JPS6161089B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display method during bulb photography and long-time photography in a camera.

2. Description of the Related Art Conventionally, in photographing with a camera, means have been provided to indicate in the viewfinder that the shutter is in operation by emitting light from a lamp or a light emitting diode. Further, there is provided means for indicating the operation of the self-timer by flashing a light emitting member.

However, when performing bulb photography or long exposure photography using an electric shutter, there is no conventional means of knowing the exposure time.

As is well known, in bulb photography, the shutter is open while the shutter button is held down, and the shutter is closed when the finger pressure is removed from the shutter button, so it has the advantage of being able to manually control the exposure time as desired. However, in this case, there was no means or clue to measure the exposure time, and it was left entirely to the discretion of the photographer. Therefore, there are individual differences in this judgment, and even photography that incorporates the photographer's intentions is accompanied by temporal instability.

On the other hand, in automatic exposure photography using an electric shutter, if the subject is dark, the photography will be a long exposure photography. In this case as well, there is no way to know the exposure time, making photography extremely uneasy.

Therefore, in the case of such long exposure photography and the above-mentioned bulb photography, if a display means is provided to serve as a guide for measuring the shooting time, this anxiety will be alleviated. be done.

In view of the above points, an object of the present invention is to provide a display member that operates at a fixed time period while the shutter is operating, and to count the operation of this display member in the case of bulb photography and long exposure photography. Therefore, it is an object of the present invention to provide a display device for a camera that allows photographing to be performed without anxiety, and in which the display member also serves as a self-timer operation display.

According to the present invention, by counting the operation of the bulb or the display member during long-time photography, it is possible to know the relatively accurate second and time, so the advantage is that photography that incorporates the photographer's intentions can be carried out with peace of mind. In addition, since the camera uses active means such as flashing or intermittent sounds to indicate that the camera is recording, it is difficult to use the camera incorrectly, such as by moving the camera or rewinding the next film while recording. It can be prevented. In particular, when the display operation is performed by sound, the exposure time can be known without using a light-emitting display means that would interfere with photographing in the dark.

Hereinafter, the method of the present invention will be explained using figures. FIG. 1 shows an electric circuit in which a display circuit to which the display method of the present invention is applied is added to a well-known electric shutter circuit. In the figure, power supply E includes a main switch SW that is turned on when the shutter release button is pressed.
between its positive voltage supply line EL ₁ and negative voltage supply line EL ₂ , the control circuit of the electric shutter
CS, self-timer circuit CT, first pulse oscillator
PO ₁ , frequency divider BF, second pulse oscillator PO ₂ , resistor R ₁
and a series circuit of transistor Q ₄ and a series circuit of resistor R ₂ and transistor Q ₅ are connected, respectively.

The above-mentioned shutter control circuit CS constitutes a part of the electric shutter circuit, and when the required time for automatic exposure has elapsed, it performs a switching operation and operates the shutter closing magnet Mg ₂ to start the shutter. It plays the role of closing. The self-timer circuit CT is composed of a delay circuit such as a well-known CR timer, and when the self-timer is used, the self-timer lever (not shown) is
is set and the main switch SW is turned on to start delay operation, and after a predetermined delay time has elapsed, the shutter opening operation magnet Mg ₁ is operated to open the shutter.

This self-timer circuit CT outputs an output signal from one output terminal a when the self _- timer is activated, and applies this to the base of the transistor Q ₂ .
is connected between the output terminal of the frequency divider BF and the line EL ₂ , and when a signal is applied to the base from the above output terminal a, it is turned on and the output of the frequency divider BF is connected to the line.
It is set to drop to EL ₂ . The other output terminal b of the self-timer circuit CT outputs an output signal when the self-timer is inactive, and this signal is applied to the base of the transistor _Q1 .
Transistor Q ₁ is connected between the output terminal of the first pulse oscillator PO ₁ and the line EL ₂ , and when a signal is applied to the base from the output terminal b, it turns on and outputs the first pulse oscillator PO _1. It is now possible to drop the line to EL ₂ .

