JP2808609B2 - Auto focus camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autofocus camera capable of obtaining focus adjustment information for a plurality of subjects in a field.

B. Prior Art An autofocus camera equipped with a multi-point distance measuring device that measures a distance to an object located in a plurality of regions in an object field and obtains a distance measurement value for each object has been conventionally known. ing.

In this type of camera, the focusing position of the photographing lens is determined based on, for example, the closest distance value or the average value of the distance measurement values among the distance measurement values corresponding to the plurality of subjects, and the focusing position is determined. The photographing lens was driven to perform only one photographing.

C. Problems to be Solved by the Invention By the way, the photographer usually performs, for example, a half-press operation of a release button at the time of photographing, confirms with a finder that a photographing lens is focused on a desired subject, and then fully presses the photographer. And shoot. However, for example, if the photographer is a beginner who does not know how to check, a desired subject may not be focused by only one photographing as described above, and an undesired photograph may be obtained. Also, it is not possible to confirm whether or not the photographing lens is focused on a desired subject even when photographing by remote control or photographing using a self-timer. Could be.

An object of the present invention is to provide an autofocus camera that can always obtain at least one photograph that is in focus on a desired subject, even if the photographer is a beginner, or performs photographing by remote operation or a self-timer. Is to provide.

D. Means for Solving the Problems To be described with reference to FIG. 1 which is a diagram corresponding to claims, an autofocus camera according to the present invention is provided with a plurality of pieces of focus adjustment information for a subject located in a plurality of focus detection areas in an object scene. , A focusing means 102 for adjusting the photographing lens LE based on the detected focus adjustment information, and a focusing means 102 operated by inputting a photographing start signal to operate the photographing lens LE. And a photographing control means 103 for sequentially performing the photographing based on the focal adjustment information of each of the above, and performing photographing each time, thereby solving the above problem.

E. Operation When a photographing start signal is input, the photographing control means 103 operates the focusing means 102 to sequentially adjust the photographing lens LE based on a plurality of pieces of focus adjustment information, and performs photographing each time. As a result, at least one photograph in which the desired subject is in focus is reliably obtained.

F. Embodiment An embodiment of the present invention will be described with reference to FIGS.

In FIG. 2 showing the overall configuration, a sequence control circuit 1 for controlling the sequence of the entire camera includes a distance measuring circuit 20.
Is connected. The distance measuring circuit 20 includes three distance measuring sensors 21
L, 21C, 21R, a distance measurement value calculation circuit 22, and a distance measurement value selection circuit 23
The distance measuring sensors 21L, 21C, and 21R respectively include light emitters 24L, 24C, and 24R that project light toward a subject, and light receiving elements 25L, 25C, and 25R that receive light reflected from the subject. The distance measurement value calculation circuit 22 activates the distance measurement sensors 21L, 21C, 21R according to the distance measurement start signal from the sequence control circuit 1, whereby the light emitted from each of the projectors 24L, 24C, 24R is
The images are guided to the subjects located in the distance measurement zones Z _L , Z _C , and Z _R within the angle of view W shown in FIG. Ranging zone Z _C is the center of the field angle, the distance measurement zone Z _L, Z _R are disposed respectively on the left and right.

The light receiving elements 25L, 25C, and 25R input a detection signal corresponding to a light receiving position of reflected light from each subject to the distance measurement value calculation circuit 22,
The distance measurement value calculation circuit 22 calculates the distances to the objects located in the three distance measurement zones Z _L , Z _C , and Z _R from these detection signals, that is, the distance measurement values, and sends them to the distance measurement value selection circuit 23. input. The distance measurement value selection circuit 23 normally selects and sets, for example, the closest distance value among the three input distance measurement values and inputs the selected distance measurement value to the sequence control circuit 1. For example, when the three distance measurement values are substantially the same, the distance measurement zone Z _{C at the} center is used.
May be selected and set, or when each measured value is within the depth of field of the photographing lens, an average value of the measured values may be calculated and set.

