JP2003222784A - Distance measuring device and photographing device equipped with distance measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distance measuring device whose number of distance measuring areas effectively used is constant and a photographing device equipped with the distance measuring device. <P>SOLUTION: The system comprises a pair of imaging devices 2a and 2b with a plurality of pixels, a pair of distance measuring optical systems, which lead light from a distance measuring area, and a distance calculating means to calculate a distance to an object of photographing on the basis of a signal from the pair of the imaging devices 2a and 2b. The distance calculating means comprises a large area setting means which sets large areas SL1 and SR1 against the pair of the imaging devices 2a and 2b and a small area setting means which sets a predetermined number of small areas L1-L5 and R1-R5 in the large area SL1 and SR1 respectively and calculates a distance to the object of photographing for each of the corresponding small areas L1-L5 and R1-R5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device and a photographing device equipped with the distance measuring device, and more particularly to a distance measuring device for measuring distances at a plurality of points and a photographing device equipped with the distance measuring device.

[0002]

2. Description of the Related Art In recent years, in cameras adopting passive AF (autofocus), a number of models that realize a multipoint AF by arranging a plurality of distance measuring areas on a pair of line sensors are increasing. This is to secure a wider range-finding area and to accurately capture the intended subject.

For example, as shown in FIG. 3, the distance measuring device includes a pair of left and right image pickup elements 2a, 2 which receive light from the distance measuring area.
b. The image pickup devices 2a and 2b have a plurality of pixels, and have small areas L1 to L5 corresponding to the distance measurement areas;
R5 is set. The positions and sizes of the small regions L1 to L5; R1 to R5 are fixed. Then, for each of the corresponding small areas L1 and R1, L2 and R2, ... L5 and L5,
The data of the pixel groups included in each are compared, and the distance measurement value for each distance measurement area is obtained. Although the small regions L1 to L5; R1 to R5 are shown shifted in the vertical direction in FIG. 3, when the line sensors are used for the image pickup devices 2a and 2b, they overlap in the direction perpendicular to the paper surface.

[0004]

By the way, a distance measuring device (so-called external light passive type) in which a photographing optical system such as a compact camera or a digital camera and a distance measuring optical system do not match each other.
In the above, in the case where the focal length of the distance measuring optical system is fixed, when the focal length of the photographing optical system is changed, the size relation of the distance measuring region with respect to the photographing region changes.

For example, as shown in FIG. 2A, when the photographing optical system is on the wide side (short focal length side), the photographing area 9
A distance measuring area 3w is arranged therein as indicated by a dotted line, and the plurality of distance measuring areas A1 to A5 are all arranged in the photographing area 9.

On the other hand, as shown in FIG. 2B, when the photographing optical system is on the tele side (long focal length side), the angle of view becomes small and the actual photographing range becomes narrow. At this time, the focal length of the distance measuring optical system is fixed, and the small areas L1 to L5; R1
When the position and size of R5 are fixed, the size of the range in which distance measurement is actually performed does not change. Therefore, on the telephoto side, the distance measuring area 3t protrudes from the photographing area 9 as shown by the dotted line, and part of the distance measuring areas A1 to A5 protrudes from the photographing area 9. The distance measuring results of the distance measuring areas A1, A2, A4, A5 thus protruding are limited in use in the related art. Therefore, the number of distance measuring areas is reduced on the tele side, and the distance measuring accuracy is higher than that on the wide side. descend. In FIG. 2, the distance measuring areas A1 to A5 are shown shifted in the vertical direction, but when a line sensor is used for the image sensor of the distance measuring device, the distance measuring areas A1 to A5 overlap in the direction perpendicular to the plane of the drawing.

Therefore, a technical problem to be solved by the present invention is to provide a distance measuring device capable of keeping the number of effective distance measuring areas unchanged and a photographing device equipped with the distance measuring device. It is to be.

[0008]

In order to solve the above technical problems, the present invention provides a distance measuring device having the following configuration.

