JPH0476093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a camera that uses a motor as a drive source to move a lens unit back and forth and stop it at a predetermined position.

[Conventional technology]

The present applicant has proposed in Japanese Patent Application No. 59-220772 a camera having a lens moving device that reciprocates a lens unit from one end to the other end using a driving member that moves a predetermined amount, the driving member moving the lens unit by a predetermined amount. An elastic member is provided, which has an overstroke for further moving beyond each end where the unit stops moving, and has one end in pressure contact with the lens unit and the other end in pressure contact with a drive member to transmit the driving force from the drive member. , the invention of a camera having a lens moving device characterized in that after the lens unit moves and is positioned at each end, the elastic member is elastically deformed to absorb an overstroke of the drive member. are doing.

[Problem that the invention seeks to solve]

In a camera configured to drive a motor and transmit it to a planetary gear mechanism, and the planetary gear mechanism drives the driving member in the invention, the following problem occurs.

That is, when the lens unit moves to the end and the drive member is in an overstroke state, when the motor stops and the movement of the drive member also stops, the overstroke is absorbed by elastically deforming the elastic member, and the lens unit is Although the driving member can be secured at the stop position, the driving member receives a reaction force from the elastic member that is elastically deformed.

At this time, when the drive member stops at the forward position, the drive gear provided to mesh with the planet gear in the planetary gear mechanism and drive the drive member receives a reaction force of reverse rotation due to the reaction force of the drive member. As a result, the bump between the drive gear and the planetary gear is eliminated, and the planetary gear is held down by the drive gear.If the motor is driven again in this state to reversely rotate the sun gear in the planetary gear mechanism, the planetary Even if an attempt is made to separate the gear and drive gear, it becomes difficult to separate. Furthermore, when the planetary gear is disengaged, the planetary gear moves in a direction in which it comes into pressure contact with the drive gear due to the circular arc movement around the sun gear, which further impedes disengagement.

The present invention provides a camera that solves the above-mentioned problems.

[Means for solving problems]

The above-mentioned problems are as follows: The present invention has a lens unit that reciprocates with a predetermined stroke and automatically stops at each end, a sun gear that transmits driving force from a motor and is rotatable in forward and reverse directions, and a sun gear that a planetary gear mechanism having a planetary gear that moves planetarily around the lens; a drive gear in which the planetary gear meshes with the rotation of the sun gear; and a drive gear that converts the rotational drive force transmitted from the drive gear into a reciprocating drive force, and a reciprocating mechanism having an overstroke for reciprocating the unit and further moving beyond each end where the lens unit stops; An overstroke absorber comprising an elastic member that transmits the driving force from the reciprocating mechanism and absorbs the overstroke of the reciprocating mechanism by elastically deforming after the lens unit moves and is positioned at each end. The camera is characterized in that the reciprocating mechanism is provided with a switch that stops the motor within the range of overstroke in the backward movement direction beyond the end of movement due to overstroke. achieved.

〔Example〕

An embodiment of the invention is shown in FIGS. 1 and 2.

FIG. 1 is a perspective view of the bottom surface of the camera body viewed from the direction of the back cover, and shows each component expanded in its mounting position.

Reference numeral 1 denotes a bottom base plate forming the bottom surface of the camera body, which is integrally connected to the camera body after the illustrated constituent members are assembled, and the functions of each drive system are connected thereto.

11, 12, and 13 are all integrally made of two large and small gears and are rotatably attached to the shaft or shaft hole on the bottom base plate 1, and the gear (not shown) on the motor shaft is connected to the large gear of the gear 11, Furthermore, the small gear of the gear 11 becomes the large gear of the gear 12, and the gear 12
The small gears of the gear 13 form a reduction gear train that sequentially mesh with the large gear of the gear 13.

Reference numerals 15 and 19 denote first and second clutch levers which are respectively pivotally attached to the shafts 10 and 20 of the bottom base plate 1, and are connected to the rotation center 1 of the first clutch lever 15.
5a is a gear 1 that meshes with the pinion of the gear 13.
6, and a planetary gear 17 that meshes with the gear 16 is pivotally attached to the end thereof, while a second clutch lever 19
A gear 20 that meshes with the pinion of the gear 13 via the intermediate gear 14 is provided at the rotation center 19a of the gear 13.
Also, at the end, there is a planetary gear 21 that meshes with the gear 20.
is attached to the shaft.

