JPS63232765A - Image pickup device - Google Patents

Abstract

PURPOSE:To remove an unnecessary part in an expanding reading without executing the high speed transfer by providing a scanning means to output a low speed transferring signal for the desired number of horizontal scannings and process the signal of other part during other horizontal scanning period. CONSTITUTION:An output signal So from an image pickup element 101 is inputted through a clamping circuit 108 and an 1H delaying circuit 109 to a clamping circuit 101, switched by a switch SW for an 1H period and inputted to a video signal processing part 111. When a part B of the image pickup element 101 is expanded and read, the switch SW is switched to an So side and an Sd side for one horizontal scanning and the signal of the expanding part B transferred at a low speed is outputted for the desired number of the horizontal scannings. While unnecessary parts Ha and Hc are horizontally transferred, the above- mentioned switch is switched to a low speed transferring signal side and the output is not executed to the processing part 111. Thus, compared with the device to transfer and remove the unnecessary part at a high speed during the same horizontal scanning period, a transfer efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an imaging device that can partially transfer imaging signals at low or high speed.

[Prior Art] FIG. 4(A) is an explanatory diagram of enlarged readout, and FIG. 4(B) is a timing chart showing the horizontal operation state during enlarged readout in a conventional imaging device.

In each figure, in order to enlarge a part B of the image formed on the area-shaped image sensor 101 and display it on the display, the enlarged part B is read out during the effective period of the TV, and the other parts are read out during the horizontal and vertical blanking periods. It is necessary to process it within.

For example, in horizontal scanning, optical black OB
The signals of the unnecessary parts A and C are transferred at high speed during the horizontal blanking period in periods ta and tc, respectively, and the signals of the enlarged part are transferred at low speed during the period tb, which matches the valid period of the TV. Similarly, in vertical scanning, the enlarged portion is driven at low speed according to the valid period, and the unnecessary portion is driven at high speed within the vertical blanking period.

The horizontal transfer frequency varies depending on the magnification ratio (zoom ratio).If the horizontal transfer frequency during normal reading is fs, for example, in the case of double enlargement, low-speed transfer of the enlarged portion is performed at a frequency of fs/2.

[Problems to be solved by inventiveness] However, in the conventional imaging device described above, it is necessary to transfer unnecessary portions at high speed within the blanking period. The problem was that the charge transfer efficiency decreased and the resolution deteriorated.

Furthermore, due to high-speed transfer, the reading period tob of the optical black signal becomes short, resulting in a problem that the reliability of reproduction of the black reference signal decreases.

[Means for Solving the Problems] An imaging device according to the present invention is an imaging device capable of partially transmitting imaging signals at low speed or high speed, in which a low speed transfer signal of one row of imaging signals is transmitted every desired number of horizontal scans. The present invention is characterized in that it has a processing means that outputs signals to the image pickup signal and processes signals of other parts of the imaging signals of the same row in other horizontal scanning periods.

[Function] With this configuration, when performing enlarged reading, for example, signals of unnecessary portions can be processed in the other horizontal scanning period, and high-speed transfer as in the prior art is not required.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an imaging section in an embodiment of an imaging apparatus according to the present invention.

In the figure, a CCD image sensor 101 is operated by a vertical transfer pulse φV, and a light shielding portion OB is formed at the end thereof.

The vertically transferred charges are input to the horizontal transfer register 102 of the COD line by line, and the horizontal transfer register 102 transfers the charges according to the horizontal transfer pulse φS, and the output amplifier 10
5 and output as a signal SO.

In addition, in this embodiment, the horizontal transfer register 102 is
An overflow drain 10'4 is provided via 103, and gate 103 is opened and closed by pulse φg. This causes register 10 to open while opening gate 103.
2 transfer charges can be removed to the overflow drain 104.

Figure gS2 is a schematic configuration diagram of the signal processing section in this embodiment.

In the figure, pulses φV, φS, and φg for driving the image sensor 101 are supplied from a driver 106, and the driver 106 operates according to a clock circuit 107.

The signal So from the image sensor 101 is sent to the clamp circuit 108.
and is input to the IH delay circuit 109.

The clamp circuit 108 clamps the signal corresponding to the light shielding portion Hob at the timing of the clamp pulse CP1 from the clock circuit 107.

The IH delay circuit 109 stores the sequentially input signals SO for l lives and outputs them to the clamp circuit 110 as the IH delayed signal Sd.

The clamp circuit 110 clamps the signal corresponding to the light-blocking portion of the delayed signal Sd at the timing of the clamp pulse CP2 from the clock circuit 107.

Each output of the clamp circuits 108 and 110 is selected by a line switch SW and inputted to the video signal processing circuit 111 as a signal 5out. Line switch SW is operated by control signal φSW from clock circuit 107.

Next, the operation of this embodiment having such a configuration will be explained with reference to FIG.

FIGS. 3A and 3B are timing charts for explaining an example of the enlarged read operation of this embodiment.

Here, a case of double enlargement will be explained.

In order to read the enlarged portion B at a double magnification rate, the vertical unnecessary portions Va and Vc are removed within the vertical blanking period, and the horizontal unnecessary portions Ha and Hc are removed within the horizontal blanking period. There is a need.

First, in the vertical blanking period VBLK, the vertical transfer pulse φV transfers the light blocking portion Vob and the unnecessary portion Vc during the periods Tvob and Tvc. The signal of the light blocking portion Vob is held by a sample and hold pulse φsh at a later stage and is used for dark current correction.

