JPH0419626A - Preview mechanism provided with automatic film rewinding function - Google Patents

Abstract

PURPOSE:To efficiently use a motor built in a camera by stopping down a stop-down structure by utilizing the one-way rotation of the motor and using the reverse rotation of the motor for a rewinding driving source. CONSTITUTION:When a preview operation button 31 is turned on, a stop driving mechanism part is driven by the one-way rotation of the motor 1 and a stop ring 24 is rotated to stop down a stop. When a rewinding signal is inputted, the motor 1 is reversely rotated and the output spindle of the motor 1 is disengaged from a driving mechanism part and connected to a rewiring driving mechanism part to transmit the reverse rotation to a spool 49. Since preview operation for previously stopping down the stop to a set stop value and film rewinding operation can be executed only by one motor 1, the motor 1 can be efficiently used within a limited camera space.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses a unidirectional rotation of a motor as a drive source for an aperture mechanism that narrows down the aperture to a preset aperture value in order to confirm the state of the subject at the set aperture value. The present invention relates to a preview mechanism that uses rotational force in the opposite direction to rewind the film.

(Prior Art and Problems to be Solved by the Invention) A single-lens reflex camera that performs aperture metering is provided with a mechanism that narrows down the aperture value to a preset aperture value.

This is necessary to check the depth of focus etc. when photographing with the set aperture value.

In this mechanism, when the desired aperture is set, an aperture pin that moves in conjunction with the aperture is set, and this aperture pin is pushed up by an aperture ring that is biased in the opening direction, and the aperture ring resists the bias force. By rotating the aperture, the set aperture state is created.

Conventionally, the selection was narrowed down by pressing a knob or the like provided on an interchangeable lens or the like.

An object of the present invention is to use the rotation of the motor in one direction to narrow down the aperture mechanism, and to use the rotation of the motor in the opposite direction as a drive source when rewinding the film, thereby improving the efficiency of the motor built into the camera. It is an object of the present invention to provide a preview mechanism that also has an automatic film rewinding function and allows for general use.

(Means for Solving the Problems) In order to achieve the above object, the preview mechanism according to the present invention, which also has an automatic film rewind function, has a preview operation button, a motor, and a rewind button. a switch that outputs a rewind signal when a rewind signal is reached, and a control that rotates the motor in one direction when the preview operation button is operated, and rotates the motor in the opposite direction when a rewind signal is input from the switch. a control circuit that outputs a signal; and when the motor rotates in one direction, the motor output is connected to the aperture drive mechanism, and when the motor rotates in the opposite direction, it is disconnected from the aperture drive mechanism and connected to the film rewind mechanism. It has a clutch mechanism section that
When the preview operation button is operated, the aperture ring is rotated to narrow down the aperture via the aperture drive mechanism, and when the rewind signal is input, the spool is rewound via the film rewind mechanism. It is composed of:

According to such a mechanism, the motor can be used efficiently within the limited space of the camera, and the photographing conditions of the camera can be checked smoothly by the drive source of the camera itself, rather than by the force applied by the photographer.

(Example) Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a mechanical part of a preview mechanism that also has an automatic film rewind function according to the present invention.
) is a plan view of the mechanism near the bottom of the camera, and FIG. 1 (bl is a side view seen from the direction of the arrow in FIG. 1 (al).

This figure shows the state during preview operation, and mainly depicts the mechanical parts that function during preview.

The clockwise rotation of motor 1 is decelerated by gears 2, 3, and 4, and is transmitted to gear 5. The gear 5 is attached to a shaft 5a provided at the other end of a lever 16 rotatably attached to the shaft of the gear 4.

The shaft 5a is guided by a guide groove 6 and is movable within the groove. The lever 16 is for keeping the distance between the shafts of the gears 4 and 5 constant when the shaft 5a moves within the guide groove 6.

The clockwise rotation of the motor 1 is transmitted to the gear 5 as clockwise rotation. Therefore, the shaft 5a is positioned above the guide groove 6, the gear 5 and the gear 10 are in mesh with each other, and the rotation of the gear 5 is transmitted to the gear IO.

The clutch mechanism has these gears 4.5 and 10° gear 1.
2 (a gear connected during the rewinding operation), a lever 16, and a guide groove 6.

The gear 10 is rotatably attached to the shaft 18 and can rotate together with the cam 9. When the gear 5 rotates clockwise, the cam 9 rotates counterclockwise.

The outer circumference of the cam 9 is such that about 1/3 of the circumference is the minimum distance from the center, 1/3 is the sloped part, and the remaining 1/3 is the maximum distance from the center. It has a shape that drops sharply at the minimum distance.

A cam driven lever pin 7a, which is implanted in a cam driven lever 7 whose one end is rotatably attached to the shaft 8, is in contact with the outer periphery of the cam 9.

The cam driven lever 7 is urged counterclockwise by a spring (not shown).

