CN1012390B - Motor-driven zoom device for video camera - Google Patents

Abstract

In an automatic film-feeding type of photography, a motor is used to wind the film when the motor rotates forward and to rewind the film when it is reversed, and a mechanism is installed in the mechanism that moves the photographic lens barrel between the normal or wide-angle position and the telephoto position. The movement of the motor can be transmitted from the rewinding fork to the clutch of the moving mechanism, and a switch is installed. When the clutch is disconnected, the switch is closed, so that the motor starts and rotates in the opposite direction, driving the lens barrel in the axial direction Or move between the two positions of wide-angle and telephoto, and at this time, keep the rewinding fork stationary.

Description

The invention relates to a video camera with a built-in variable focal length lens, in particular, the focal length of the lens is changed by motor driving in the video camera.

Mechanisms for varying the focal length of a camera lens between two different values are previously known, as disclosed in U.S. Patent No. 3,388,650. This previously known mechanism is adapted for use in optical systems in which the combination of lens components is varied: (e.g. rear shifter type); the positive and negative power of the lens varies according to a prescribed law (eg zoom lens type); and long and short focal length lenses are interchangeable types.

Since the work of changing the focal length of any lens in these types of optical systems requires a much longer distance than focusing and is very complicated, the distance changing operation is automated by a simple structure, such as in the focus adjustment operation Automating it with a spring is very hard to do.

Therefore, most zoom mechanical devices can be divided into two types: one is to operate by means of external force, such as a manually operated actuating device on the camera lens barrel or on the camera housing, (such as Japanese No. sho 56-50504 Patent disclosed); Another kind is to only use a motor (such as the No. sho57-146232 patent published by Japan).

Moreover, in the motorized application of the camera lens of this type of camera, the film winding and rewinding are driven by two motors respectively. In this way, the size of the cost and whether there is enough space in the camera housing become problems, which will lead to Increased production costs. Also cause the increase of video camera volume equally, equip motor-driven variable focal length device for this type of video camera, still have many difficulties to be solved.

The purpose of the present invention is to solve the kind of problem mentioned above, in the video camera, for self A clutch with a simple structure is installed on the gear train of the moving rewind, which is controlled to be turned on or off by the actuating device. Thereby, the motion of the common motor is transmitted from the rewind fork to the lens barrel, thereby moving the lens barrel from one of the two positions to the other.

Other objects of the invention will be clarified in the following description of the embodiments.

Brief description of the drawings

Fig. 1 is an exploded perspective view of an embodiment of a camera motor driven zoom apparatus according to the invention.

2 and 3 are plan views of the mechanism for moving the camera lens barrel between the first and second positions, respectively.

Detailed description of the preferred embodiment:

An example of a camera motor-driven zoom device will be described below with reference to the drawings. First, referring to accompanying drawing 1, the reversible motor 1, as a public power source, is not only responsible for driving the winding, rewinding, shutter and other parts of the camera, but also adjusts the camera lens so that it is positioned on the two axes. in one of the positions. In this case it is located within the spool 10 . The pinion 2 on the output shaft of the motor 1 is connected with the gear 3, 3a installed on the common shaft, and the reduction gear train composed of the gear 4, 4a installed on another common shaft, and meshes with the gear 3, and the gear 3a and Gear 4 meshes.

The gear 5 on the disc clutch 5b is used to transmit the rotational motion of the gear 4a to the ring gear 9, which is fixed on the outer diameter of the upper end of the film winding shaft 10, and has the function of winding the film when the motor is on. The movement is only transmitted when the direction of the direction is turned. The gear 6 on the second clutch connecting rod 6a transmits motion to the sprocket 7 or the middle love wheel 11 through the gear 4a according to the different rotation directions of the winding or rewinding of the motor 1 respectively. Driven by the rotation of the gear 7, the sprocket 8 makes the film go through a prescribed length frame. It should be noted that the plate clutch gear 5 and the winding plate clutch gear 6 are always meshed with the gear 4a and are always It is frictionally coupled with the corresponding connecting rods 5b and 6b to disengage or engage the clutch.

