JP2002072058A - Device and method for adjusting camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for adjusting a camera capable of accurately focusing at a low cost by simply and rationally adjusting the positional relation among a light projecting element, a light receiving element and a finder in order to find a range. SOLUTION: As for the device and the method for adjusting the camera, a chart 13 is irradiated with range finding beam light from the light projecting element 10 in the case of adjusting the position of a range finder, and the reactive light is received by the light receiving element 8a (8b), then, respective components are accurately positioned by using the peak of the output characteristics (luminance distribution) of the light receiving element and the detection position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a distance measuring device used for an autofocus function mounted on a camera, and more particularly, to an adjusting device for a camera with light projection for distance measuring and an adjusting method thereof.

[0002]

2. Description of the Related Art Generally, an auto focus function mounted on a camera is roughly classified into a passive type using an image signal of a subject and an active type using a reflected light from a camera for projecting distance measuring light. being classified. However, even if a passive type is used, if the subject image is dark, it is necessary to use auxiliary light, and a hybrid type combining these has recently been commercialized.

When a distance measuring device for performing the autofocus is mounted on a camera, a light for distance measurement is accurately projected from a light projecting means toward a subject reflected in a finder, and the reflected light is used as a light receiving element. If it could not receive the light, correct distance measurement could not be performed. So, when assembling to the camera,
It was necessary to adjust the positional relationship between these components. Therefore, there is a demand for a technique capable of performing such adjustment with simple and inexpensive equipment.

As this adjusting technique, for example, Japanese Patent Application Laid-Open
In the technology disclosed in Japanese Patent Application Laid-Open No. 183790, the position of the light projecting element is adjusted by monitoring the projection position of the distance measuring light to be projected on the subject with a CCD camera. FIG. 9 (a)
2 shows an outline of the light emission adjustment. In this light projection adjustment, the target mark 32 provided on the chart 37 is provided in the optical path A of the finder 31 and
The adjusting mechanism 38 is moved to move the light projecting element 35 so that the light spot 36 projected from the light projecting element 35 driven by the driver 34 through the light projecting lens 39 enters the target mark 32 viewed by the CD camera 33. The position is adjusted. In this adjustment method, an infrared light emitting diode is often used as a light emitting element, and is often invisible to the naked eye.
A CCD camera 33 capable of receiving infrared light was required. FIG. 9B is a diagram showing a state of the correctly adjusted light spot 36 in the finder screen 40.

This publication also discloses an adjustment method as shown in FIG. This is a unit 43 that mounts a light projecting direction of a light projecting unit composed of an infrared light emitting diode 35 and a light projecting lens 39 and a light receiving unit composed of a light receiving lens 41 and a light receiving element 42 and matches the light receiving direction. It is. When the unit 43 is mounted on the finder section 31 of the camera body 44, the orientation of the unit 43 is
This is an adjustment method for adjusting with 5 or screw 46.

[0006]

SUMMARY OF THE INVENTION The aforementioned Japanese Patent Application Laid-Open No.
The adjustment technique disclosed in Japanese Patent Application Laid-Open No. 183790 requires the movement of a unit on which a light-emitting unit and a light-receiving unit are mounted for adjustment at the time of assembling to a camera body. There was a possibility that miniaturization of the device could not be achieved.

Accordingly, the present invention provides a light emitting element for distance measurement,
It is an object of the present invention to provide a camera adjustment device and a method for adjusting the position of a light receiving element and a finder simply and rationally, thereby achieving accurate focusing at low cost.

[0008]

In order to achieve the above object, the present invention provides a light projecting means for projecting light for distance measurement toward a subject, an image detecting means for measuring a luminance distribution of the subject, In the method for adjusting a camera having viewfinder means for observing the subject, the image detection means determines an area for detecting an image at a predetermined position in the viewfinder,
There is provided an adjustment method for a camera which determines a state in which the signal light from the light projecting unit is incident on the area, and adjusts a position of the light projecting unit in accordance with the result of the incident judgment.

