JPS6091335A - Film feeding device of camera - Google Patents

Abstract

PURPOSE:To attain size reduction and to reduce a load during winding operation by short-circuiting and stopping a winding and a rewinding motor on one-frame winding. CONSTITUTION:A motor M1 rotates a take-up spool 1 to take up a film 3 and the rewinding motor M2 idles in winding and photographing operation. The projection part 8b of a brake lever 8a engages a groove 7a by almost one turn of an index plate 7, and motors M1 and M2 are short-circuited and stop speedily. Thus, the camera enters the charger completion stae of a film winding and shutter device, automatic focus device, etc. A rewinding lever 19 is moved in the rewinding operation as shown by an arrow to engage a projection part 19a with the side 8c of the lever 8, and switch contacts 10 and 11 move; while the motor M2 rotates, the motor M1 reverses to rewind the film.

Description

DETAILED DESCRIPTION OF THE INVENTION In particular, this invention relates to a camera in which winding and rewinding are performed using dedicated motors.

Conventionally, electric film winding and rewinding cameras use a motor (i-1) for driving and winding and rewinding.Therefore, to drive the rewinding fork, gears and bells from the winding system are used. If it is installed in one camera, it requires a large amount of space, and the gears and levers move when switching between winding and rewinding, so space is also required. And the transmission mechanism requires considerable cost.

In the case of such a motor drive, the following means have been used to stop the film frame upon completion of winding.

a. A means of detecting the rotation of the index plate and shorting both terminals of the motor to stop it.

In this case, it depends on the stopping ability of the motor and the friction of the transmission system, and most of it depends on the stopping ability of the motor.

Therefore, variations in screen spacing often occur due to voltage changes, resulting in screen overlap and the like.

b. A means of short-circuiting both terminals of the motor or cutting off current, and mechanically engaging a locking pawl in a groove of an index plate to act as a brake.

In this case, the brakes are applied mechanically, so
Although it always stops at the same position, the locking pawl and the surface of the groove on the index plate engage with considerable pressure, so a large force is required to remove the pawl from the groove. Normally, the return lever of an operating lever such as a shovel is used, but in order to increase the return lever,
The springs tend to need to be strengthened, and as a result, increased spring pressure increases the charging load and drains the battery faster.

The present invention eliminates the drawbacks of the conventional example described above, eliminates the transmission system and switching mechanism such as gear trains and belts, and simplifies the winding and rewinding mechanisms, making the camera compact and making effective use of its space. It is an object of the present invention to provide a film feeding device that can reduce the load during winding.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a perspective view of essential parts of an embodiment of a winding and rewinding mechanism in a camera film feeding device according to the present invention.

In the figure, 1 is a take-up spool, 2 is a fork that engages with the cartridge, and a winding motor M and a rewinding motor M2 are connected to these motors, and these motors should preferably be motors with high torque and low rotation speed. In particular, the winding system spool 1 is connected to the motor M1 via a traction mechanism (not shown).

Reference numeral 4 denotes a sprocket that meshes with the perforation giant of the film 3, and is rotatably supported by a structural member of the camera (not shown), and its rotating shaft is connected to a charge cam 6 via a one-way launch 5. Rotational force is transmitted to the charge cam 6 only when the sprocket 4 rotates in the winding direction, that is, in the counterclockwise direction of the arrow shown in the figure. Reference numeral 1 denotes an indexing plate, which is integrally formed with the charge cam 6 and has a groove 7a on its circumferential surface. Reference numeral 8 denotes a brake lever made of a non-conductive material, one end of which is rotatably supported by the structural member on a shaft 8a, and is always biased counterclockwise by a spring 9. It has a protrusion 8bt on its side 8c that can engage with the groove 1a of the splitting plate 7, and has independently winding switch contact pieces 10 on its lower surface.
And a rewinding switch contact piece 11 is fixed. 1
2 is a printed circuit board with which the switch contacts 10 and 11 are in contact. Reference numeral 13 denotes a charge lever, one end of which is rotatably supported by the structural member on a shaft 13a, biased clockwise by a lever spring 14, and a roller 15 on the bottom surface of the charge lever.
is rotatably supported, and the roller 15 is configured to abut against a peripheral cam portion of the charge cam 6. 16
is a charging plate for a shunter device, an autofocus device, etc. (not shown), and its elongated hole 16a is slidably fitted in the left and right direction on a support shaft 17 fixed to a structural member of the camera (not shown), The protruding portion 16 b k which is biased leftward and comes into contact with the charge lever 13 on its upper edge, and the brake lever 8
Each has a left end portion 16c that abuts the side edge 8C of the left end portion 16c. 19 is a rewind lever, which is configured to slide in the left direction of the arrow by a knob (not shown);
A vertically bent portion 19a provided at the right end thereof can come into contact with the tip of the side 8C of the brake lever 8.

