JPH0627514A - Zoom camera - Google Patents

Abstract

PURPOSE:To obtain a camera having a high-magnifying power zooming function suitable for preventing jiggling easily occurring in long focal distance photographing. CONSTITUTION:In this zoom camera, a zooming lens 2 is driven by a zooming motor 1 to detect the current position at that time by a focal distance detecting part 3, a limit focal distance calculating part 4 calculates shutter speed from ISO information and object brightness information to calculate a focal distance limit value not for having the jiggling at the shutter speed, and when the shutter speed is one having the jiggle, warning is issued, and setting to a focal distance is inhibited by an inhibiting part 5, in accordance with the focal distance limit value, for instance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement in preventing camera shake in a zoom camera incorporating a high-power zoom lens.

[0002]

2. Description of the Related Art Generally, when shooting with a zoom lens, if the brightness is the same, the opening time (exposure time) of the shutter increases as the zoom ratio increases. In other words, the higher the magnification of the zoom (long focus), the more likely the camera shake will occur.

As a solution to such a problem, there is a system, as described in Japanese Patent Laid-Open No. 182623/1983, for changing the level of a low-brightness warning (camera shake warning) in conjunction with switching the focal length. is there. In addition, JP-A-54
There is also one that shifts the program diagram according to the focal length as described in Japanese Patent Publication No. 156533.

Further, when a strobe is used, it is disclosed in Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 2-1403034 describes a method in which the maximum shutter speed at the time of using a strobe is long at short focal lengths and short at long focal lengths.

[0005]

However, in the method described in Japanese Patent Laid-Open No. 58-182623, only a low-brightness warning is given, and a photographer who is skilled in using a high-magnification zoom can Although it is sufficiently used, it is difficult for a general photographer who does not have a high-level photographing technique to judge by the display, which is not sufficient.

On the other hand, mounting a system for shifting the program diagram according to the focal length as described in Japanese Patent Laid-Open No. 54-156533 on a compact camera has no structural space and is technically difficult. difficult.

Further, the system described in Japanese Patent Laid-Open No. 143034/1987 makes no mention when the strobe is not used. Therefore, when a strobe is not used and long-focus shooting is performed, a blurred photo may be taken without noticing that the shutter speed is slower than the handshake limit second. Therefore, an object of the present invention is to provide a camera having a high-magnification zoom function, which is suitable for preventing camera shake that tends to occur during long focal length photography.

[0008]

In order to achieve the above object, the present invention comprises a shutter speed setting means for calculating a shutter speed or manually setting a shutter speed based on a subject brightness, and the shutter speed setting means. There is provided a zoom camera configured by means for obtaining a maximum focal length that is free from the risk of camera shake on the basis of a set shutter speed, and prohibiting means for prohibiting setting to a focal length longer than the maximum focal length.

[0009]

With the zoom camera configured as described above, when the shutter speed is such that camera shake may occur based on the brightness of the subject, setting to high-magnification zoom is prohibited, and the focal length that has already been set. If there is a risk of camera shake, move to a shutter speed where there is no risk of camera shake.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, a conceptual configuration of the zoom camera of the present invention is shown in FIG. 1 and will be described.

In this zoom camera configuration, the zooming motor 2 is driven by the zooming motor 1,
The current position at that time is detected by the focal length detection unit 3. The limit focal length calculation unit 4 calculates the shutter speed from the ISO information and the subject brightness information, and calculates the focal length limit value that does not cause camera shake at the shutter speed. The prohibition unit 5 carries out a prohibition process according to the focal length limit value. Although there are individual differences, generally, when the shutter opening time is T (sec), the relationship with the focal length f for preventing camera shake is T <1 / f.

For the shutter opening time, a program exposure method is adopted in many cameras, and an Ev value (Lv value) is obtained from ISO information and subject brightness information.
The shutter opening time is uniquely determined by referring to the program diagram. Next, FIG. 2 shows a schematic configuration of a zoom camera as a first embodiment of the present invention, which will be described. In the structure of this zoom camera, the CPU 11 measures the distance and
A signal detected from a photometric circuit or the like is processed to control the driving of the constituent members.