Also, there are first and second light projecting means for projecting distance measuring light to the subject, image detecting means for measuring the luminance distribution of the subject, and finder means for observing the subject. In the camera adjusting device, among the image detecting means, area determining means for determining first and second areas for detecting images at first and second predetermined positions in the viewfinder; and the first area And a state in which the signal light from the second light projecting means is incident on the second area. According to the output results of the second incidence determination means and the first and second incidence determination means,
An adjustment device for a camera, comprising: a projection adjustment unit that adjusts the position of the projection unit.

In the camera adjusting device and the adjusting method as described above, when adjusting the position of the distance measuring device, the light projecting device irradiates the chart with the beam for distance measuring, and the reaction light is captured by the light receiving device. The position is accurately adjusted using the peak and the detection position of the output characteristic (luminance distribution) of the light receiving element.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows and describes a conceptual configuration of a camera adjustment device according to a first embodiment of the present invention. In this embodiment, FIG.
As shown in the figure, the distance L is determined by the parallax of the two light receiving lenses.
A distance measuring device using, as an example, a passive AF module 1 that detects a position difference x of an image signal of a subject H located away from the image sensor with a sensor array will be described.

This distance measuring device is roughly divided into a light projecting unit 1 for projecting a light beam for distance measurement to a subject, a light receiving unit 2 for receiving reflected light from the subject to obtain a subject image, and a fan lid 3. An A / D converter 4 for A / D converting a subject image signal obtained by the light receiving unit 2 and outputting a digital image signal; and a personal computer for calculating and processing adjustment position information based on the digital image signal. It comprises a processing / control unit 5, a display unit 6 for displaying a processing result, and a storage unit 7 for storing the number of a sensor in a sensor array described later as data N. The light receiving unit 2 includes two sensor arrays 8
The light projecting unit 3 includes light emitting elements (IRED) 10 that emit infrared light, and condenses the emitted infrared light as distance measuring beam light. And a light projecting lens 11 for irradiating the object. still,
Here, the adjustment is performed using the chart 13 on which the “+” target mark 12 is written instead of the subject. A spot pattern 14 is described at the center of the cross of “+”. When the light beam for distance measurement is projected from the light projecting element 10 to the chart 13 through the light projecting lens 11, the projected image 2
A light projection area such as 6 is formed. FIG. 1 (b)
FIG. 3 is a diagram illustrating a cross-sectional structure of the light receiving unit 2. The light receiving section 2 has a structure in which a light incident direction of reflected light from a subject can be changed in a vertical direction.

FIG. 1C is a diagram showing the concept of light reception. Assuming that the focal lengths of the light receiving lenses 9a and 9b are f and the parallax (base line length) is B, a subject image H at a distance L has a difference of a relative position difference x and two sensor arrays 8a and 8b.
b. When x is obtained by comparing these two images, the processing / control unit 5 performs distance calculation according to the calculated value, and determines the focusing position of a photographic lens (not shown). When the subject image is dark or a contrast image cannot be obtained, a beam for distance measurement is projected from the light projecting element 10 shown in FIG. Light enters the sensor arrays 8a and 8b to obtain image signals.

In general spot distance measurement, the user often considers a composition in which a main subject is captured at a predetermined position in the viewfinder 3, for example, at the center when photographing. A beam for ranging must be projected. At this time, if the center of the viewfinder 3 (the main subject position on the viewfinder screen) does not match the position actually illuminated (the actual main subject position), the main subject is projected onto the ranging beam light. Accurate focusing is not possible. Therefore, a target mark 12 'shown at the distance measuring point is provided in the finder 3.
At the time of camera manufacture and repair, this target mark 12 '
, The field of view and the projection position of the light receiving section 2 must be adjusted.