When the aperture is open, the cam driven lever pin 7a is in the position f in Fig. 1.
As shown in al, it is located at the outer circumferential surface of the cam, which is the minimum distance from the center, and narrowing is performed by climbing the inclined part of the cam, and the narrowing is completed when it reaches the outer circumferential surface of the cam, which is the maximum distance from the center. Then, by falling from the maximum distance part of the outer periphery to the minimum distance part, it returns to the original open side position.

The tip 7b of the cam driven lever 7 locks the L lever 20.

Figure 2 is a diagram showing an embodiment of the transmission mechanism from the cam driven lever to the aperture pin.
Fig. 2 shows the aperture ring viewed from the right side of the figure, and bl shows the aperture ring viewed from the front.

The cam driven lever 7 locks the tip of the L lever 20 which is rotatably fixed to the shaft as described above.

The other end of the L lever 20 is rotatably connected to a link lever 21, and the link lever 21 is connected to the aperture ring drive lever 2.
It is rotatably connected to approximately the center of 2. One end of the aperture ring drive lever 22 is rotatably fixed to a shaft, and the other end engages an aperture ring pin 23 of an aperture ring 24 .

The aperture ring drive lever 22, the link lever 21, and the L lever 20 drawn with solid lines are in the position when the aperture ring is on the open side.

Further, the levers 20, 21 and 22, which are drawn with two-dot chain lines, are in the position when the aperture ring is on the aperture side.

The aperture ring 24 is biased counterclockwise, and its movement in the counterclockwise direction is restricted by the aperture ring pin 23 of the aperture ring 24 coming into contact with the tip of the aperture ring drive lever 22 as described above.

On the other hand, a protrusion 24a provided on the inner circumference of the aperture ring 24
restricts the movement of the aperture pin 26 in the clockwise direction.

The aperture value of the aperture (not shown) is determined by the position of the aperture pin 26, and the aperture pin 26 is connected to the aperture ring 2.
4, it moves to the aperture setting position.

When the cam driven lever 7 moves to the position indicated by the two-dot chain line, the aperture ring drive lever 22 rotates counterclockwise, causing the aperture ring 24 to rotate in the direction of the hour hand.

At this time, the projection 24a of the aperture ring 24 moves to the minimum aperture position of the camera.

Along with this, the aperture pin 26 also follows the clockwise movement of the projection 24a, but when it reaches the aperture setting position, it stops there, and the aperture becomes the set aperture value.

After the narrowing operation is completed in this way, when the motor 1 further rotates in the same direction, that is, clockwise, the cam driven lever pin 7a falls from the maximum distance position to the minimum distance position on the outer periphery of the cam, so that the cam driven lever 7 is aligned with the solid line. The connecting member also returns to the position indicated by the solid line. Therefore, the aperture ring 24 is rotated counterclockwise by the biasing force, and the aperture pin 26 is moved toward the open side.

The preview operation ends with the above series of operations.

FIG. 3 shows the film rewinding operation state of the preview mechanism shown in FIG. 1, and mainly depicts the mechanical parts that function during film rewinding.

When motor 1 rotates counterclockwise, it is decelerated by gears 2, 3 and 4, and the counterclockwise rotation is transmitted to gear 5. Therefore, gear 5 and gear 10 are disengaged,
The shaft 5a moves down the guide groove 6 and is positioned below the guide groove 6, and a state in which the gear 5 and the gear 10 are meshed is formed, and the counterclockwise rotation of the gear 5 is transmitted to the gear 12.

The gear 12 rotates through the gear 13 and further through the link shaft 45.
is transmitted to a gear 14 fixed to. The link shaft 45 transmits this rotation to the upper part of the camera.
is rotated by a gear 46 fixed to its upper end. Furthermore, gear 4
7.48 to the spool 49.

The film is rewound by the above operation.

FIG. 4 shows an embodiment of the circuitry for operating the mechanism according to the invention.

The preview switch 31 is provided on the top of the top cover of the camera or the like.

When the preview switch 31 is operated and turned on, the CPU (1) 32, which controls the entire camera, sends a command to the CPU (2) 33, which controls each motor.

The CPU (2133) sends a control signal to the motor drive circuit 34 to reverse the motor 1 (when viewed from the motor output shaft side), and the drive signal of the motor drive circuit 34 causes the motor 1 to reverse (see Fig. 1). (Since we are looking from the opposite direction of the motor output shaft, the rotation will be clockwise).When the motor 1 starts to reverse rotation, that is, when the aperture is on the open side, the preview opening notch provided at the bottom of the cam 36 (not shown in Figures 1 and 3)
is on. When the motor 1 reverses and rotates a certain amount, the preview close switch 36 is turned off. This state is the state immediately before the start of narrowing down. Further rotation turns on the preview closing switch notch 37 (not shown in FIGS. 1 and 3), which is also provided at the bottom of the cam.

This on/off information of the preview opening and closing switch notches 36 and 37 is input to the CPU(2) 33.

On the other hand, as the cam 9 rotates in accordance with the reverse rotation of the motor 1, the aperture ring 24 rotates twice in the direction opposite to the urging direction.
An aperture pulse signal is generated from the encoder 38 (indicated by T in FIG. 1) and input to the CPU (2) 33.