The sequence control circuit 1 includes a lens drive control circuit
3, an exposure control circuit 4 and a winding circuit 5 are connected to each other, and a focusing motor 6 is connected to the lens drive control circuit 3. The lens drive control circuit 3 drives the photographing lens LE to a predetermined focusing position by the motor 6 according to the lens drive signal from the sequence control circuit 1. The exposure control circuit 4 drives an exposure control device such as an aperture and a shutter according to a command from the sequence control circuit 1 to perform photographing, and the winding circuit 5 winds the film by one frame in response to the winding signal.

Further, the sequence control circuit 1 includes switches SW1 and SW
2 is connected. The switch SW1 is a release switch that turns on in conjunction with operation of a release button (not shown),
When the switch SW1 is turned on, a shooting start signal is input to the sequence control circuit 1. The sequence control circuit 1
The above-described circuits are operated in response to the photographing start signal.

The switch SW2 is connected to an AFB (Auto Focus Bracketin
g) A switch that turns on in conjunction with the operation of the setting button.
When the switch SW2 is turned on, the sequence control circuit 1 sets the AFB mode. When the release switch SW1 is subsequently turned on, the sequence control circuit 1
Outputs FB signal. When the AFB signal is output, the ranging value selection circuit 23 inputs all the ranging values from the ranging value calculation circuit 22 to the sequence control circuit 1.

Next, the shooting procedure when the AFB mode is set by the sequence control circuit 1 will be described with reference to the flowcharts of FIGS.

When the AFB setting button is operated and the switch SW2 is turned on, the sequence control circuit 1 activates the program of FIGS. 4 and 5, and first sets the AFB mode in step S1 of FIG. Next, in step S2, the release switch SW1
Is determined to be on, and if not, the process remains in step S2 until affirmative. If step S2 is affirmed, step
Proceeding to S3, a distance measurement start signal is output to the distance measurement value calculation circuit 22, and an AFB signal is output to the distance measurement value selection circuit 23. Ranging start signal with distance measurement sensor 21L to output, 21C, 21R is activated, the distance measurement value computing circuit 22 is distance measuring sensor 21L, 21C, ranging zone from the detection signal of 21R Z _L, Z _C, Z _R distance value D _L in (FIG. 3), D _C, and calculates each D _R to enter the ranging value selection circuit 23. Since the AFB signal is input, the ranging value selection circuit 23 inputs all of the ranging values D _L , D _C , and D _R to the sequence control circuit 1.

Then the sequence control circuit 1 determines in step S4, 3 single distance measurement value D _L that is input, D _C, at least two of D _R whether contained within a given approximation range.

Here, FIG. 6 (a), (b) shows the positional relationship between the camera and the _{subject, O L, O C, O} R each distance measuring zone _{Z L, Z C, Z R} ( FIG. 3) , D _L , D _C , and D _R indicate distances to the respective subjects, that is, distance measurement values. FIG. 6 (a)
, Each distance measurement value D _L, D _C, shows the case where D _R each is outside a predetermined approximation, FIG. 6 (b) is, distance measurement value D _C, D _R is within a predetermined approximate range Indicates that it is included. To be included in the predetermined approximate range specifically means that the two distance measurement values D _C , D
Towards the short distance of _R (in this case D _R) it is to be included object position O _C corresponding to the distance measurement value D _C within the depth of field is in the present specification, the two distance measurement values D _C, if the D _R satisfy such a relationship, expressed as "D _C ≒ D _R", otherwise expressed as "D _C ≠ D _R".

When each of the distance measurement values D _L , D _C , and D _R is outside the predetermined approximate range as shown in FIG. 6A, step S4 is negative and the process proceeds to step S5. In step S5, photographing with calculates a lens driving amount M _L based on the distance measurement value D _L, and outputs a lens driving signal corresponding to the lens drive amount M _L, by a motor 6 via a lens drive control circuit 3 proceeds to step S6 in brought focus to an object positioned a lens LE to the distance measuring zone Z _L.

