JPH05164955A - Controller for camera - Google Patents

Abstract

PURPOSE:To take a photograph without cutting part of a subject by controlling a shutter speed to a high speed and automatic zooming to a wide-angle size at the time of successive shooting. CONSTITUTION:A control circuit 1 finds the control focal length of a lens 4 by referring to specific data based upon the distance of the subject so as to obtain manification factor matching a photograph of a child. A switch S4 is checked and when the S4 is OFF and a drive motor is in single-shooting mode, the data are used so as to take a picture wherein the subject is large, but data which are wider in angle than that data are used for driving with the S4 ON. Further, when the subject is under dark conditions, the shutter speed becomes slow, the photography of a moving subject is reduced, and the focal length of the lens need not be varied frequently, so the timing of focal length variation is varied according to the subject brightness. Thus, when successive photography is performed, the shutter speed is controlled to a faster speed and the automatic zooming is controlled to a wide-angle side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to camera exposure control and automatic zoom control.

[0002]

2. Description of the Related Art Conventional cameras use the same AE for single shooting and continuous shooting.
Control, power zoom control. In this case, the continuous shooting often shoots a moving subject and moves the camera frequently.Therefore, if the shutter speed is too slow, the subject may shake, or if the subject is zoomed and the angle of view of the lens is narrowed There was a problem that it couldn't be captured properly and couldn't be captured properly.

Japanese Patent Laid-Open No. 2-153330 proposes to switch the drive mode between single shooting and continuous shooting according to the AE diagram, but the number of films to be shot automatically changes. There was the problem of shooting more than necessary.

[0004]

As described above, in the case of continuous shooting, it is necessary for the photographer to change the shutter speed and zoom position by himself.
For this reason, there are inconveniences such as missing the opportunity to take a picture, and especially a beginner fails to take a picture.

An object of the present invention is to make it possible to carry out a simple photographing without missing the opportunity of photographing by automatically performing this operation.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a photometric means for measuring the brightness of an object, a means for detecting the sensitivity of a film,
Distance measuring means for measuring the distance to the subject, means for driving the focusing lens, focal length changing means for changing the focal length of the lens based on the distance measurement value of the distance measuring means, and single shooting and continuous shooting The shooting changing means for switching with, the calculating means for calculating the shutter speed and aperture of the exposure from the photometric means and the film sensitivity detecting means, and the focal length changing means for the continuous shooting of the shooting changing means than for the single shooting. And a control unit for changing the shutter speed of the calculation unit to a higher speed.

[0007]

According to the above construction, in the case of continuous shooting, the shutter speed is controlled at a high speed, and the auto zoom is controlled at a wider angle side, so that the shooting without blurring or the part of the subject is not cut off. It will be possible.

[0008]

FIG. 1 is a block diagram showing the circuit configuration of this embodiment.

The control circuit 1 is composed of a microcomputer and receives information from switches and a photometric circuit 5,
The shutter speed T _VC and the aperture value A _VC are calculated and the AE circuit 3 is controlled. Also, the distance measuring circuit 6 receives information from the lens 4.
The focal length of the lens is changed based on the subject distance data from.

The film detection circuit 2 detects the ISO sensitivity S _{V of the} film and sends it to the control circuit.

The AE circuit 3 calculates A _VC calculated by the control circuit 1,
Exposure is performed based on T _VC .

The lens 4 sends lens information to the control circuit 1. Further, the position of the lens moves under the control of the lens driving means.

The photometric circuit 5 measures the brightness of the object for exposure control and sends the value to the control circuit 1.

The distance measuring means 6 measures the distance to the object for AF, and sends to the control circuit 1 distance measuring data D for changing the AF lens movement amount GLP and the lens focal length.

The lens driving means 7 receives the AF lens movement amount GLP from the control circuit 1 for performing focusing, and drives the motor M1 based on the AF lens movement amount GLP to move the position of the focusing lens. Further, in order to change the focal length, the lens focal length f _ZOOM is received from the control circuit 1 and the motor M2 is driven based on it to change the focal length of the lens.

The switch S1 starts the exposure calculation. The switch S2 performs release. The switch S3 switches between the normal mode and the child mode. The switch S4 switches between single shooting and continuous shooting.