CPU (2133 is the preview close/open switch/7chi3
Based on the information from 6 and 37 and the encoder 38, control such as reversing the motor 1 or applying the brake is performed.

When the preview close switch 37 is turned on, the narrowing down is completed and the motor 1 is stopped.

Next, when the preview switch 31 is turned off by the photographer, this signal is transmitted to the CPLI(a) 32 via the CPLI(a) 32.
The signal is sent to U(2) 33, and the motor 1 further rotates in the same direction. When the preview close switch 37 is turned off again, the signal causes the motor 1 to stop and the cam driven lever to return to its original position, that is, the open position.

Next, the film rewinding operation will be explained.

During winding, the sprocket 52 is driven by the winding motor 42.

When the photographer presses the rewind button 51, the switch 50 is turned on and the shaft of the sprocket throat 52 is also pushed, causing the sprocket 52 to disengage from the output transmission shaft of the motor 42 and become idle.

The on signal of the switch 50 is sent to the CPU (2) as a rewind signal.
) 33.

When the CPU (2) 33 receives this rewinding signal, it controls the motor drive circuit 34 to rotate the motor 1 in the forward direction.

As the motor 1 rotates forward, the motor output shaft is connected from the gear on the aperture drive mechanism side to the gear on the rewind drive side, and the film is rewound.

When the rewinding of the film is completed, a film rewinding completion signal is sent to the CPU 12 from a switch or the like (not shown) that detects whether or not the film has been pulled out to the aperture.
)33. Based on this rewinding completion signal, the CPU (2+33) rotates the motor 1 from the forward direction to the reverse direction, rotates the cam 9, and returns the aperture to the open side.

The reason why the diaphragm is returned to the open position after film rewinding is completed is to maintain the state in which gear 5 is meshed with gear 12 and to avoid any hindrance to the winding operation.

Note that if the rewind button is pressed while the preview switch is being operated, the rewind operation will take priority over the preview operation, and the rewind completion signal will cause -
Once the aperture returns to the open position, if the preview switch is still being operated at that point, the preview operation is performed again.

Although this embodiment describes a mechanism in which the photographer presses the rewind button to rewind the film, a mechanism that automatically generates a rewind signal when the film reaches a predetermined number of shots may also be used. .

In addition to the above-mentioned control, the CPtJ(2) 33 also controls the motor 40 that charges the shutter and mirror up.

(Effects of the Invention) As described above, when the preview operation button is operated, the aperture drive mechanism is actuated by rotation of the motor in one direction, the aperture ring is rotated to perform aperture, and a rewind signal is sent. When input, the motor is rotated in the opposite direction, the output shaft of the motor is disconnected from the aperture drive mechanism and connected to the rewind drive mechanism, and the rotation in the opposite direction is transmitted to the spool. be.

Therefore, according to the present invention, a single motor can perform the preview operation to narrow down the aperture value to the set aperture value and the film rewind operation, and the motor can be used efficiently within the limited camera space. This has the advantage that confirmation can be smoothly performed using the drive source of the camera itself, rather than the force applied by the photographer.

[Brief explanation of the drawing]

FIGS. 1 and 3 are diagrams showing an embodiment of a mechanical section of a preview mechanism that also has an automatic film rewind function according to the present invention, and show states during a preview operation and an automatic film rewind operation, respectively. FIG. 2 is a diagram showing an embodiment of the transmission mechanism from the cam driven lever to the throttle bottle, and FIG. 4 is a diagram showing an embodiment of the circuit section for operating the mechanism according to the present invention. 1.40.42...Motor 2.3.4,5,10,12,13.14...Gear 6
... Guide groove 7 ... Cam driven lever 9 ... Cam 15 ... Body 16 ... Lever 18 ... Shaft 20 ... L lever 21 ... Link lever 22 ... Aperture ring Drive lever 23... Aperture ring bin 24... Aperture ring 25... Lens barrel 26... Aperture bin 31... Preview switch 32.33... CPLI 34... Motor drive circuit 36... Preview close switch 37... Preview close switch 38... Encoder 39... Charge motor drive circuit 41... Winding motor drive circuit 45... Link shaft 46, 47, 48... Gear 9... Spool 0... Switch... Rewind button 2... Sprocket non-stop

Claims (1)

[Claims] By operating the preview operation button, motor, and rewind button, or when the film reaches the end number of shots,
A switch that outputs a rewind signal, and a control that outputs a control signal that rotates the motor in one direction when the preview operation button is operated, and rotates the motor in the opposite direction when a rewind signal is input from the switch. a clutch mechanism that connects the motor output to the aperture drive mechanism when the motor rotates in one direction, and disconnects the motor output from the aperture drive mechanism and connects it to the film rewind mechanism when the motor rotates in the opposite direction; When the preview operation button is operated, the aperture ring is rotated through the aperture drive mechanism to narrow down the aperture, and when the rewind signal is input, the spool is rotated through the film rewind mechanism. A preview mechanism that also serves as an automatic film rewind function, characterized in that it is configured to rewind the film.