JPH09284630A - Control method for ccd area sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain panning a valid area subjected to electronic zooming up to upper and lower ends of a light receiving area by varying a generating timing of a read pulse within a vertical blanking period in the cease of changing a size of an invalid area other than the valid area. SOLUTION: In the case of conducting panning to change a size of an invalid area other than a valid area, a generating timing of a read pulse XSG1 set in a vertical blanking period VBLK is made variable. In the case of setting the number of lines of the invalid area (m) to be '0', the read pulse XSG1 is shifted toward a side close to a start of the vertical blanking period VBLK with respect to the vertical blanking period VBLK. Thus, a time after the read pulse XSG1 is generated till the vertical blanking period VBLK is finished is extended so as to extend the processing time of the invalid area (n) for line shift and also to increase the number of lines of a processes enable invalid area (n).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for electronic zooming and electronic panning in a CCD area sensor.

[0002]

2. Description of the Related Art A CCD area sensor converts light received in its light receiving region into electric charges, transfers the electric charges in a vertical direction and a horizontal direction, and outputs the electric charges to an external monitor to obtain a predetermined image. In order to magnify (zoom) an image using this CCD area sensor, there are a case where an optical lens is used and a case where it is electronically performed. In recent years, electronic zoom performed electronically from the viewpoint of simplification of the mechanism. Is being actively conducted.

FIG. 4 is a timing chart for explaining a conventional example, and FIG. 5 is a schematic diagram for explaining valid / invalid areas. 4 is a vertical sync signal, is a read signal,
Indicates a vertical transfer clock, and indicates a CCD output signal. Further, the vertical blanking period is indicated by VBLK and the read pulse is indicated by XSG1.

When performing electronic zooming using a CCD area sensor, the light receiving area S of the CCD area sensor is divided into an effective area x and ineffective areas n and m, as shown in FIG. Only the photoelectrically converted charges are output to an external monitor (not shown) so that enlarged display is performed on the entire screen.

FIG. 4 shows a timing chart when electronic zoom is performed. In the vertical blanking period VBLK during the read pulse XSG1, the frame shift of the invalid region n and the sweeping out of the invalid region m are performed, and the vertical blanking period is completed. The electric charges in the effective area x are line-shifted.

That is, in the case of enlarging and displaying the effective area x of the light receiving area S, first, after the read pulse XSG1 set at the center of the vertical blanking period VBLK is generated, the invalid area n is limited to the vertical transfer limit frequency (use). The frame shift is performed by driving at the limit frequency at which the charges in the region x can be transferred.

After that, the effective area x is line-shifted within the vertical effective period to obtain a CCD output signal, and the effective area x is enlarged and displayed on an external monitor. And
During the next vertical blanking period VBLK, the charges in the invalid area m are swept out until the next read pulse XSG1 is generated.

Thus, the vertical blanking period VBL
By performing frame shift and sweeping out of the ineffective areas n and m in K, it becomes possible to prevent charges in portions other than the effective area x from being output to an external monitor, and perform electronic zooming of the effective area x. It becomes possible.

[0009]

Here, focusing on the amount of panning in the vertical direction during such electronic zooming, for example, the effective area x shown in FIG. When the area m is set to "0", the number of lines in the other invalid area n is the total number of lines-the number of lines in the effective area x.

However, as shown in FIG. 4, since the read pulse XSG1 is set at the center of the vertical blanking period VBLK, this read pulse XSG is set.
After the occurrence of 1, there is a limit on the number of lines in the invalid area n in which the frame shift can be performed during the vertical blanking period VBLK.

That is, when the transfer period at the limit frequency at which the charges in the effective area x can be normally frame-shifted is T, and the period during which the invalid area n can be frame-shifted is FRT,
The number of lines that can frame shift the invalid area n is FR
It becomes T / T.

As described above, since the number of lines that can frame shift the invalid area n is limited, the number of lines in one invalid area m cannot be set to "0", and as a result, the used area x is received. There is a problem that it is not possible to pan up to the end of the region S.

[0013]

The present invention is a method of controlling a CCD area sensor, which has been made to solve such a problem. That is, the present invention is a method of controlling a CCD area sensor that transfers charges photoelectrically converted in a light receiving region in the vertical and horizontal directions and outputs the charges to an external monitor. When outputting to the monitor and changing the size of the invalid area other than the effective area, the generation timing of the read pulse set in the vertical blanking period in the charge read is made variable within the vertical blanking period, and the read pulse is changed. Is used as a reference to process the charges in the ineffective region.

According to the present invention, when a part of the light receiving area is used as an effective area, the electronic zoom for outputting the electric charge to the external monitor is performed, and the panning for changing the size of the ineffective area other than the effective area is performed during the vertical blanking period. Since the generation timing of the read pulse set to is variable within the vertical blanking period, it is possible to control the time for processing the invalid region in the vertical blanking period according to the size of the invalid region. become able to. As a result, it is possible to pan the effective area in which the electronic zoom is performed up to the upper and lower ends of the light receiving area.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method of controlling a CCD area sensor according to the present invention will be described below with reference to the drawings. FIG. 1 is a timing chart for explaining the present embodiment, and FIG. 2 is a schematic diagram for explaining valid / invalid areas.

In the control method of the CCD area sensor according to the present embodiment, when panning is performed while the effective area x of the light receiving area S shown in FIG. 2 is enlarged and displayed by the electronic zoom, the number of lines of the invalid area n or the invalid area m is set. "0"
It is characterized in that it can be done.

