JPH05122594A - Video camera and video camera lens - Google Patents

Abstract

PURPOSE:To improve convenience by automating the adjustment of the display position of a center marker. CONSTITUTION:An optical lens 11 forms the image of an object on a CD 21. The CCD 21 generates image pickup signals by converting beams to electric signals. A process circuit 22 outputs video signals by executing a prescribed signal processing to the image pickup signals. A memory 12 stores the position information of the optical axis of the optical lens 11 on the CCD 21. Based on the position information of the optical axis supplied through an interface 13, a control circuit 23 controls the display position of the center marker so as to be corresponding to the optical axis position of the optical lens 11. Video signals for displaying the center marker are generated by a VF interface 24 and superimposed to the video signals from the process circuit 22. A view finder 25 displays images corresponding to the video signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera,
In particular, the present invention relates to a video camera with interchangeable lenses.

[0002]

2. Description of the Related Art Although it is widely used in commercial video cameras, even in recent years high performance consumer video cameras, the user can replace the lens according to the subject. In such a video camera in which the lens can be exchanged, a center marker indicating the optical axis of the lens is displayed on a so-called viewfinder so as to be superimposed on the captured image.

By the way, the optical axis of a lens is peculiar to the lens, and when the lens is attached to a video camera,
The optical axis of the lens does not always coincide with the center of the image pickup surface of the image pickup element (hereinafter, simply referred to as the image pickup element). Therefore, for example, if the display position of the center marker is fixed so that the center marker is always displayed at the position on the viewfinder corresponding to the center of the image sensor, it does not cause much problem at the so-called zoom-out. , When zooming in (zooming up), the intended close-up image moves on the viewfinder due to the displacement of the optical axis position of the lens with respect to the center of the image sensor. Chipped.

Therefore, in a commercial video camera or the like, the display position of the center marker can be adjusted. Specifically, for example, open the side plate of the video camera,
Adjust the display position of the center marker For example, turn the volume using the adjustment driver, so that the display position of the center marker matches the position on the viewfinder corresponding to the optical axis position of the lens on the image sensor, The display position of the center marker is adjusted. The procedure is to fix the video camera after zooming out so that the center marker is aligned with the horizontal and vertical reference subjects, such as the corners of the window frame and the corners of the door, while looking at the viewfinder. The zoom-up is performed, the shift of the center marker with respect to the reference is observed, and the display position of the center marker is adjusted using the volume so that the shift is eliminated. Then, the zoom-out is performed again, and the above procedure is repeated a plurality of times to adjust the display position of the center marker. The adjustment range is, for example, about 3% in both horizontal and vertical directions (corresponding to 5 μs in the horizontal direction and 16 lines in the vertical direction).

[0005]

Therefore, in the conventional video camera in which the lens can be replaced, the display position of the center marker as described above must be adjusted every time the lens is replaced, which is very troublesome. There was a problem of this.

The present invention has been made in view of such a situation, and as described above, it is necessary to manually adjust the display position of the center marker, which is very troublesome every time the lens is replaced. It is intended to provide a video camera which can be automated and is convenient for users.

[0007]

According to the present invention, in order to solve the above problems, in a video camera having a viewfinder for displaying an image based on an image pickup signal from an image pickup device, an image of a subject is displayed on the image pickup device. An optical lens for forming an image on the image pickup device, storage means for storing positional information of the optical axis of the optical lens on the image pickup device, and output positional information of the optical axis of the optical lens stored in the storage means. A lens unit that has an electrical output means and is detachably attached to the camera body, and a video signal for displaying the center marker is generated, and the video signal is superimposed on the imaging signal from the imaging device. Output to the viewfinder, and based on the position information of the optical axis of the optical lens supplied through the output means of the lens unit, the display position of the center marker is And having a control means for controlling so as to position on the viewfinder corresponding to the optical axis position of the optical lens on the element.

Further, according to the present invention, an optical lens for forming an image of a subject on an image pickup device, a storage means for storing position information of the optical axis of the optical lens on the image pickup device, and the storage means are provided. And an electrical output means for outputting the stored optical axis position information of the optical lens.

[0009]

In the video camera according to the present invention, the position information about the optical axis of the optical lens is stored in the storage means of the lens unit.
When the lens unit is attached to the camera body, the display position of the center marker is changed to the view corresponding to the optical axis position of the optical lens on the image sensor based on the stored optical axis position information of the optical lens. Control so that the position on the viewfinder is reached.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video camera to which the present invention is applied will be described below with reference to the drawings. The video camera of this embodiment, as shown in FIG. 1, for example, attaches and detaches a lens unit 10 that collects light from a subject and forms an image, and images the light collected by the lens unit 10. It is composed of a camera body 20 for converting into a signal.

The camera body 20 is also shown in FIG.
As shown in FIG. 3, an image sensor 21 for converting light from the lens unit 10 into an electric signal, for example, a so-called CCD image sensor, and a process circuit 22 for converting the image signal from the image sensor 21 into a predetermined video signal. And a control circuit 23 for controlling the display position of the center marker on the basis of optical axis data described later from the lens unit 10 and a video signal for displaying the center marker, and the control circuit 23 described later. The VF interface 24 superimposes the video signal on the video signal from the process circuit 22 based on the position data to be displayed, and the viewfinder 25 for displaying an image corresponding to the video signal from the VF interface 24. ..

