JPH0531607Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a photographing device equipped with a zoom lens whose zoom operation is performed by driving a motor, and a focus adjustment device which performs focus adjustment by driving the motor.

B. Prior Art Video cameras and the like are equipped with a power zoom function in which a zoom lens is operated by driving a motor, and an automatic focus adjustment function.
When taking pictures in the field, you may want to stop the autofocus function and focus manually. In such cases, as shown in JP-A No. 57-11523, for example, if the lens can be driven electrically with an operation button located at the appropriate location on the camera body, just like a power zoom, it is possible to move the lens barrel one by one. It's very convenient because you don't have to turn it by hand and can adjust the focus while holding the camera. Furthermore, in the photographing device shown in Japanese Patent Application Laid-Open No. 60-19827, automatic focus adjustment is performed when the first stroke of the release button 3 is operated, and when the zoom operation member 4 is operated without pressing the release button. Only power zoom is performed,
Automatic focus adjustment does not work and the first release button 3
If the zoom operation member 4 is operated while performing the stroke operation, manual or electrical focus adjustment (power focus) is performed.
The feature is that switching between manual and automatic focus adjustment can be done by pressing the release button one step, but with this configuration, if the focus shifts due to lens drive during power zoom operation, is not configured to allow two or more of auto focus, power zoom, and power focus to be performed at the same time. You need to adjust the focus accordingly.

C. Problems to be Solved by the Invention The present invention is an imaging device equipped with a power zoom function and a focus adjustment function operated by a motor drive. Providing these two operating members on the camera body hinders the reduction in size and weight of the camera, so a single operating member is used for these two operating members, and the lens is driven by the power zoom operation to prevent the focus from shifting. Even in cases where
The aim is to always perform focus adjustment using an autofocus circuit.

D. Means for solving the problem A switching operation means for selectively switching and specifying zooming operation and focusing operation, a manual operation member that outputs an operation signal in response to manual operation, and a zooming operation operated by this operation signal. and a focusing means, and the operation signal outputted from the manual operation member is switched between being input to the zooming means and the focusing means by operating the switching operation means.

E. Effect The focusing means and zooming means are
Both are operated by an operation signal that causes the motor to rotate forward or reverse, but the switching means switches whether this operation signal is input to the focusing means or the zooming means, so both are common. Any operation can be performed using the manual operation member, reducing the number of operation parts on the camera body.

F. Embodiment Fig. 1 shows a control circuit for a lens drive motor for power zoom and autofocus of a photographing device according to an embodiment of the present invention, and Fig. 2 shows a cross-sectional structure of a zoom lens in the same embodiment. .

In Fig. 2, 1 is the front lens group of the zoom lens;
2 is the same variable magnification lens 2-1 and correction lens 2.
-2 is a zooming lens group, and 3 is also a rear lens group. Reference numeral 4 denotes a helicoid portion provided at the front end of the lens barrel 14, into which the lenses of the front lens group 1 are screwed together, and a focus gear 5 is provided around the outer periphery of this lens frame. Reference numeral 7 denotes a lens drive motor for autofocus, which is connected to the lens frame of the front lens group 1 via an intermediate gear 6 and a focus gear 5, and the front lens group 1 is moved back and forth by forward and reverse rotation of the motor 7. Focus adjustment is performed. 8 is a zoom cam ring, and its guide groove has cam pins 3 provided on each lens frame of the variable power lens 2-1 and the correction lens 2-2.
0.31 is fitted through. Therefore, when the power zoom lens drive motor 13 rotates, the gears 10,
The zoom cam ring 8 is rotated via the zoom lens 9, and the variable power lens 2-1 and the correction lens 2-2 are moved back and forth while maintaining a predetermined relationship, thereby performing zooming.

In FIG. 1, reference numeral 7 denotes the above-mentioned autofocus lens drive motor, and this motor 7 is driven by a signal from the focus detection circuit 22. 1
3 is a power zoom lens driving motor.
Reference numeral 15 is an operating member for both power zoom and manual focus adjustment, and reference numeral 16 is an operating member for switching between power zoom and manual focus adjustment. Operation member for power zoom and manual focus adjustment (hereinafter simply referred to as operation member) 1
5 consists of two push buttons. One is the operation member that drives the lens toward the telephoto side when operating the power zoom, and toward the near distance side when adjusting the focus manually, and has Tele/Near written on the surface. is an operating member that drives the lens toward the wide-angle side (Wide) when operating the power zoom, and toward the far distance side when adjusting the focus manually.
Wide/Far is written. As shown in FIG. 3, two operating members 15 are provided side by side at appropriate locations on the top surface of the camera body.