As shown in FIG. 2A, the first pulse oscillator PO ₁ generates a square wave pulse with a regular period on the order of several times per second, and this output pulse is transmitted from its output terminal to a transistor through a resistor R ₃ . It is being added to the base of Q ₃ . Transistor Q ₃ is the above transistor
Q ₄ is connected in parallel to the first pulse oscillator.
The output pulse of PO ₁ or the frequency divider BE described below
When a square wave pulse from is applied to the base,
It's starting to turn on.

The frequency divider BF is connected to the first pulse oscillator PO ₁
It divides the output pulse of the oscillator PO ₁ and divides the pulse interval by 2 as shown in Figure 2B.
This pulse is then doubled and applied to the base of the transistor _Q3 through the resistor _R4 .

In addition, the second pulse oscillator PO ₂ is
As shown in , it generates an output pulse with a regular period on the order of several tens of times per second, and this output pulse is applied to the base of the transistor Q ₄ mentioned above, and the same pulse causes the transistor Q ₄ to repeats on and off. Transistor Q ₄ is synthesized with its collector connected to the collector of transistor Q ₃ above,
While the transistor Q ₃ is turned on by the output pulse from the first pulse oscillator PO ₁ (see Fig. 2A) or the output pulse from the divided period BF (see Fig. 2B), the second pulse oscillator It serves to apply the oscillating output pulse of PO ₂ (see Figure 2C) to the base of transistor Q ₅ . Therefore, the transistor _Q3 forms a gate for applying the output pulse of the second pulse oscillator _PO2 to the transistor _Q5 .

A light emitting diode P serving as a display member and a sounding member BU are connected to both ends of the resistor R ₂ connected in series to the transistor Q ₅ . The light emitting diode P has a resistor _R5 in series and is connected in parallel to a resistor _R2 , and emits light when the transistor _Q5 is turned on. Further, the sound generating member BU is composed of, for example, a piezoelectric buzzer (product name), and is designed to generate a sound when the transistor _Q5 is turned on.

The display circuit is configured as described above. Next, its operation will be explained. First, when performing automatic exposure photography using the self-timer, the output terminal a is connected to the circuit by setting the self-timer lever (not shown) to the self-position. After that, all you have to do is press the shutter release button and close the main switch SW. main switch
When SW is closed, the self-timer circuit CT starts delay operation and at the same time outputs an output signal from output terminal a to turn on transistor _Q2 . When it is turned on, the output pulse of frequency divider BF is dropped through the same transistor Q ₂ to line EL ₂ , so that the output pulse of frequency divider BF is passed through transistor Q _3.
The output pulse of the first pulse oscillator PO ₁ is applied to the transistor Q ₃ . Therefore,
The number of pulses in 1 second T of this output pulse is
For example, if it is set to two as shown in Figure 2A,
Transistor Q ₃ is turned on for 1/2 second every 1/2 second, and only while it is on, the second
The output pulse of the pulse oscillator PO ₂ is a transistor
It is applied to transistor _Q5 through _Q4 . When this is applied, the transistor _Q5 is finely turned on and off by the output pulse of the second pulse oscillator PO2, as shown in FIG. 2D, only while the output pulse of (see FIG. _2A ) is applied. Repeat the action. Therefore, as a result, the sound generating member BU and the light emitting diode P also perform fine sound generation and light emission operations for 1/2 seconds every 1/2 second, thereby indicating that the self-timer is in delay operation.

Furthermore, the operation of emitting light and emitting sound, which is continuously turned on and off for 1/4 second by the output pulse of the second pulse oscillator PO ₂ , appears to the human eye and ear as always emitting light and emitting sound. , so it feels like the display operation is being performed at 1/4 second intervals. Therefore, if the display shows equal intervals between activation and non-activation, it can be visually and audibly confirmed that the self-timer is activated.