This video camera uses an image pickup signal from an image pickup device (hereinafter referred to as CCD) 21 as, for example, NT.
It is adapted to be converted into a video signal conforming to the SC system and output via the terminal 26. Further, this video camera displays the center marker on the viewfinder 25 by superimposing the center marker on the captured image, and based on the optical axis data from the lens unit 10, the display position of the center marker is changed to the CCD.
A viewfinder 25 corresponding to the optical axis position of the lens unit 10 on the imaging surface of 21 (hereinafter, simply referred to as CCD 21).
The control is performed so as to match the above position.

Specifically, as shown in FIG. 1, the lens unit 10 includes an optical lens 11 for forming an image of a subject on the CCD 21, and an optical axis of the optical lens 11 on the CCD 21. A memory 12 for storing position information of
It is composed of an interface 13 which supplies the position information of the optical axis stored in the memory 12 to the control circuit 23 as optical axis data. The circuit system of the interface 13 may be either a serial system or a parallel system.

The memory 12 stores the position information of the optical axis of the optical lens 11 with respect to the center of the CCD 21, for example, when the lens unit 10 is attached to the camera body 20 at the manufacturing stage. The interface 13 is electrically connected to the control circuit 23 when the lens unit 10 is attached to the camera body 20, and the lens unit 10 is stored in the memory when the lens unit 10 is attached to the camera body 20. The stored position information of the optical axis is supplied to the control circuit 23 as optical axis data. The optical axis data is, for example, data indicating the position of the optical axis with the center of the CCD 21 as the origin of the coordinates (hereinafter referred to as optical axis data (x, y)).

The control circuit 23 uses the optical axis data (x, y) supplied via the interface 13 as horizontal and vertical position data (hereinafter referred to as position data) with the upper left corner of the viewfinder 25 as the origin of coordinates. (H,
V)) and convert this position data (H,
VF as the data of the display position of the center marker.
Supply to the interface 24.

The VF interface 24 is shown in FIG.
As shown in A, a video signal for displaying "+" as the center marker SM is generated, and the generated video signal is displayed so that the center marker SM is displayed at the position corresponding to the position data (H, V). Is superimposed on the video signal from the process circuit 22. Then, the obtained video signal is supplied to the viewfinder 25. The shape of the center marker may be, for example, the center marker SM shown in FIG. 2B.
₁ , it may be shaped like the center marker SM ₂ shown in FIG. 2C.

Thus, the viewfinder 25 displays an image corresponding to the video signal obtained by photographing the subject, and the viewfinder 25 on the viewfinder 25 corresponds to the optical axis position of the optical lens 11 on the CCD 21. A center marker is displayed at the position. That is, it is possible to automatically adjust the display position of the center marker to match the optical axis position of the optical lens 11, and it is possible to eliminate the manual adjustment of the display position of the center marker which has been performed conventionally. As a result, even if the lens is replaced and the center marker is adjusted to the desired subject and zoomed up, the image of the subject does not move laterally, for example.

The present invention is not limited to the above-described embodiment. For example, the memory 12 is a so-called dip switch, and the position information of the optical axis of the optical lens is set in the dip switch. Good. Further, as the position information of the optical axis of the optical lens, an analog signal may be used instead of the digital signal of the embodiment.

[0019]

As is apparent from the above description, in a video camera having a viewfinder that displays an image based on an image pickup signal from the image pickup device, information on the position of the optical axis of the optical lens on the image pickup device is stored. Incidentally, when the lens unit is attached to the camera body, a video signal for displaying the center marker is generated, and the video signal is superimposed on the imaging signal from the imaging device and output to the viewfinder, Based on the position information of the optical axis of the optical lens supplied via the output means of the lens unit, the display position of the center marker corresponds to the optical axis position of the optical lens on the image sensor, the position on the viewfinder. By controlling so that the display position of the center marker is very time-consuming, which is required every time the lens is replaced in the conventional video camera. You can automate Le adjustment, thereby improving the convenience.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of a video camera to which the present invention is applied.

FIG. 2 is a diagram showing a specific example of a center marker.

[Explanation of symbols]

 10 ... Lens part 11 ... Optical lens 12 ... Memory 13 ... Interface 23 ... Control circuit 24 ... VF interface 25 ... Viewfinder

Claims (2)

[Claims] 1. A video camera having a viewfinder for displaying an image based on an image pickup signal from an image pickup device, comprising: an optical lens for forming an image of a subject on the image pickup device;
A storage unit that stores the position information of the optical axis of the optical lens on the image pickup device, and an electric output unit that outputs the position information of the optical axis of the optical lens stored in the storage unit are provided. Then, a lens unit detachably attached to the camera body and a video signal for displaying the center marker are generated, and the video signal is superimposed on the imaging signal from the imaging device and output to the viewfinder. The display position of the center marker corresponds to the optical axis position of the optical lens on the image pickup device based on the optical axis position information of the optical lens supplied via the output means of the lens unit. A video camera having a control means for controlling the position on the viewfinder. 2. An optical lens for forming an image of a subject on an image pickup device, a storage means for storing position information of an optical axis of the optical lens on the image pickup device, and the storage means. A video camera lens, comprising: an electric output unit that outputs position information of the optical axis of the optical lens.