When the vertical blanking period ends, in order to read out the enlarged portion vb during the vertical effective period, the image sensor 10 is activated with a vertical transfer pulse φV of half the normal frequency, thus a period of 2H.
Drive 1.

By inputting one vertical transfer pulse φV, one line of the enlarged portion vb (referred to as the n-th scanning line nH).
The signal is transferred to the horizontal transfer register 102. Subsequently, the horizontal transfer register 102 is transferred by the horizontal transfer pulse φS.
The electric charge is transferred to the water and output through the amplifier 105.

The first few pixels of this output signal So are signals corresponding to the light shielding portion Hob, and the black reference level is set by the clamp circuit 108 using the clamp pulse CPi (period Thob).

Subsequently, the unnecessary portion Ha is horizontally transferred within the horizontal effective period of the nH line (period Tha), and the signal of this portion is ignored. This is because, during the valid period of the nH line, the line switch SW is connected to the clamp circuit 110 side (delay signal Sd side) by the control signal φ5W. This point will be discussed further later.

Therefore, the signal of the unnecessary portion Ha can be removed within the effective period of the nH line, and there is no need to perform high-speed transfer within the horizontal blanking period as in the conventional art. Further, since high-speed transfer is not required, a margin can be given to the clamp operation during the period Thob, and clamp errors can be eliminated.

At the same time, the signal of the unnecessary portion Ha is transferred to the IH delay circuit 109.
Enter.

Next, during the horizontal blanking period of the (n+1)H line, the control signal φSW is inverted and the line switch SW is connected to the signal So side. For this reason, the delayed signal Sd corresponding to the unnecessary portion Ha output from the delay circuit 109 after the IH has elapsed is ignored. However, the signal corresponding to the light shielding portion Hob is used to set the black reference level in the clamp circuit 110 at the timing of the clamp pulse CP2.

(n+・1) During the effective period of the H line, f s / 2
A horizontal transfer pulse φS having a frequency of is input to the register 102, and a signal SO corresponding to the enlarged portion Hb is transferred during a period Thb.・The black level of this signal is fixed by the clamp circuit 108, and the signal 5o is output through the line switch SW.
The signal is input to the video signal processing circuit 111 as ut.

At the same time, the signal So corresponding to the enlarged portion Hb is IH
Input to delay circuit 109.

Next, the valid period of the (n+1)H line will end.
2) In the horizontal blanking period of H, the gate pulse φg is input to the gate 103 to open the gate, thereby all the charges in the horizontal transfer register 102 are removed, and the register 102 becomes the initial state (period The). That is, the signal corresponding to the unnecessary portion Hc remaining in the register 102 is removed during the period The. This eliminates the need for high frequency transfer to remove the unnecessary portion Hc as in the conventional case.

Next, the control signal φSW is inverted and the line switch S
Connect W to the signal Sd side. In addition, vertical transfer pulse ΦV
Vertical transfer of the image sensor 101 is performed by this, and the signal of the next line is transferred to the horizontal transfer register 102.

Then, as in the case of the nH line, after the clamping operation of the signal of the light shielding portion Hob, the signal So of the unnecessary portion Ha is ignored by the horizontal transfer pulse φS.

At the same time, during the valid period of (n+2) lines,
The signal of the expanded portion Hb stored in the previous line is output as a delayed signal Sd after the IH period has elapsed. The black level of this signal is fixed by the clamp circuit 110, and is output as a TE signal 5out through the line switch SW. In other words, the enlarged portion Hb transferred at line (n+1)
By passing through the delay circuit 109, the signal is read out again at the (n+2) line and is output.

Further, the line switch SW changes the connection for each line so as to select only the signal of the enlarged portion Hb.

Thereafter, the enlarged portion vb is read out as [Dou-sama].

When this ends, at the start of the next vertical blanking period, the unnecessary portion V is
A is removed at high speed (period Tva).

The above operation is repeated as one frame operation.

Although the present embodiment shows the case of 2 times magnification, it goes without saying that the same invention can be applied to the general case of m times magnification. In that case, (m-1) IH delay circuits may be connected in series and the output from each delay circuit may be selected by a line switch.

[Effects of the Invention] As explained in detail above, the imaging device according to the present invention has the following effects:
The present invention is characterized in that it has a scanning means that outputs a low-speed transfer signal every desired number of horizontal scans and processes other portions of signals in other horizontal scan periods.

With this configuration, when performing enlarged readout, for example, unnecessary portions of signals can be processed in the horizontal scanning period of the above-mentioned capacity, and high-speed transfer as in the prior art is not required. For this reason, even when COD is used, there is no decrease in charge transfer efficiency, there is little deterioration in resolution, and the clamping operation of the optical black level is also stable.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an imaging section in an embodiment of an imaging device according to the present invention. FIG. 2 is a schematic configuration diagram of a signal processing section in this embodiment. ) is a timing chart for explaining an example of the enlarged readout operation of this embodiment, FIG. 3 is a timing chart showing the horizontal operation state of the controller. 101...Image sensor 102...Horizontal transfer register 103...Yu gate 104...Operating flow olein 105...Fist output amplifier 108.110...Clamp circuit 109-φ-IH delay circuit SW・Φ・Line Switch Agent Patent Attorney Sekihira Yamashita Figure 1 Figure 2 ot Figure 3 (A) 3rd (8) Figure 4 (A) (B)

Claims (1)

[Claims] (1) In an imaging device that can partially transfer image signals at low speed or high speed, the low speed transfer signal of the image signals of one row is output for each desired number of horizontal scans, and the other of the image signals of the same row is output. An imaging device comprising a processing means for processing a signal of a portion during another horizontal scanning period.