2, 3 and 4 are flow charts showing the control of the camera of this embodiment.

First, in step (1), the switch S1 is used to determine whether to start the photographing operation of the camera.
I see. If S1 is ON, the process proceeds to step (2) to start the shooting operation. On the other hand, if S1 is OFF, RL = 0 is reset to perform a single shooting operation, and AZ = 0 is reset to limit the changing operation of the focal length to only once after S1, and the switch S1 is set. Is O
Wait for N. It should be noted that both bits operate only once after S1 is turned on, and after that, the same operation is not repeated so that they are reset.

In step (2), data required for control is obtained. Here, from the photometry circuit 5 to B _V (brightness of the subject)
However, S _V (film sensitivity) from the film detection circuit 2
From the lens 4, A _V0Z (open aperture of the lens), A _VMAXZ (minimum aperture of the lens), ZFZ (focal length of the lens) are obtained from the distance measuring circuit 6 as subject distance information D, AF lens movement amount GL.
P receives the switch data from each of the switches S1, S2, S3, S4. Note that T _VMIN (minimum shutter speed) and T _VMAX (maximum shutter speed) are determined by the body.

In step (3), the main subject exposure amount E _VS is calculated from the main subject brightness B _V and the film sensitivity S _V. This value is used to calculate the aperture value and shutter speed that will be controlled in later processing. E _V is calculated from the equation E _V = B _V + S _V.

In step (4), the switch S3 is viewed to switch between shooting in a child mode suitable for shooting a child and shooting in a normal mode. Here, S3 OFF
If so, the control aperture value A _VC and the shutter speed T _VC are calculated by a well-known method, and after calculation, the process jumps to step (15) to perform the photographing process.

On the other hand, if S3 is ON, the process proceeds to step (5), and in order to control the exposure with the AE diagram with less camera shake, the camera shake limit shutter speed T _{VH is} more than the lens focal length.
Ask for. T _VH = 1.25 × (ZFZ−56) /16+5.875 (focal length ≧ 50mm) T _VH = 1.125 × (ZFZ−56) /16+5.875 (focal length <50mm) where ZFZ = 16 × log ₂ ( f / 50) +56, f is the focal length.

In step (6), looking at the switch S4,
In the case of continuous shooting with S4 ON, the shutter speed is shifted to the high speed side to set T _VH = T _VH +1 to shoot a moving subject, and if S4 OFF, the process directly proceeds to step (7) in FIG.

In steps (7) to (12), hand shake is less likely to occur, and in order to obtain a certain depth of field, A shown in FIG.
I am calculating the E diagram.

In step (7), processing is performed when the value of E _VS is too large or too small. Here, the exposure value that can be controlled by the camera is limited by the range of the aperture value of the lens and the range of the shutter speed of the camera. That is,
Lens open aperture A _V0Z, minimum aperture A _VMAXZ, camera slowest speed T _VMIN, and the maximum speed T _VMAX exposure value A _V0Z
The range is from + T _VMIN to A _VMAXZ + T _VMAX . Therefore,
E _VS performs limitations as the following at the minimum and maximum values that can be exposed so or wrong calculation of A _VC, T _VC when outside this range. When E _VS ≦ A _V0Z + T _VMIN A _VC = A _V0Z , T _VC = T _{VMIN When} E _VS ≧ A _VMAXZ + T _VMAX A _VC = A _VMAXZ , T _VC = T _VMAX Then, in step (13) of FIG. To jump.

When E _VS is within this range, step (8)
In order to reduce the possibility of camera shake, calculate T _V = E _V −A _V0Z in order to create an AE diagram that does not _reduce the shutter speed by opening the diaphragm to A _V0Z , and T _V is T _VH It is determined whether the area is below. If T _V <T _VH , A _VC =
Jump to step (13) with A _V0Z and T _VC = T _V. Meanwhile, since the possibilities of camera shake if T _V ≧ T _VH less, using _{A V = 0.5 × (E V} -A V0Z -T VH) + A V0Z of formula in order to obtain a depth of field in step (9) Change the aperture and shutter speed at the same rate.