The distance measuring device includes a pair of image pickup elements having a plurality of pixels, a pair of distance measurement optical systems for guiding light from the distance measurement areas to the pair of image pickup elements, and the pair of image pickup elements. A predetermined number of small areas, and a distance calculating means for calculating the distance to the subject based on the signals from the pixels contained in each of the small areas corresponding to the pair of image pickup devices. It is of the type provided. The distance calculation means includes a large area setting means and a small area setting means. The large area setting means sets a large area for the pair of image pickup devices. The small area setting means sets a predetermined number of small areas in the large area set by the large area setting means.

In the above structure, the size of the large area and the position of the boundary of the large area are changed according to the setting of the large area setting means. Even if the setting of the large area is changed, the small area setting means includes a predetermined number of small areas in each large area, and the predetermined number is set based on the signals from the pixels included in the corresponding small area. The distance measurement result of is obtained.

With the above arrangement, the large area setting means can appropriately change the setting of the large area, whereby the number of distance measuring areas that can be effectively used can be kept unchanged. For example, the large area can be set so that all the distance measurement areas are included in the shooting area.

Preferably, the small area setting means sets the small area so that the number of the pixels included in each of the corresponding small areas of the pair of image pickup devices becomes a predetermined number. .

According to the above arrangement, the number of pixels included in each small area does not change even if the setting of the large area is changed. Therefore, the distance measurement calculation for the corresponding small area can be the same. it can. Therefore, it is possible to shorten the distance calculation processing and measure the distance with the same accuracy.

The distance measuring device having each of the above structures is suitable as a distance measuring device for a photographing device having a photographing optical system, and the present invention provides a photographing device having the following two structures.

The photographic device of the first structure is of a type including the distance measuring device of each of the above structures and a photographic optical system.
The large area setting means sets the large area according to the focal length of the photographing optical system.

With the above arrangement, even if the focal length of the photographing optical system is changed, a large area can be set so that a predetermined number of distance measuring areas are set within the photographing area.

The photographic device having the second structure is of a type including the distance measuring device having each of the above structures and a photographic optical system.
The image capturing device has at least two different large areas.
A mode setting means for selectively setting one of the two modes is provided. The large area setting means sets the large area having a size corresponding to the mode set by the mode setting means.

With the above arrangement, the position where the distance measuring area is set in the photographing area can be changed according to the selected mode. Thus, for example, it is possible to provide a mode in which the distance measuring areas are wholly arranged and the distance is averagely measured, and a mode in which the distance measuring areas are intensively arranged in a specific portion and the distance is focused. .

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 and 4 to 12.

First, the first embodiment will be described with reference to FIGS.
~ It demonstrates based on FIG.

As shown in FIG. 1B, the camera 4 as a photographing device includes a distance measuring module 2, a photographing lens 5 as a photographing optical system, an image pickup section 6, a motor 7 for driving the photographing lens 5, and a camera. 4 is provided with a microcomputer 8 which controls the entire control. A subject image is formed on the imaging unit 6 by the taking lens 5. A film and an image pickup device are arranged in the image pickup unit 6.

As shown in FIG. 1 (a), the distance measuring module 2 uses a pair of image pickup devices 2a, 2t, 2t, 2t, which are light sources from the distance measuring region 3, by using lenses 2s, 2t which are a pair of distance measuring optical systems. 2b
Lead to the top respectively. The light receiving states of the image pickup devices 2a and 2b are
Since the deviation occurs in a fixed relationship according to the distance to the subject 1, the distance to the subject 1 can be calculated based on the deviation.

The microcomputer 8 reads out signals from the image pickup devices 2a and 2b of the distance measuring module 2 and performs distance measuring calculation based on the deviation of the light receiving state. The distance measuring module 2 and the microcomputer 8 constitute a distance measuring device. The microcomputer 8 functions as distance calculating means.

The microcomputer 8 controls the driving of the motor 7 based on, for example, the distance measurement result, and the photographing lens 5
To focus.

