JPS6239406B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera equipped with a so-called multiple exposure device that exposes the same screen of film multiple times, and particularly relates to a camera that allows the number of multiple exposures to be set in advance. .

Conventionally, when attempting to perform multiple exposures on a camera, the rewind lever was set to prevent the film from being rewound, and then the shutter was charged, allowing the same screen to be exposed again. was. In conventional multiple exposure devices of this type, if the user continues to take multiple shots even after multiple shots have been taken, there is a risk that the user will forget this and operate the device incorrectly.To prevent this, Even if multiple photography is set, when one exposure is completed, the rewind lever is automatically released from the setting and returns to normal photography.

For this reason, with conventional devices, even if you want to perform multiple exposures several times in a row, you have to reset the camera to the multiple exposure state every time one exposure is completed, which is extremely troublesome. It was hot.

In order to solve this problem, it may be possible to set the number of multiple exposures in advance, but in this case, there is a problem in that the more the number of multiple exposures increases, the more the overexposure becomes significant.

In particular, for example, when trying to obtain an exploded photo of a golf swing using multiplex photography, the main subject, the person, hardly moves, so the main subject will be overexposed by multiplying the number of exposures. This is extremely inconvenient if the only subject to be overexposed is the main subject.

The present invention was developed in view of the above circumstances, and is a camera equipped with a multiple exposure device that exposes the same screen of film multiple times. a multiplex number setting operating means; a counter for driving the shutter drive circuit to perform multiple exposures for the set number of multiple exposures in response to the multiple exposure number set by the multiplex number setting operating means; A reference value setting circuit that switches the reference value so that the exposure amount for each exposure is equal to one of the set number of multiple exposures of the appropriate exposure amount according to the set number of multiple exposures; a shutter control circuit that controls the shutter drive circuit based on a reference value;
In particular, in multiplex photography when the main subject is stationary, such as an exploded photo of a golf swing, an appropriate exposure amount can be obtained for the main subject, and the photograph as a whole can be sufficiently satisfactory. It is an object of the present invention to provide a camera equipped with a multiple exposure device in which the number of times of multiple exposure can be set in advance.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 shows, as an example, a case in which the present invention is applied to an electromagnetic drive device for opening and closing shutter blades that also serve as an aperture, and FIG. 2 shows a cross section taken along line A--A. In Figures 1 and 2, 3 is a non-conductive shutter blade made of thermoplastic resin or thermosetting resin that has a light-shielding property and also serves as a diaphragm. Two of the blades (one of them is a sub-blade described later) (equipped with an aperture) are shown. 2 is a sector ring made of an insulator such as non-magnetic glass epoxy or plastic, and conductive patterns 2a and 2b are printed on both the front and back sides of the sector ring 2. Under this influence, a rotational force is generated to drive the shutter blade 3. That is, the printed patterns 2a and 2b are set to generate a force that rotates the sector ring 3 in accordance with Fleming's law within the magnetic field of the fixed magnetic pole. Note that the sector ring 2 has a closing spring 6.
The shutter blades 3 are biased in the direction of closing, and normally the shutter blades 3 are held in the closed state. The shutter blade 3 is connected to the base plate 10
The sector ring 2 rotates around a fixed shaft 8 fixed to the sector ring 2, and the rotational force at this time is transmitted by the conductive dowel 5 fixed to the sector ring 2. Here, the dowel 5 is fixed to the sector ring 2 by crimping or soldering, and is one of a plurality of dowels.
The pieces also serve as connections between the printed patterns drawn on both sides of the sector ring. Further, reference numeral 9 denotes a sub-diaphragm which limits the light incident on the light receiving element 50 for exposure control. On the other hand, in order to allow magnetic flux to pass through the conductive printed patterns 2a and 2b of the sector ring 2, the printed patterns 2a and 2b are
A plurality of fixed magnetic poles 1a and 1b are set opposite to b. Permanent magnets magnetized in the direction of the aperture optical axis are used as the fixed magnetic poles 1a and 1b, and the magnetic poles N and S are sequentially arranged in the circumferential direction so that the directions are alternate. For example 1a
For 1b, the north pole should face upward, and for 1b, the south pole should face upward. In addition, in Fig. 2, 4 is the fixed magnetic pole 1a.
and 1b to effectively cross the printed patterns 2a and 2b on the sector ring 2.

