JPH0357380A - Smear correction circuit - Google Patents

Abstract

PURPOSE:To attain the elimination of smear by subtracting a smear signal component of a vertical register from which no video signal is given from a video signal of a succeeding or a preceding line. CONSTITUTION:A CCD area sensor output signal is inputted from an input terminal 1 and only one line is delayed by a one line delay circuit 2 and the delay signal and the original are subtracted by a differential amplifier 4. In this case, a line switch 3 selects the case that the delay signal is the video signal and the original signal is the smear signal component or vice versa, then the smear signal component is always subtracted from the video signal through the action of the line switch 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a smear correction circuit in an NTSC or PAL VTR camera using a pseudo-field-driven CCD area sensor. This paper relates to a smear correction circuit that subtracts the smear signal component of a vertical register that does not undergo charge transfer from the video signal that includes the smear component of the line before or after it. [Prior Art] Generally, in pseudo-field driving using this type of CCD sensor, as shown in the schematic plan view of FIG. Is going. Therefore, lines with no image charge are created between lines with image charge due to the field. In the conventional COD circuit, as shown in FIG.
The line switch 3a switches between the input signal, which is delayed by the l-line delay circuit 2, and the input signal, which is then output from the output terminal, so lines with no video charge are not used in external circuits, etc. [Problems to be Solved by the Invention] As mentioned above, in conventional CCD circuits, the smear component added to the signal in the vertical register section is not corrected and is reproduced as a video signal as it is, causing deterioration in image quality. An object of the present invention is to eliminate such drawbacks and provide a smear correction circuit that removes smear from a video signal by using the smear component signal of the vertical register, which was conventionally discarded as no signal, as a smear correction signal. There is a particular thing. [Means for Solving the Problems] The structure of the present invention is an NTSC or In the smear correction circuit of a PAL type VTR camera, the smear signal component of the vertical register of the line where charge is not transferred from the photodiode of the CCD area sensor is
The feature is that the smear component of the video signal is removed by subtracting the video charge before or after the line from the video signal of the line to be transferred. [Example] Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In this embodiment, a CCD area sensor output signal is input from an input terminal 1, and this input signal is delayed by one line in a one line delay circuit 2. This delayed signal and the original input signal are subtracted by a differential amplifier 4. In this case, the line switch 3 switches between the case where the delayed signal is a video signal and the original signal becomes a smear signal component, and vice versa, for each line, so the line switch 3 always subtracts the smear signal component from the video signal. It works as if [Effects of the Invention] As explained above, the present invention subtracts the smear signal component of the vertical register from which the video signal is not read from the video signal of the line before or after that line, thereby causing a significant deterioration in image quality. It has the effect of being able to remove smears.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a plan view showing a general ellipse of a general CCD area sensor, and FIG. 3 is a block diagram of a conventional configuration example.

Claims (1)

[Claims] The CCD is driven by a pseudo-field driving method that uses only the signal of 1/2 period of the signal accumulated for one frame time.
NTSC or PAL V using area sensor
In the smear correction circuit of the TR camera, by subtracting the smear signal component of the vertical register of the line where charge is not transferred from the photodiode of the CCD area sensor from the video signal of the line where the video charge is transferred before or after that line. , a smear correction circuit characterized in that it removes smear components from a video signal.