A photometry circuit 12 and a distance measurement circuit 13 are connected to the CPU 11, and the output of each circuit is input from an A / D input terminal. The photometric circuit 12 changes the output level according to the subject brightness obtained from the light receiving element 14 for subject brightness photometry. The distance measuring circuit 13 assumes active triangulation, and projects light from a light projecting element 15 onto a subject (not shown), and the reflected light is measured by a light receiving element 16 for distance measurement such as PSD. Then, the output level corresponding to the subject distance is input to the A / D input terminal of the CPU 11. The distance measuring circuit 13 may be a passing type AF.

The CPU 11 has a display unit 17 for displaying a warning, such as an LED, and a DX for ISO input.
A code reading terminal 18 is provided. Further, the CPU 11 is provided with a release switch that assumes a two-step push switch as a release button, and
The first-stage 1st release switch 19 that performs preparatory operations such as metering and display (not shown) necessary for the measurement, and the second-stage 2n that serves as a trigger for performing the actual exposure operation.
There is a release switch 20.

The CPU 11 is provided with a zoom-up switch 21 for zooming to the tele side and a zoom-down switch 22 for zooming to the wide side, and a zoom motor 23 in response to a command from the CPU 11. Drive circuit 24 for reversing
And an encoder 26 for detecting the movement of the lens barrel (zooming lens) 25. In general, various types of encoders have been put into practical use, such as a sliding switch attached to a zooming lens and a type in which the rotation of a motor is read by an optical encoder, but the encoder 26 of the present embodiment is not limited by the method. . In addition, although the display unit displays a warning by using an LED or the like, it may be a sounding element that emits a warning sound. The operation of the thus configured zoom camera when the 1st release is pressed will be described with reference to the flowchart of FIG.

First, when the 1st release switch is pressed (step S1), the photometric value (subject brightness) from the light receiving element 14 of the photometric circuit 12 is fetched into the CPU 11 (step S2). Then, from the DX code reading terminal 18, I
SO is input (step S3), and the distance measurement value from the distance measurement circuit 13 is taken into the CPU 11 (step S4). The shutter opening time T is obtained by referring to the program diagram of the camera based on the photometric value and the value obtained by ISO (step S5).

Next, the current focal length f is obtained from the position of the zooming lens 25 obtained from the encoder 26 and input (step S6), and whether or not there is a possibility of camera shake at that focal length, that is, T> Determine α / f (step S7). Here, α is a constant, and is generally set to “1” as described above, but it depends on the user's photography experience and the like. It may be possible to make it smaller than 1.

When it is determined in step S7 that the shutter opening time T is larger than α / f and there is a risk of camera shake (YES), the focal length f is set to the shortest focal length of the camera. (Wide end) fmin is set again, and T> α / fmin is set, and comparison is performed (step S8). This step S8
If the shutter opening time T is larger than α / fmin, that is, if there is a possibility of camera shake (YES), a warning is given by the display on the display unit 17 (step S9) and the zooming lens 25 To set the focal length to the shortest focal length fmin (step S1
0).

However, in the determination of step S8, T is α / f
If the value is not larger than min (NO), a warning is given (step S11), and the zooming lens is moved to the focal length f =
Drive to α / T (step S12). This warning may be given by the sounding element as described above, or the zooming lens 25 is moved to the wide end in the next step 12, but generally the finder field of view is also changed in conjunction with the movement of the zooming lens. The warning may be omitted because it is visible.

In the determination in step S7 described above, T is α /
When the value is not larger than f (NO), and after the focal length is set in steps S10 and S12, it is determined whether or not the 2nd release switch is pressed (step S1).
3) If the 2nd release switch is pressed (Y
ES), the procedure shifts to the next shooting routine, and if the 2nd release switch is not pressed (NO), it is determined whether or not the 1st release switch is continuously pressed.
If it is pressed (YES), the system waits until the 2nd release is reached, and if the release switch is released and the release is not the 1st release (NO), returns and returns to the initial state.

Next, the operation of the zoom camera according to the first embodiment when the zoom-up switch 21 or the zoom-down switch 22 is pressed will be described with reference to the flowchart of FIG.

First, the photometric value obtained by the photometric circuit 12 is C
It is taken into PU11 (step S21), and ISO is input from the DX code reading terminal 18 (step S22).
The shutter opening time T is obtained by referring to the program diagram of the camera based on the photometric value and the value obtained by ISO (step S23).