FIG. 2 shows an embodiment of the electric circuit for fully operating the winding and unwinding mechanisms, and FIG. 3 shows the printed circuit board 1.
2 shows an enlarged pattern diagram of No. 2.

In FIG. 2, 20 is a power supply, 21 is a transistor Tr which is activated in conjunction with the shirt release operation and is operated for a predetermined period of time.
, is connected in series to the power supply 20 by a known drive control circuit (for example, the one shown in Japanese Patent Application Laid-open No. 185027/1983). Sl +
Sl a + s, b l s, (2 is the contact part for the winding motor M, S2 * S2a + Szb
+ S2c is a contact part for the rewind motor M2, and each contact part has a pattern shown in FIG. 3 formed on the printed circuit board 12, and a switch contact piece 10°11.
are in sliding contact with each other. And contact parts S1 and Se
a are connected to the positive side and negative side of the winding motor M, respectively, contact parts Sob and Sle are connected to the positive side and negative side of the power supply 20, and contact parts S2 and S2a are connected thereto. The contact portion S2b is an idle contact, and the contact portion S
2c is connected to the positive side of the power supply 20. Dl and D
Reference numeral 2 indicates a backflow prevention diode, which is connected in parallel to the winding motor M and the rewinding motor M2, respectively. Trl is an NPN) transistor, and the winding motor M,
and the negative side of the power supply 20, and its base is connected to the drive control circuit 21. Tr2 is a PNP transistor connected to the positive side of the power supply 20 and the transistor Tr, and its base is connected to the collector of the NPN transistor Tr3 via a limiting resistor &.

The emitter of the transistor Tr3 is connected to the negative side of the power supply 20, and its base is connected to the positive side of the rewinding motor M2 via a limiting resistor R2.

Furthermore, in the turn of the printed circuit board 12 shown in FIG. 3, A indicates a pattern portion i when winding is completed, B indicates a pattern portion when winding up, and C indicates a pattern portion when unwinding.

Next, the operation of this embodiment having the above configuration will be explained.

First, the operations during winding and photographing will be explained.

FIGS. 1 and 2 show states in the middle of charging the shutter and the like.

That is, the winding motor M is energized, the winding gear 1 rotates counterclockwise, and the film 3 is completely wound. At this time, the rewinding motor M2 is in a sudden rotation. and,
The tin rocket 4 is rotated by the film 3 in the counterclockwise direction of the υ arrow, and the charge cam 6 and splitting plate 7 are also rotated counterclockwise via the one-way flange 5.

Further, since the protruding portion 8b of the brake lever 8 is in contact with the circumferential surface of the indexing plate 1, the switch contact pieces 10 and 11 are maintained at the position of the pattern portion B in FIG. 3 and are connected to the contact portion S1. The contact Sob is turned off, and therefore the winding motor M1 continues to rotate.

On the other hand, the charge lever 13 is pushed out by the rotation of the charge cam 6 and the roller 15 is pushed outward.
3 is rotated counterclockwise against the biasing force of the spring 14, and as a result, the charge plate 16 is moved to the right via its protruding portion 16bt against the biasing force of the spring 18, thereby closing the shutter device. and an autofocus device, etc., and is locked at the charging position by a locking lever (not shown).

