JP3335419B2 - Camera ranging device - Google Patents

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 for a camera for measuring a distance to a plurality of objects in a photographing screen.

[0002]

2. Description of the Related Art Heretofore, there has been a so-called multi-point distance measuring device for measuring a subject distance for a plurality of points on a photographing screen. For example, as described in JP-A-60-60511,
A distance measuring device has been proposed in which the closest distance information is simply selected from the subject distance information of each distance measurement area, and the distance is focused.

[0003] USP. No. 4,943,824 discloses a distance measuring device that detects the size of a subject in a shooting screen and detects a main subject based on the size of the subject occupying the shooting screen. I have.

[0004]

However, in the above-described conventional distance measuring device, the closest object among the objects in each distance measuring area is specified as the main object, or the size of the object occupying in the photographing screen is determined. This is a method for detecting a main subject.

In the former method, in which the closest object is set as the main object, if another object exists at a position closer to the main object, the object other than the one intended by the photographer may be focused. is there.

Further, in the latter method, in which the main subject is determined by the size of the subject, the size of the main subject in the photographing screen changes depending on the distance of the main subject. Then it was necessary to take into account the focal length.

Accordingly, an object of the present invention is to provide a distance measuring apparatus for a camera which classifies distance data of a plurality of measured distance measuring points into groups and determines the main object with a predetermined size. .

[0008]

In order to achieve the above object, the present invention provides a light projecting means for projecting light toward a plurality of points, a light receiving means for receiving reflected light from the plurality of points, Calculating means for calculating the distance to the object on the plurality of points using the output of the light receiving means, grouping means for grouping the plurality of points based on a distribution of position and distance data, determination means for determining the size of the divided obtained respective groups, a large can of the respective groups, the object than the predetermined distance
If it is close, it is compared with the first size and it is farther than the predetermined distance
If so, identify the main group compared to the second size
And, comprising a selecting means for selecting the distance to the group as the distance data for focusing the photographing optical system, focus of the imaging optical system
Provided is a camera distance measuring device that changes the predetermined distance according to a point distance .

[0009]

The camera ranging apparatus configured as described above emits light toward a plurality of points, receives reflected light from those points, and subjects a subject to an object based on the output current value. The distance to the object is calculated as distance data. A plurality of points are grouped based on the distribution of the obtained distance data, and the size of the group is determined by a predetermined distance.
If the target is closer than the separation, it is compared with the first size and
If the distance is longer than the fixed distance,
Identify the appropriate group and measure the distance to this group.
Focusing is performed as academic focusing distance data .

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows and describes the configuration of a camera distance measuring apparatus as a first embodiment according to the present invention. The distance measuring method of the distance measuring device of the camera is basically an active triangular distance measuring and is a well-known technique, and thus a detailed description is omitted here.

First, in the light emitting section of the distance measuring device, the IRED driver 2 causes the IRED 3 to emit light in response to a command from the central processing unit (CPU) 1. The signal light emitted from the IRED 3 is reflected by the light projection scanning mirror 4, and is emitted to a subject (not shown) through the light projection lens 5. When the light projection to one distance measuring point is completed in this way, the motor driver 6 drives the light projecting scan motor 7 in accordance with a command from the CPU 1 to move the scanning mirror 4 to the next distance measuring point. Is rotated to the position where the light is reflected.

In this way, the signal light is sequentially projected on each distance measuring point. Here, the projection mirror 4 is rotated by the motor 7, but the rotation of the mirror may be any method that can control the position of the mirror, such as driving by an electromagnet.

Next, in the light receiving section, the reflected light from the subject is received by the PSD 9 through the light receiving lens 8. PS
Based on the current value output from D9, the distance data is calculated by the ratio data calculation circuit 10, and this distance data is A / D converted by the A / D conversion circuit 11 and sent to the CPU 1. The distance data sent to the CPU 1 is grouped by the grouping unit 12 in the CPU 1 according to the difference between the distance measurement data of the adjacent distance measurement points, and the human width detection unit 13 is selected from the groups. A group close to the width of the person is selected, and based on the distance data of that group,
The CPU 1 operates the motor driver 14 for driving the AF lens to focus a photographic lens system (not shown).

As described above, the distance measuring apparatus of the camera according to the present embodiment performs distance measurement of the group B shown in FIG. 2B when the distance is measured in the composition as shown in FIG. , It is possible to focus on a subject intended by the photographer, especially on a person.