Next, the current focal length f is calculated from the position of the zooming lens 25 obtained by the encoder 26 and input (step S24). Then, it is determined whether or not the zoom-up switch 21 is pressed (step S2
5) If it is pressed (YES), T> α / f is set, and it is determined whether or not there is a possibility of camera shake at the current focal length f (step S26).

If it is determined in step S26 that the shutter opening time T is larger than α / f (Y
ES), the focal length f is the shortest focal length fmin of the camera
And the shutter opening time T is compared as α / fmin (step S27). Also in the determination in step S27, if the shutter opening time T is larger than α / fmin (YES), a warning is given by the display on the display unit 17 (step S28), the zooming lens is driven, and the focal length is set to the shortest focus. Set to the distance fmin (step S2
9) The zoom drive is stopped (step S40). However, it is determined in step S27 that the shutter opening time T is α / f.
If the value is not larger than min (NO), a warning is given (step S30), the focal length is set to the current focal length f by driving the zooming lens (step S31), and the zoom drive is stopped (step S40). ). Further, when it is determined in step S26 that the shutter opening time T is not larger than α / f (no camera shake occurs) (NO), the longest focal length of the current camera (tele end) f
If it is not at T (step S32), if it is not at the tele end (NO), the motor 23 is driven so that the zooming lens is driven to the tele side (step S33), and the process returns to step S25. However, if it is at the tele end (Y
ES), and zoom driving is stopped (step S40).

After that, when the zoom-up switch 21 is continuously pressed, steps S25, S26 and S3 are performed unless the determination routine of steps S26 and S32 is completed.
2. Go around the loop of S33.

If it is determined in step S25 that the zoom-up switch 21 is not pressed (N
O), and it is determined whether or not the zoom down switch 22 is pressed (step S34).

If it is determined in step S34 that the zoom down switch 22 is pressed (YES), it is determined whether the current zooming lens is at the wide end (step S35). If it is already at the wide end (YES), the zoom drive is stopped (step S40). However, if it is not the wide end (N
O), the motor 23 is driven so that the zooming lens is driven to the wide side (step S36), and step S2
Return to 5.

If it is determined in step S34 that the zoom down switch 22 is not pressed (N
O), it is determined whether or not there is a risk of camera shake at the current focal length f (step S37). In this determination, if the shutter opening time T is larger than α / f (YE
S), a warning is given (step S38), the zooming lens is driven to the focal length f = α / T (step S39), and the zoom drive is stopped (step S40). However, if the shutter opening time T is not larger than α / f (NO), the zoom drive is stopped. After stopping the zoom drive, it returns and returns to the initial state.

After that, when the zoom down switch 22 is continuously pressed, steps S25, S34, S35 and S36 are performed unless the wide end is set in step S35.
Around the loop.

Next, the operation of the camera including the automatic zoom function will be described with reference to the flowchart of FIG.
This camera automatically adjusts the auto zoom so that the focal length becomes fa = L / (1 / β + 2) from the preset photographing magnification β and subject distance L.

First, the 1st release switch is pressed to take in the photometric value obtained from the photometric circuit 12 into the CPU 11 (step S41). And the DX code reading terminal 1
ISO input from 8 (step S42), distance measuring circuit 13
The distance measurement value from is taken into the CPU 11 (step S
43). With the photometric value and the value obtained by ISO, referring to the program diagram of the camera, the shutter opening time T
And a focal length based on the shutter opening time T is input (step S44).

Next, it is determined whether or not the auto zoom mode is set by the operation switch provided on the camera (not shown) (step S45). When the auto zoom mode is set (YES), the focal length fa is obtained from the above equation (step S46), and it is determined whether the focal length fa to be set by the auto zoom may cause camera shake. The determination is made (step S47). Here, the photographer finds out that auto zoom is not performed correctly. If there is a possibility of camera shake in this determination (YES), the focal length fa is set to the shortest focal length (wide end) f of the camera.
It is reset to min, α / fmin is compared with the shutter opening time T, and it is determined whether or not there is a possibility of camera shake even at the focal length at the wide end (step S48). If there is a possibility of camera shake in this determination (YES), a warning is given (step S49), and the focal length fa is set to the focal length f at the wide end.
The value is reset to min (step S50), and the zooming lens is driven to the focal length fa (step S5).
3). However, if there is no risk of camera shake in step S48 (NO), a warning to that effect is issued (step S51),
The focal length fa is set to α / T (step S5
2), the zooming lens is driven to the focal length fa (step S53).

