JPH05150291A - Video camera - Google Patents

Abstract

PURPOSE:To eliminate the need of switching operation to a manual mode from an automatic mode as for an operation mode for focusing. CONSTITUTION:When a manual focusing device 7 is rotated while the AF (automatic mode) is set by operating an AF/MF switching device 6, the rotation thereof is detected by a rotation detection circuit 8 and a detection signal corresponding to the degree of the rotation (displacement quantity) is outputted to a microcomputer 5. By the computer 5, the mode is switched to the manual mode from the automatic mode in response to the detection signal from the detection circuit 8 and a focus motor 3 is controlled according to the detection signal from the detection circuit 8. Then, a master lens 2 is moved. In the case that the mode is returned to the automatic mode thereafter, it is switched to the automatic mode by operating the switching device 6. Thus, the focusing intended by a photographer can be quickl executed while photographing is executed in the automatic mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera capable of focus adjustment in two operation modes, a manual mode and an automatic mode.

[0002]

2. Description of the Related Art In recent years, various improvements such as miniaturization have been added to video cameras. In particular, recently, an inner focus system for focusing by moving a master lens of a lens unit has been adopted to perform automatic focus adjustment. The speed and the breadth of focus are improved.

A conventional inner focus system for a video camera will be described below with reference to the drawings.
FIG. 2 is a block diagram of an inner focus system of a conventional video camera. In FIG. 2, 1 is a front lens, 2 is a master lens, 3 is a focus motor for moving the master lens 2, 4 is an AF signal processing circuit, 5 is a microcomputer, 7 is a manual focus adjustment device, and 8 is a manual focus adjustment. A rotation detection circuit for detecting rotation of the device 7, and an AF / MF switching device 11 for switching between an automatic mode (AF; auto focus) and a manual mode (MF; manual focus) which are operation modes of focus adjustment.

The operation of the inner focus system of the video camera constructed as above will be described below. First, when the AF / MF switching device 11 is set to AF (automatic mode), the light passing through the front lens 1 and the master lens 2 is input to the AF signal processing circuit 4. The AF signal processing circuit 4 processes the video signal,
The focus voltage is output to the microcomputer 5. The microcomputer 5 controls the focus motor 3 so that a certain high frequency component in the video signal becomes the largest, and moves the master lens 2 to a position where it is always in focus.

Next, the AF / MF switching device 11 is set to the MF.
When set to (manual mode), the manual focus adjustment device 7
The rotation detection circuit 8 detects the change in rotation of No. 2, and the microcomputer 5 controls the focus motor 3 according to the detection signal to move the master lens 2 to change the focus.

[0006]

However, in the above-mentioned conventional configuration, when the AF / MF switching device 11 is set to AF and it is out of focus, or when it is desired to blur the focus, first the AF / MF switching device is used. There is a problem that it takes time to switch from the automatic mode to the manual mode because the operation in the manual mode is performed after switching 11 to the MF.

An object of the present invention is to provide a video camera which does not require a switching operation from an automatic mode to a manual mode in a focus adjustment operation mode.

[0008]

The video camera according to the present invention is characterized in that the control device switches from the automatic mode to the manual mode in response to the detection signal of the detection circuit.

[0009]

According to the structure of the present invention, the control device is adapted to switch from the automatic mode to the manual mode in response to the detection signal of the detection circuit. Therefore, by operating the manual focus adjusting device during photographing in the automatic mode. The control device switches from the automatic mode to the manual mode in response to the detection signal from the detection circuit that detects the displacement amount of the manual focus adjustment device, and drives the focus motor according to the detection signal of the detection circuit to control the focus adjustment lens. To move. As described above, the focus can be manually adjusted by directly operating the manual focus adjusting device without performing the switching operation to the manual mode by the mode switching device during the photographing in the automatic mode.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an inner focus system of a video camera according to an embodiment of the present invention. In FIG. 1, 1 is a front lens, 2 is a master lens (focus adjustment lens), 3 is a focus motor for moving the master lens 2, 4 is an AF signal processing circuit (signal processing circuit), and 5 is a microcomputer (control). Device), 6
Is an AF / M including a push button for switching between an automatic mode (AF; auto focus) and a manual mode (MF; manual focus), which are focus adjustment operation modes.
F switching device (mode switching device), 7 is a manual focus adjustment device, 8 is a rotation detection circuit (detection circuit) that detects rotation of the manual focus adjustment device 7, and 9 is an electric viewfinder normally mounted on a video camera. AF / MF status display device for displaying the operation mode, 10 is a lens unit,
The parts corresponding to those of the conventional example are designated by the same reference numerals as those in FIG.