Then, when the self-timer elapses, the self-timer circuit CT is activated, the shutter opening operation magnet _Mg1 is activated, the shutter is opened, and exposure is started. When the shutter is opened, the output signal at the output terminal a of the self-timer circuit CT disappears, and the output signal is output from the other output terminal b.
Transistor Q ₂ is off and transistor Q ₁ is on. Then, as the transistor Q ₁ turns on, the output pulse of the first pulse oscillator OP ₁ is dropped to the line EL ₂ through the same transistor Q ₁ , so that the output pulse of the frequency divider BF (Fig. 2 (see B) is added to transistor _Q3 . When this is added, the gate by transistor Q ₃ passes the output pulse of the second pulse oscillator OP ₂ for only 1/4 of a second, thereby also causing the gate by transistor Q ₅ to
The second pulse oscillator OP ₂ is activated for 1/4 second as shown in
The light emitting diode P and the sounding member BU also perform display operation for 1/4 second by repeating on and off by the output pulse. It then becomes inactive for the remaining 3/4 seconds. Therefore, when the camera is in shooting mode, 3/
A constant periodic display in which the display member operates for 1/4 second every four seconds is repeated.

In this state, if proper exposure is obtained,
The shutter control circuit CS is activated by the signal from the automatic exposure circuit to close the shutter.
The Mg ₂ is activated, the shutter is closed, and the shooting ends. However, if the subject is dark and you have to shoot for a long time, the flash will be displayed for only 1/4 second every 3/4 seconds. Then, the number of times the display member that displays the sound may be counted. Since the display operation is performed once per second, by sensing this display circuit with the eyes and ears and counting it, it is possible to know approximately how many seconds the exposure time for long-time photography is.

As described above, according to the present invention, by sensing and counting the display operation cycle of the display member,
You can get an estimate of the shooting time.

In addition, during normal shooting without using the self-timer, when the main switch SW is closed, the shutter opening operation magnet Mg ₁ operates to open the shutter, and at the same time the transistor opens.
Q ₁ is turned on and drops the output pulse of the first pulse oscillator PO ₁ onto the line EL ₂ , and the output pulse of the frequency divider BF (see Figure 2B) is applied to the transistor Q ₃ and the light emitting diode P and The sounding member BU displays for 1/4 second every 3/4 second, so if you detect this visually or aurally and count the number of times, you can easily calculate the exposure time when shooting for a long time. You can get an idea of the time.

In addition, during bulb photography, the electric shutter circuit is disconnected, and only while the shutter release button is pressed down, the main switch SW is closed, the above display circuit is activated, and the above self-timer is used. The display operation is performed in the same way as when normal shooting is performed. Therefore, by counting the number of display operations, it is possible to obtain a rough estimate of the shooting time.

As described above, according to the present invention, it is possible to provide a bulb in a camera that enables worry-free photography by counting the number of display operations of a display member auditorily or visually, and a display method for long-time photography. can.

Note that the display operation cycle of the display member is not limited to 1 second, and can of course be arbitrarily selected.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing an example of a display circuit for explaining the method of the present invention, and FIG. 2 is a diagram showing an output pulse waveform in the electric circuit shown in FIG. 1. P, BU...Display members (light emitting diodes, sounding members).

Claims (1)

[Claims] 1. In a camera having a self-timer, a first control signal generating means PO ₁ that emits a first frequency pulse output, and a second control signal generating means PO 1 that emits a pulse output of a second frequency having a longer period than the first frequency. control signal generating means BF; switching circuits Q ₃ and Q ₅ that operate in response to the first control signal output and second control signal output; display members P and BU connected to the switching circuit; a first blocking circuit Q1 that is activated when the self-timer is activated to prevent the first control signal output from being input to the switching circuit; and a first blocking circuit _Q1 that is activated when the self-timer is activated and prevents the second control signal output from being input to the switching circuit. a second blocking circuit _Q2 that blocks input to the switching circuit; when the first blocking circuit operates, the frequency is the second frequency; when the second blocking circuit is operating, the frequency is the first frequency. A display device for a camera, characterized in that the switching circuit and the display member are operated respectively in the following steps.