With reference to the flowchart shown in FIG. 2, a description will be given of the position adjustment of the camera in the distance measuring apparatus according to the first embodiment. First, the position of the light receiving unit 2 is adjusted (step S1). Specifically, first, a chart 13 on which a spot pattern 14 is written is prepared, and the center of the target mark 12 'in the finder and the spot pattern 1 are set.
Positioning is performed in the direction in which the viewfinder 3 faces so that the position of the viewfinder 4 coincides. As shown in FIG. 3, this adjustment may be performed visually by the operator 100 while holding the camera body 18 on which the finder 3 and the finder module are mounted. Thereafter, as shown in FIG. 1B, when the light receiving unit 2 is turned up and down (y direction), the spot pattern 14 on the chart 13 is changed.
Is incident on the sensor array 8a (8b). The subject image signal obtained here is A / D converted by the A / D converter 4 and the digital image signal is output to the processing / controller 5.
Then, an output characteristic of the adjustment position data output from the processing / control unit 5 is displayed on the display unit 6. The operator fixes the light receiving unit 2 so as to have a peak value by looking at the displayed output characteristics, and ends the adjustment in the vertical (y) direction. At this time, the target mark 12 in the finder visual field 16 and
FIG. 4A shows the relationship between the glaring positions 17 of the sensor arrays 8a (8b).

The horizontal (x) direction corresponds to the sensor array 8.
Since a and 8b are horizontally long, one of the sensor arrays always sees the spot pattern (minimum part of the dotted line) as shown in the output characteristic of FIG. As described above, which sensor receives the spot pattern in the sensor array is stored in the storage unit 7 as data N including the sensor number.

Next, the position of the light projecting section 1 is adjusted. This position adjustment is performed by changing the relative relationship between the light projecting element 10 and the light projecting lens 11. First, the light emitting element is moved so as to emit light and scan in the vertical (y) direction (step S2). In this case, the output of the light receiving unit 2 reaches a peak when the horizontally long sensor array comes to the position where it gazes, and this position is determined as the y-direction position of the light projecting unit 3 and temporarily fixed.

In step S2, the data N indicating the sensor number is read from the storage unit 7, and the adjustment amount in the horizontal (x) direction is calculated. In other words, the difference is the difference between the sensor indicating the peak of the light reception in the sensor array and the difference, and the difference is equal to the peak position calculated by the light projection and the peak position calculated by the light reception by moving the light emitting element 10. The light projecting element 10 is moved in the x direction as described above (step S5). Then, whether or not the moved position is appropriate, that is, by monitoring the outputs of the light receiving elements 8a and 8b and confirming the sensor having the peak value, as shown by the solid line showing the luminance distribution shown in FIG. It is determined whether or not the peak values coincide with each other (step S6).

If the peak values do not match yet (NO), the process returns to step S5 to continue the adjustment. However, if the peak values match (YES),
Assuming that it is in the proper position, fix it (Step S
7), the position adjustment of the light projecting unit 1 ends. In addition, horizontal (x)
In the adjustment in the direction, it is desirable that the sensor for detecting the peak is adjusted to be at the center of the sensor array. As described above, according to the present embodiment, a CCD camera for infrared light detection for adjustment is not required by using the sensor array that responds to the light beam for distance measurement at the time of adjustment. In addition, without moving the entire distance measuring unit, the finder, the light projecting unit, and the light receiving unit
Alignment between the two functions is simple and space-saving.

Next, a second embodiment according to the present invention will be described. FIG. 5 shows conceptual features of a camera adjustment device and an adjustment method thereof according to the second embodiment. In the second embodiment, a description will be given of position adjustment in a distance measuring apparatus that performs distance measurement using a light source using two distance measuring light projecting elements. In this embodiment,
Parts that are the same as the constituent parts of the first embodiment described above are given the same reference numerals (FIG. 1), and detailed descriptions thereof are omitted.

As shown in FIG. 5A, the camera of this embodiment has two light emitting elements (LEDs) 21 and 22.
When these are separately used for the long distance and the short distance, and the light is projected on the same subject, the positions of the light emitting elements that project light for the distances L ₁ and L _{2 due} to parallax are determined by the respective light sources. It must be placed off-axis. For example, the light projecting element 21 for a distance L ₁ must be projected light at an angle of theta _1, the light projecting element 22 for the distance L ₂ is necessary to throw light at an angle of theta ₂ is there.

