JPH08186767A - Field discrimination method and circuit - Google Patents

Abstract

PURPOSE: To provide a field discrimination method/device which can surely discriminate the fields of TV signals on any scene in a camera system using a solid state image pickup element. CONSTITUTION: The fields of TV signals' are discriminated for a period covering the solid state image pickup element read pulse (XSG1) outputted from a timing generation circuit which reads out a solid sate image pickup element through the rise of the horizontal synchronizing signal (HD) or the TV signal and according to the presence or absence of the frame shift pulse of a vertical register drive pulse of the image pickup element. In such a constitution, the fields of TV signals can be surely discriminated from each other.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Industrial Application Conventional Technology (FIGS. 13 and 14) Problems to be Solved by the Invention Means for Solving Problems (FIGS. 1 to 4) Actions (FIGS. 1 to 4) Embodiments (FIGS. 1 to 1) Figure 12) Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field discriminating method and a field discriminating circuit, and more particularly to a solid-state image sensor (CC).
It can be applied when discriminating the field of a television signal obtained by a camera system using D (Charge Coupled Device).

[0003]

2. Description of the Related Art Conventionally, as a color television projection camera system using a CCD, many home-use camera-integrated video tape recorders and the like to which an image stabilization function is added have been commercialized. Further, in a normal television camera system, a field determination signal FLD generated by a sync signal generation circuit (SG (Sync Signal Generator)) is used for field determination of a video signal.

Further, in a TV camera system or the like which does not have the field discrimination signal FLD, each functional block (IC)
Discriminate based on the phase difference between the vertical synchronizing signal (VD) and the horizontal synchronizing signal (HD). That is, FIG. 13 and FIG.
As shown in, the field determination method determines the field based on whether the falling edge of the horizontal synchronizing signal HD is synchronized with the falling edge of the vertical synchronizing signal VD. This is sufficient to distinguish between odd (ODD) and even (EVEN) fields in a normal video signal.

Practically, as shown in FIG. 13, a predetermined period tp from the fall of the vertical synchronizing signal VD (FIG. 13 (A)).
When the logical level of the horizontal synchronizing signal HD (FIG. 13 (B)) after d1 is “L”, the ODD field in the NTSC system,
In the PAL system, the EVEN field is determined. vice versa,
As shown in FIG. 14, the vertical synchronization signal VD (see FIG.
When the logical level of the horizontal synchronizing signal HD (FIG. 14 (B)) after a predetermined period tpd1 from the fall of (A)) is "H", it is determined that the NTSC system is the EVEN field and the PAL system is the ODD field.

[0006]

However, in a television camera system in which vertical correction of camera shake correction is realized by driving a CCD, the timing generation circuit is controlled by a microcomputer regardless of the original field during camera shake correction operation. In some devices, a TG (Timing Generator) is controlled, and the read pixel and the number of frame shifts are changed according to the motion of camera shake.

In a CCD defect correction block, for example, as a system in which it is necessary to perform field determination in synchronization with the readout pixels of the timing generation circuit TG, it is necessary to individually determine which field the timing generation circuit TG is reading. I have to. This is not possible by the discrimination based on the vertical synchronizing signal VD and the horizontal synchronizing signal HD, and there is a problem that there is no choice but to obtain some discrimination signal from the timing generation circuit TG or to receive a control signal from a microcomputer.

That is, in the image stabilization television camera system as described above, the ODD field is normally the CCD.
The first field for reading is the so-called V1 field, and the EVEN field is the second field, so-called V3 field.
The relationship that was usually the field was maintained, but V1 / V3 regardless of the ODD / EVEN field.
The problem is that the field changes.

[0009] This is a field determination ODD / EVEN
There is a problem that a circuit used for distinguishing V1 / V3 fields rather than distinguishing fields is more likely to fail. Further, in the current television camera system, the integrated circuit is advanced and the synchronizing signal generating circuit SG is built in the signal processing IC,
Since the microcomputer control is undecided, there is a problem in many TV camera systems in which the field determination signal FLD does not exist as in the conventional case.

The present invention has been made in consideration of the above points, and provides a field discriminating method and a field discriminating circuit which can surely discriminate the field of a television signal even in a situation where a camera system using a solid-state image sensor is used. It is a proposal.

