JP2877523B2 - Video camera with electronic viewfinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera having an electronic viewfinder.

[0002]

2. Description of the Related Art In a home video camera, an image of a subject such as a scene currently being recorded can be confirmed by an electronic viewfinder. In this case, the entire subject image projected by the electronic viewfinder is recorded. Is selected so as to be the same as the range of the subject.

[0003]

Therefore, since the electronic viewfinder cannot confirm the surrounding situation other than the range of the subject to be recorded, the subject of the video camera is determined by the electronic camera when the subject moves fast. There was a problem that it was difficult to chase while looking through the viewfinder. In addition, even when the subject does not move, the second image to be captured next is located outside the monitor range of the first target subject.
It is difficult to find the second subject continuously from the first subject (while looking at the electronic viewfinder) and take an image of the second subject when there is the target subject of (1).

In such a case, in the related art, the surroundings are checked with the eyes that do not look into the electronic viewfinder. However, this method is difficult when the user is unfamiliar.
In this case, the imaging is generally stopped, the user temporarily removes his / her eyes from the electronic viewfinder to search for a target subject, and then starts shooting again. Therefore, at this time, the captured image is discontinuous, and there is a problem that the interest is reduced by half depending on the captured scene.

In the present invention, in consideration of the above points, a wider range (hereinafter, referred to as a monitor range) including a target recording range (hereinafter, simply referred to as a recording range) can be easily confirmed in the electronic viewfinder. It is like that.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a video signal obtained from an image pickup device is supplied, and an electronic viewfinder for monitoring a subject image thereof is obtained. Selecting means for selecting a video signal in a range to be recorded from the video signal; memory means for temporarily storing the selected video signal selected by the selecting means; A conversion means for converting the video signal into a video signal that matches the signal, and a video signal obtained from the imaging element are supplied, and a luminance level of the range to be recorded is within a monitor range located outside the recording range. Brightness change means for obtaining a video signal for a viewfinder having different brightness levels.

[0007]

According to the present invention, of the video signals obtained from the image sensor 1, a signal in a range to be recorded is selected by the selection means 3 and temporarily stored in the memory 4, and a signal read out of the memory 4 is used as a television signal. The video signal is converted by the conversion means 5 so that the video signal matches the video signal.

On the other hand, a luminance changing means 7 is provided, whereby the luminance of the video signal supplied from the image pickup device 1 to the electronic viewfinder 10 and the luminance of the video signal selected by the selecting means 3 in the video signal are provided. Can be monitored, the monitor image of the electronic viewfinder 10 can monitor portions other than the recording range, and even a fast-moving subject can follow the electronic viewfinder without taking his eyes off the electronic viewfinder.

[0009]

Next, an example of a video camera having an electronic viewfinder according to the present invention will be described with reference to the drawings.

In FIG. 1, a video signal from an image pickup device (hereinafter, referred to as a CCD) 1 such as a CCD is converted into a digital signal by an A / D converter 2 and the video signal picked up by the CCD 1 is recorded. The video signal is input to the memory 4 via the write processing circuit 3 constituting a selecting means for selecting a video signal in a range to be stored, and is temporarily stored therein.

The digital signal read from the memory 4 is processed by a read processing circuit 5 constituting a conversion means for converting the digital signal into a video signal suitable for a television signal. It is converted into a signal and output as a video signal. This video signal is used for recording or for external monitoring.

On the other hand, a video signal obtained from the CCD 1 is sent to an electronic viewfinder 10 through a brightness changing means 7.
Is input to In the example shown in the figure, the brightness changing means 7 includes a gain control circuit 8 and an electronically configured changeover switch 9.

A video signal from the CCD 1 is supplied to one fixed terminal 9a of the changeover switch 9, and
The voltage is supplied to the other fixed terminal 9b of the changeover switch 9 via the gain control circuit 8, and the changeover terminal 9c of the changeover switch 9 is switched to the fixed terminal 9a or 9b in the state shown by the solid line or the state shown by the dotted line, and C
The video signal obtained from the CD 1 is supplied to the electronic viewfinder 10 with or without gain control. In this case, the gain of the gain control circuit 8 is selected to be 1 / n. Therefore, when the changeover switch 9 is in the state shown by the dotted line, the video signal from the CCD 1 is attenuated by the gain control circuit 8 and the electronic viewfinder 1
0 is supplied.

From the control signal generating circuit 11, a vertical drive signal Sv and a horizontal drive signal Sh are supplied to the CCD 1,
A drive clock Sk for the A / D converter 2 and the D / A converter 6, a processing clock Sc for each processing for the write processing circuit 3 and the read processing circuit 5, and a processing clock Sc for the memory 4. In addition, a write pulse Pw and a read pulse Pr are output to the gain control circuit 8, and a switch control signal Sw is output to the changeover switch 9. Note that the gain control signal Sg may be arbitrarily adjusted manually or may be semi-fixed.