A T-shaped connecting rod 13 is hinged on the common shaft 13c of the gear 12, and bears the force in the counterclockwise direction given by the spring 16. One end of the spring 16 is hooked on a pin 13d, and the other end is hooked on a pin 17. on the frame of the camera housing (not shown in the figure). When the connecting rod 13 is moved clockwise by the biasing force generated by the photographer's finger touching the button 13e, the normally closed gear train 11→(12)→(15)→19→20 terminated with the fork joint 20b , because the gears 15 and 19 are disengaged and disconnected, the gear 15 is meshed with a telephoto/wide-angle gear 18, so the motion of the motor 1 is transmitted to the telephoto/wide-angle gear 18. There is a rotatable gear 15 at the bottom of the T-shaped end of the connecting rod 13, and a roller 13a is equipped with the left end elbow part of the connecting rod. At the right end, a push pin 13b is provided for the switch 14 . A crank 18a is fixed to the shaft on which the telephoto/wide-angle gear 18 is housed, and the crank pin 18b is inserted into the laterally elongated groove 21a of the slide plate 21, and when the crank plate 18a rotates, the camera lens 21c is fixedly carried and mounted on the flange. Sliding plate 21 of lens barrel 21b with lens barrel hanger 21c on 21d moves axially between telephoto and wide angle positions. There is a cylindrical cover plate 28 in front of the slide plate 21, and leaf springs 22, 22' are respectively fixed on its left and right sides. The switch 14 has two contacts 14a, 14b. When the link 13 rotates clockwise to make the gear 15 mesh with the telephoto/wide-angle gear 18, the push pin 13b makes 14a and 14b contact each other, except for this meshing state , the switch 14a is always open, when the switch 14 is closed, the motor 1 starts to rotate in reverse.

Soon after the motor 1 starts to rotate, as the slide plate 21 starts to move back and forth, the roller 13a rolls out of any one of the cam recesses 21f or 21g at the wide-angle or telephoto position, and is pressed on the cam surface 21h parallel to the axis, wherein , the notches 21f and 21g are on the front and rear corners of the slide plate respectively, and due to the meshing state of the gears 15 and 18, the roller 18a Sustained by the return force of the spring 16, the photographer can remove his finger after the button 13e has been pressed once. When the camera lens 21c arrived at an opposite position (telephoto or wide-angle position), the roller 13a was driven by the spring 16 and immediately dropped into the telephoto or wide-angle cam notch 21g or 21f, and like this, the gear 15 was automatically aligned with The telephoto/wide-angle gear 18 is disengaged, and the switch 14 is automatically disengaged. During the time of non-zoom operation, the gear trains 11, 12, 15, 19 and 20 remain active, allowing rewinding operations to be performed whenever necessary. When the motor 1 rotates in the opposite direction, this gear train transmits the motion of the motor 1 to the rewind fork 20b, through the rewind fork 20b, in a film blind or patrone (not shown), the exposed film Transfers from the spool 10 to the supply spool in the film nest.

Fig. 2 and Fig. 3 are plan view, respectively represent the partial cross-sectional view of the positioning mechanism of the zoom device of the present invention when the lens is in telephoto and wide-angle two different working positions. In both figures, the same reference numerals as in FIG. 1 are used to designate the same parts. An outer sleeve 23 is firmly installed on the camera housing (not shown), and this sleeve has a pair of positioning grooves 23a and 23'a, and this pair of positioning grooves is the position of the camera lens at a conventional distance near the front end, and along the diametrically aligned with each other. In addition, for the lens to perform distance-selective photography, there are positioning grooves 23b and 23'b at the rear end, which are also aligned with each other in the diameter direction. The reeds 22 and 22' mounted on the outer wall of the cylindrical cover plate 28 expand outward from the front end of the slide plate 21, and self-deflect and expand in the diameter direction of the outer sleeve 23 so that its end almost forms a V shape. When the slide plate 21 is pushed to the position of the conventional focal length or folded back to the position of the telephoto focal length, the pair of springs are respectively engaged in the positioning grooves 23a and 23'a or the second pair of positioning grooves 23b, 23' corresponding to these two positions b. A pin-shaped reaction member whose peripheral surface is lubricated, or a smooth rotatable guide roller is installed in the direction opposite to the roller 13a on the opposite side of the slide plate 21 to the roller 13a, so that the slide plate The side of the left end of 21 is pressed against the reaction member 24. This pressure is generated by the force of the spring 16 acting on the roller 13a to avoid unnecessary lateral movement of the slide plate 21, but it cannot prevent the axial movement of the lens barrel 21b. sports. A guide rail 26 is placed between the two ends of the mounts 27a, 27b, which is firmly fixed on the body frame of the camera body, and the lens barrel can move along its axial direction. On the guide rail 26 , an annular sleeve 21 i is matched with it in a sliding manner, and the sleeve 21 i is fixedly mounted on the slide plate 21 . The two stoppers 25 and 25' limit the backward movement of the sliding plate 21 in the axial direction. In this position, the leaf springs 22 and 22' engage the grooves 23b and 23'b, forcing the slide 21 against the stops 25 and 25'. When abutting against the front end face 21j of the sleeve 21i, the forward axial movement of the slide plate 21 is limited by the rear end face 27c of the front mount 27a. In this position, the leaf springs 22 and 22' engage the front pair of slots 23a23'a, forcing the slider 21 against the mount 27a. An additional stop block 29 is used to limit the counterclockwise rotation of the connecting rod 13 . It should be noted that the width of the slot 21a is greater than the diameter of the pin 18b.

