthermore, if the range of movement of the distance plate l3 is set to a certain sufficient length, the distance measurement test of the distance measurement module 3 can be carried out even if there is only one optical member for bending the beam path. In this case as well, the test device can be made smaller and save space.

Next, the distance measurement test system configured as described above will be explained along with its test procedure based on FIGS. 4 and 5.

FIG. 4 shows a schematic diagram of the entire distance measurement test system.

This distance measurement test system includes a machine main body section 40 and a comprehensive controller section 50 that comprehensively controls this machine main body section 40.
It is composed of g, t-t.

The machine main body part 40 includes a base part 4l, and this base part 4
A camera mounting mechanism 42 for removably fixing the camera l to be tested is provided on the camera l.

Furthermore, a single-axis robot 43 is provided on the base portion 41 to control the one-dimensional movement of a movable table 4315a, and a distance plate operation mechanism 44 for operating the distance plate l3 is attached on the movable table 43a. There is.

Further, the base portion 41 includes a power supply/controller unit 4 that supplies power to the camera mounting mechanism 42, the single-axis robot 43, and the distance plate operation mechanism 44, and controls them.
5 is provided.

In this embodiment, a wedge prism 17A is used as the optical member, and this wedge prism 17A is fixed to a prism mounting portion provided on the camera mounting mechanism 42.

The general controller unit 50 is mainly configured with a computer set 5l such as a personal computer, and the computer set 5l is connected to the power supply/controller unit 45 via a first interface 52.

Further, the computer set 51 is configured to be connectable to an internal electronic control circuit of the test camera 1 via a second interface 53 and a connector (not shown).

The second interface 53 is connected to the computer set 51
This is so that electrical command signals and distance signals can be communicated between the test camera and the test camera.

The test camera 1 causes the light emitting section 5 to emit light in response to an external electric signal through the function of an internal electronic control circuit, and also performs distance measurement based on the direction in which the light receiving section 7 receives the spot beam image. It is configured to be able to output to the outside an electrical distance signal representing the distance traveled.

The test camera l may be placed on the camera mounting mechanism 42 automatically using a transfer robot, or may be placed manually.

This camera mounting mechanism 42 is equipped with an air solenoid (not shown), and by operating this air solenoid with an electric signal from the outside, it can fix the mounted test camera l at a predetermined position, Unfixing is performed.

The single-axis robot 43 is a commercially available product that is controlled by an external electric signal, and for example, the single-axis robot 43 is controlled by an external electric signal.
A movable table 43a that is guided dimensionally, a high-precision lead screw for moving the movable table 43a, a DC servo motor that rotates the lead screw, and an encoder that reads the rotational position of the DC servo motor and performs feedback control. It also consists of electronic control circuits, etc.

In this embodiment, the distance plate operating mechanism 44 mounted on the movable table 43a of the single-axis robot 43 is a distance plate l3.
This is a rotary actuator for rotating 180 degrees.

Note that the distance plate 13 has different light reflectance on its front and back sides, and if it is desirable to change the light reflectance of the distance plate 13 during the execution of a distance measurement test, it is possible to The distance plate operating mechanism 44 is controlled by , and the distance plate 13 is rotated.

The computer set 5l includes, for example, main bodies 51a and C.
It is equipped with a 5lb RT display, a 51c keyboard, and a 5l Conbuque set and a power supply/
The first interface 52 connected to the controller unit 45 is, for example, of the Rs-232-C standard.

The camera mounting mechanism 42, single-axis robot 43, and distance plate operating mechanism 44 described above are controlled by electrical signals sent from a power supply/controller unit 45 under the control of a computer set 51.

Next, a specific distance measurement test method procedure using the above distance measurement test system will be explained with reference to the flowchart of FIG.

First, in step S1, the power of each part constituting the system is turned on.

In the next step S2, a program for a distance measurement test is loaded into the memory of the computer set 51 and started to be executed.

When execution of the program is started, the computer set 51 enters a standby state waiting for an instruction to start the distance measurement test routine to be input from the keyboard 51c.

l9 In the next step S3, the test camera 1 is placed, for example, manually, on the camera mounting mechanism 42, and then in step S4, an instruction to start the distance measurement test routine is inputted from the keyboard 51c.

Once this routine is started, in step S5, the camera mounting mechanism 42 is transferred from the computer set 5l.
A command signal is sent to the camera mounting mechanism 42.
The solenoid is activated and the test camera 1 is fixed. At this time, the second interface 53 and the electronic control circuit of the test camera 1 are also connected.

Subsequently, in step S6, a distance variable representing the test distance is set.

This test distance is not the actual distance from the test camera l to the distance plate 13 in the distance measurement test system, but is expressed as the distance to the distance plate 13 assuming that the optical path is not bent.

For this test distance, for example, a total of three distances may be determined in advance, one each for short distance, medium distance, and long distance, and the values of these predetermined distances may be written in the program in advance. If necessary, it may be possible to input a desired value or change a specified value by operating the keyboard 51c.

If the test is conducted for the above three distances (short distance, medium distance, and long distance), step S
6, the distance variable is the first value of them (
In this example, it is set to short distance).