The operation of this configuration will be described with reference to FIG. FIG. 2A shows a captured image of the CCD 1, and the whole is monitored by the electronic viewfinder 10. FIG. 2B shows this monitor image, and the entire range projected on this monitor image is defined as a monitor range P. In addition, a range to be recorded in the monitor range P is indicated by Q, and this range is hereinafter referred to as a recording range Q. The monitor range P and the recording range Q are
For each of the vertical scanning period and the horizontal scanning period,
For example, a ratio of 2: 1 can be selected.

In FIG. 2B, a is from the upper end of the monitor range P to the upper end of the recording range Q, b is from the upper end to the lower end of the recording range Q, and c is from the lower end of the recording range Q to the lower end of the monitor range P. Each vertical scanning period, and the monitor range P
The horizontal scanning period is d from the left end to the left end of the recording range Q, e is from the left end to the right end of the recording range Q, and f is from the right end of the recording range Q to the right end of the monitor range P.

A video signal from the CCD 1 is converted into a digital signal by an A / D converter 2 and is written into a write processing circuit 3.
Is input to FIG. 2C shows an image before being processed by the write processing circuit 3. In this write processing circuit 3, A
Of the digital signals input from the / D converter 2, the digital signals input during the vertical scanning periods a and c;
The digital signal input to the horizontal scanning periods d and f of the vertical scanning period b is prevented from passing, and only the digital signal input to the horizontal scanning period e of the vertical scanning period b is passed. It is processed. Therefore, the digital signal output from the write processing circuit 3 is a digital signal only within the recording range Q.

The digital signal in the recording range Q is input to the memory 4 and temporarily stored therein. The digital signal read from the memory 4 is input to a read processing circuit 5, where the digital signal is processed so as to be a video signal (original video signal) suitable for a television signal.
That is, the digital signal in the recording range Q is such that its vertical and horizontal scanning periods are shorter than those of the original video signal.
Since the scanning period is short in both cases, this signal cannot be used as it is as a video signal. Therefore, the digital signal read from the memory 4 needs to be converted so as to be in the vertical and horizontal scanning periods of the original video signal, and the read processing circuit 5 performs this processing.

As a specific example of this processing, when the vertical and horizontal scanning periods of the digital signal read from the memory 4 are １ ／ of the original video signal, each horizontal scanning period is The line is scanned twice and the horizontal line is interpolated.
By interpolating the preceding pixel between the preceding and succeeding pixels, a video signal that matches the original video signal and the corresponding television signal can be obtained, and a so-called electronically zoomed video signal can be obtained. FIG. 2D shows the image after the reading process.

On the other hand, the changeover switch 9 is switched as described below. That is, the vertical scanning periods a and c
In the vertical scanning period b, during the horizontal scanning period d, the state is switched to the dotted line state, during the horizontal scanning period e, the state is switched to the solid line state, and during the horizontal scanning period f, the dotted line state is restored. Is switched to.

Therefore, in the vertical scanning periods a and c and the horizontal scanning periods d and f in the vertical scanning period b, the video signal whose gain has been suppressed is input to the electronic viewfinder 10, and In the horizontal scanning period e, a video signal whose gain is not suppressed is input to the electronic viewfinder 10. Therefore, in the electronic viewfinder 10, as shown in FIG. 2B, the monitor range P has a normal luminance, and the monitor range P around the record range Q (shaded area) has a lower luminance than the record range Q. Is obtained.

Note that the ratio of the size of the image in the recording range Q to the image (image in the monitor range P) viewed in the electronic viewfinder 10 can be set in the control signal generation circuit 11, and this setting can be made in a semi-fixed system. Alternatively, a plurality of selection methods may be used.

[0023]

As described above, according to the video camera having the electronic viewfinder according to the present invention, the surrounding situation other than the subject in the range to be recorded can be confirmed while looking only at the electronic viewfinder. Therefore, a necessary scene can be imaged without taking an eye from the viewfinder during the imaging by the video camera as in the related art. Therefore, even a fast-moving subject can be imaged following the subject, and there is an effect that imaging with a video camera can be performed more smoothly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a video camera having an electronic viewfinder according to the present invention.

FIG. 2 is an explanatory diagram of an operation of a video camera having an electronic viewfinder according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CCD imaging device 2 A / D converter 3 Recording range selection means 4 Memory 5 Conversion means to video signal 6 D / A converter 7 Brightness change means 8 Gain control circuit 9 Changeover switch 10 Electronic viewfinder 11 Control signal generation circuit

Claims (1)

(57) [Claims] 1. An electronic viewfinder to which a video signal obtained from an image sensor is supplied and an object image thereof is monitored, and a selection means for selecting a video signal in a range to be recorded from the video signal obtained from the image sensor. Memory means for temporarily storing the selected video signal selected by the selecting means; converting means for converting the selected video signal read from the memory means into a video signal suitable for a television signal; The obtained video signal is supplied, and a luminance change is performed to obtain a video signal for a viewfinder in which the luminance level in a monitor range located outside the recording range is made different from the luminance level in the range to be recorded. A video camera having an electronic viewfinder.