As shown in FIG. 4, the microcomputer 8 sets the distance measuring areas A1 to A5 for the photographing area 50 and performs the distance measuring calculation for each of the distance measuring areas A1 to A5.

When the focal length of the taking lens 5 changes, on the wide side, as shown in FIG.
Although w is arranged in the photographing area 50, on the tele side, FIG.
As shown in (b), the distance measuring area 52t is the photographing area 50.
Out of the way. Even in this case, the distance measuring areas A1 to A5 are arranged in the photographing area 50. That is, the microcomputer 8 determines the distance measuring area A1 for the distance measuring areas 52w and 52t according to the focal length of the taking lens 5.
~ Change the settings of A5, all ranging area A1 ~ A5
Is always included in the photographing area 50. In FIG. 4, the distance measuring areas A1 to A5 are shown shifted in the vertical direction, but when line sensors are used for the image pickup elements 2a and 2b, they overlap in the direction perpendicular to the plane of the drawing.

Specifically, the microcomputer 8 is
When the focal length of the photographing lens 5 is read, as shown in FIGS. 5 and 6, the left and right image pickup devices 2a,
2b, large areas SL1, SR1; SL2, SR2
, And small areas L1 to L5; R1 to R5 are respectively set in the large areas SL1 and SR1 at appropriate intervals. Here, the small areas L1 to L5; R1 to R5 correspond to the distance measuring areas A1 to A5, respectively. 5 and 6, the small regions L1 to L5; R1 to R5 are shown shifted in the vertical direction, but when line sensors are used for the image pickup devices 2a and 2b, they overlap in the direction perpendicular to the plane of the drawing.

That is, when the taking lens 5 is on the wide side, as shown in FIG. 5, relatively large large areas SL1 and SR1 are set for the left and right image pickup devices 2a and 2b, respectively. On the other hand, when the taking lens 5 is on the tele side,
As shown in FIG. 6, relatively large large areas SL2 and SR2 are set for the left and right imaging elements 2a and 2b, respectively. Then, the set large areas SL1, SR1; SL
2, small areas L1 to L5; R1 to R5 are set in SR2, respectively.

For example, a table in which the focal length of the taking lens 5 is associated with the positions of pixels at which data reading is started for the pair of image pickup devices 2a and 2b and the arrangement intervals of the small regions L1 to L5; Prepare in advance. The microcomputer 8 refers to this table and sets the small areas L1 to L5; R1 to R5.

Preferably, the small areas L1 to L5; R1 to R
5 has a predetermined size (number of pixels) for each of the large regions SL1, SR1; SL2, SR2, regardless of the size. This facilitates the subsequent distance measurement calculation processing, and since the number of pixels does not decrease, a certain distance measurement accuracy can be maintained.

The sizes of the small areas L1 to L5; R1 to R5 do not necessarily have to be the same. For example, both ends may be small and the center may be large. In addition, FIG.
As shown in FIG. 6, ranging areas A1 to A5 and small areas L1 to L
5; If R1 to R5 overlap each other,
The number of pixels is increased to enable highly accurate distance measurement, but the present invention is not limited to this.

The microcomputer 8 reads out the data of the pixels included in the corresponding small areas L1 and R1, L2 and R2, ... R5 and L5, and performs the distance measurement calculation. For example, with respect to the data of one small area, the data of the other small area is shifted pixel by pixel, the correlation value is sequentially calculated, and the pixel shift amount having the highest correlation is obtained. To decide.

As described above, even if the focal length of the taking lens 5 changes, a fixed number of distance measuring areas A1 to A5 are always provided.
Is set in the photographing area 50, it is possible to prevent the number of distance measuring areas that can be effectively used from changing.

Further, by keeping the number of pixels included in each of the small areas L1 to L5; R1 to R5 constant, the accuracy of the distance data indicated by the distance measuring area can be always kept optimum. . That is, in general, the larger the number of pixels included in the distance measurement area, the higher the distance measurement accuracy.
~ L5; If the number of pixels included in R1 to R5 is changed according to the focal length of the taking lens, the accuracy of the distance measurement data changes, but if the number of pixels is fixed, this will not occur.