That is, the gear 16 is rotated by the rotation of the motor.
and 20 are driven in mutually opposite directions, the planetary gears 17 and 21 also rotate in opposite directions and also revolve in the opposite direction of rotation to rotate the first and second clutch levers 15 and 19. It constitutes a clutch mechanism that switches the power transmission system.

Reference numerals 18 and 22 are engagement pins implanted in the first and second clutch levers 15 and 19, respectively, and by operating these and regulating their positions, as will be described later, the aforementioned clutch mechanism is controlled. ing.

Reference numerals 31 and 41 denote a rewinding gear and a lens drive gear which are rotatably mounted on the shafts 30 and 40 of the bottom base plate 1, respectively, so as to be rotatable in free directions, and the rewinding gear 31 is a rewinding gear mounted on the shaft 30a. meshes with the large gear 32,
The lens drive gear 41 meshes with a lens drive large gear 42 which is pivotally attached to the shaft 40a.

33 and 34 are pulleys for the timing belt,
When the pulley 33 coaxially integrated with the rewinding large gear 32 is rotated, the pulley 34 is driven via the timing belt TV, and the rewinding clutch 35 coaxially integrated with the pulley 34 is rotated to rewind the film. People are starting to do this.

Reference numeral 43 denotes a gear coaxially integrated with the large gear 42 for driving the lens, and the gear 43 is a large gear of a gear 44 which is pivoted to the shaft 40b, and a small gear of the gear 44 is a gear 45 which is pivoted to the shaft 40c. Next, the gear 45 meshes with the drive gear 51 of the planetary gear set 50, and these gears 43, 44, 45 form a reduction gear train.

The planetary gear device 50 is a device that performs another operation operated by the drive system of the camera, that is, in this embodiment, moves the lens for changing the focal length.

In this embodiment, the focal length of the photographic lens is changed by moving the lens barrel in the optical axis direction, that is, by extending and collapsing the lens barrel, and inserting and removing the conversion lens from the optical axis. Therefore, in order to switch the focal length, a driving member with a relatively large stroke in the optical axis direction is required. In this embodiment, an example in which the stroke is obtained from the drive pin 54 is shown.

That is, when the driving gear 51 rotates, the planetary gear 52 eccentrically attached to it meshes with an internal gear 53 having a stepped circle diameter twice that of the planetary gear 52, and rotates on its axis at the same time as the drive gear 51 revolves. The planetary gear 52
The driving pin 54, which is fixed at a position corresponding to the notched circle of the internal gear 53 via the support plate 54a, is caused to move linearly from the illustrated position in the direction of the optical axis of the camera with a stroke corresponding to the notched circle diameter of the internal gear 53. It's summery.

On the other hand, the upper surface of the bottom base plate 1 in which the above driving members are installed is covered with a partition plate (not shown), and each operating member described below is mounted on the partition plate (not shown).

Reference numeral 61 denotes a rewind button which is a rewind operation member that can be slid on the partition plate in the direction of the arrow, and is operated against a tension spring 63 by a hook knob 62 exposed outside the camera. The rewind button 61 has protrusions 64, 65, 66 on its lower surface that pass through the partition plate.
A protrusion 67 is provided on the side surface.

The protrusion 64 is pivoted to the shaft 70 of the bottom base plate 1 and locks the side surface of the first protruding end 73 of the foot lever 71 which is biased counterclockwise by the torsion spring 72. The protrusion 66 is positioned slightly apart from the engagement pin 18 on the first clutch lever 15, and the protrusion 66 is positioned slightly further apart from the engagement pin 22 on the second clutch lever 19. ing.

On the other hand, the second protruding end 74 of the clutch lever 71
occupies a position facing the pin 83 of the release lever 81 which is pivoted on the shaft 80 of the bottom base plate 1 and biased counterclockwise by a torsion spring 82, but the tip of the release lever 81 is The protrusion 8 of the back cover (not shown) in which 84 is in a closed state with respect to the camera body
5, the second protruding end 7
4 and the pin 83 are kept slightly apart.

Reference numeral 91 is a switch lever biased counterclockwise by a tension spring 93 with a shaft hole 92 in the side surface of the partition plate as a counterpoint, and its right end portion is also pivoted on the side surface of the partition plate; weak torsion spring 95
Bell crank 9 biased counterclockwise by
4 is locked by receiving its bent portion 96, and its left end is in contact with the right end of a swing lever 98 which is pivoted on the same side surface.

Reference numeral 100 designates an electric circuit switch that causes the motor to rotate in the reverse direction, by pushing down the contact piece 103 and separating it from the contact piece 101, once contacting the contact piece 102, and then bringing it into contact with the contact piece 101 again as shown in the figure. When the electrical circuit of reverse rotation is maintained and a predetermined operation is completed, the electrical circuit is cut off and the motor is stopped by a corresponding signal.

