JPS5949523A - Controller of camera - Google Patents

Abstract

PURPOSE:To prevent power consumption when a film is not loaded, by inserting a film loading detection switch in series to a partial circuit of electric operating circuits such as a display circuit and a rear curtain holding circuit, and making these circuits inactive when the film is not loaded. CONSTITUTION:When the film is not loaded, a film loading detection switch 5 is turned off, and a rear curtain detaining magnet Mg is not energized even if a release button is depressed to turn on a power switch SW1. Consequently, a shutter runs in mechanical control seconds. When the film is loaded, the magnet Mg is energized by turning-on of the power switch, and the detention of the rear curtain is released after seconds determined by a time constant circuit RsCs, the shutter operation is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a camera having a plurality of electrically actuated circuits, which detects the presence or absence of film and makes some of the electrically actuated circuits inactive when no film is loaded. Regarding a control device.

In recent years, with the electrification of cameras, there are automatic exposure, automatic focus, electronic shutters, and electronic self-timers.

The proportion of electrical controls replacing conventional mechanical controls such as motor drives, strobes, data imprinting, remote controls, and viewfinder displays is rapidly increasing. Accordingly, cameras currently available on the market typically include a large number of electrically actuated circuits.

On the other hand, the size and weight of cameras are required to be smaller and lighter, and the storage space for the batteries that supply the necessary energy for each of these electrically operated circuits (2) is extremely limited, making it impossible to use large-capacity batteries. In the current situation.

Under such limited conditions, the only way to use batteries as effectively as possible is to prevent wasteful battery consumption as much as possible.

However, all cameras currently on the market operate in the same way regardless of the presence or absence of film, and as a result, the camera is often operated without film being loaded, which significantly accelerates battery consumption. It has become.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a camera control device that can perform normal operations only when film is loaded.

Therefore, the camera control device according to the present invention is provided with a normally open film detection switch that detects the presence or absence of film and is closed only when the film is in the device. It is inserted in series with some of the operating circuits, so that some of the electrically operating circuits are rendered inactive when no film is loaded.

The most effective control device for preventing battery consumption would be to prevent the camera from operating or displaying anything when no film is loaded.

However, with such a camera, it is not possible to test the camera's operation or even check the battery, resulting in unnecessary anxiety for the user.

Accordingly, this invention (part 2) focuses on circuits that consume a particularly large amount of electricity among various electric operating circuits, such as display circuits using a large number of LEDs, trailing curtain holding circuits using magnets, and winding circuits using motor drives. circuit, strobe light emitting circuit.

To disable some electric operating circuits such as a light source lighting circuit of a data imprinting device when no film is loaded.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figures 1 and 2 show an example of a means for detecting the presence or absence of film in a camera. A detection pin 4 that slides is provided, and a normally open film detection switch 5 is provided so that a movable contact piece 5a comes into contact with the tip of the detection pin 4.

When no film is loaded, as shown in FIG.
is pressed backward, and the rear end thereof is inserted into a through hole 6a formed in the film pressure plate 6, and the film detection switch 5 is opened.

In the state shown in FIG. 2 in which the film F is loaded, the rear end of the detection pin 4 is pressed forward by the film F, the movable contact piece 5a contacts the fixed contact piece 5b, and the film detection switch 5 is activated. Closed.

Here, a case where such a film detection switch is inserted into a part of an aperture-priority automatic exposure control circuit of a camera as shown in the block diagram of FIG. 6 will be described.

This circuit includes a photometer 7 that measures the subject brightness using external light.
．． Condition setting section 8 for setting film sensitivity (ASA) and aperture value (F). A calculation unit 9 that calculates the exposure time (Nyatta seconds) according to the exposure conditions from the photometry unit 7 and the condition setting unit 8. Display unit 10 that displays the calculated Nyatta seconds in the finder. The exposure time control section 11 is configured to control the shutter operating section 12 at the time of shutter release in response to an exposure time control signal from the calculation section 9 to control the shutter speed.

Of these, each part except the shutter actuating part 12 constitutes an electrical actuating circuit.

FIG. 4 shows a time control section of an aperture-priority automatic exposure camera having an electronic four-force lens system, and reference numeral 13 denotes a voltage signal VT for exposure time control from the arithmetic circuit 9 of FIG. SWl is a power switch, sw2 is a normally closed trigger switch that is opened when the front curtain of the focal plane shutter is started, and Mg
6 is a magnet that attracts the trailing curtain locking member in the shutter actuating section 12 of FIG. 6 and keeps it locked, and Cs is a capacitor for controlling the seconds, which together with the resistor Rs constitutes a time setting circuit.

The film detection switch 5 and the power switch SWi are connected in series to a power supply circuit using a battery 14, and when no film is loaded, the shutter speed controller 11 shown in FIG. 6 is rendered inactive. That's what I do. Note that the battery 14 is also used as a power source for other electrically operated circuits shown in FIG.

In the above configuration 2, when the release button (not shown) is pressed with the film loaded and the film detection switch 5 turned on, the power switch SW1 closes and the circuit becomes operational (at this time, the transistor Tr1 is off, T
(r2+Tr3 is turned on) Magnet Mg is excited, and after the trailing curtain locking member of the shutter actuating section 12 is attracted and locks the trailing curtain at the charged position, the leading curtain starts. .