Returning to FIG. 1, 20 and 21 are the motors 7 and 21, respectively.
13 is a drive circuit, and 17 is an analog switch section consisting of six switches 17-1 to 17-6. Reference numeral 18 denotes a control unit, to which a high (High) or low (Low) signal is output. is connected to the analog switch 17-1,
The gate terminals of 17-2, 17-5, and 17-6 are each directly connected to the output terminal of the control section 18. In addition, analog switches 17-3 and 17-5 receive a signal emitted by a switch (not shown) that is turned ON by pressing the wide-angle, long-range side operation member W/F of the operation members 15. Analog switch 17-4,
17-6 receives a signal emitted by a switch (not shown) that is turned on by pressing the telephoto and short distance side operating members T/N of the operating members 15. .

Assume that the switching operation member 16 is now pushed toward the power zoom side. At this time, when the signal generated in response to the operation of the switching operation member 16 is input to the control circuit 18, the output terminal of the control circuit 18 becomes high level, and the analog switches 17-1, 17-2, 1
7-5, 17-6 are conductive, 17-3, 17-4
is blocked. When the operating member W/F is pressed, a signal is input to the motor drive circuit 21 through the analog switch 17-5, and the motor 13 rotates in the normal direction, causing the zooming lens groups 2-1 and 2-2 in Fig. 2 to move to the wide-angle side. driven to. When the operating member T/N is pressed, a signal is input to the drive circuit 21 through the analog switch 17-6, the motor 13 is reversed, and the zoom lens groups 2 and 33 are driven to the telephoto side.

At this time, the autofocus lens is driven by a signal input from the focus detection circuit 22 to the drive circuit 20 through the analog switches 17-1 and 17-2, and focus adjustment is automatically performed. Next, assume that the switching operation member 16 is pushed to the manual focus adjustment side. At this time, the output terminal of the control circuit 18 becomes low level, and this low level signal is inverted to a high level signal by the inverter 19 and applied to the gates of analog switches 17-3 and 17-4. 17-4 becomes conductive, and 17-1, 17-2, 17-5, and 17-6 become cut off. Therefore, among the operating members 15, W/
When F is pressed, a signal is applied to the motor drive circuit 20 through the analog switch 17-3, the motor 7 rotates forward, the front lens group 1 shown in FIG. 1 is driven, and the focus shifts to the far side. When T/N is pressed, a signal is input to the drive circuit 20 through 17-4, the motor 7 is reversed, and the front lens group 1 is driven toward the short distance side.

In the above embodiment, the focus adjustment motor and the power zoom motor are provided separately, but a single motor may be used for both. At this time, if it is necessary to drive power zoom and focus adjustment simultaneously, it is sufficient to first perform the power zoom operation and then perform the focus adjustment operation. By doing so, it is possible to eliminate the inconvenience that the focus shifts when zooming.

G Effect According to the present invention, when performing manual focus adjustment,
There is no need to turn the lens barrel by hand, and you can adjust the focus with your fingers while holding the camera, making camera operations smooth and quick. Moreover, the power zoom operation element is included in the manual focus adjustment operation element. Since the camera is also used as a camera, the installation space for operating members does not increase, and the camera can be made smaller and more weighed. Furthermore, since the autofocus lens is driven by the signal from the focus detection circuit even during power zoom, there is an advantage that the focus adjustment operation is always performed even if the focus shifts due to power zoom operation.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the main parts of an embodiment of the present invention, Figure 2
The figure is a vertical cross-sectional view of the zoom lens in the same example.
FIG. 3 is a perspective view of the operating member of the same embodiment. 1... Front lens group, 2... Variable power lens group, 3... Rear lens group, 4... Helicoid section, 5... Focus gear, 6... Intermediate gear, 7... Auto focus lens drive motor , 8...Guide rod, 9...Variable lens group holder, 10...Feed screw, 11...
Zoom gear, 12... Intermediate gear, 13... Power zoom lens drive motor, 14... Lens barrel, 1
5... Operating member, 16... Switching operating member, 17
...Analog switch section, 18...Control section, 19
... Inverter, 20 ... Drive circuit, 21 ... Drive circuit.

Claims (1)

[Scope of utility model registration request] A zooming means that electrically drives the zooming lens of the photographic lens in response to an input signal, a focusing means that electrically drives the focusing lens of the photographic lens in response to an input signal, and selective switching and designation of the zooming operation and the focusing operation. a focus detection circuit that outputs a signal indicating a focus state; a manual operation member that outputs an operation signal according to the manual operation; the manual operation member is coupled to the zooming means and the focusing means; When a focusing operation is selected by the switching operation means, an operation signal output from the manual operation member is input to the focusing means, and when a zooming means is selected, an operation signal output from the manual operation member. and control means for inputting the output of the focus detection circuit to the focusing means.