Reference numeral 110 denotes a lens movement button which is a lens movement member that can be operated from outside the camera in the same way as the rewind button 62, and when it slides in the direction of arrow B against the tension spring 112 using the long groove 111 as a guide. The implanted pin 113 comes into contact with the switch lever 91 and acts to rotate it clockwise.

Hereinafter, the film winding, rewinding, and lens movement operations according to the present invention and the operations thereof will be explained.

FIG. 1 shows that when the release button of the camera is pressed, the shutter opens and closes and exposure of the film is completed, and then the motor rotates in the clockwise direction, the gear 11 rotates counterclockwise, and the gear 12 rotates clockwise. direction, and the gear 13 is in a state of rotating counterclockwise.

Therefore, the gear 16 meshing with the gear 13
rotates clockwise, and the first clutch lever 15, which is in frictional contact with the gear 16, is also rotated clockwise to engage the planetary gear 17 with the film winding reel gear G1. . Therefore,
Since the planetary gear 17 is rotated counterclockwise by the gear 16, the reel gear G1 is rotated clockwise to wind up the film.

On the other hand, at the same time, the gear 13 is connected to the intermediate gear 1.
Since the gear 20 is rotated counterclockwise via the gear 20, the second
Similarly, the clutch lever 19 is rotated counterclockwise to mesh the planetary gear 21 with the sprocket gear G2. Therefore, the planetary gear 21 is
0, the sprocket gear G2 rotates counterclockwise to feed the film.

That is, after the film is fed by a sprocket, it is transferred to a take-up reel (none of which is shown).
The film is wound upside down when the motor stops rotating based on a signal detected from the rotation angle of the sprocket.
An appropriate means is provided so that the pieces can be wound up.

Next, in the first state, when the lens movement button 110 is slid in the direction of the arrow B, the switch lever 91 is rotated clockwise by the pin 113, and its left end is moved against the swing lever 98. Since the lens is rotated clockwise and the contact piece 103 is pushed down, when the lens movement button 110 is released, the switch 100 is activated as described above to reversely rotate the motor.

As a result, since the gear 16 rotates counterclockwise, the first clutch lever 15 is also rotated counterclockwise, but at a position where the planetary gear 17 is disengaged from the reel gear G1, the engagement pin 18 is locked by the projection 65 of the winding button 61. Therefore, the planetary gear 17 idles at that position and does not transmit its rotation to any drive system.

On the other hand, at the same time, the gear 20 rotates clockwise and the second clutch lever 19 also rotates clockwise, so that the planetary gear 21 is disengaged from the sprocket gear G2 and the engagement pin 22 is rotated clockwise. By the time it comes into contact with the protrusion 64 of the rewind button 61, it is in a state of meshing with the lens driving gear 41.

Therefore, the rotation of the motor is transmitted from the lens driving gear 41 to the lens driving large gear 42 and then to the planetary gear device 50 via the gears 43, 44, and 45.

The drive pin 5 in the planetary gear device 50
4, the lens barrel is extended and retracted, and the focal length of the photographic lens is changed. However, the rotation of the motor is stopped by a signal that detects a half rotation of the drive gear 51. Round trip or return 1
This is the end of the lens movement.

Therefore, when you press the release button from this state, the shutter opens and closes and after the exposure of the film is completed,
The motor starts rotating in the normal direction again, and the first and second clutch levers 15, 19 are returned to the positions shown in FIG. 1, allowing the film to be wound.

On the other hand, when the rewind button 61 is slid in the direction of arrow A in the state shown in FIG. 81 pin 8
3 and is in a stopped state, so that even if the rewind button 61 is released, the protrusion 64 remains in the first position.
The rewind button 61 is held in the slid position by being supported by the protruding end 73.

In this state, the protrusion 65 is moved away from the engagement pin 18 of the first clutch lever 15 to a position where it does not interfere with its rotation range, and on the contrary, the other protrusion 66 is moved away from the engagement pin 18 of the first clutch lever 15. It is in a state where it is slightly close to the engagement pin 22 of and occupies a position that partially restricts its rotation range.

When the rewind button 61 is further slid in the direction of arrow A from this state, the protrusion 67 presses the bent portion 97 of the bell crank 94 and rotates the bell crank 94 counterclockwise. , the switch lever 91 by the other bent portion 96.
Rotate clockwise.

