JPH0446266Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic film rewinding mechanism, and is particularly suitable for a motor drive camera in which a single motor operates various functions of the camera, and furthermore, it is suitable for rewinding the film using the same motor. This invention relates to an automatic film rewinding mechanism that can be used for.

Various motor drive cameras have been proposed in which a single motor built into the camera body is rotated in the forward direction to wind the film and charge the shutter, and rotated in the opposite direction to raise the mirror and perform the aperture operation. Also, an automatic focusing camera has been proposed in which the same motor drives the lens to focus.
In such a camera, if the same motor is used to rewind the film, a clutch must be used to switch and connect the gear train that is driven to raise the mirror during normal photographing.

In this case, the clutch is reliably switched while instructing the film to rewind, and at the same time the film has finished rewinding, the motor drive is stopped and all mechanisms are restored so that the next camera operation can be performed. It has to be something.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic film rewinding mechanism that can be suitably used when automatically rewinding film in a motor drive camera.

In order to achieve the above object, the automatic film rewinding mechanism according to the present invention is a motor-driven camera in which a single motor built into the camera body drives various camera operation parts such as a film winding mechanism, and furthermore, The film rewinding mechanism includes a first rewinding button for separating the sprocket from the film winding mechanism, and a first rewinding button for rewinding the film in conjunction with operation of the first rewinding button. a first switch that outputs a rewind signal, a second rewind button, and a second switch that outputs a second rewind signal in conjunction with the operation of the second rewind button;
a third switch that detects whether or not the film rewinding is completed and outputs a signal to that effect; a clutch that connects and connects the motor drive system and the film rewinding mechanism; a clutch mechanism comprising a first suction and holding means for switching and a second suction and holding means for switching the clutch to the cutting side; a rewind signal from the first and second switches; and a film rewind signal from the third switch. In response to a signal indicating that film rewinding is not completed, the first suction/holding means connects the clutch and drives the motor, and in response to a signal from the third switch indicating that film rewinding is complete, the first suction/holding means connects the clutch and drives the motor. and a control circuit for disengaging the clutch and stopping the drive of the motor by the suction and holding means of No. 2.

According to the above structure, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 1 is a perspective view showing an embodiment of an automatic film rewinding mechanism according to the present invention.

The motor 1 has upper and lower output shafts, and a pinion 2 is provided on the upper output shaft. The pinion 2 is connected to a gear 5 via friction gears 3 and 4. The gear 5 cooperates with the cam 6, spring 7, and ball 7a to form a one-way clutch. In other words, when gear 5 rotates clockwise in Figure 1,
The rotational force is transmitted to the succeeding gear train 8, but the rotational force in the counterclockwise direction is not transmitted. Gear train 8 is gear 9, gear 1
It is connected to gear 11 via 0. gear 11
is also connected to a drive system that drives a shutter charge spring (not shown). A sprocket 15 is provided on the shaft 13 on which the gear 11 is provided, and works together with the spool 42 to wind up the film to the left. A first rewind button 12 is provided on the shaft 13. 1st rewind button 1
2 is a button for disengaging the clutch of the sprocket 15. The operation of the first rewind button 12 is monitored by a switch 14, and when the first rewind button 12 is pressed, the switch 14 is closed and a first rewind signal is output.

A pinion 16 is provided on the output shaft on the lower side of the motor 1, and only the rotational force of the pinion 16 in the counterclockwise direction is transmitted to the gear train 17, contrary to the rotation on the upper side. The gear train 17 is connected to a gear 19 via a gear 18. A gear 20 is provided coaxially with the gear 19. The gear 20 is connected to a drive system (not shown) that performs mirror lifting, narrowing down, and the like. Gear 19 meshes with clutch gear 21.

The clutch gear 21 is provided on a clutch shaft 22, and a gear 23 disposed on the upper part of the clutch shaft 22 is normally not connected to any gear (as shown in FIG. 1). A notch 41 is provided in the clutch shaft 22, and the lever 32 is engaged with the notch 41. One side of the lever 32 forms an iron piece 29, which is attracted by a combination magnet 28. In the combination magnet 28, a coil 28a is wound around a permanent magnet 28b, and normally an iron piece 29 is attracted by the permanent magnet 28b, and when the coil 28a is energized, it is demagnetized and loses its attractive force. combination magnet 28
A magnet 30 is disposed on the opposite side of the iron piece 29.