In order to adjust the position by placing a chart for each target distance and irradiating each with a beam for distance measurement,
There is a problem in the work space and a problem in the equipment for switching the chart. Therefore, if the adjustment is performed at a distance L ₀ that is shorter than the distances L ₁ and L ₂ , these space problems can be solved. Further, the closer the distance is, the greater the intensity of the reflected light from the subject (chart) is, and the more excellent the S / N ratio can be adjusted.
However, it is necessary to consider that the light for distance measurement is projected at a point in consideration of the angles θ ₁ and θ ₂ described above.

FIG. 5C shows a positional relationship for adjustment in consideration of the angle θ. On the distance L _1, the predetermined position of the sensor (which is the target 1 in the finder
2 ′) and the light source of the projected spot must have an angle θ as shown in FIG. At this time, point 2 of chart 13 at distance L ₀
It may be irradiated distance measuring light 3, but during the adjustment, for monitoring this point 23 is a sensor represented by N ₁ in the sensor array 8a.

When the distance between the principal points of the two lenses is B ₁ , the angle φ formed by the sensor N ₁ with the optical axis of the light-receiving lens is L ₀ tan θ + L ₀ tan φ = B ₁ , so that tan φ = (B ₁ / L ₀ ) −tan θ. Here, since tan θ is B ₁ / L ₁ , the relation φ = arctan (B ₁ / L ₀ ) − (B ₁ / L ₁ ) is established. The sensor in the position of φ may be set to N _1. In the case of projection the distance L _2, as reflected light L ₁ of the formula in the sensor N ₂ corresponding to the position of φ obtained in place of the L ₂ is incident, so as to adjust the light emitting element To

The adjustment of the position of the light emitting element in such a positional relationship will be described with reference to the flowchart shown in FIG. First, the light receiving unit 2 is adjusted with respect to the target mark 12 in the same manner as in step S1 of FIG. 2 described above (step S11). Thereafter, as shown in FIG. 4B, the position N of the spot pattern 14 of the target mark 12 is calculated based on the distance L ₁ and the sensor number N _{1 using the} above-described formula.
Calculates (step S12), the in consideration of sensor number N _1, to adjust the projection position of the light projecting device 21 (step S
13). Similarly, from the distance _{L 2} calculates the sensor number _{N 2} (step S14), and by adding a sensor number N _1,
The light projecting position of the light projecting element 22 is adjusted (Step S1)
5).

That is, as shown in FIG. 5B, the distance L ₀
When the light reflected by the light projecting elements 21 and 21 is incident on a portion corresponding to the sensors N ₁ and N ₂ on the range 17 monitored by the sensor on the chart, the adjustment is correctly performed. That is, using the configuration shown in FIG. 1A, the sensor number to which each beam from the light emitting elements 21 and 22 is to be incident by the processing / control unit 5 in a form in which the sensor numbers N ₁ and N ₂ are added. N ₀ is obtained, and when the corresponding sensor is scanned and received light, the display unit 6 displays the fact.
What is necessary is just to notify the operator 100 and fix the light emitting element at that position.

As described above, according to the present embodiment, parallax of each light projecting unit provided for each distance so as to correspond to a long distance and a short distance is taken into consideration. the distance ranging beam of share since it is possible to correct adjusted by placing the chart further short distance L ₀ different, it is possible to reduce the space for adjustment process. Further, similarly to the first embodiment described above, a CCD camera is not used.

The first and second embodiments described above are simple adjustments because sensor data of a distance measuring device is used. However, the output of the sensor array 8a (8b) shown in FIG.
The adjustment time is limited by the processing speed of the A / D converter 4 that performs D conversion. Read all sensor data,
If the incident spot position is determined each time, it takes a long time for adjustment. In a third embodiment that solves this problem, the x direction of the light emission adjustment is set to the CC direction as shown in FIG.
A camera adjustment device and method for monitoring and adjusting at which position in a finder a light-emitting element projects a distance measuring light beam using a D camera 33.
The configuration of the third embodiment is equivalent to the configuration shown in FIG.