Next, the processing in the CPU 1 of the distance measuring apparatus thus configured will be described with reference to the flowcharts shown in FIGS. FIG. 3 is a main flowchart of the distance measuring apparatus. First, the above-described scan distance measurement is performed, and the distance measurement data is taken into the CPU 1 (step S).
1). Then, the distance measurement data taken into the CPU 1 is divided into groups (step S2). This grouping
The data of adjacent ranging points are compared, and if the difference is within a predetermined value, they are grouped together.

Next, the average of the distance data constituting the group is determined for each of the divided groups, and the average value is set as the distance to the subject indicated by each group (step S3). Then, it is determined whether or not the distance data of the group including the center of the ranging point is the closest data (Step S).
4) If the data is the closest data (YES), focusing is performed with the group as the main subject (step S).
5) If it is not the closest data (NO), the human width is detected based on the distance data of the group and the number of distance measurement points forming the group (step S6).

Then, it is determined whether there is a human-like group by the human width detection (step S7). If there is a human-like group (YES), focusing is performed using the group as a main subject (step S8). However, if there is no person-like group (NO), focusing is performed with the group including the center of the distance measurement point as the main subject (step S9). The reason why the center of the distance measuring point is focused in this way is that the main subject is usually located at the center when photographing a subject other than a person or a landscape photograph.

Next, the subroutine for grouping will be described with reference to the flowchart shown in FIG. Here, in the flowchart, i indicates a ranging point number, j indicates a group number, and k indicates the number of ranging points constituting a group. Gjk is the group number, j is the group number of the number k of constituent points, Li is the distance measurement data of the i-th distance measurement point, and L is a predetermined value to be compared with the difference between the distance measurement data of adjacent distance measurement points. .

First, in performing grouping,
i, j, and k are set to “0” (steps S11 and S1).
2, S13). Then, the absolute value | L _i −L _{i + 1} | <L of the difference between the distance measurement data of the adjacent distance measurement points is compared (step S14), and if the absolute value of the difference is smaller than the predetermined value L (YES). , Li in Gjk (step S1).
5), k is incremented (step S16).

However, in step S14, | L _i −L _{i + 1} |
<L, if the absolute value of the difference is larger than the predetermined value L (N
O), j is incremented (step S17), k is set to "0", and the group Gjk is set to the next group (step S18).

After one of the above two processes, i is incremented and the process proceeds to the next distance measuring point (step S).
19) The above process is repeated until all the distance measurement points are completed (step S20).
S), and the process proceeds to step S3 shown in FIG.

Next, a subroutine for human width detection will be described with reference to the flowchart shown in FIG. In this flowchart, m is a register number for storing a group number indicating a person, j is a group number, Lj is the reciprocal of the average distance of the group, kj is the group number, j is the number of ranging points, and nj is Lj in FIG. The number of ranging points (indicating the width of a person) in the group referred to in the table as shown in the table is shown. N is a predetermined value for comparing the absolute value of the difference between the width of the group and the person, and Mm is a register for storing a group number j determined to indicate a person.

In human width detection, first, j and m are set to "0".
(Steps S21 and S22). And FIG.
The number of points indicating the width of the person is set to nj with reference to a table as shown in (step S23). Then, take the absolute value | k _j −n _j | of the difference between kj and nj,
| K _j −n _j | <N, and if the absolute value of the difference is smaller than the predetermined value N (YES), m is incremented (step S25), and the group number j is stored in the register Mm (step S26). And move on to the next. But step S
In the determination at 24, if the absolute value of the difference is larger than the predetermined value N (NO), j is incremented, and it is determined whether the processing has been completed for all the groups (step S28). Returning to S23, the process is repeated, and if the process is completed for all the groups (YES), the process returns to step S7 in FIG.

Next, a description will be given of a camera distance measuring apparatus according to a second embodiment of the present invention. Here, the configuration of the second embodiment is the same as that of the first embodiment.
Is different.

Although the first embodiment is effective when only one person exists in the distance measurement field of view, actual photographing is performed with the composition shown in FIGS. 7 (a) and 7 (b). Often do. That is, in the first embodiment, in the case of the composition as shown in FIG. 7A, it is not possible to determine which one of a plurality of persons to focus on. FIG.
When two persons as shown in (b) are adjacent to each other and do not include the central ranging point, the width of the two persons is larger than the width determined as a person. It is largely determined as another one subject, and as a result, it is determined that the photographing is performed without a person such as a landscape photograph. Accordingly, the center of the screen is focused, and the two persons are not focused.