Next, the operation of the electromagnetically driven shutter device will be explained. Drive circuit by release (Figure 3)
works to connect the coil first terminal 7a to the coil second terminal 7.
A current is applied in the direction b. Then, since the printed patterns 2a and 2b are within the magnetic field of the fixed magnetic poles 1a and 1b, due to the current component flowing in the radial direction of the printed patterns, according to Fleming's law, the printed patterns 2a and 2b have: As shown in FIG. 1, a force F ₁ is generated in the tangential direction of the aperture opening. This force F ₁ causes the sector ring 2 to rotate against the restoring force of the closing spring 6, and the shutter blade 8 is driven by the sector pin 5, so that the shutter blade 3 is gradually opened. Accordingly, when the amount of light passing through the sub-diaphragm 9 and entering the light receiving element 50 reaches a predetermined amount, the current applied from the drive circuit to the coil first terminal 7a and the coil second terminal 7b from the printed patterns 2a and 2b continues. The sector ring 2 is rotated in the opposite direction by the force of the closing spring 6, and the shutter blade 3 is closed.

Next, FIG. 3 is a circuit connection diagram showing an embodiment of a multiple exposure apparatus according to the present invention. In the figure, 10
0 is a power supply ground, 102 is a release switch which is normally closed and is turned on by pressing the release button, 103 is a power supply holding transistor which is turned on when the switch 102 is turned on, and 101 is a constant voltage circuit. 106 and 107 are time constant resistors and capacitors of the timer circuit, 108 is a resistor,
109 is an inverter, 110 is a flip-flop circuit, and 128 is a subtraction counter. Reference numeral 111 denotes a light receiving element for controlling exposure, which uses a silicon photocell (SPC), for example, and receives object light through the sub-diaphragm shown in the first diagram. A photometric operational amplifier 113 constitutes a logarithmic compression circuit together with the diode 112. Reference numeral 117 denotes an integrating capacitor, which is charged through a transistor 116 with a current corresponding to brightness information and other photographic information from the photometry circuit. 118 is a switching transistor that opens and closes both ends of the integrating capacitor 117, and 119 is a comparator whose output is connected to an AND gate 120 and a buffer 121.
The signal is input to the second comparator 123 via the . 125 is a transistor that controls the shutter drive coil 126. 127 is a timer circuit, and 129a, 129b and 129c are interlocking switches for setting the number of multiple exposures, and these are provided as many times as the number of bits in the subtraction counter 128. Although FIG. 3 shows the number of bits as three, it is possible to provide any number of bits. 1
85 is an operational amplifier, and 140 is an OR gate.