For example, when performing panning to move the effective area x to the upper end (the lower end of the screen on the screen of the external monitor) of the light receiving area S by setting the number of lines of the invalid area m to "0", one of the invalid areas is performed. The number of lines of n is the total number of lines-the number of lines of the effective area x. Conventionally, when the line shift of the invalid area n is performed, the read pulse XSG set at the center within the vertical blanking period VBLK.
Since the process was performed after the occurrence of 1, the number of lines was limited, and the panning amount of the effective area x was limited (see FIG. 4).

In the present embodiment, as shown in FIG. 1, since the generation timing of the read pulse XSG1 set during the vertical blanking period VBLK is variable, the processing is performed during the vertical blanking period VBLK. Read pulse XSG1 according to the size of invalid areas n and m to be performed
Can be controlled. 1 shows a vertical synchronizing signal, shows a read signal, shows a vertical transfer clock, and shows a CCD output signal.

As a specific control, when the number of lines in the invalid area m is set to "0", the vertical blanking period VB is set.
With respect to LK, the read pulse XSG1 is generated by shifting to the side closer to the beginning of the vertical blanking period VBLK. As a result, the time until the vertical blanking period VBLK ends after the read pulse XSG1 is generated becomes longer, and the processing time of the invalid region n in which the line shift is performed can be lengthened during this time.

Therefore, it is possible to increase the number of lines in the invalid area n that can be processed at the line shift limit frequency,
The effective area x can be panned to the upper end of the light receiving area S in the figure.

Further, when panning the effective area x to the lower end of the light receiving area S in the figure, the number of lines in the invalid area n is set to "0" and the number of lines in the invalid area m is set opposite to the above example. The total number of lines needs to be equal to the number of lines in the effective area x.

In this case, the vertical blanking period VB
The read pulse XSG1 is generated by shifting it to the side closer to the end of the vertical blanking period VBLK with respect to LK. As a result, the time from the start of the vertical blanking period VBLK to the generation of the read pulse XSG1 becomes long, and the processing time of the invalid region m for performing the sweep can be lengthened during this time. As a result, the number of lines of the ineffective area m that can be swept out can be increased, and the effective area x can be panned to the lower end of the light receiving area S in the figure.

As described above, when panning the effective area x in which the electronic zoom is performed in the light receiving area S, the vertical blanking period VBLK is set according to the number of lines of the invalid areas n and m according to the panning amount. By shifting the generation timing of the read pulse XSG1 for
The effective area x can be panned to the upper and lower ends of the light receiving area S.

Further, in this way, the vertical blanking period V
When changing the generation timing of the read pulse XSG1 for BLK, the changing step is performed at an integral multiple of one cycle at the limit frequency of vertical charge transfer.

3A and 3B are views for explaining the control steps. FIG. 3A shows the first control and FIG. 3B shows the second control. That is, as shown in FIG. 3A, in the first control, for example, the number of lines (m) in the invalid area m is 5
In the case of the number of lines, the read pulse XSG1 is generated at a timing at which the five lines can be processed, and after the read pulse XSG1 is generated, the line shift for (n) lines of the invalid area n is performed.

Further, for this first control, FIG.
In the second control shown in (b), the read pulse XSG1 is shifted in the step of minimizing the transfer limit period T of the vertical transfer clock when performing line shift, and the number of lines (m-1) in the invalid area m is changed. Is swept out, and the number of lines (n + 1) in the invalid area n is line-shifted.

In this example, the transfer limit cycle T is set as the minimum step. However, when the transfer limit cycle T is set to a unit of an integral multiple of the transfer limit cycle T, the invalidation is performed based on the read pulse XSG1 whose generation timing is variable. Area n, m
It is possible to perform the processing of (1) without waste. That is, the read pulse XSG1 is controlled by controlling the read pulse XSG1 in steps with an integral multiple of the transfer limit period T as a unit.
It is possible to perform continuous processing of the invalid areas n and m with 1 as the boundary.

[0028]

As described above, the control method of the CCD area sensor of the present invention has the following effects. That is, when performing panning during electronic zoom,
Since the generation timing of the read pulse with respect to the vertical blanking period is shifted according to the change of the invalid area of the light receiving area, it is possible to move the effective area to the upper and lower ends of the light receiving area. This makes it possible to greatly increase the amount of panning during electronic zoom.

[Brief description of drawings]

FIG. 1 is a timing chart illustrating the present embodiment.

FIG. 2 is a schematic diagram illustrating valid / invalid areas.

3A and 3B are diagrams illustrating control steps, where FIG. 3A shows the first control and FIG. 3B shows the second control.

FIG. 4 is a timing chart illustrating a conventional example.

FIG. 5 is a schematic diagram illustrating a valid / invalid area.

[Explanation of symbols]

n, m Invalid area S Light receiving area x Effective area VBLK Vertical blanking period XSG1 Read pulse

Claims (2)

[Claims] 1. A CC for transferring charges photoelectrically converted in a light receiving region in a vertical direction and a horizontal direction and outputting the charges to an external monitor.
A method for controlling a D area sensor, comprising: outputting a charge to the external monitor by using a part of the light receiving area as an effective area, and changing the size of an invalid area other than the effective area in reading out the charge. A method of controlling a CCD area sensor, characterized in that the generation timing of a read pulse set in a vertical blanking period is variable within the vertical blanking period, and charges in the invalid area are processed with the read pulse as a reference. . 2. When the generation timing of the read pulse in the next vertical blanking period is changed with reference to the read pulse in one vertical blanking period, the changing step is set to 1 at the limit frequency of the vertical transfer of charges.
C according to claim 1, wherein the period is an integral multiple of the period.
Control method of CD area sensor.