[0011]

In order to solve such a problem, according to the present invention, in a field discriminating method for discriminating a field of a television signal obtained by a camera system using a solid-state image sensor, the solid-state image sensor is read. Is there a frame shift pulse of the vertical drive pulse for driving the vertical register of the solid-state image sensor during the period from the read pulse of the solid-state image sensor output from the timing generation circuit to the rise of the horizontal synchronizing signal of the television signal? The field is discriminated depending on whether or not it is.

Further, in the present invention, in the field discriminating circuit (1) for discriminating the field of a television signal obtained by a camera system using a solid-state image sensor,
Generate a detection window (FF1 / Q) during the period from the solid-state image sensor read pulse (XSG1) output from the timing generation circuit for reading the solid-state image sensor to the rise of the horizontal synchronizing signal (HD) of the television signal. Window generation means (2) for performing detection window (FF1 /
The determination means (3, 4) for determining the field depending on whether or not the frame shift pulse of the vertical drive pulse (XV1) for driving the vertical register of the solid-state imaging device is provided during the period of Q). I did it.

[0013]

In the period from the solid-state image sensor read pulse (XSG1) output from the timing generation circuit for reading the solid-state image sensor to the rise of the horizontal synchronizing signal (HD) of the television signal, the vertical direction of the solid-state image sensor is increased. The field can be reliably determined by determining the field depending on whether or not the frame shift pulse of the vertical drive pulse (XV1) for register drive exists.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

Among the image stabilization functions of a color television camera using a CCD, there is a television camera system that is realized by driving the CCD instead of using the image memory. This uses a CCD having an image pickup area and pixels larger than that of a normal CCD, and cuts out a part of this to use, and camera shake correction is performed by moving the cutout part.

In the vertical correction operation, in such a television camera system, the frame shift is usually performed after the CCD is read, and the sweep operation is performed after the video period ends. As a result, the screen in the vertical direction is cut out, and this cut out portion is moved by changing the frame shift number.

As a method of further improving the correction accuracy and smoothing the correction in this system, there is a method of forcibly changing the combination of pixel mixture of CCD. Normally, the readout of the CCD is a field determined by the vertical synchronizing signal VD and the horizontal synchronizing signal HD, that is, ODD field / EV.
Reading of the V1 field and the V3 field is switched according to the EN field. That is, the ODD field is V1 field and the EVEN field is V3 field.
It is fixed at the field.

In this state, only the movement in units of one line can be performed during the camera shake correction operation. However, if the relationship between the ODD field and the EVEN field is ignored and the reading of the V1 field and the V3 field is switched,
The cutout screen can be moved in units of 0.5 lines, and smooth movement can be realized.

The timing of the CCD drive pulse in the television camera system having the image stabilization function is shown in FIGS.
It shows in FIG. First, FIGS. 5 and 6 show NTSC, respectively.
FIG. 5 shows an ODD field / V1 field, and FIG. 6 shows an EVEN field / V3 field when the correction is performed in the vertical direction when there is no camera shake correction. Next, FIG. 7 and FIG. 8 respectively show timings in the vertical direction at the time of correction when there is camera shake correction in field reading of the NTSC system, FIG. 7 is ODD field / V1 field, and FIG. 8 is EVEN field / It is a V3 field. There is no field reversal at this time.

9 and 10 are NTSC, respectively.
FIG. 9 shows an ODD field / V3 field, and FIG. 10 shows an EVEN field / V1 field when the camera shake is corrected by the field read of the method. At this time, there is a field reversal. Further, FIG. 11 and FIG.
12 shows the timing of the horizontal frame shift start portion at the time of correction when there is camera shake correction in the TSC field reading, and FIG. 11 shows the V1 field and FIG.
Is the V3 field.

1 and 2 show an embodiment of the field discriminating method according to the present invention. The signal actually used is a CCD read pulse XS which indicates the start of reading of the CCD.
G1 and the horizontal synchronizing signal HD and the vertical drive pulse XV1 for driving the CCD vertical register. Vertical drive pulse XV1
As described above with reference to FIGS. 11 and 12, since the frame shift portion is different between the V1 field and the V3 field during camera shake correction, the field is determined based on this.