Thereafter, the index plate 7 rotates approximately once, and the brake lever 8 is rotated counterclockwise by the biasing force of the spring 9 to engage the protrusion 8b in the groove 7a.

At the same time, the switch contacts 10 and 11 move to the position of pattern portion A in FIG. In this position, contact part S1
The contact S+a, the contact S2, and the contact Sza are turned on, and the winding motor M1 and the rewinding motor M2 are short-circuited, and both motors immediately stop. At this time, the roller 15 of the charge lever 13 and the charge cam 6
The roller 15 rotates to the lowest position on the cam surface of the charge cam 6 and then stops.

In this way, the camera enters a state in which the film advance, shutter device, autofocus device, etc. have been fully charged.

Then, by pressing a release button (not shown), the tension (not shown) is released in the order of activation of the autofocus device and then activation of the 7-pointer, and the charging plate 16 and the biasing force of the spring 18 cause the camera to travel in the left direction of the arrow. And charge plate 1
6, the left end 16c of the charging plate 16 pushes the side 8c of the brake lever 8, causing the brake lever 8 to rotate clockwise, so that the protruding portion 8b of the charging plate 16 pushes the side 8c of the brake lever 8, and the protruding portion 8b of the charging plate 16 presses the side 8c of the brake lever 8, causing the protruding portion 8b to move into the groove portion 7a of the indexing plate 1. As it comes out of the switch contact piece 10
and 11 reach the position of the pattern part B in FIG. Therefore, the winding motor M starts rotating again, and the state shown in FIG. 1 is reached.

Next, the rewinding operation will be explained.

If you want to rewind the film after all frames have been photographed, press the rewind lever 19 using an external operation knob (not shown).
When it is moved to the left of the arrow, its vertically bent portion 19a engages with the tip of the side 8C of the brake lever 80, thereby rotating the brake lever 8 clockwise. Then, the switch contact pieces 10 and 11 are connected to the pattern part B in FIG.
Or move from the position A to the position C, contact part S2 and contact part S2 (! + contact part Sl and contact part S1c are respectively turned on, and at the same time as the rewinding motor M rotates, the transistor Tr3 is turned on. By turning on the transistor Tr2, the winding motor M1 is energized in the reverse direction and rotated in the reverse direction.Therefore, the film is rewound.

At this time, the reverse rotation of the winding motor M1 is caused by the winding spool 1
is reversed, the tightness Mk between spool 1 and film 3 is eliminated, and film 3 causes motor M1. The rotation of the spool 1 is prevented from becoming a load on the rewinding motor M2. Further, although the sprocket 4 also rotates in reverse due to the film 3, since there is a one-way flange 5, rotation is not transmitted to the charge cam 6.

When the rewinding of the film is completed and the rewinding lever 19 is moved to the right and returned to the position shown in FIG. 1, the rewinding operation will be stopped.

As explained above, the present invention doubles the stopping capacity of the motor at the completion of winding one frame in an electric power lathe having dedicated motors for film winding and two-winding, thereby eliminating variations in screen spacing. Further, there is an effect that the charging load can be made as small as possible.

[Brief explanation of drawings]

The figures show an embodiment of the film feeding device for a camera according to the present invention, in which Fig. 1 is a perspective view of the main parts of the winding 9 rewinding mechanism, and Fig. 2 is an electric circuit for operating the winding 9 rewinding mechanism. FIG. 3 is an enlarged pattern diagram of a printed circuit board. Ml/winding motor, M2/rewinding motor, 1...
Winding system spool, 2... fork, 4 sprocket,
5-One-way latte, 6-Charge cam, 7-Split plate, 8-Brake lever, 10.1 Toss-to-separate contact piece, 1
2 Printed circuit board, 13... Charge lever, 16
...Charge plate, 19...Rewind lever. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. In a camera in which film winding and film rewinding are driven by dedicated motors, when winding of the - frame is completed, the film winding
A film feeding device for a camera, characterized in that both rewinding motors are stopped by short-circuiting.