The operation of the inner focus system of the video camera constructed as above will be described below mainly with respect to the difference from the conventional example. When the AF / MF switching device 6 is set to AF (automatic mode), the light passing through the front lens 1 and the master lens 2 is detected by the AF
The signal is processed by the signal processing circuit 4 and is output to the microcomputer 5 as a focus voltage. The microcomputer 5
So that a certain high frequency component in the video signal becomes the largest,
The focus motor 3 is controlled so that the master lens 2 is always moved to the in-focus position. The process up to this point is the same as in the conventional example. Here, when the manual focus adjustment device 7 is rotated, the rotation is detected by the rotation detection circuit 8, and a detection signal corresponding to the degree of rotation (displacement amount) is output to the microcomputer 5.
Output to. In the microcomputer 5, the automatic mode is switched to the manual mode in response to the detection signal from the rotation detection circuit 8, the focus motor 3 is controlled according to the detection signal from the rotation detection circuit 8, and the master lens 2 is moved. The operation in this manual mode is similar to the conventional example. After that, when returning to the automatic mode, the AF / MF switching device 6 is operated to switch to the automatic mode.

Further, since the AF / MF status display device 9 displays the operation mode, it is always possible to confirm whether the mode is the automatic mode or the manual mode. As described above, according to this embodiment, by operating the manual focus adjusting device 7 during photographing in the automatic mode, the microcomputer 5 responds to the detection signal of the rotation detection circuit 8 to switch from the automatic mode to the manual mode. , According to the detection signal of the rotation detection circuit 8,
The microcomputer 5 drives and controls the focus motor 3 to move the master lens 2. As described above, the focus can be manually adjusted by directly operating the manual focus adjusting device 7 without performing the switching operation to the manual mode by the AF / MF switching device 6 during the photographing in the automatic mode. Therefore, it does not take time to switch from the automatic mode to the manual mode, and the photographer can quickly adjust the focus to his or her intention.

[0013]

According to the video camera of the present invention, since the control device is switched from the automatic mode to the manual mode in response to the detection signal of the detection circuit, it is possible to operate the manual focus adjusting device during photographing in the automatic mode. Causes the controller to switch from automatic mode to manual mode in response to a detection signal from the detection circuit that detects the amount of displacement of the manual focus adjustment device, and drives and controls the focus motor according to the detection signal from the detection circuit to adjust the focus. Move the lens. As described above, the focus can be manually adjusted by directly operating the manual focus adjusting device without performing the switching operation to the manual mode by the mode switching device during the photographing in the automatic mode. Therefore, it does not take time to switch from the automatic mode to the manual mode, and the photographer can quickly adjust the focus to his or her intention.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an inner focus system of a video camera according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an inner focus system of a conventional video camera.

[Explanation of symbols]

 2 master lens (focus adjustment lens) 3 focus motor 4 AF signal processing circuit (signal processing circuit) 5 microcomputer (control device) 6 AF / MF switching device (mode switching device) 7 manual focus adjustment device 8 rotation detection circuit (Detection circuit) 10 Lens part

Claims (1)

[Claims] 1. A lens unit having a focus adjustment lens,
A mode switching device for switching between a manual mode and an automatic mode, which are operation modes for moving the focus adjustment lens,
A focus motor that moves the focus adjustment lens, a signal processing circuit that converts light that has passed through the lens unit into a focus voltage, a manual focus adjustment device that is manually displaced, and a displacement amount of the manual focus adjustment device is detected. And a control device that drives and controls the focus motor in response to a detection signal of the detection circuit in the manual mode and drives and controls the focus motor in response to the focus voltage of the signal processing circuit in the automatic mode. A video camera provided with the control device, wherein the control device switches from an automatic mode to a manual mode in response to a detection signal from the detection circuit.