Further, since the number and size (number of pixels) of the distance measuring areas are constant depending on the focal length, only one type of distance measuring algorithm is required, and as a result, the processing is simplified and the calculation is performed. The time is shortened and the release time lag is shortened. This improves the operational feel of the camera.

Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment has substantially the same configuration as that of the first embodiment, and therefore the differences will be mainly described below.

In the camera of the second embodiment, either the wide AF mode or the spot AF mode can be selected and set. The microcomputer sets the distance measurement areas A1 to A5 in the photographing area 50 according to the selected mode, as shown in FIG.

In the wide AF mode, as shown in FIG. 7A, the distance measuring areas A1 to A5 are set in the predetermined first area SW of the distance measuring area 53 within the photographing range 50, Measure the distance. In spot AF mode,
As shown in (b), the distance measuring areas A1 to A5 are set in the predetermined second area SS of the distance measuring area 53 within the photographing range 50 to measure the distance. The first area SW is relatively large and the second area SS is relatively narrow. As a result, in the spot AF mode, it is possible to select more accurate distance data by arranging the distance measurement areas A1 to A5 in a narrow area with high density. In FIG. 7, the distance measuring areas A1 to A5 are shown shifted in the vertical direction, but when line sensors are used for the image pickup devices 2a and 2b, they overlap in the direction perpendicular to the plane of the drawing.

Specifically, when the microcomputer reads the mode setting, in the wide AF mode, as shown in FIG. 8, a relatively large large area SL3.
Set SR3. On the other hand, in the spot AF mode, as shown in FIG. 9, a relatively small large area SL4.
Set SR4. Then, as shown in FIGS. 8 and 9, the set large areas SL3, SR3; SL4, SR4.
Small regions L1 to L5; R1 to R5 are set therein at appropriate intervals. Small areas L1 to L5; R1 to R5 correspond to distance measuring areas A1 to A5, respectively. 7 and 8, the small regions L1 to L5; R1 to R5 are shown shifted in the vertical direction, but when line sensors are used for the image pickup devices 2a and 2b, they overlap in the direction perpendicular to the paper surface.

The small areas L1 to L5; R1 to R5 are irrespective of the sizes of the large areas SL3, SR3; SL4 and SR4.
By setting a predetermined size (the number of pixels) for each of them, the subsequent distance measurement calculation processing becomes easy, and a constant distance measurement accuracy can be maintained.

The sizes of the small regions L1 to L5; R1 to R5 do not have to be all the same. For example, both ends may be small and the center may be large.

If the small areas L1 to L5 and R1 to R5 are overlapped with each other, it is possible to measure the distance in a small size and with high accuracy, but the present invention is not limited to this.

As in the first embodiment, the microcomputer reads the data of the pixels included in each of the corresponding small areas L1 to L5; R1 to R5, and performs the distance measurement calculation.

As described above, the optimum range-finding sensitivity range can always be maintained in the finder according to the mode selection. Further, since the number of distance measuring areas is constant, it is not necessary to change the distance measuring algorithm according to the mode change, the algorithm is simplified, and it is possible to provide a high-speed response camera with a short release time lag. .

Next, a specific example will be described with reference to FIGS.

As shown in FIG. 10, the main body 1 of the camera 10
The distance measuring module 20 shown in FIG. 11 and FIG. 12 is arranged inside the distance measuring window 14 provided on the front surface of 2. Body 1
Although not shown in the figure, an operation button for selecting and setting the wide AF mode or the spot AF mode is arranged on the back surface of the unit 2 as mode setting means.

The distance measuring module 20 is shown in FIGS.
As shown in, the lens 22 is fixed to one opening of the outer casing 24 having the through hole, the sensor package 26 is fixed to the other opening, and the diaphragm mask 23 is fixed inside. Light from the subject is measured by the distance measuring window 14 and the lens 2.
2. It is guided to the sensor chip 27 arranged on the sensor package 26 through a through hole (not shown) of the aperture mask 23.

