JPS5945791A - Color solid-state image pickup device - Google Patents

Abstract

PURPOSE:To improve the picture quality, by correcting a defective part of a video signal corresponding to a defective photo sensitive section of a solid-state image pickup element. CONSTITUTION:If there exists a defect in one picture element (shown in the arrow), e.g., W in one line of the video signal outputted from the solid-state image pickup element, e.g., CCD41, the position of the defective part corresponds to the defective position produced in the photo sensitive section of the CCD41, and the defective part is included in the video signal at the same position at all times and outputted. This video signal is outputted from a buffer circuit 43 and applied to a sample-and-hold circuit 47, and a switching circuit 44 is switched with a control signal (b) outputted from an ROM (not shown). Thus, the picture element of the defective part is outputted at the same color signal W from an amplifier 46 preceding two picture elements. This output is applied to a sample-and-hold circuit (signal eliminating and synthesis circuit) 53. A signal eliminated for the defective video signal and synthesized with the same color signal W preceding two picture elements stored mentioned above in the eliminated part is outputted from an amplifier 52 of the circuit 53.

Description

[Detailed Description of the Invention] [41-Mei's Technological Developments] This year, Akira was concerned with a solid-state sensor applied to, for example, a color television camera. The present invention relates to a circuit that corrects defects in video signals caused by defects.

[Technical background of the invention and its problems]

As is well known, in a color television camera that uses one solid-state camera, the solid-state camera 't'i +:4
: Color filters are vapor-deposited or fused to correspond to the photosensitive areas of the device. FIG. 1 shows an example of a color filter. Color filters usually have white (Cyro), green (G) or cyan (Cy),
Color filter elements A' (Ye) are arranged corresponding to the photosensitive portions of a solid-state sensor (not shown).

By the way, in this type of television camera, defects called smears, white scratches, and black scratches occur in the image, corresponding to the defects that occur in the photosensitive area of the solid-state camera.

For example, tc 41 corresponds to W on line 11 shown in Figure 1 V! (*If a defect occurs in both sides of the element, the video signal output from this line 11 of the solid-state 114m element will be as shown in Figure 2. In this way, if there is a defect in the photosensitive part of the solid-state image sensor, this defect will cause a defect in the image order signal at te, 1-, and a normal image will not be produced. It is not possible to obtain one word for one word.Therefore, there is a problem that the picture quality deteriorates.

[The purpose of enlightenment]

This invention was made based on the above-mentioned month s, la, and the 1:1 ratio is (・'li, l K i
The present invention aims to provide an inexpensive color solid-state device that improves υ'Ll by % by correcting the outside of the defective part of the picture space signal corresponding to the defective value yt part of S. .

[Invention Ii! ]

This invention removes the defective part of the image 1st image + tS, and stores the defective part in this part.The defective area corresponds to the video signal of the same line as the 1st image signal and the same color as the outside of the defective area, and the defect is removed. Part i) A nearly normal U*1 signal is obtained by combining video signals output several pixels earlier. That is, when a defect occurs in the W part roughly indicated by the arrow shown in fa 21'J1, the image signal of W two pixels before this is synthesized with the defective part f+, as shown in the 31st hit. .