As a result, when the rewind button 61 is released, the switch 100 is activated and the motor begins to rotate in the reverse direction, as in the case of lens movement described above.
The first clutch lever 15 is connected to the reel gear.
After separating from G1, the planetary gear 17 is rotated further counterclockwise than in the case of lens movement, so that the planetary gear 17 meshes with the rewinding gear 31, and the rewinding gear 31 is rotated counterclockwise.

Therefore, the large unwinding gear 32 and the pulley 33 rotate clockwise, and the timing belt
The pulley 34 is driven via the TV, and the rewinding clutch 35, which is coaxial, is rotated clockwise to rewind the film.

On the other hand, the second clutch lever 19 rotates clockwise to disengage the planetary gear 21 from the sprocket gear G2, and attempts to rotate further clockwise, but at that position the protrusion 66 disengages from the engagement. Since it occupies the position where the dowel pin 22 is locked, the planetary gear 21 idles and does not transmit its rotation to any drive system.

In this way, after the film is rewound and the rotation of the motor is stopped based on a signal indicating the end of rewinding obtained from the result of detecting the presence or absence of film, when the back cover of the camera is opened, the protrusion 85 will move as shown by the arrow. C direction, the release lever 81 rotates counterclockwise, and the pin 83 presses the second protruding end 74 of the foot lever 71 to release the foot lever 7.
1 in the clockwise direction.

Therefore, when the back cover is opened, the rewind button 61
returns to the position shown in FIG. 1, and after loading a new film and closing the back cover, the release button is operated again to wind the film and start autoloading.

However, in cameras with such functions,
For the reasons described below, when moving to another operation after lens movement, the planetary gear 21 of the second clutch lever 19 becomes difficult to disengage from the lens drive gear 41, and therefore, the operation for moving to another operation becomes difficult. It may become heavy and may not be able to switch smoothly.

That is, it can be said that it is generally preferable that the operating amount of the drive pin 54 in the planetary gear device 50 is set to be larger than the predetermined moving amount of the lens unit with some margin.

Therefore, after the focal length is switched to a predetermined focal length and the lens movement is forcibly stopped, a device that absorbs the driving force from the planetary gear device 50 can be considered, and one example is shown in FIG. show.

Reference numeral 201 denotes a lens unit housing a bifocal photographic lens (not shown), to which a plate 202 having a pair of rising portions 202a is fixed inside its bottom surface, and rotates together with the plate 202 through a shaft 203. It is held freely.

A pair of falling portions 204 are provided at the upper end of the shaft 203.
A lever 204 is fixed to the lower end, that is, the outside of the lens unit 201, and a crank 20 is attached at an angle substantially perpendicular to the lever 204.
5 is fixed to the shaft 2 together with the lever 204.
It is built in so that it can rotate freely using 03 as a pivot.

A torsion spring 206 is a stroke absorbing member for the amount of operation of the drive pin 54 that exceeds a predetermined amount of movement of the lens unit, and is wound around the shaft 203, and both ends thereof are connected to the rising portion 202a and the falling portion 204a. The levers 204 are held in a biased state by the levers 204 and 204, and the levers 204 are held in a balanced position without being biased to either the left or right side.

FIG. 2 shows that the drive gear 5 of the planetary gear device 50 is rotated by the clockwise rotation of the lens drive gear 41.
1 rotates clockwise to move the drive pin 54 linearly in the direction of arrow D, the focal length switching is completed, and the lens unit 201 is placed at the stop position.

Until this state is reached, the elastic resistance of the torsion spring 206 is set to be greater than the movement resistance of the lens unit 201.
Therefore, the balanced state of the lever 204 remains unchanged, and therefore the lens unit 201 is moved in the direction of the arrow D by performing balanced movement in the state shown in the figure, which makes it difficult to remove the planetary gear 21 as described above. Such a phenomenon has not yet occurred.

However, when the planetary gear 52 on the drive gear 51 further revolves clockwise from the illustrated position and simultaneously rotates counterclockwise to further actuate the drive pin 54 in the direction of arrow D, the lens unit 201 stops. Since it is still there, the crank 2
05 receives a strong urging force in the clockwise direction.

Therefore, the lever 204 is also connected to the torsion spring 2.
06 in the clockwise direction, and as a result, the drive pin 54 is operated to the peak of the operating amount given by the planetary gear device 50 without moving the lens unit 201. It is possible to do so.

In other words, when the driving pin 54 is at the peak of its linear motion, the elastic resistance of the torsion spring 206 is at its maximum value, and in this state, the motor power is normally turned on to stop lens movement. In this method, the planetary gear 21 and the lens drive gear 4
The pressure on tooth base No. 1 also reaches its maximum value, leading to the phenomenon that separation becomes difficult as described above.

