JPH09185099A - Exposure controller for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set shutter time in a step required in terms of control or the condition of a subject in a quick shutter time area and to set the shutter time which is easily set from photographer's habit in a range other than the above area by providing the time set areas different between the setting at a 1st interval and that at a 2nd interval in accordance with the selecting operation of an operating member. SOLUTION: This controller is provided with a CPU 27 functioning as a control means controlling the setting of the shutter time. A subject luminance signal from a photometry circuit 20, a focusing state signal from a range-finding circuit 22, and a state signal from the state detection circuit 25 of various switches are inputted in the CPU 27 via an interface circuit 26. The CPU 27 is provided with the 1st time set area set at the 1st interval and the 2nd time set area set at the 2nd interval different from the 1st interval in the case of operating the same shutter time selecting operation member. Thus, fine setting can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control device for a camera, which is most suitable for shooting with long exposure.

[0002]

2. Description of the Related Art Conventionally, in a camera, an aperture value and a shutter time are important exposure conditions. Regarding the former aperture value, since it is related to the aperture of the lens, the upper and lower limits are naturally limited, but since the shutter time is electronically controlled, there is virtually no limit on the long side without mechanical limitation. Is.

On the other hand, the concept of step is incorporated in the exposure amount. For example, when the shutter time is 1/8000 seconds and 1/4000 seconds, the latter exposure amount is one step larger.

In the past cameras, due to the physical size of the shutter dial and the size of characters printed on the surface of the shutter dial, the shutter time could only be selected every other step. However, in recent cameras, by using an endless dial (hereinafter referred to as a command dial) and a liquid crystal display (hereinafter referred to as an LCD) together under the control of a microcomputer, the shutter time step that can be selected is arbitrary. Unlike 1/3 step, the general specifications are. This makes it possible to perform delicate exposure control according to the conditions such as the movement of the subject and the aperture value of the lens.

Table 1 shows an example of such a shutter time selection range. The left half has a shutter time of less than 1 minute and the right half has a shutter time of 1 minute or more, all of which are prepared in 1/3 step increments. The one marked with * is the shutter time in steps of 1 second. Since the series is based on 1 second, the exposure time is actually controlled to be 64 seconds for 1 minute (60 seconds) and 1024 seconds for 16 minutes (960 seconds), but it is simplified on the display. It looks like Table 1.

[Table 1]

[0006]

The first problem in the shutter time of 1 minute or more on the right side of Table 1 is that all shutter speeds are uniformly set in 1/3 steps. There is a point that it takes a long time to set up because you have to turn the dial a considerable amount until you can select it.

The second problem is that the time is unfamiliar and detailed. 1.3 seconds or 3.2 seconds is very halfway and it is intuitively difficult to grasp the length.

Further, for example, in a long-time exposure state when shooting a night view, even if a fine exposure amount such as 1/3 step is changed, the obtained image does not have a great difference. It is said that the subject is in a special situation such as a night view, and that reciprocity is irregular in the film, that is, the change in the exposure amount and the change in the image density of the film do not match when the exposure is extremely short or long. It is due to the nature.

From the above, in the prior art, it can be said that many options are prepared unnecessarily.

The present invention has been made in view of the above problems, and is set in steps required for control or subject conditions, such as ⅓ step in the fast shutter time range. It is possible to set the shutter speed in a range other than the above, which is easy to set by the photographer according to the custom.

[0011]

In order to achieve this object, an exposure control device for a camera of the present invention comprises a control means (27) for performing shutter speed setting control, and the control means are the same. When operating the shutter time selection operation member, a first time setting area set at a first interval and a second time setting area set at a second interval different from the first interval Have and.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a camera exposure control device according to the present invention.

In FIG. 1, the subject image that has passed through the mounted lens 2 can be visually recognized by the finder 3, and when the shutter button 4 is pressed, the film on the back cover 8 is exposed under the set conditions. The exposure mode, for example, switching between the manual mode and the shutter priority mode is performed by the LCD 6
It is possible to make a selection with the dial 7 while checking the information shown above. Further, the shutter time that can be selected in the above mode can be selected by rotating the command dial 5 while confirming the value displayed on the LCD 6. The command dial 5 is an endless rotating member, and has a mechanism in which the rotating direction and the rotating amount are recognized by an internal circuit by interlocking contacts. Unlike the conventional analog dial method, the rotation direction and the rotation amount are recognized by digital processing.

FIG. 2 is an example of an electric circuit diagram of the camera 1.
The battery and its power supply circuit necessary for the operation of the circuit are omitted. The control of the camera 1 is executed mainly by the CPU 27. In the CPU 27, the object brightness signal from the photometry circuit 20, the focus state signal from the distance measurement circuit 22, the film sensitivity signal from the film sensitivity detection circuit 23, and the status signals from the status detection circuits 25 of various switches are sent to the interface circuit. It is input via 26. The switch detection circuit 25 includes a power switch associated with the shutter button 4, a release switch, a dial 7 and a command dial 5, as well as internal switches representing a sequence state.

The CPU 27 has an interface circuit 28.
The motor 24 is rotated via the, and the focusing lens 21 is moved to focus the subject. Further, the above-mentioned LCD 6 is used to display the exposure conditions through the interface circuit 28, the shutter 11 is opened and closed to expose for a predetermined time, the aperture diameter of the diaphragm 30 is changed to control the transmitted light amount, and the motor 31 is used.
Rotate to wind and rewind the film.

