JPH0771200B2 - Electronic buffer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention extracts a finder image based on a finder image signal obtained by extracting an edge signal from an original image signal and synthesizing the edge signal with the original image signal. The present invention relates to an electronic viewfinder device for displaying.

[Prior Art] When a subject is imaged using a television camera, a cameraman uses a small television monitor such as a so-called electronic viewfinder to focus a lens attached to the television camera. .

In general, a small monitor such as an electronic viewfinder of this type has a small screen and often has a poor resolution, so that it is difficult to perform focusing without skill. Therefore, conventionally, a method of facilitating focusing by adding an edge signal which is a contour signal of a subject video signal or a high frequency signal to the original video signal to emphasize the contour of the finder video has been used. Still,
Often not enough for focusing.

[Problem to be Solved by the Invention] Therefore, an object of the present invention is to easily process a focus of a television camera and appropriately process an original video signal so that a cameraman can easily recognize a focused state. To provide the electronic viewfinder device.

Another object of the present invention is to provide an electronic viewfinder device in which an edge signal for visually enhancing the edge signal is added to the original video signal.

[Means for Solving Problems] In order to achieve such an object, an electronic viewfinder device according to the present invention extracts an edge signal from an original video signal, and uses the edge signal as the original video signal. In an electronic viewfinder device that displays a finder image based on a finder image signal obtained by combining, by intermittently thinning out the edge signal, it is converted into an intermittent edge signal that appears at a constant repeating cycle with high visibility. Conversion means, detecting means for detecting that the focusing operation of the television camera has been performed, and a constant value during the focusing operation period of the television camera and after the operation based on the detection output of the detecting means. Signal generating means for generating a time window signal over a period of time, and the intermittent edge signal in response to the generation of the time window signal. And a display means for displaying the image as the finder video signal.

It is preferable to set the above-mentioned repetition period between 10 Hz and 50 Hz.

[Operation] In the present invention, instead of simply adding an edge signal which is a contour signal or a high frequency signal, for example, a repetition cycle of 10 Hz to
By adding intermittently at about 50Hz temporally, thereby displaying edge signals that are contour signals and high-frequency signals in a so-called flicker shape, the added edge signals are emphasized and focusing is further facilitated. To be able to.

The flicker-like edge signal is added to the flicker-like edge only for a predetermined period related to the focusing operation in accordance with the focusing operation information extracted from the focus position information, considering that the eye is likely to be tired. As a result, it is possible to eliminate eye fatigue caused by the photographer's long working hours.

EXAMPLES The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a contour or high frequency component extraction circuit, 2 is an intermittent processing circuit, 3 is a synthesis circuit, 4 is a viewfinder section, 5 is a camera lens system,
6 is a change detector, and 7 is a time window generator.

An original video signal output from a television camera (not shown) is guided to a contour or high frequency component extraction circuit 1, where a so-called edge component is extracted in the form of a contour signal or a high frequency component. The extracted edge signal is then supplied to the intermittent processing circuit 2. In the intermittent processing circuit 2, the intermittent edge signal output from the circuit 1 is not always added to the original video signal, but is added to the original video signal only intermittently at a repetition cycle of 10 Hz to 50 Hz only during focus adjustment. Perform "decimation" of signals. For example, the frame is dropped according to the edge signal, and the edge signal is output once every several fields. By performing the intermittent processing as described above, the edge signal appears to flicker like a flicker on the screen of the viewfinder unit 4 and is visually very noticeable. The intermittent processing in the intermittent processing circuit 2 does not necessarily need to be locked to the field rate.

The intermittent edge signal subjected to the intermittent processing is supplied to the synthesizing circuit 3, where it is synthesized with the original video signal. The synthesized signal is supplied to the viewfinder section 4 to display a finder image with an enhanced contour. According to this, the photographer
A good focusing operation can be performed by focusing on the contour portion of the image which is projected most noticeably by the flicker-like intermittent edge signal.

On the other hand, focus position information from the camera lens system 5, for example, a signal extracted from a potentiometer linked to the focusing operation is supplied to the change detector 6, and when the focus position changes, that is, the cameraman performs the focusing operation. To detect that The detection output is used as a focusing operation signal to generate a time window generator 7
A window signal for operating the intermittent processing circuit 2 during the focusing operation and for a certain period after the focusing operation is completed, for example, for 1 to 2 seconds.

This window signal is supplied to the intermittent processing circuit 2, and the edge signal subjected to the intermittent processing is taken out only during the occurrence period of the window signal.
This intermittent edge signal is combined with the original video signal. In this way, the flicker-like edge signal is superimposed on the original video signal, so that the edge in the video image is flickered by the cameraman, so that it is visually noticeable.
On the other hand, since such a flicker-like edge easily causes eye fatigue, the edge of the image is not flickered and displayed when the focusing operation is not performed. That is, the edge signal is displayed by being superimposed on the original video signal without causing flicker. In this way, in the present invention, the cameraman can perform good focusing.