In the second embodiment, even in such a case, the main subject is focused. The operation of the camera distance measuring apparatus according to the second embodiment will be described with reference to the flowchart shown in FIG. Here, the operation of the distance measuring apparatus is the same as that of the first embodiment in steps S31 to S36, and a description thereof will be omitted.

At step S37, it is determined whether there is a group close to the width of a person (step S37). If there is no group close to the width of a person (NO), whether a group having a constant multiple of the width of a person exists or not is determined. (Step S
38). This determination is made by performing the processing in step S24 shown in FIG. 5 as shown in FIG. 9 described later.

That is, the flowchart shown in FIG.
The value obtained by dividing the number kj of ranging points forming the group by the number nj of points referred to in the table shown in FIG. 6 by the ranging data Lj of the group is stored in a (step S51), and a> 2 is set. Compare (Step S5
2) If a is smaller than 2 (NO), the flow shifts to step S27 in FIG. 5 to shift to the next group. However, when a is greater than 2 (YES), a
(Step S53). Then, b <N 'is compared (step S54). If b is smaller than a predetermined value N' (YES), it is determined that a plurality of persons are arranged, and FIG.
The process proceeds to step S39 (step S25). If b is larger than the predetermined value N '(NO), the process proceeds to step S4 in FIG.
0 (step S27).

Therefore, if it is determined in step S54 in FIG. 9 that a plurality of persons are lined up, the flow shifts to step S39 in FIG. 8 to focus on the distance measurement data of the group (step S39). ). However, step S5
If it is determined in step 4 that there is no person, the process proceeds to step S40 in FIG. 8, and focusing is performed using the distance measurement data of the group including the center (step S40).

If it is determined in step S37 that there is a person (YES), it is determined whether there are two or more groups of people (step S41). If it is determined that there is only one person (NO) ), Focusing is performed using the distance measurement data of the group indicating the person (step S4).
2). However, when there are a plurality of persons (YES), focusing is performed on the distance measurement data of the group closest to the center of the group including the persons (step S43).

Next, a description will be given of a camera distance measuring apparatus according to a third embodiment of the present invention. In the present embodiment, in the distance measuring apparatus of the second embodiment, when an object is present on the close side, the main object is detected based on the width of the face of the person. For example, in a composition as shown in FIG. 10A, if the distance between the groups is at a position as shown in FIG. 10B, the group C is determined to be the main subject.

FIGS. 11 and 12 are flow charts for explaining the present embodiment. In FIG. 11, first, the above-described scan distance measurement is performed, and distance measurement data is taken into the CPU 1 (step S61). Then, the distance measurement data taken into the CPU 1 is divided into groups (step S6).
2). In this grouping, data of adjacent distance measurement points are compared, and if the difference is within a predetermined value, the data is classified into the same group.

Next, the average of the distance data constituting the group is determined for each of the divided groups, and the average value is set as the distance to the subject indicated by each group (step S63).

Then, it is determined whether or not the distance data of the group including the center of the distance measuring point is the closest data (step S64). If it is the closest data (YES), focusing is performed with the group as the main subject. (Step S65) If it is not the closest data (NO), it is determined whether there is a group whose distance data is shorter than a predetermined distance (Step S66). If there is a group in this determination (YES), the flow shifts to step S75 in FIG. 12 to perform the same processing as the human width detection shown in FIG. However, the number of constituent points of the group referred to by the table Lj is a number indicating the width of the face, and the predetermined value N for determining the human width is also for the face width.

Then, it is determined whether there is a group close to the face width (step S76). If there is a group determined to indicate the face width (YES), the group indicating the face width is 2
It is determined whether there are more than one (step S77). If there are a plurality of groups indicating the width of the face (YES), focusing is performed using the distance data of the group near the center among the groups (step S78). However, if there is only one group indicating the width of the face (NO), focusing is performed using the distance data of the group (step S79).

If it is determined in step S76 that no group indicating the face width is detected (NO),
The same processing as step S38 in FIG. 8 described in the second embodiment is performed on the face width. That is, it is determined whether there is a group close to an integral multiple of the face width (step S80). If there are a plurality of adjacent face groups (YES), focusing is performed using the distance data of the group (step S81). . However, when it is determined that there is no group of a plurality of adjacent faces (NO), step S in FIG.
The flow shifts to 67, where a human width detection is performed (step S67).