In step S6, an exposure control device (not shown) such as an aperture and a shutter is driven via the exposure control circuit 4 to perform photographing. Then, in step S7, the film is wound up by one frame via the winding circuit 5. The processing in step S5~S7 and imaging sequence S _L.

Then, the lens drive amount based on the distance measurement value D _C in step S8
Thereby calculating the M _C, it outputs a lens driving signal corresponding to the lens drive amount M _C, allowed to focus on the subject that is located a photographing lens LE in the distance measurement zone Z _C, similar to that described above taken in step S9 Then, in step S10, the film is wound up by one frame. The processing in step S8~S10 the imaging sequence S _C.

Then with calculates a lens driving amount M _R on the basis of the distance measurement value D _R in step S11, the distance measuring zone photographing lens LE outputs a lens driving signal corresponding to the lens drive amount M _R Z _R
Is focused on, and photographing is performed in step S12, and the film is wound up by one frame in step S13. The processing in step S11~S13 and imaging sequence S _R.
Then, in step S14, the AFB mode is canceled and the process is terminated. That is, in this case, a total of three shootings are performed.

On the other hand, if step S4 is affirmed, step S2 in FIG.
In step S20, it is determined whether D _L ≒ D _C ≒ D _R is satisfied, that is, the other two values are set within the depth of field corresponding to the shortest value of the distance measurement values D _L , D _C , and D _R. It is determined whether or not subjects corresponding to the two distance measurement values are both included. When step S20 is affirmed, in step S21, the above-described photographing sequence S _L , S _C , S _R
One photographing is performed by a photographing sequence based on the shortest distance measurement value, and the process proceeds to step S14 in FIG. That is, for example, if the distance measurement value _DL is the shortest, the photographing sequence _SL is performed.

If step S20 is denied, the process proceeds to step S22, where D _L ≒
Determines whether the D _C ≠ D _R. Step S22 is the photographic sequence S _L in If an affirmative step S23, performs an imaging sequence based on shortest distance value among the S _C, the process proceeds to step S14 of FIG. 4 performs imaging sequence S _R in step S24. That is, in this case, a total of two shootings are performed.

If step S22 is denied, at step S25, D _L ≒ D _R ≠ D _C
Is determined. If step S25 is affirmed, a photographing sequence based on the shortest distance measurement value of the photographing sequences S _L and S _R is performed in step S26, and step S27 is performed.
In performing imaging sequence S _C proceeds to step S14 of FIG. 4. Also in this case, a total of two shootings are performed.

When step S25 is negative, i.e. D _C ≒ D _R ≠ D _L when it is determined imaging sequence S _C at step S28, and executes the imaging sequence based on the shortest distance value among the S _R, step S29 Then, the photographing sequence _SL is performed, and the process proceeds to step S14 in FIG. In this case as well, a total of two shootings are performed.

According to the above procedure, when the AFB mode is set, as shown in FIG. 6A, if the three distance values D _L , D _C , and D _R do not fall within a predetermined approximate range, distance measurement value D _L, D _C, one by each once with the focus position based on D _R, a total of 3 times imaging is performed. Therefore, even when the photographer is a beginner, or when performing photographing by remote operation or a self-timer, at least one photograph in which the desired subject is in focus is obtained.

For example, as shown in FIG. 6B, the distance measurement values D _L , D
_C, and when two of D _R contained within a given approximation range, a total of two imaging because one shot is performed for the two distance measurement values. To be included in the predetermined approximate range means that, as described above, the subject corresponding to the other distance measurement value is included in the depth of field at the short distance measurement value of the two, and therefore, 1 By operating the release switch several times, it becomes possible to focus on the subject corresponding to both distance measurement values. In addition, all the distance values D _L , D _C ,
If D _R is within the predetermined approximation range, these three
One photographing is performed for one distance measurement value. According to this, in the same manner as described above, at least one photograph can be obtained that is in focus on a desired subject, and the number of photographed images can be minimized.