Therefore, in the present invention, as shown in FIG.
A cam plate 211 is provided coaxially with the drive gear 51, and the cam plate 211 is configured to stop the rotation of the motor when the drive pin 54 reaches a position slightly beyond the peak of its linear operation. are doing.

211a is a pair of notches provided at symmetrical positions on the circumferential surface of the cam plate 211; 212 is a bell crank made of an insulating material that is pivoted at a fixed position; one end thereof is a movable contact of a switch 213 for stopping the motor; The other end is brought into pressure contact with the peripheral surface of the cam plate 211 by the reaction force that presses the piece 213a. Note that in this state, the movable contact piece 213a is connected to the fixed contact piece 213.
b, and closes the switch 213 to continue rotating the motor.

After the lens unit 201 has stopped, the drive gear 51 further rotates, and at a position where it has passed the peak of the linear action and entered a slightly backward action in the direction of arrow D, the notch 211a drops the other end of the bell crank 212. Rotate the bell crank 212 clockwise.

As a result, the switch 213 opens and the motor ends its operation for moving the stop lens, but since the drive pin 54 is in the returning operation, albeit slightly, the elasticity of the torsion spring 206 causes the drive pin 54 to move. Therefore, the load on the planetary gear 21 is greatly reduced, and the pressure on the tooth base with the lens drive gear 41 is also reduced, which prevents a situation that may hinder disengagement. will be prevented.

Incidentally, such a function is also necessary when the drive pin 54 is operated back, that is, when the lens unit 201 is operated in the opposite direction of the arrow D direction, and in that case, the lens unit 201 is in the symmetrical position described above. Notch 2
11a acts on the switch 213 to stop the motor.

Note that the present invention is not limited to the embodiments described above, and various modifications are possible. In the above embodiment, the lens is moved by converting the rotational movement of the motor into linear movement, but other operations such as movement of the lens cover, movement of the flashlight, etc.
Alternatively, it may be used to perform a shutter charge or the like.

〔Effect of the invention〕

As explained in detail above, in the present invention, the reciprocating mechanism is provided with a switch that stops the motor within the range of the overstroke in the backward movement direction beyond the end of the movement due to overstroke, so that the drive gear is connected to the drive member. If the sun gear is rotated in the opposite direction by receiving more propulsive force and the motor is driven again in this state without pressing the planetary gear by the drive gear, the planetary gear can be easily disengaged. Therefore, when the sun gear is reversely rotated and the planetary gears are switched, there is no need to apply a large load to the motor.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a power transmission mechanism of a camera to which the present invention is applied. FIG. 2 is a perspective view of the lens moving mechanism of the camera according to the present invention. 15...First clutch lever, 19...Second clutch lever, 20...Gear, 21...Planetary gear, 41...Lens drive gear, 42...Lens drive large gear, 43, 44, 45... Gears, 50...
... Planetary gear device, 51 ... Drive gear, 52 ... Planetary gear, 53 ... Internal gear, 54 ... Drive pin,
201...Lens unit, 202...Plate, 202a...Rising portion, 203...Axis, 20
4... Lever, 204a... Falling portion, 205...
... Crank, 206 ... Torsion spring, 211 ... Cam plate, 211a ... Notch, 212 ... Bell crank, 213 ... Switch, 213a ... Movable contact piece, 213b ... Fixed contact piece.

Claims (1)

[Scope of Claims] 1. A lens unit that reciprocates with a predetermined stroke and automatically stops at each end, a sun gear that transmits driving force from a motor and is rotatable in forward and reverse directions, and a periphery of the sun gear. a planetary gear mechanism that has a planetary gear that makes planetary motion; a drive gear that meshes with the planetary gear as the sun gear rotates; and a drive gear that converts rotational drive force transmitted from the drive gear into reciprocating drive force to drive the lens unit. a reciprocating mechanism having an overstroke for reciprocating the lens unit and further moving beyond each end where the lens unit stops; and a reciprocating mechanism having one end pressed against the lens unit and the other end pressed against the reciprocating mechanism. an overstroke absorption mechanism having an elastic member that transmits a driving force from the mechanism and absorbs an overstroke of the reciprocating mechanism by elastically deforming after the lens unit moves and is located at each end; A camera comprising: a switch for stopping the motor within a range of an overstroke in a backward movement direction beyond a movement end portion of the reciprocating mechanism due to an overstroke.