In the next step S7, the machine body 40 of the system is
Set to the set test distance.

That is, the single-axis robot 43 is operated to move the distance plate l3 toward and away from the distance measurement module 3 of the test camera 1 (the fourth direction).
arrow M) in the figure, so that the light receiver 7 receives the spot beam image at the same angle as if the distance plate were present at the actual test distance set at that time.

Next, in step S8, the test camera 1 is operated to perform an autofocus (AF) operation, and in the next step S9, the distance signal output from the test camera 1 as a result of the AF operation is read, and the signal is The represented distance value is stored in the memory of computer set 5l.

In the next step SIO, it is determined whether a predetermined number of tests have been completed using the test distance at that time.

In order to make the test more accurate, it is preferable to repeat the test multiple times (for example, five times) for the same distance.

If the predetermined number of tests have not been completed, the process returns to step S8.

Once the predetermined number of tests have been completed, the process proceeds to step Sll.
, where it is determined whether the test for the last of the plurality of test distances (the long distance in this example) has been completed.

If the determination result is rNOJ, the process advances to step S12 to change the test distance setting, and then returns to step S7.

On the other hand, if the result of this determination is rYEsJ, the process advances to step S13.

In step S13, the camera attachment mechanism 42 is operated to release the fixation of the test camera 1, and the distance measurement test routine ends in step S13.

Subsequently, in step S14, by comparing the results obtained in the distance measurement test routine with predetermined criteria,
A final pass/fail judgment is made on the distance measuring module 3 of the test camera 1, and the judgment result is displayed on the CRT display 5lb of the computer set 5l.

In the next step S15, the camera 1 that has been tested is manually removed from the camera mounting mechanism 42, and the
Depending on the pass/fail judgment result displayed on the RT display 5lb, it is sorted into a passing product line, an adjustment line, etc.

In the following step S16, it is determined whether or not to test the next camera I. If the test is to be performed, the process returns to step S3, and if not, the computer set 51 is caused to perform a termination operation in step S17.

In this case, when the end operation 23 is manually instructed from the keyboard 51c, the data that needs to be saved will be saved.

Next, in step S18, the power to each part of the system is turned off, thereby completing the procedure.

Although the procedure has been explained briefly above, if necessary, it is possible to input the identification number of the test camera 1 into the computer set 5l and save the distance test results as information for each camera. You can also do this.

In particular, if the distance measurement module 3 of the camera 1 is configured to perform distance measurement in a stepwise manner, that is, it divides the distance from the closest distance to infinity into several distance ranges, and the distance measurement is divided into several distance ranges. If the device is designed to generate a distance signal indicating which distance range it belongs to, more accurate test results can be obtained by setting the test distance at the boundary between those distance ranges.

In that case, if the distance immediately before and the distance immediately after the boundary are used as test distances, a more accurate test can be performed.

2 4 (Effects of the Invention) As is clear from the explanation below, according to the distance measurement test method for a side distance module according to the present invention, it is possible to reduce the size and space of the test device, and furthermore, it is possible to It is possible to perform distance measurement tests at various distances using a simple device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a distance measurement test method according to an embodiment of the present invention;
Figure 2 is a front view of the rotating plate, Figure 3 is an explanatory diagram of the test method,
FIG. 4 is a schematic diagram of the entire distance measurement test system, FIG. 5 is a flowchart showing a test procedure by the distance measurement test system, and FIG. 6 is a schematic diagram of a conventional distance measurement test method. In the figure, 1 is a camera, 3 is a distance measuring module, 5 is a light emitting unit, 7 is a light receiving unit, l3 is a distance plate, 15 is a rotary plate, 17 is a concave lens, xo is a baseline length, A is a beam projection direction, B,B'
is the direction in which the spot beam image is received, 40 is the machine main body,
43 is a single axis robot, 50 is a general controller section, 51
is a computer set. U)

Claims (2)

[Claims] (1) Project a beam from the light-emitting unit to the subject, form a spot beam image projected onto the subject with this beam on the light-receiving unit, and receive the beam projection direction in the light-emitting unit and the spot beam image in the light-receiving unit. In a ranging module that measures the distance to a subject from the angle it makes with a direction, the subject is placed at a desired distance from the ranging module, and multiple beams with different degrees of bending the beam path are used. Optical members are prepared, at least one of the optical members is disposed in an optical path connecting the light emitting section, the object to be measured, and the light receiving section, and a distance measurement test is performed while replacing the optical member. , A distance measurement test method for a distance measurement module. (2) Project a beam from the light emitting unit to the subject, form a spot beam image projected onto the subject with this beam on the light receiving unit, and receive the beam projection direction at the light emitting unit and the spot beam image at the light receiving unit at that time. In a ranging module that measures the distance to a subject based on the angle formed with a direction, the subject is placed at a desired distance from the ranging module, and the light emitting section, the subject, and the light receiving section are connected to each other. An optical member for bending the course of the beam is disposed in the connecting optical path, and the distance measurement test is performed while moving the object to be measured in a direction toward and away from the distance measurement module. Module ranging test method.