[IM Example J of the Invention An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 4, 4) is solid state 1: 'it lψ element is CCD (Charge 'Coupled De
This C0D 41 is provided with a color filter (not shown) in which color filter elements are arranged at the same opening ζ as in FIG. 1, corresponding to the photosensitive portion. A video signal is outputted from this CCD 41 in the horizontal direction according to the arrangement order of the color filter elements. This signal is branched, and one side is supplied with direct current to the primary circuit 42 and the other side is supplied to the buffer circuit 43. Here, the video image outputted from the C and CD41 (
It is assumed that one line of FJ is shown as shown in FIG. 5(a), and one pixel of W (indicated by an arrow) has a defect. The position of this defective part corresponds to (f'l If) of the defect that occurred in the photosensitive part of the CCD 41,
The defective part is outputted in the image signal at the same time as the image signal. This video signal is outputted from the buffer circuit 43 and sample-and-hold circuit 4 consisting of a switch circuit 44, a capacitor 45, and a high input impedance amplifier 46.
7. The switch circuit 44 is switched by a control signal (shown in FIG. 5(b)) output from a read-only memory (R'OM), not shown. Therefore, from the amplifier 46, as shown in FIG.
), the pixel in the defective portion is output as the same color signal W of the previous two pixels. This output signal is sent to the DC regeneration circuit 48 at 16. After the current level is fixed, the signal is supplied to a sample and hold circuit (signal removal and synthesis circuit) 53 consisting of a switch circuit m4y+so, a capacitor 51, and a Hatake input impedance amplifier 52. Here, the switch circuit 50 is switched by a control fIl+ signal (shown in FIG. 5(d)) output from a V,x ROM (not shown), and the switch circuit 49 is switched by a control signal (shown in FIG. It is switched by a signal (shown in FIG. 5<6)). This switch circuit 49 receives the output 1! from the DC regeneration circuit 42! ! Signal (4t 5 IQ
(shown in (a)) is supplied. Therefore, from the amplifier 52, as shown in FIG. This signal is passed through the sample hold circuit 5 which also includes a switch circuit 54, a capacitor 55, and a high input impedance amplifier 56.
7. The switch circuit 54 includes an R (not shown).
A control signal 18 shown in FIG. 5(g) is supplied from the OM, and switching is performed by this signal. This sample-and-hold circuit 57 produces the result shown in FIG. 5(b).

The low frequency components of (d) and (8) are removed. Therefore, the amplifier 56 outputs a substantially normal video signal as shown in FIG. It is said that

In addition, each of the above-mentioned switch circuits 44, 49, 50° 54/ should always appear at the same position eζ outside the defective part of the image 1 & signal.
A predetermined duty 1 signal corresponding to the timing of its appearance is stored in advance in a ROMK, and from this ROM the CCD4101
At the same timing as JυJ, the trough) +till signal is output, and the configuration is such that switching is performed by this 1- signal. Each control signal is generated from the image signal, and each switch circuit 44, 4 is generated by this No. 1b.
9°50.54' switching control is also possible.

In addition, it goes without saying that the gist of this @4 cannot be summarized in the 12-circle box with interspersed illustrations.

[Effect of clearing j As detailed above, the present invention has the advantage of removing the defective part of the picture signal and adding the picture (picture signal) on the same line as the picture 1ψ signal which has the defect lit 'J) to this part. In addition, by combining the video signals that correspond to the same color filter element as the defective part and are output several times ago from outside the defective part 1'i+i, it is possible to obtain an almost normal Therefore,
A color solid-state imaging device that can suppress the deterioration of image quality and is advantageous in practical use will be developed.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing an example of a Tomoe filter. Figure 2 is a waveform shown to clarify defective parts of a video signal. 1
',,-1, The 41st prisoner is this 1', The color solid related to the town) RF41i Zo 1 Tsuji showing an actual example of the 7 anti-one-image device, 11) 5 Figures (a) to (b) are This is a waveform diagram shown to explain the operation of the fourth factor.
7' /l/bold circuit, 53...Zangleholt IIJI 1lIl! (A1) Elimination and synthesis circuit).

Claims (1)

[Claims] A solid body in which color filter elements that receive predetermined colored light are arranged in a fixed order corresponding to the photosensitive area (the first four-dimensional element and the first four-dimensional element are outputted from the solid four-dimensional element in the order in which the color filter elements are arranged). a signal removing means for removing defective Pils of the image 1.s! signal corresponding to the defective photosensitive area of the solid-state imaging element from the output image signal; means for holding a video signal corresponding to a filter element of the same color positioned on the same line as the video signal containing the image signal and several pixels before the defective part; and outputting the video signal held by the video signal from the signal removing means. A color system characterized in that it has a means for compositing outside the defective part of the video signal.
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