The following describes the operation process of the camera with reference to FIGS. 1 to 3 .

Before describing the zoom operation, let us study the operation of the film transport mechanism.

When the roller 13a falls into one of the telephoto or wide angle cams 21g and 21f (Fig. 2 or 3), the action of the spring 16 causes the link 13 to rotate counterclockwise about the axis 13c. At this time, the gear 15 is disengaged from the telephoto/wide-angle gear 18 and meshed with the gear 19, and the switch 14 is turned off.

In the state of loading the film, the motor 1 rotates in the forward direction (in the counterclockwise direction). At this time, the sheet shaft clutch 5b and the winding sheet clutch 6b rotate independently in the counterclockwise direction, thereby, the sheet shaft clutch gear 5 and the sheet shaft gear 9 enter the meshing state, and the winding sheet clutch gear 6 and the sprocket 7 enter the meshing state. Therefore, the driving torque of motor 1 is passed through the gear train 2-3- 3a-4-4a-(5)-8 is passed to the film reel 10, and the film roll is wound up on the film reel 10. Through the gear train 2-3-3a-4-4a-(6)-7, the driving torque of the motor 1 is transmitted to the sprocket 8. Through the rotation of the sprocket 8, the film advances by one frame. During the operation of the film, the idler gear 11 is not meshed with the film clutch gear 6, and the driving torque of the motor is not transmitted to those gears driven by the idler gear 11 in the gear train.

In the working state of rewinding, manipulate a working state selector switch (not shown) to reverse the motor 1 (rotate clockwise), and the disc shaft clutch 5b and winding disc clutch 6b rotate clockwise. Thus, the spool clutch gear 5 and the winding spool clutch gear 6 are disengaged from the spool gear 9 and the sprocket 7 respectively, and are engaged with the idler gear 11 . Therefore, the drive torque of the motor is transmitted through the gear train 2-3-3a-4-4a-6-11-(12)-(15)-19-20 to rotate the fork joint 20b in the clockwise direction, thus making The film is rewound onto the supply spool in the cassette.

How the two clutches 5b and 6b are connected is neglected in the above description. Now, an explanation will be made on this issue. Since the gear train 2-3-3a-4-4a-5-6 transmits the drive torque, a frictional force acts between each pair of gears 5 and clutch 5b, gear 6 and clutch 6b, and the effect of this frictional force The clutches 5b and 6b are automatically turned on independently.

Let us now describe the operation of the zoom device step by step. Assume that the components of the device are in the positions shown in FIG. 2 . When the control button 13e is pressed to the left against the force of the spring 16, the connecting rod 13 rotates clockwise, thereby disengaging the gear 15 from the gear 19 and engaging with the telephoto/wide-angle gear 18. The shaft 13a is moved out of the telecam notch 21g, and the push pin 13b then presses the movable contact 14a against the fixed contact 14b, closing the switch 14. At this time, the motor 1 starts to rotate in reverse. As described above, the conventional rewind gear train transmits the reverse rotational motion of the motor 1 to Give gear 12. However, since the connecting rod 13 rotates in the clockwise direction, the rotational motion of the gear 15 is transmitted to the telephoto/wide-angle gear 18, and due to the rotation of the gear 18, the crankshaft 18b rotates in the counterclockwise direction, and at the same time, the slide plate 21 is pushed to the elongated The rear inner side of the groove 21a. Accordingly, the lens barrel 21b starts to move backward. When the roller 13a is just pressed against the cam notch 21h, the connecting rod 13 can no longer rotate in the counterclockwise direction. Thus, the drive torque conversion clutch is maintained in this state.

As the crankshaft 18b continues to rotate backwards, the position reached by the lens barrel 21b and the slide plate 21 is slightly forward than the prescribed adjustment position, and the "V"-shaped parts 22a and 22'a of the positioning leaf springs 22 and 22' are under their own elastic force. The action falls down into the grooves 23b and 23'b. Afterwards, lens barrel 21b and slide plate 21 are no longer driven by crank 18b, but are moved to the rear end of slide plate 21 by the effect of leaf spring 22 and 22 ′ against the specified adjustment position of stop block 25, 25 ′ . At this time, the roller 13a falls into the wide-angle cam notch 21f, whereby the connecting rod 13 rotates counterclockwise under the action of the spring 16, disengages the gear 15 from the telephoto/wide-angle gear 18, and makes the switch 14 disconnect. At this point, a zoom operation process for changing the lens from long-distance to wide-angle photography is completed. (See Figure 3)

It should be noted here that the leaf spring driven movement of the slide plate 21 brings the front inner side of the elongated slot 21 a into contact with the crank pin 18 a, as shown in FIG. 3 . It should also be noted that during the process of moving out the slide plate 21 together with the lens barrel 21b, the slide plate 21 is not only guided by the guide rail 26, but also guided by the joint of the roller 13a and the pin-shaped reaction member 24, so as to ensure that the light of the lens 21c is avoided. Axes are misaligned or skewed from the geometric center.