The lever 32 is engaged with a pin 33 implanted in a slide plate 31 constituting the second rewind button, and is urged by a spring 40 hooked between the lever 32 and the pin 39 to come into contact with the pin 33. . The slide plate 31 is provided with guide grooves 34 and 37.
It can be moved up and down by being guided by pins implanted in the fixed part. The slide plate 31 is provided with a protrusion 35, and when the slide plate 31 is lowered to the lowest position, a switch 36 is turned on and outputs a second rewind signal. A spring 38 is provided at the lower end of the slide plate 31, and urges the slide plate 31 upward.

The gear 27 can mesh with the gear 23 when the clutch shaft 22 moves downward, and the gear 27
A gear 24 provided coaxially with the gear further meshes with a gear 25. The gear 25 is provided on a rewind shaft 26 for rewinding the film.

The reason why the first and second switches, which close the first rewind button with the second rewind button, are provided separately is to prevent the film from being cut if either switch is operated by mistake during shooting. This is to prevent the film from being rewound.

FIG. 2 is a circuit diagram of a circuit for controlling the automatic film rewinding mechanism according to the present invention.

The first switch 14 turns on when the first rewind button 12 is pressed, the second switch 36 turns on when the second rewind button is pressed, and the second switch 36 detects the presence or absence of film and turns on when the film is present. The outputs of the third switches 64 are connected to the NAND circuits 43, respectively. The output of the NAND circuit 43 is connected to NOT circuits 44, 45, and 50. The output of the knot circuit 44 is connected to the base of a transistor 47. When the transistor 47 is conductive, the coil 30a of the electromagnet 30 is energized. The knot circuit 45 includes a capacitor 48 and a resistor 49.
It is connected to the base of the transistor 46 via a differentiator circuit consisting of the following. When transistor 47 becomes conductive, coil 28a of combination magnet 28 is energized.

The output of the NOR circuit 50 is connected to one input terminal of a NOR circuit 52. A release signal is connected to the terminal 51, and a high level signal is input when a release button (not shown) is pressed, and becomes a low level signal when the mirror is raised.
The output of the terminal 51 is connected to the other input terminal of the NOR circuit 52, and the output of the NOR circuit 52 is branched and one side is connected to the transistor 5 via the amplifier circuit 55.
7 and the other is connected to the base of transistor 60 via a knot circuit 62. The output of the NOR circuit 52 is further branched and connected to one input terminal of a NAND circuit 54. A terminal 53 is connected to the other input terminal of the NAND circuit 54. A film winding signal is connected to the terminal 53, which becomes high level when winding is performed and becomes low level when winding is completed. The output of the NAND circuit 54 is branched, one being connected to the base of a transistor 59 via a not circuit 56, and the other being connected to the base of a transistor 58 via an amplifier circuit 61. The transistors 57 to 60 are connected in a bridge configuration, and form a motor drive circuit that connects the current from the battery 63 to the outputs of the NOR circuit 52 and the NAND circuit 54 to control the motor 1 to rotate in forward and reverse directions. .

Note that by inserting a differential circuit into the base of the transistor 46, it is possible to use a combination magnet as the electromagnet 30.

Next, the operation of an embodiment of the automatic film rewinding mechanism according to the present invention will be described.

First, when the first rewind button 12 is pressed to rewind the film, the clutch of the sprocket 15 is disengaged and the film is ready to be rewound. At the same time, the first switch 14 is turned on,
A high level signal is sent to the NAND circuit 43 shown in FIG.

Next, slide plate 3, which is the second rewind button.
1 in the direction of the arrow in Figure 1, the slide plate 31
is guided by guide grooves 34 and 37 and descends. As the slide plate 31 descends, the spring 40 attached to the pin 39 is pulled, so the clutch lever 32
try to lower it. However, since the iron piece 29, which is one end of the clutch lever 32, is attracted and held by the permanent magnet 28b of the combination magnet 28, the clutch lever 32 cannot be moved.

Now, the slide plate 31 has descended to the lowest end,
When the second switch 36 is turned on by the protrusion 35 of the slide plate 31, a high lever signal is input to the input of the NAND circuit 43 as shown in FIG. At this time, if the third switch 64 for checking the presence or absence of film is turned on, high-level signals will be input to all inputs of the NAND circuit 43, and the output of the NAND circuit 43 will be low. become the level. Therefore, the output side of the NOT circuit 45 becomes high level, so the capacitor 48 and the resistor 4
The transistor 46 connected through the differential circuit consisting of 9 and 9 is momentarily turned on, and a cancel current temporarily flows through the coil 28a of the combination magnet 28, holding the iron piece 29 in FIG. I lose my power. At this time, since the spring 40 is stretched, the restoring force of the spring 40 causes the lever 32 to fall counterclockwise in FIG. On the other hand, the output side of the NAND circuit 43 shown in FIG.
Since the output of 4 is at a high level, the transistor 47 is turned on and the coil 30 of the electromagnet 30 is turned on.
A is energized to hold the iron piece 29. Therefore, the clutch shaft 22 is maintained in a downwardly switched state against the restoring force of the spring 38 of the switch plate 32. By moving the clutch shaft 22, the gears 21 and 23
moves downward, the gear 23 meshes with the gear 27, and a drive system from the gears 27, 24, 25 to the rewind shaft 26 is completed. Therefore, by rotating the motor 1 in the counterclockwise direction, the rewinding shaft 26 is rotated, so that the film can be rewound.