As shown in FIG. 12, the sensor chip 27 has a pair of left and right image pickup devices 28a and 28b corresponding to the pair of left and right distance measuring optical systems 22 and 23, that is, seven left and right islands S1 to S7. ; T1 to T7 are arranged.
Each of the islands S1 to S7; T1 to T7 is a line sensor, and a plurality of pixels are arranged in a line in the direction connecting the optical axes of the pair of left and right distance measuring optical systems 22 and 23, respectively.

Corresponding left and right islands S1 and T1, S
2 and T2, ... S7 and T7, similarly to the image pickup devices 2a and 2b of the first embodiment, the distance measurement area is set according to the focal length of the photographing lens, and distance measurement is performed. Accordingly, the camera 10 can prevent the number of distance measurement areas that are two-dimensionally arranged with respect to the shooting area from changing.

The present invention is not limited to the above embodiment, but can be implemented in various other modes.

For example, the size of the small area may be changed according to the size of the large area. Further, an area sensor may be used instead of the line sensor in the image sensor for distance measurement.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a distance measuring module and a camera according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of setting a distance measuring area in a conventional example.

FIG. 3 is an explanatory diagram of setting a small area in a conventional example.

FIG. 4 is an explanatory diagram of setting a distance measurement area in the camera of FIG.

FIG. 5 is an explanatory diagram of setting a small area on the wide side.

FIG. 6 is an explanatory diagram of small area setting on the tele side.

FIG. 7 is an explanatory diagram of setting a distance measurement area in the camera of the second embodiment of the present invention.

FIG. 8 is an explanatory diagram of small area setting in the wide AF mode.

FIG. 9 is an explanatory diagram of small area setting in spot AF mode.

FIG. 10 is a front view of the camera.

FIG. 11 is an external view of a distance measuring module.

FIG. 12 is a (a) top view, a (b) cross-sectional view, and a (c) sensor top view of the distance measuring module.

[Explanation of symbols]

2 Distance measuring module (distance measuring device) 2a, 2b image sensor 2s, 2t lens (distance measuring optical system) 4 camera (shooting device) 5 Shooting lens (shooting optical system) 8 Microcomputer (distance measuring device, distance calculation means) 22 lens (distance measurement optical system) 23 Aperture mask (ranging optical system) 28a, 28b image sensor L1-L5 small area R1 to R5 small areas SL1, SR1 Large area SL2, SR2 Large area SL3, SR4 Large area SL4, SR4 Large area

Claims (4)

[Claims] 1. A pair of image pickup devices having a plurality of pixels, a pair of distance measurement optical systems for guiding light from a distance measurement area to the pair of image pickup devices, and a predetermined image pickup device for the pair of image pickup devices. A plurality of small areas, and a distance calculating means for calculating the distance to the subject based on the signals from the pixels included in each of the small areas corresponding to the pair of image sensors. In the distance measuring device, the distance calculating means includes a large area setting means for setting the large area for the pair of image pickup devices, and a predetermined number of small areas in the large area set by the large area setting means. A distance measuring device comprising: small area setting means for setting each area. 2. The small area setting means sets the small area so that the number of pixels included in each of the corresponding small areas of the pair of image pickup devices is a predetermined number. The distance measuring device according to claim 1, wherein: 3. A photographing device comprising the distance measuring device according to claim 1 or 2, and a photographing optical system, wherein the large area setting means is arranged to correspond to the focal length of the photographing optical system. An imaging device, characterized by setting a region. 4. A photographing device comprising the distance measuring device according to claim 1 and a photographing optical system, wherein mode setting selectively sets at least two modes in which the size of the large area is different. An imaging apparatus, comprising: means, wherein the large area setting means sets the large area having a size corresponding to the mode set by the mode setting means.