FIG. 3 is a CPU in the camera 1 shown in FIG.
27 is an example of a processing routine by 27. This routine is CP
It is repeatedly executed while power is being supplied to U27. In the processing routine described below, the description of the operation of the distance measuring circuit 22 is omitted.

In step S1, various conditions such as the exposure mode selected by the dial 7 and the previously set shutter time are read. In the case of the present embodiment, it is assumed that only the manual mode and the shutter priority mode are prepared as the exposure mode. In both cases, it is necessary for the photographer to select the shutter time.
In step S2, the brightness signal of the subject is read from the photometric means 20. In step S3, the sensitivity signal is fetched from the sensitivity detecting means 23. In step S4,
Both of the above are calculated to calculate the aperture value that should be controlled to obtain proper exposure in the shutter priority mode. In the manual mode, the difference between the exposure amount obtained from the set shutter time and aperture value and the optimized exposure amount is obtained. In step S5, the various conditions relating to the exposure thus obtained are displayed on the LCD 6. In step S6, it is determined whether the command dial 5 is rotated. If the command dial 5 is rotated, the rotation amount and direction are recognized in step S7,
The shutter time is updated, the same calculation as in step S4 is executed, and the display content of the LCD 6 is changed. If the command dial 5 has not been rotated, step S8 is immediately executed.
Move to

In step S8, the release button 4
It is determined whether or not is pressed to instruct exposure. If it has not been pressed, the process returns to step S1 to repeat the above process. If it has not been pressed, the process proceeds to step S9. In step S9, a reflecting mirror (not shown) is raised and retracted from the photographing optical path. Step S10
At, the diaphragm 30 is controlled to have a predetermined diaphragm opening. In step S11, the shutter 11 (not shown) is opened and the film is exposed for the predetermined time determined in step S1 or step S7. Step S1
In step 2, since all the operations are completed, the motor 31 is rotated in the normal direction to perform the film feeding and the mechanism urging operation, and the process returns to step S1 to repeat the above process.

Table 2 shows the command dial 5 according to the present invention.
4 is a list of shutter times that can be selected on the LCD 6 by rotating. The left half has a shutter time of less than 1 minute and the right half has a shutter time of 1 minute or more. Shutter times less than 1 minute are set in 1/3 step increments, and shutter times of 1 minute or more are intuitively understandable. There is. Therefore, there are chances such as those marked with * that correspond to 1-step increments starting from 1 second, and those that correspond to 1/3 step. However, unlike the past,
The value displayed on the LCD 6 is a value controlled as the actual exposure time.

[Table 2]

Unlike Table 2, Table 3 is an example in which the boundary is set to 1/60 seconds. On the higher speed side than 1/60 seconds, finer setting is possible by 1/3 step, but on the low speed side, shutter time is prepared in 1-step increments. In the case of general amateurs and the like, the low shutter speed is not used so much because of concern about camera shake. Therefore, from the viewpoint that it is better to avoid unnecessary fine settings, 1/60 seconds is set as the boundary. Note that the photographer may be allowed to select either Table 1 or Table 2.

[Table 3]

Although the embodiment has been described by taking 1/3 step as an example, according to the technical idea of the present invention,
It is also possible to have / n (n is an integer) steps.

[0023]

As described above, according to the exposure control device for a camera of the present invention, the control means (27) for performing the setting control of the shutter time is the first time time set at the first interval. Since it has a setting area and a second time setting area that is set at a second interval different from the first interval, in the area of a fast shutter time, due to control or subject conditions such as 1/3 step. It is possible to set the shutter speed in steps required from the above, and in the range other than that, it is possible to set the shutter speed which is easily set by the photographer according to the custom.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an exposure control device for a camera according to the present invention.

FIG. 2 is a block connection diagram showing an embodiment of an exposure control device for a camera according to the present invention.

FIG. 3 is a flowchart showing an embodiment of a camera exposure control device according to the present invention.

[Explanation of symbols]

 1 camera 5 command dial 6 LCD 27 CPU

Claims (5)

[Claims] 1. An operation member which is externally operable and which selects a desired shutter time in accordance with the operation, and a control unit which controls the setting of the shutter time in accordance with the operation of the operation member. The control means is configured to perform a first operation according to a selection operation of the operation member.
A second time setting area for setting the second time at an interval, and a second time setting area for setting a second time at a second interval different from the first interval according to a selection operation of the operation member. An exposure control device for a camera, comprising: 2. The exposure control device for a camera according to claim 1, wherein the first time zone and the second time zone have boundaries of 1 second or 1 minute. 3. The first interval according to claim 1, wherein the first interval is an interval expressed in 1 / n (n is an integer) steps, and the second interval is expressed in other steps. An exposure control device for a camera, which is characterized in that 4. The shutter time display device according to claim 1, further comprising a shutter time display unit for the setting control by the control unit, wherein the shutter time display unit for the setting control is at least in the first time region. And the display value displayed by the display means match, the exposure control device for a camera. 5. The exposure control device for a camera according to claim 1, wherein a boundary between the first time zone and the second time zone is changeable.