The subsequent steps S68 to S74 correspond to steps S37 to S37 in the second embodiment.
A process equivalent to S43 is performed. Next, a description will be given of a camera distance measuring apparatus according to a fourth embodiment of the present invention. In the above-described third embodiment, since the criterion for determining the main subject is determined to be the width of the person or the width of the face according to the subject distance on the closest side, the composition is determined by the focal length of the photographing lens even in the same scene. Are different. That is, on the short focus side, the composition is as shown in FIG. 13A, and on the long focus side, it is as shown in FIG. 13B.

Therefore, in the fourth embodiment, when the focal length f _TL of the taking lens is larger than the predetermined focal length f, the main subject is determined based on the width of the face. Q × E
Only features of the fourth embodiment different from the third embodiment will be described.

FIG. 14 is a flowchart for explaining the distance measuring apparatus according to the fourth embodiment. This is because in step S66 of the flowchart of FIG. 11 of the third embodiment, when the distance of the closest group is within a predetermined distance, the face width detection processing of FIG. 12 is performed. when the focal length f _TL in step S95 of the taking lens is larger than the predetermined focal length, performs the face width detection processing of FIG. 12, other processing steps S91~S94, S96~S10
4 is a process equivalent to steps S61 to S74 of the third embodiment, and the description is omitted.

Next, a description will be given of a camera distance measuring apparatus according to a fifth embodiment of the present invention. This embodiment is the third and fourth embodiments.
This is a combination of the examples. As shown in the flowchart of FIG. 15, when the subject exists within the predetermined distance in step S114 (YES), and when the focal length f _TL of the taking lens is larger than the predetermined focal length f (step S114).
115), the face width detection processing of FIG. 12 is performed. Other processing steps S110 to S114, S1
16 to S124 are steps S61 to S74 of the third embodiment.
This is the same processing as described above, and the description is omitted here.

Next, a description will be given of a camera distance measuring apparatus according to a sixth embodiment of the present invention. In the present embodiment, a predetermined distance, which is a criterion for determining whether to perform the face width detection processing of FIG. 12 in the third embodiment, is changed by the focal length _fTL of the photographing lens. That is, as shown in step S135 of the flowchart shown in FIG. 16, the focal length f _TL of the photographing lens, when there is an object closer than a predetermined distance, which is referenced in the table as shown in FIG. 17, FIG. Twelve face width detection processes are performed.

Next, a description will be given of a camera distance measuring apparatus according to a seventh embodiment of the present invention. In the above-described first to sixth embodiments, after grouping is performed, the average of the distance measurement data of the distance measurement points forming the group is obtained, and the average value is used as the distance to the subject indicated by the group. In the example, the closest value among the distance measurement data of the distance measurement points forming the group is set as the distance to the subject indicated by the group.

Next, a description will be given of a camera distance measuring apparatus according to an eighth embodiment of the present invention. After the grouping is performed in the first to sixth embodiments, the average of the distance measurement data of the distance measurement points forming the group is obtained, and the value is used as the distance to the subject indicated by the group. The distance measurement data of a point at the center position among the distance measurement points constituting the distance measurement is defined as the distance to the subject indicated by the group.

Next, a description will be given of a camera distance measuring apparatus according to a ninth embodiment of the present invention. In the above-described first to eighth embodiments, the grouping is performed after the scan distance measurement. In the present embodiment, the time lag is reduced by performing the grouping simultaneously with the scan distance measurement.

FIG. 18 is a flowchart of a subroutine of scan distance measurement grouping. In the flowchart of FIG. 6 described above, the data of the adjacent distance measurement points are compared after all the distance measurement data have been collected. In contrast, in the present embodiment, each time one point is measured, the measurement of the previous point is performed. The comparison of the distance data is sequentially performed.

The embodiments of the present invention have been described above.
The present invention is not limited to the above-described embodiment of one-dimensional multi-point ranging, but may be modified and applied to two-dimensional multi-point ranging without departing from the gist of the invention. Needless to say.

As described above, in the camera distance measuring apparatus of the present embodiment, when performing multi-point ranging, a plurality of measured distances are grouped into approximate distances and a predetermined width is determined. Based on the above, it is possible to determine a group close to the size of a person among the groups as a main subject, and to provide a camera distance measuring apparatus that focuses on a subject intended by a photographer, particularly a person. In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and applications are possible without departing from the spirit of the invention.