Next, as described above, several methods are conceivable for detecting the focus position change information from the focus position information in the change detector 6, but here, two examples thereof are shown in FIG. 2 and FIG. Shown in the figure.

In the example of FIG. 2, the potentiometer 8 linked to the focus position detects the voltage of the focus position information and outputs the voltage to the Nyquist sampling low-pass filter 9
Then, the sample and hold circuit 10 performs sample and hold at an appropriate frequency. This sample-and-hold output, that is, the position information of one clock before is output to the comparator 10
Input to one of the input terminals. The output of the low-pass filter 9, that is, the current position information is directly input to the other input terminal, the two signals are compared, and if a difference occurs between the two signals, it is considered that the focusing operation is in progress, The comparison output is taken out as focus position change information.

In the example of FIG. 3, the output from the potentiometer 8 is passed through the low pass filter 9 as in the case of FIG. Then, the A / D converter 12 performs A / D conversion to obtain the current position information. While supplying the output of the A / D converter 12 directly to the comparator 14,
The data is supplied to the latch 13, and the position information one sample before from the latch 13 is supplied to the other input terminal of the comparator 14.
Therefore, in the comparator 14, the present and 1
The position information before the sample is compared, and when there is a difference between the two, an output indicating that the focusing operation is being performed, that is, focus position change information is obtained. Here, the latch 13 and the comparator 14 may be configured by a microprocessor.

Next, if the image content changes without changing the mirror position, such as panning and zooming, basically it is determined by the field memory that the image is a moving image. A flicker-like contour or a high frequency component may be displayed.

For example, as shown in FIG. 4, the input video signal is passed through a two-dimensional low-pass filter 15 for Nyquist, and then the signal delayed by one field by the field memory 16 and the output of the two-dimensional low-pass filter 15 are subtracted. Circuit 17
To subtract the field difference signal. This field difference signal is supplied to the binarization circuit 18, and when the field difference signal exceeds a certain level, it is judged to be a moving image, its output is guided to the time window generator 7, and the period of the moving image and thereafter fixed. The edge component which is the contour or the high frequency component is displayed in a flicker shape over the period. Here, the field memory 16 does not need to have a large capacity so as to store the data of each picture element, and may be one corresponding to a rough picture element number.

Furthermore, in order to facilitate focus adjustment, for example, as shown in FIG. 5, the output of the extraction circuit 1 may be supplied to the intermittent processing circuit 2 via a circuit 19 having a non-linear characteristic.

As for the non-linear characteristic, as shown in FIG. 6, for example, the edge signal may not be added when the edge signal is small, and may be added only for the edge signal having a certain level or higher. In FIG. 6, the horizontal axis is the input level of the contour or the high frequency component, and the vertical axis is the output level.

[Effects of the Invention] As is apparent from the above, according to the present invention, the edge signal, which is an important clue for focusing by the cameraman, is made into a visually enhanced flicker-like signal, and the contour in the viewfinder image is It can be displayed on the viewfinder or the like while flickering, which makes it easier for the cameraman to determine the best focus state.

Moreover, considering that the flicker-shaped edge signal easily causes fatigue to the eyes, the flicker-shaped edge signal is added only for a predetermined period related to the focusing operation according to the focusing operation information extracted from the focus position information. This has the effect of eliminating eye fatigue caused by the photographer's long work hours. As a result, the effect of reducing the fatigue of the photographer is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2 to 4 are block diagrams showing three examples of change detection circuits thereof, and FIG. 5 is a block diagram showing an example of a non-linear circuit. The figure is a characteristic diagram showing a non-linear characteristic example. 1 ... contour or high frequency component extraction circuit, 2 ... intermittent processing circuit, 3 ... synthesis circuit, 4 ... viewfinder section, 5 ... camera lens system, 6 ... change detector, 7 ... time window generation Potentiometer, 8 ... Potentiometer, 9 ... Low-pass filter, 10 ... Sample-hold circuit, 11 ... Comparator, 12 ... A / D converter, 13 ... Latch, 14 ... Comparator, 15 ... Two-dimensional low-pass Filter, 16 ... Field memory, 17 ... Subtraction circuit, 18 ... Binarization circuit, 19 ... Non-linear circuit.

Claims (2)

[Claims] 1. An electronic viewfinder apparatus for displaying a finder image based on a finder image signal obtained by extracting an edge signal from an original image signal and combining the edge signal with the original image signal. By intermittently thinning out, a conversion means for converting into an intermittent edge signal that appears in a constant repetition cycle with high visibility, a detection means for detecting that a focusing operation of the television camera has been performed, and the detection Signal generating means for generating a time window signal during the focusing operation period of the television camera and for a fixed period after the end of the operation based on the detection output of the means; and the intermittent edge in response to the generation of the time window signal. A signal for synthesizing a signal with the original video signal and displaying it as the finder video signal. A view finder device. 2. The electronic viewfinder device according to claim 1, wherein the repetition period is 10 Hz to 50 Hz.
Electronic viewfinder device characterized by being set between Hz.