When the front curtain is started, the switch SW2 is turned off and charging of the capacitor Cs by the control voltage VT is started, and when the potential reaches a predetermined value, the transistor Tr1 is turned off.
is turned on, thereby causing transistors Trz, T
r3 is turned off, the magnet Mg is demagnetized, the trailing curtain locking member releases its lock by its own biasing force, the trailing curtain closes, and the Nyatta operation is completed.

However, when no film is loaded in the camera, the film detection switch t5 is off, so even if the release button is pressed and the power switch SWl is turned on, the second time control section remains inactive. kept,
Since magnet 1-Mg is not excited, the shutter is
The shutter actuating unit 12 shown in the figure causes the vehicle to run at a predetermined mechanically controlled time such as the maximum time, and to waste the battery.
It never wears out.

Another example is shown.

This display section includes a display control circuit 15 and a large number of light emitting diodes LEDz to LED that are selectively turned on by the display control circuit 15.
Each light emitting diode LED 1-LED
A power supply voltage +Vc is applied to the anode side of the lens via a series circuit consisting of a protective resistor 0, a film detection switch 5, and a normally open power switch sw3 that is closed when the release button is pressed.

The display control circuit 15 inputs the voltage signal VT for exposure time control from the arithmetic unit 9 in FIG. The light emitting diode that displays the seconds is made to emit light by grounding the can F side.

Incidentally, when displaying an intermediate time between the two light-emitting diodes, both light-emitting diodes may be made to flash alternately.

Also, in case of overexposure, the top light emitting diode LED
I is the bottom light emitting diode LED when underexposed.
Warn by blinking n.

Therefore, when film is loaded in the camera and the release button is pressed while the film detection switch 5 is on, the power switch fsWa is closed and the circuit is activated, causing one of the light emitting diodes in the viewfinder to light up or blink. However, when no film is loaded in the camera, the film detection switch 5 is off, so even if the release button is pressed and the power switch SWl is turned on, the light emitting diode will not light up or blink. If you do not do this, you will not waste battery power.

Note that the display section 10 in FIG. 6 shows not only the shirt time, but also
Various information such as the aperture value, various photographing modes, and charging light r of the strobe may be displayed.

Even when the display section 10 is made inactive when no film is loaded, the photometry section 71, condition setting section 8.degree. calculation section 9. If the Nyatta time control circuit 11 is kept in operation, everything other than the display will operate normally.

Further, the display section 10 may be activated and the shutter speed control circuit 11 is deactivated, or both of these may be deactivated to further reduce power consumption. good.

Fig. 6 shows still another embodiment in which the present invention is applied to a camera with a built-in strobe.A main capacitor CM charged by a high-voltage power supply engineer is connected between the two electrodes of a xenon discharge tube Xe. , the capacitor CT was connected in series with the transformer Tr, and connected in parallel with the normally open synchro contact X of the shutter in series.

The film detection switch 5 described above is inserted, and this parallel circuit is connected in parallel to the main condenser CM via a resistor R1.

In this embodiment, when the release button is pressed with the film loaded and the film detection switch 5 turned on, when the synchro contact
The electric charge is discharged through the transformer Tr, and a high voltage of several KV is generated on the secondary side of the xenon discharge tube Xe.
When the internal gas is partially ionized, the internal resistance decreases and a discharge occurs.

However, when no film is loaded in the camera, the film detection switch 5 is off, so even if the synchro contact X closes due to release button suppression, the circuit does not operate, and the xenon discharge tube do not.

In the same way, a film detection switch can be inserted in series with the winding circuit using the motor drive, and when no film is loaded, the motor will be inactive and only manual winding will be possible. By inserting a switch in series (= inserting a switch so that the light source does not turn on when no film is loaded, or by connecting a film detection switch in series with the motor drive circuit of an autofocus camera,
When no film is loaded, the automatic focus function may be disabled so that only manual focus adjustment is possible, which also prevents unnecessary battery consumption.

As described above, according to the present invention, a normally open film detection switch that detects the presence or absence of film and is closed only when film is loaded is provided, and this detection switch is connected to multiple cameras of the camera. By inserting some of the electrically operating circuits (two in series), some of the electrically operating circuits are inactive when no film is loaded, so the camera can be used without film being loaded. It has an excellent effect of minimizing battery consumption during operation and greatly extending battery life.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the film presence/absence detecting mechanism of the camera control device according to the present invention when the film is not loaded; FIG. 2 is a cross-sectional view showing the film loading state; FIG. 4 is a block diagram showing an automatic exposure control circuit of an aperture-priority camera. FIG. 4 is a circuit diagram showing one embodiment of the invention. FIG. 5 is a partial circuit diagram showing another embodiment of the invention. , FIG. 6 is a circuit diagram showing still another embodiment of the present invention. 4...Detection pin 5...Film detection switch 6...Film pressure plate 16...Control voltage input terminal 14. ...Battery 15...Display control circuit F.
・・Film Mg・Magi-it-X・・・
Synchro contact diagram 1

Claims (1)

[Claims] 1. In a camera having a plurality of electrically actuated circuits, a normally open film detection switch that detects the presence or absence of film and is closed only when film is loaded is provided, and the film detection switch is connected to the plurality of electrically actuated circuits. 1. A camera control device, characterized in that the circuit is connected in series with a portion of the circuits, and the portion of the electrically operated circuit is rendered inactive when no film is loaded.