In the configuration of the above embodiment, the distance measuring circuit 20 constitutes the focus adjustment information detecting means 101, the lens drive control circuit 3 and the focusing motor 6 constitute the focusing means 102, and the sequence control circuit 1 constitutes the photographing control means 103.

In the above embodiment, three distance measurement zones are used as shown in FIG. 3, but two or four or more distance measurement zones may be used. Although the example in which the distance measurement zones are arranged side by side in the horizontal direction of the angle of view has been shown, they may be arranged in the vertical direction, or the horizontal and vertical directions may be combined.

Further, the distance measurement values D _L , D _C , and D _R are collectively calculated prior to the three imaging sequences S _L , S _C , and S _R , but each of the imaging sequences S _L , S _C , and S R is performed. _The distance measurement values D _L , D _C , and D _R may be calculated each time before _R.

Furthermore, a camera of a type that calculates a distance measurement value indicating a distance to a subject as focus adjustment information and guides a photographing lens to an in-focus position based on the distance measurement value has been described, for example, a TTL position of a single-lens reflex camera. As in the phase difference detection method, instead of the distance measurement value, the shift amount between the imaging plane of the subject and the expected imaging plane is calculated as focus adjustment information, and the photographing lens is adjusted based on the shift amount and the shift direction. The present invention can also be applied to a camera that guides the camera to a focal position. In this case, when a plurality of pieces of focus adjustment information are included within the predetermined depth of focus, a single photographing operation may be performed on the pieces of focus adjustment information as described above.

Furthermore, for example, when a confirmation button is separately provided and this confirmation button is pressed at the time of the above-mentioned AFB mode setting, the photographing lens is only sequentially driven to the focusing position based on each focus adjustment information so that the photographing is not performed. This makes it possible to confirm in advance which subject the photographing lens has focused on, which is convenient.

G. Effects of the Invention According to the present invention, the photographing lens is sequentially focused on the objects in the plurality of focus detection areas in accordance with the input of the photographing start signal, and photographing is performed each time. Even in the case of, or when taking a picture by a remote operation or a self-timer, at least one photograph in which the desired subject is in focus is reliably obtained.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims. 2 to 6 show one embodiment of the present invention, and FIG.
FIG. 3 is a block diagram showing a control system of the camera according to the present invention. FIG. 3 is a diagram showing a distance measuring zone in an object field.
FIG. 6 is a flowchart showing a processing procedure, and FIG.
(B) is a figure which shows the positional relationship between a camera and an object, respectively. 1: Sequence control circuit 3: Lens drive control circuit 20: Distance measurement circuit 21L, 21C, 21R: Distance measurement sensor 22: Distance measurement value calculation circuit 23: Distance measurement value selection circuit 101: Focus adjustment information detection means 102: Focusing means 103: Shooting control means LE: Shooting lens SW1, SW2: Switch

Claims (2)

(57) [Claims] 1. A focus adjustment information detecting means for detecting a plurality of pieces of focus adjustment information for a subject located in a plurality of focus detection areas in an object scene, and adjusting a photographing lens based on the detected focus adjustment information. Focusing means; and photographing control means for operating the focusing means in response to input of a photographing start signal to sequentially adjust the photographing lens based on the plurality of pieces of focus adjustment information, and performing photographing each time. An auto-focus camera that features. 2. The photographing control means performs one photographing of a plurality of pieces of focus adjustment information included within a predetermined approximate range of the plurality of pieces of focus adjustment information, and performs the plurality of focus adjustments. 2. The auto-focus camera according to claim 1, wherein when the adjustment information is not included in a predetermined approximate area, the photographing is performed for each adjustment based on each focus adjustment information.