However, in the vertical (y) direction, as shown in FIG. 7 (c), if the distance measuring light beam is not correctly incident on the sensor array, the distance measuring device deteriorates in accuracy due to insufficient light quantity. As shown in FIG. 7D, the glare position 1 of the sensor array
In order to accurately detect that the reflected signal light 26 is correctly incident on No. 7, an adjustment is made by feeding back using the output of the sensor array.

Usually, many sensor arrays have a function of outputting the peak output of the incident light. Therefore, even if the output of the processing / control unit is not used, the output of the processing / control unit can be used without using the outputs of all the sensors. The y-direction adjustment can be performed (see FIG. 7A). Since it is not known which sensor gives the peak value, detection in the x direction is not possible. Therefore, in the x direction, as shown in FIG. 7B, the operator 100 visually adjusts the position via the CCD camera. In the x direction, the S / N is not degraded even if it is slightly shifted, if it is in the target mark 12 correctly.

The position adjustment in the third embodiment will be described with reference to the flowchart shown in FIG. This work routine may be performed by an operator,
If the output of the CCD camera is image-processed and the robot performs positioning, the robot can be automated. In this case, the sequence of the program of the processing / control unit 5 is used. First, as shown in FIGS. 1A and 1B, the light receiving elements 8a and 8b
Is performed (step S21). As shown in FIG. 7A, the adjustment is completed when the target mark 12 and the sensor monitor position 17 coincide with each other.

Next, the light projecting element 10 is adjusted in the y direction. While irradiating the light beam for distance measurement from the light emitting element 10, the light is received by the light receiving element 8a and its output is monitored (step S2).
2). Then, while detecting the peak value of the monitor output of the light receiving element (step S23), the light emitting element is slightly moved in the y direction until the peak value is detected (NO) (step S24). If the peak value is detected in the monitor output (YES), the adjustment in the y direction ends because the reflected signal light 26 is correctly incident on the monitor position 17 of the light receiving element as shown in FIG. (Step S2)
5).

Next, as shown in FIG. 9 (b), the inside of the finder 3 is imaged by the CCD camera 33 as shown in FIG. Then, the adjustment in the x direction is performed so that the beam is incident on the target mark 14 (step S27). When the predetermined sensor position is reached as described above, the light projecting element 10 is fixed.

As described above, in the third embodiment, the adjustment in the x direction and the adjustment in the y direction are performed by different methods which are suitable for each, and the S / N is better than the distance measuring device. Achieve highly accurate adjustment. Also, if installed in the camera,
Since the distance measuring beam light is correctly projected into the target mark, it is possible to correctly focus on the main subject aimed at the time of photographing. In particular, if the present invention is applied to a sensor array having a function of removing stationary light, the present invention is designed for hybrid AF, so that accurate light projection is possible regardless of external light noise such as fluorescent lights in factories. The spot position can be adjusted.

Although the above embodiments have been described, the present invention includes the following inventions. (1) A camera adjusting device according to the present invention includes: a light projecting unit that projects light for distance measurement to a subject; an image detecting unit that measures a luminance distribution of the subject; and a finder unit that observes the subject. In the method for adjusting a camera having, among the image detecting means, an area for detecting an image at a predetermined position in the finder is determined, and a state in which the signal light from the light projecting means is incident on the area is determined. The position of the light projecting means is adjusted according to the result of the incident determination. (2) The area is determined in consideration of an error between the finder and the image detecting means or a distance between the adjustment charts.

(3) A camera adjusting device according to the present invention comprises first and second light projecting means for projecting light for distance measurement to a subject, and image detecting means for measuring a luminance distribution of the subject. A camera adjustment device having a finder means for observing the subject, wherein the image detection means detects first and second images at first and second predetermined positions in the finder.
Area determining means for determining an area of the first area; first incidence determining means for determining a state in which the signal light from the first light projecting means has entered the first area; and
The position of the light projecting means is adjusted according to the output results of the second incidence determining means and the first and second incidence determining means for determining the state of the signal light incident by the second light projecting means.