The operation of the circuit shown in FIG. 3 having the above configuration will be explained. First, set the number of times for multiple exposure using the exposure number setting switches 129a, 129b and 129c.
Set to . Next, when the switch 102 is turned on by the release operation, the resistor 106 and capacitor 1
One pulse is generated by the time constant circuit composed of 07, resistor 108, and inverter 109, and this pulse enters the set input of flip-flop circuit 110, setting flip-flop 110, and its output becomes low level ( “L”). This "L" signal is the OR gate 14
0 to turn off transistor 118. Note that at this point, the inverting input terminal (-) of the comparator 119 is still at a low level ("L"), so the output of the comparator 119 is "H". At this time, the Q output of the timer circuit 127 is also set to "H", so the output of the AND gate 120 becomes "H", and this "H" level signal is passed through the buffer 121 to the non-inverting input terminal of the comparator 123 ( +). At this time, since the inverting input terminal of the comparator 123 is "L", the output of the comparator 123 becomes "H", the transistor 125 is turned on, and a drive current flows through the shutter drive coil 126. On the other hand, the pulse from the inverter 109 is input to the subtraction counter 128, and each bit of 128 is preset in the multiple exposure circuit set in the exposure number setting switches 129a, 129b and 129c. Furthermore, switches 129a, 129b and 129c
These outputs are inputted to an operational amplifier 135 via resistors 131, 132, and 133 connected to each other, respectively. This results in 135
The output of is inputted to the non-inverting input terminal of the comparator 119, a reference voltage corresponding to the setting of the number of exposures, that is, a reference voltage that reduces the amount of each exposure to 1/the number of multiple exposures set for the appropriate exposure amount. It turns out. When current flows to the drive coil 126 as described above, the shutter blades are gradually opened by electromagnetic force, and at the same time, the sub-diaphragm aperture is opened and the amount of light incident on the light receiving element 111 increases. The integrating capacitor 117 is charged via the photometric circuit of the output of the light receiving element 111. capacitor 117
The transistor 118 connected across the
Since the Q output of the timer circuit 127 is "L", it is in an off state, and the capacitor 117 is charged by the transistor 116. The terminal voltage of the capacitor 117 is the comparator 11
When the reference voltage applied to the non-inverting input terminal of the comparator 119 is reached, the output of the comparator 119 becomes “H”.
As a result, the non-inverting input terminal of the comparator 128 becomes "L" through the AND gate 120 and the buffer 121 as described above.
When the output of 123 is “L”, the transistor 12
5 is turned off. This cuts off the current to the coil 126, and the shutter blade is closed by the return spring. When the output of the comparator 119 changes to "L" as described above, the "L" signal is input to the timer circuit 127 via the AND gate 120, thereby causing the Q output of the timer circuit 127 to become "H". This “H” signal is the OR gate 140
The transistor 118 is turned on via the integrating capacitor 117, and both ends of the integrating capacitor 117 are short-circuited to discharge the charge in the capacitor. Also, the timer circuit 127
The Q output “H” is input to the subtraction counter 128, and the previously set value of the counter becomes 1.
will be subtracted. The above closing signal (comparator 1
When the timer circuit 127 is reversed and the Q output becomes "L" after a certain period of time has elapsed from the time when the shutter actually completes the shutter closing operation, the Q output becomes "L". transistor 1
18 is turned off, the above-mentioned operation is repeated to open and close the shutter blade, and the second exposure is completed. The opening and closing operations of the shutter are performed sequentially until each bit of the subtraction counter 128 becomes "0", that is, "L". When the exposure is performed a preset number of times and the shutter opening/closing operation is completed, a reset signal is output from the subtraction counter 128, which is input to the R terminal of the flip-flop circuit 110, and the output of the flip-flop circuit becomes "H". . This signal turns on the transistor 118, discharging the charge in the capacitor 117, and thereafter, unless the release switch 102 is closed again, the shutter drive coil 126 is not energized and the shutter is closed.

As explained above, according to the present invention, in a camera equipped with a multiple exposure device that exposes the same screen of film multiple times, the shutter drive circuit that drives the shutter and the multiple number setting for presetting the number of multiple exposures are provided. an operating means, a counter for driving the shutter drive circuit to perform multiple exposures for the set number of multiple exposures in response to the number of multiple exposures set by the multiple number setting operating means; A reference value setting circuit that switches the reference value so that the exposure amount of each time becomes one of the set number of multiple exposures of the appropriate exposure amount according to the number of multiple exposures, and a reference value set by the reference value setting circuit. Since the shutter control circuit is provided with a shutter control circuit that controls the shutter drive circuit based on the above-mentioned shutter control circuit, it is possible to perform proper adjustment for the main subject in multiple shooting, especially when the main subject does not move, such as in an exploded photograph of a golf swing. It is possible to provide a camera equipped with a multiple exposure device in which the number of multiple exposures can be set in advance so that a sufficient amount of exposure can be obtained, and even when viewed as a whole, a sufficiently satisfactory photograph can be obtained.
Its effectiveness is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of an electromagnetic shutter device according to the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a circuit diagram of a multiple exposure device according to the present invention. FIG. 1a, 1b...Magnet, 2...Sector ring,
2a, 2b...Conductor coil pattern on the sector ring, 3...Shutter blade that also serves as an aperture, 4...
Yoke, 5... Sector pin, 6... Return panel,
7a, 7b... Coil lead wire, 8... Shutter blade rotation axis, 9... Sub-diaphragm aperture, 10... Main plate, 50... Light receiving element.

Claims (1)

[Claims] 1. In a camera equipped with a multiple exposure device that exposes the same screen of film multiple times, a shutter drive circuit that drives the shutter, a multiple number setting operating means for presetting the number of multiple exposures, and the multiple number setting operating means a counter for driving the shutter driving circuit for the set number of multiple exposures in response to the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures set by the number of multiple exposures; a reference value setting circuit that switches the reference value so that the appropriate exposure amount is equal to one of the set number of multiple exposures; and a shutter that controls the shutter drive circuit based on the reference value set by the reference value setting circuit. A camera equipped with a multiple exposure device, characterized by comprising a control circuit.