[0048]

As described above in detail, according to the present invention, the distance data of a plurality of measured distance measuring points are divided into groups, and the distance measurement of a camera which is determined to be the main subject at a predetermined size. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a camera distance measuring apparatus as a first embodiment according to the present invention.

FIG. 2 is a diagram illustrating an example of a composition in which distance measurement is performed by the camera distance measurement device according to the first embodiment.

FIG. 3 is a flowchart for explaining the operation of the distance measuring device for the camera of the first embodiment.

FIG. 4 is a flowchart for explaining a subroutine for grouping the distance measuring devices of the camera according to the first embodiment;

FIG. 5 is a flowchart illustrating a subroutine for detecting a human width of the range finder of the camera according to the first embodiment;

FIG. 6 is a diagram showing a table of the number of points of the human width with respect to the distance.

FIG. 7 is an example of a composition in which a plurality of persons exist on a screen.

FIG. 8 is a flowchart for explaining the operation of the camera distance measuring apparatus according to the second embodiment of the present invention.

FIG. 9 is a flowchart for explaining a determination as to whether or not there is a group having a constant multiple of the width of a person in the operation of the camera distance measuring apparatus of the second embodiment.

FIG. 10 is a diagram illustrating an example of a composition for performing distance measurement by a camera distance measuring apparatus according to a third embodiment.

FIG. 11 is a flowchart for explaining the operation of a distance measuring apparatus for a camera according to a third embodiment of the present invention.

FIG. 12 is a flowchart for explaining human width detection in FIG. 11;

FIG. 13 is a diagram showing the composition of the short focus side and the long focus side of the photographing lens in the same photographing scene.

FIG. 14 is a flowchart for explaining an operation of the distance measuring apparatus for a camera according to the fourth embodiment of the present invention.

FIG. 15 is a flowchart for explaining the operation of the range finder of the camera according to the fifth embodiment of the present invention.

FIG. 16 is a flowchart for explaining the operation of the distance measuring apparatus for a camera according to the sixth embodiment of the present invention.

FIG. 17 is a diagram illustrating a table of a relationship between a focal length of a photographing lens and a predetermined distance.

FIG. 18 is a flowchart of a subroutine of scan distance measurement grouping of the distance measurement apparatus for a camera according to the sixth embodiment.

[Explanation of symbols]

1. Central processing unit (CPU), 2. IRED driver,
3 ... IRED, 4 ... Projection scan mirror, 5 ... Projection lens, 6 ... Motor driver, 7 ... Projection scan motor, 8 ... Light receiving lens, 9 ... PSD, 10 ... Ratio data calculation circuit, 11 ... A / D conversion circuit, 12 grouping unit,
13: Human width detection unit; 14: AF lens driving motor driver; 15: AF lens driving motor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B ^7/ 28-7/40 G03B 13/36

Claims (5)

(57) [Claims] 1. A light projecting means for projecting light toward a plurality of points, a light receiving means for receiving light reflected from the plurality of points, and an object on the plurality of points using an output of the light receiving means. Calculating means for calculating a distance to an object; grouping means for grouping the plurality of points based on a distribution of position and distance data; and determining means for determining the size of each of the divided groups. , a large can of the respective groups of objects than the predetermined distance
Is closer to the first size and is longer than a predetermined distance.
If it has compared the second magnitude, especially the leading group
Camera constant, and comprising selection means for selecting the distance to the group as the distance data for focusing the photographing optical system, and is characterized by changing the predetermined distance according to the focal length of the photographing optical system Distance measuring device. 2. A camera distance measuring apparatus according to claim 1, wherein the selection criterion of said selection means is a distance to the group by averaging distance data of a plurality of points in said main group. . 3. The camera according to claim 1, wherein the selection criterion of the selection means is that distance data of one of a plurality of points in the main group is a distance to the group. Distance measuring device. 4. The apparatus according to claim 1, wherein, when there are a plurality of groups corresponding to the predetermined size, the selecting unit sets a group close to an optical axis of the photographing optical system as a main group. Camera ranging device. 5. A detecting means for detecting a distance to a plurality of objects in a photographing screen; a grouping means for grouping the plurality of objects based on a distribution of position and distance data; comparing the magnitude of each group divided, if Target product than a predetermined distance is short first and size and <br/> comparison, if farther than the predetermined distance and the second magnitude in
To, features and determining means for determining a key group, that comprises a selection means for the distance measurement data a distance to the main group, to change the predetermined distance according to the focal length of the photographing optical system Camera ranging device.