(4) In the camera adjusting method of the present invention, the light projecting means for projecting the distance measuring light to the object, the image detecting means for measuring the luminance distribution of the object, and observing the object. In the adjusting method of the camera adjusting device having the finder means, a step of adjusting the position of the image detecting means so as to detect an image at a predetermined position in the finder;
Determining a state in which the signal light from the light projecting means has entered the sensitive range of the image detecting means; confirming a light projecting position through the viewfinder; and Adjusting the position of the light projecting means.

(5) In the camera adjusting method according to the above mode (4), the adjustment of the light emitting means in the x direction is performed by the light emitting confirmation means, and the adjustment of the light emitting means in the y direction is performed by the light emitting means. This is performed in accordance with the output result of the incident determination means.

[0039]

As described above in detail, according to the present invention, the positional relationship between the light emitting element, the light receiving element, and the finder for distance measurement is simply and rationally adjusted, thereby achieving low cost and accurate adjustment. It is possible to provide a camera adjustment device capable of focusing and an adjustment method thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conceptual configuration of a camera adjustment device according to a first embodiment of the present invention.

FIG. 2 is a flowchart for explaining position adjustment in a camera distance measuring apparatus according to the first embodiment.

FIG. 3 is a view for explaining alignment of a finder by a worker's eyes.

FIG. 4 is a diagram for describing position adjustment of a light receiving element and a light projecting element in the first embodiment.

FIG. 5 is a diagram for explaining a camera adjustment device and an adjustment method thereof according to a second embodiment.

FIG. 6 is a flowchart for explaining position adjustment in a camera distance measuring apparatus according to a second embodiment.

FIG. 7 is a diagram illustrating a camera adjustment device and an adjustment method according to a third embodiment.

FIG. 8 is a flowchart for explaining position adjustment in a camera distance measuring apparatus according to a third embodiment.

FIG. 9 is a diagram showing a conceptual configuration for explaining adjustment of a distance measuring device mounted on a conventional camera.

FIG. 10 is a diagram for describing adjustment when a distance measuring device is mounted on a camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light-emitting part 2 ... Light-receiving part 3 ... Fan lid 4 ... A / D conversion part 5 ... Processing / control part 6 ... Display part 7 ... Storage part 8a, 8b ... Sensor array 9a, 9b ... Light-receiving lens 10 ... Light-emitting element (IRED) 11: Projection lens 12: Targate mark 13: Chart 14: Spot pattern

Claims (4)

[Claims] 1. A method for adjusting a camera having a light projecting means for projecting distance measuring light toward a subject, an image detecting means for measuring a luminance distribution of the subject, and a finder means for observing the subject. Among the image detecting means, an area for detecting an image at a predetermined position in the viewfinder is determined, and a state in which the signal light from the light projecting means is incident on the area is determined. According to the incident determination result, A method for adjusting a camera, comprising adjusting the position of the light emitting means. 2. The camera adjustment method according to claim 1, wherein the area determination is performed in consideration of an error between the viewfinder and the image detection unit or a distance between the adjustment charts. . 3. An image forming apparatus comprising: first and second light projecting means for projecting distance measuring light onto a subject; image detecting means for measuring a luminance distribution of the subject; and finder means for observing the subject. In the camera adjusting device, a first and a second in the finder among the image detecting means are provided.
Area determining means for determining first and second areas for detecting an image at a predetermined position, and first for determining a state in which the signal light from the first light projecting means has entered the first area. An incident determining means, a second incident determining means for determining a state in which the signal light from the second light projecting means has entered the second area, and a first and a second incident determining means. An adjustment device for a camera, comprising: a projection adjustment unit that adjusts a position of the projection unit according to an output result. 4. A method for adjusting a camera having a light projecting means for projecting distance measuring light toward a subject, an image detecting means for measuring a luminance distribution of the subject, and a finder means for observing the subject. Adjusting the position of the image detecting means so as to detect an image at a predetermined position in the viewfinder; and determining a state in which the signal light from the light projecting means has entered the sensitive range of the image detecting means. And a step of confirming a light projecting position through the finder; and a step of adjusting a position of the light projecting means according to an output result of the incident determining means.