Furthermore, since the output of the NOT circuit 50 is also at a high level, the high level signal of the NOR circuit 52 is input. At this time, since the output of the NOR circuit 52 is at a low level regardless of the output of the terminal 51, the transistors 57 and 60 are made conductive via the amplifier circuit 55 and the NOR circuit 62, and the motor 1 is connected to the solid line in FIG. Rotate in the direction of the arrow. For this reason, the first
The rewinding shaft 26 is rotated by the driving force from the lower side of the motor 1 shown in the figure, and the film can be rewound.

When the rewinding of the film is completed, the third switch 64 detects that there is no film and turns off, so the output of the NAND circuit 43 becomes high level, the output of the NOT circuit 44 becomes low level, and the transistor 47 is turned off. Since conduction is established and the magnet 30 is turned off, the switch plate 31 is urged by the spring 38 and moves upward, and the clutch shaft 22 also moves upward via the lever 32, so that the gears 23 and 27
The mesh is released. Furthermore, since the output of the NOR circuit 50 is at a low level and the signal from the terminal 51 is also at a low level, the output of the NOR circuit 52 is at a high level, transistors 57 and 60 become non-conductive, and the motor 1 stops.

As explained in detail above, according to the present invention,
With a simple configuration, the clutch can be reliably switched simply by pressing a film rewind button, the film can be automatically rewound, and the film end can be detected to stop the rewind drive and return the clutch. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the automatic film rewinding mechanism according to the present invention, and FIG. 2 is a circuit diagram of a circuit for controlling the automatic film rewinding mechanism according to the present invention. 1... Motor, 2... Pinyon, 3, 4... Friction gear, 5... Gear, 6... Cam, 7...
...Spring, 7a...Ball, 8...Gear train, 9...
Gear, 10, 11... Gear, 12... First rewinding ball, 13... Shaft, 14... First switch,
15... Sprocket, 16... Pinyon, 17
...Gear train, 18, 19, 20...Gear, 21...
...Clutch gear, 22...Clutch shaft, 23,2
4, 25, 27...Gear, 26...Rewinding shaft, 2
8... Combination magnet, 29... Iron piece, 30... Magnet, 31... Slide plate,
32...Lever, 33, 39...Pin, 34,3
7...Guide groove, 35...Protrusion, 36...Second
Switch, 38, 40... Spring, 41... Notch, 42... Spool, 43... NAND circuit, 4
4, 45, 50...not circuit, 46, 47...
Transistor, 48... Capacitor, 49... Resistor, 51, 53... Terminal, 52... NOR circuit, 5
4...Nand circuit, 55, 61...Amplification circuit, 5
6, 62...Knot circuit, 57, 58, 59, 6
0...Transistor, 63...Battery, 64...
...Third switch.

Claims (1)

[Scope of utility model registration request] This is a motor-driven camera in which a single motor built into the camera body drives various camera operation parts such as a film winding mechanism, and an automatic film rewinding mechanism in which the film rewinding mechanism is operated by the motor. a first rewind button that is disconnected from the film winding mechanism; and a first rewind button that outputs a first rewind signal for rewinding the film in conjunction with the operation of the first winding button.
switch, a second rewind button, and the second rewind button.
a second switch that outputs a second rewind signal in conjunction with the operation of the rewind button; and a third switch that detects whether rewinding of the film is completed and outputs a signal to that effect. A clutch consisting of a switch, a clutch that connects and disconnects the motor drive system and the film rewinding mechanism, a first suction and holding means that switches the clutch to the connection side, and a second suction and holding means that switches the clutch to the cutting side. a mechanism, and the first
and in response to a rewinding signal from the second switch and a signal from the third switch indicating that film rewinding is not completed, the first suction and holding means connects the clutch and drives the motor; A control circuit for causing the second suction holding means to disconnect the clutch and stop driving the motor in response to a signal from the third switch indicating that film rewinding is completed. Automatic rewind mechanism.