[0027] to see if A _V <6 to determine whether the step (10) in sufficient depth of field is obtained, A _V <
6 If A _VC = A _V, step a _{T V = E V -A V (} 1
Jump to 3), and if A _V ≧ 6, the depth of field is sufficient, so go to step (11).

In step (11), T _V = E _V −6 in order to maintain a constant depth of field and obtain a faster shutter speed.
If T _V <T _VMAX , jump to step (13) with A _VC = 6, T _VC = T _V , and if T _V ≧ T _VMAX , the subject is too bright and keep A _V = 6 Since there is none, the process proceeds to step (13) after the process of step (12).

In step (12), A _VC = E _V -T _VMAX and T _V = T _VMAX are set in order to control A _V with a diaphragm close to 6.

In the flow of FIG. 4, in order to set the focal length so that the magnification is suitable for photographing a child, the control focal length f of the lens is referred from the distance of the object with reference to the data in Table 1.
_Ask for a _ZOOM . Here, since the shooting conditions are different between the single shooting and the continuous shooting, the control is switched as follows in order to correspond to the shooting conditions.

In step (13), looking at the switch S4,
When S4 is OFF and the drive mode is single shooting, the data 1 in Table 1 is used to make the subject larger. On the other hand, S4O
When the drive mode is N and the continuous shooting mode is selected, data 2 slightly wider than data 1 is used in order to reliably capture a moving subject.

[0032]

[Table 1]

In step (14), the following processing is performed in order to prevent an unnecessary change in the lens focal length. First, when the subject is in a dark condition, the shutter speed slows down and a moving subject is rarely photographed, and it is unnecessary to frequently change the focal length of the lens. Therefore, the timing of changing the focal length is changed depending on the subject brightness. That is, when B _V ≧ 0, the focal length of the lens is constantly changed, and when B _V <0, S
After changing the focal length only once after 1 ON, f _ZOOM obtained in step (13) is output to the lens drive circuit 7.

In step (15), the switch S2 is viewed for the exposure operation. If S2 is OFF, the AF lens movement amount GLP is output to the lens driving circuit 7 to perform AF, and the process returns to step (1).

On the other hand, if S2 is ON, look at the switch S4 to change the single shooting / continuous shooting of the shooting operation. If S4 is ON, continuous shooting is performed, so the exposure operation is performed based on A _VC and T _VC, and the bit has been exposed. Set RL = 1 and return to step (1).
If S4 is OFF, it is a single shot, so see if RL = 0. R
If L = 0, the exposure operation is performed because the exposure has not been performed after S2ON. If RL = 1, it is already exposed, so S1OF
The exposure operation is not performed until F is reached and RL = 0.

[0036]

As described above, according to the present invention, when a photographer takes a continuous shot of a moving subject or many photographs, the photographer can automatically take a photograph with few failures simply by setting the drive mode to the continuous shot. It is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit configuration of a camera embodying the present invention.

FIG. 2 is a flowchart showing the control operation of this embodiment.

FIG. 3 is a flowchart showing a control operation of this embodiment following FIG.

FIG. 4 is a flowchart showing the control operation of this embodiment following FIG.

FIG. 5 is an AE diagram in the child mode of this embodiment.

[Explanation of symbols]

 1: Control circuit 2: Film detection circuit 3: AE circuit 4: Lens 5: Photometric circuit 6: Distance measuring circuit 7: Lens drive circuit M1: Focus drive motor M2: Zoom drive motor S1: Exposure calculation start switch S2: Release switch S3: Mode selection switch S4: Single / continuous shooting switch

Claims (1)

[Claims] 1. A photometric means for measuring the brightness of an object, a means for detecting the sensitivity of a film, a distance measuring means for measuring the distance to the object, a means for driving a focusing lens, and a distance measuring means for the distance measuring means. Focal length changing means for changing the focal length of the lens based on the value, shooting changing means for switching the shooting method between single shooting and continuous shooting, and calculating means for calculating the shutter speed and aperture of exposure from the photometric means and film sensitivity detecting means And a control means for changing the focal length changing means to a shorter focal length when the photographing changing means is continuous shooting than for single shooting and changing the shutter speed of the calculating means to a higher speed. Control device.