The determination method is as follows. First, a detection window is formed in the period from the timing of the read pulse XSG1 to the timing of the rise of the horizontal synchronizing signal HD, and within the period of this detection window, the frame shift pulse of the vertical drive pulse XV1. If there is a frame shift pulse, it is determined to be V1 field.
Determined as 3 fields.

In practice, as shown in FIG. 1, when the logical level of the horizontal synchronizing signal HD is "L" after a predetermined period tpd2 from the rising of the vertical drive pulse XV1 at the frame shift start portion immediately after the CCD read pulse XSG1. , V1 field. On the contrary, as shown in FIG. 2, when the logical level of the horizontal synchronizing signal HD is “H” after a predetermined period tpd2 from the rising of the vertical drive pulse XV1 of the frame shift start portion immediately after the CCD read pulse XSG1, the V3 field is set. Determine.

FIG. 3 shows a field discriminating circuit 1 for realizing the above-mentioned discriminating method, which is composed of first to third flip-flops 2,
3 and 4, the operation is shown in FIG. As a result, the difference in the V1 / V3 field of the vertical drive pulse XV1 is discriminated, and the logical level of "L" is output for the V1 field and "H" for the V3 field.

According to the above configuration, the conventional ODD / EV
It is possible to determine whether V1 / V3 fields are read out instead of the EN fields, which can be completely replaced in place of the conventional field determination using the vertical sync signal VD and the horizontal sync signal HD, and frame reading and field Both reading can be supported.

Further, according to the above configuration, the field can be discriminated even in the system in which the V1 field / V3 field reading at the time of camera shake correction is changed. Further, in a television camera system having a camera shake correction function, when it is necessary to determine the drive field for defect correction, the defect correction designation can be reliably determined.

In the above-described embodiment, only the waveform at the time of camera shake correction has been described above, but since this relationship has the same determination result at the time of normal frame reading / field reading, the conventional ODD field and EVEN field are compared. It can also be used for discrimination.

[0028]

As described above, according to the present invention, during the period from the solid-state image sensor read pulse output from the timing generation circuit for reading the solid-state image sensor to the rise of the horizontal synchronizing signal of the television signal, Since the field is discriminated depending on whether or not the frame shift pulse of the vertical drive pulse of the solid-state image sensor is present, it is possible to realize the field discriminating method and the field discriminating circuit which can surely discriminate the field.

[Brief description of drawings]

FIG. 1 is a signal waveform diagram showing an embodiment of a field discriminating method according to the present invention.

FIG. 2 is a signal waveform diagram showing an embodiment of a field discriminating method according to the present invention.

FIG. 3 is a block diagram showing an embodiment of a field discriminating circuit according to the present invention.

4 is a timing chart showing the operation of the field discrimination circuit of FIG.

FIG. 5 is a signal waveform diagram showing CCD driving timing for camera shake correction.

FIG. 6 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 7 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 8 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 9 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 10 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 11 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 12 is a signal waveform diagram showing CCD drive timing for camera shake correction.

FIG. 13 is a signal waveform diagram for explaining a field determination method based on a phase difference between a vertical synchronizing signal and a horizontal synchronizing signal in the related art.

FIG. 14 is a signal waveform diagram for explaining a conventional field identification method based on a phase difference between a vertical synchronization signal and a horizontal synchronization signal.

[Explanation of symbols]

1 ... Field discrimination circuit 2,3,4 ... Flip-flop.

Claims (2)

[Claims] 1. A field discriminating method for discriminating a field of a television signal obtained by a camera system using a solid-state image sensor, comprising: a solid-state image sensor read pulse output from a timing generation circuit for reading the solid-state image sensor; During the period until the horizontal synchronization signal of the television signal rises,
Depending on whether or not there is a frame shift pulse of a vertical drive pulse for driving the vertical register of the solid-state image sensor,
A field discriminating method characterized in that the field is discriminated. 2. A field discriminating circuit for discriminating a field of a television signal obtained by a camera system using a solid-state image sensor, wherein a solid-state image sensor read pulse output from a timing generation circuit for reading the solid-state image sensor is used. Window generation means for generating a detection window during the period until the horizontal synchronizing signal of the television signal rises, and a frame of vertical drive pulses for driving the vertical register of the solid-state image pickup device during the period of the detection window. A field discriminating circuit comprising: discriminating means for discriminating the field according to whether or not a shift pulse exists.