If the automatic zoom mode is not set in step S45 (NO), it is determined whether or not there is a possibility of camera shake at the current focal length f (step S54). In the determination of step S54, T is α
If it is determined that the value is larger than / f (YES), there is a risk of camera shake, the focal length f is reset to the shortest focal length fmin of the camera, and α / fmin is compared with the shutter opening time T ( Step S55). Even in the determination of step S55, the shutter opening time T is α / fmin.
If the value is larger (YES), a warning is given by the display on the display unit 17 (step S56), the zooming lens is driven, and the focal length is set to the shortest focal length fmin (step S57).

However, if it is determined in step S55 that the shutter opening time T is not larger than α / fmin (NO), a warning is given (step S56) and the focal length is set to the current focal length f and the zooming lens is set. The zoom drive is stopped after driving and setting (step S57).

If it is determined in step S54 that the shutter opening time T is not larger than α / f (no camera shake occurs) (NO), and step S5
7, after the focal length is set in S60, it is determined whether or not the 2nd release switch is pressed (step S13),
When the 2nd release switch is pressed (YE
S) Then, the procedure shifts to the next photographing routine, and when the 2nd release switch is not pressed (NO), it is determined whether or not the 1st release switch is continuously pressed. If it is pressed (YES), the system waits until the 2nd release is reached, and if the release switch is released and the release is not the 1st release (NO), returns and returns to the initial state.

Next, as a second embodiment, an example of application to a camera having a strobe light emission mode will be described with reference to the flowchart of FIG. Here, in the flow chart of FIG. 6, steps that perform the same operations as in FIG. 3 are assigned the same step numbers, explanations thereof are omitted, and only the characteristic portions will be explained.

That is, in the shooting mode in which the strobe light is emitted, there is no risk of camera shake because the shooting is performed with sharp light, and when the setting to the long focus is prohibited like in the zoom camera of the first embodiment described above, the shooting is performed. May be harmful. In order to prevent this adverse effect, the prohibition process may be skipped when the strobe emits light.

First, the 1st release switch is pushed to take in the photometric value obtained by the photometric circuit 12 into the CPU 11. The shutter opening time T is obtained from the output photometric value and the value obtained by ISO, and the current focal length f is input.

Next, it is determined whether or not the strobe light emission mode is set (step S72), and if it is set (YES), it is determined whether or not the 2nd release switch is pressed (step S13). However, if it is not set, the process proceeds to step S7, and processing for prohibiting the setting to the long focus is performed.

Next, as a third embodiment, an application example when the zoom-up switch 21 or the zoom-down switch 22 of the camera having the strobe light emission mode is pressed will be described with reference to the flowchart of FIG. Here, in the flow chart of FIG. 7, steps that perform the same operations as in FIG. 4 are assigned the same step numbers, explanations thereof are omitted, and only characteristic portions will be explained. In the zoom camera according to the third embodiment, the prohibition process for setting the long focus may be skipped, as in the second embodiment.

First, the 1st release switch is pressed to take the output photometric value obtained by the photometric circuit 12 into the CPU 11. The shutter opening time T is obtained from the output photometric value and the value obtained by ISO, and the current focal length f is input.

Thereafter, when the zoom up switch 21 is pressed or the zoom down switch 22 is not pressed, it is determined whether or not the strobe light emission mode is set (steps S75 and S76). If it is set in step S75 (YES), it is determined whether or not it is at the longest focal length (tele end) fT of the current camera (step S32). If it is set in step S76 (YES), the zoom drive is stopped (step S40). As described above, when the flash emission mode is set, the process of prohibiting the setting to the long focus is skipped.

Next, an application example of a zoom camera for applying a limiter to the shutter speed according to the focal length will be described as a fourth embodiment in the flowchart of FIG. Here, FIG.
In the flowchart, the same step numbers are assigned to the steps that perform the same operations as in FIG. 3, the description thereof is omitted, and only the characteristic part will be described.