The following instructions are the inverse of the procedure described above, explaining the zooming process of the lens from normal or wide-angle photography to telephoto photography.

When the control button 13e is pressed to the left, the connecting rod 13 rotates in the clockwise direction, by At this time, the roller 13a is moved out of the wide angle cam notch 21f, at the same time, the gear 15 is engaged with the telephoto/wide angle gear 18, and the switch 14 is closed. Thus, the reverse rotation of the motor 1 transmits the motion to the crank pin 18b through the above-mentioned gear train, and the crank pin 18b pushes the slide plate 21 to the front inner side of the groove 21a, so that the slide plate 21 moves forward together with the lens barrel 21b, at this time , the roller 13a is in contact with the cam notch 21h, so that the connecting rod 13 cannot be reversed or rotated counterclockwise again. Like this, make conversion clutch be on the working position.

As the crank pin 18b continues to rotate forward, when the slide plate 21 and the lens barrel 21b reach a slightly forward position than the prescribed adjustment position, the leaf springs 22 and 22' force their "V"-shaped parts to fall into the positioning groove 23a and 23'a, after that, the slide plate 21 no longer relies on the power of the motor, but is driven by the leaf springs 22 and 22', so that it continues to move until the front end surface 21j of the sleeve 21i leans against the seat 27a of the guide rail 26. on the opposite end face 27c and is held stationary in the position described in FIG. At this time, the roller 13a is in contact with the telecam notch 21g, so the link 13 rotates clockwise, the gear 15 is disengaged from the tele/wide gear 18, and the switch 14 is turned off to cut off the power to the motor 1. This leaf spring driven movement of the slide plate 21 causes the rear inner side of the elongated slot 21a to abut the crank pin 18a.

As mentioned above, a clutch coupled with the one-way crank pin is added to the rewind gear train, and this clutch drives the photographic lens to move between two different focal length positions. Therefore, the automatic film feeder type camera can be easily changed into a motor-driven zoom type camera. With the increase of the zoom capability, the photographic range of the camera is significantly expanded. In addition, the operation of this device can be easily mastered by anyone. Therefore, it can be said that the present invention unquestionably achieves the object of increasing the attractiveness of this type of video camera. However, to introduce this capability to the camera only needs to add a clutch device and a switch device, which avoids the A sharp increase in production costs. Moreover, these devices do not need to take up a lot of space. Therefore, the present invention greatly improves the performance of the camera without greatly increasing the production cost and the size of the camera.

Claims (4)

1. A motor-driven zoom device for a video camera, characterized by comprising: (a). A first drive system for transporting the image recording material; (b). A second drive system for moving the optical system to change the focal length; (c). A drive system; (d) a clutch for transmitting the driving force of said drive system to one of said first and second transmission systems, said clutch enabling said first transmission system to operate during normal operation; (e). An actuating device for changing said clutch to transmit the driving force of said driving system from the first transmission system to the second transmission system, said device being manually operated. 2. Apparatus according to claim 1, wherein said drive system comprises an electric motor. 3. A motor-driven zoom device for a video camera is characterized by comprising: (a). The first transmission system for the winding film; (b). Second drive system for film rewinding; (c). The third transmission system for moving the lens barrel to change the focal length; (d). A drive system; (e). For transmitting the driving force of the above-mentioned driving system to the above-mentioned first transmission system corresponding to the normal rotation of the above-mentioned driving system, and corresponding to the reverse rotation of the above-mentioned driving system. the first clutch of the aforementioned second drive train; (f). A second clutch for transmitting the driving force of said drive system to said second and said third transmission systems, said clutch enabling said second transmission system to operate during normal operation; (g). Change the above-mentioned second clutch so that the driving force of the above-mentioned driving system is transmitted to the actuating device of the above-mentioned third transmission system, and the above-mentioned device is manually operated; (h). The switching device for turning on the above-mentioned driving system to make it reverse. The closing of this switching device corresponds to the manual operation of the above-mentioned actuating device. At this time, the above-mentioned driving system rotates in reverse. 4. The apparatus according to claim 3, further comprising means for automatically resetting said second clutch, said means operating in accordance with the detection time after the focal length change of the optical system.

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