In this zoom camera, in step S10, the zooming lens is driven to set the focal length to the shortest focal length fmin, and then the shutter opening time T is set to 1 / f.
Set to min (step S77). Then step S
In 13, it is determined whether or not the 2nd release switch has been pressed.

By this step S77, the shutter speed becomes a limiter according to the focal length. The fourth embodiment can be similarly applied to the embodiments of FIGS. 4 to 7. If the limiter is applied in this way, underexposure may occur in the triangular aperture type sector shutter, but the aperture and shutter are independent,
Proper exposure can be obtained by individual control.

As described above, the program exposure camera has been described in the present embodiment. However, the shutter speed itself is set in the case of manual exposure or shutter priority exposure, and ISO is set in the case of aperture priority exposure.
The shutter speed obtained from the sensitivity, the subject brightness, and the set aperture value may be applied to the shutter speed as shown in step S5 of FIG. 3, for example. Further, the present invention is
It is needless to say that the present invention is not limited to the above-described embodiments, and that various modifications and applications can be made without departing from the scope of the invention.

[0047]

As described above in detail, according to the present invention, it is possible to provide a camera having a high-magnification zoom function, which is suitable for preventing camera shake that tends to occur during long focal length photography.

[Brief description of drawings]

FIG. 1 is a diagram showing a conceptual configuration of a zoom camera of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a zoom camera as a first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation when a 1st release switch of the zoom camera of the first embodiment is pressed.

FIG. 4 is a flowchart showing an operation when a zoom up switch or a zoom down switch of the zoom camera of the first embodiment is pressed.

FIG. 5 is a flowchart showing an operation of a camera including an auto zoom function.

FIG. 6 is a flowchart showing an application example to a camera having a stroboscopic light emission mode as a second embodiment.

FIG. 7 is a flow chart showing an operation of an application example when a zoom up switch or a zoom down switch of a camera having a strobe light emission mode is pressed as a third embodiment.

FIG. 8 is a flow chart showing an application example of a zoom camera for applying a limiter according to a focal length at a shutter speed as a fourth embodiment.

[Explanation of symbols]

1 ... Zooming motor, 2 ... Zooming lens, 3 ...
Focal length detection unit, 4 ... Limit focal length calculation unit, 5 ... Prohibition unit, 11 ... CPU, 12 ... Photometric circuit, 13 ... Distance measuring circuit,
14 ... Light receiving element, 15 ... Light emitting element, 16 ... Distance measuring light receiving element, 17 ... Display section, 18 ... DX code reading terminal, 19
... 1st release switch, 20 ... 2nd release switch 20, 21 ... Zoom up switch, 22 ... Zoom down switch, 23 ... Zoom motor, 24 ... Zoom drive circuit, 25 ... Lens barrel (zooming lens), 26 ... Encoder.

[Procedure amendment]

[Submission date] October 8, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

In the zoom camera having the above-described configuration, when the shutter speed is such that camera shake may occur based on the brightness of the subject, setting to high-magnification zoom is prohibited, and the focal length that has already been set. If there is a risk of camera shake, use a shutter speed that does not cause camera shake.
Set .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

A photometry circuit 12 and a distance measurement circuit 13 are connected to the CPU 11, and the output of each circuit is input from an A / D input terminal. The photometric circuit 12 changes the output level according to the subject brightness obtained from the light receiving element 14 for subject brightness photometry. The distance measuring circuit 13 assumes active triangulation, and projects light from a light projecting element 15 onto a subject (not shown), and the reflected light is measured by a light receiving element 16 for distance measurement such as PSD. Then, the output level corresponding to the subject distance is input to the A / D input terminal of the CPU 11. The distance measuring circuit 13 may be a passive type AF.

Claims (1)

[Claims] 1. A shutter speed setting means for calculating a shutter speed or manually setting a shutter speed on the basis of subject brightness, and a possibility of occurrence of camera shake based on the shutter speed set by the shutter speed setting means. A zoom camera comprising: means for obtaining a maximum focal length that does not exist; and prohibiting means for prohibiting setting to a focal length longer than the maximum focal length.