JP2568594B2 - Solid-state imaging device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a solid-state imaging device having an electronic zoom function.

2. Description of the Related Art An optical method is used for a zoom function of a conventional solid-state imaging device, and a zoom lens using a complicated cam mechanism is required to obtain a zoom effect.

Problems to be Solved by the Invention However, in the case of the zoom function using the above-mentioned zoom lens, it is difficult to obtain an instantaneous zoom effect because a time for moving the lens is required, and in recent years, a video camera has been used. Is desired. This is a major problem in reducing the size, weight, and cost.

Means for Solving the Problems In view of the above problems, the present invention provides the following configuration, by providing a simple method, without increasing the maximum operating frequency of the solid-state imaging device, and instantaneously. An object of the present invention is to provide a solid-state imaging device having a zoom function.

When performing an n-times zoom, first, signal charges are read out from a photoelectric conversion element (hereinafter abbreviated as a pixel) to a vertical transfer unit within a vertical retrace period, and then signal charges corresponding to unnecessary pixels are reverted to vertical retrace. The signal charge corresponding to the pixel to be vertically zoomed is intermittently vertically transferred once every n horizontal periods, and the remaining signal charge is thereafter transferred during the vertical blanking period. As a result, a signal in a 1 / n vertical scanning period in a normal case is output over one vertical scanning period for every n horizontal scanning lines. The output of this vertical transfer stage is input to the horizontal transfer stage during the horizontal scanning period, and signal charges corresponding to unnecessary pixels are transferred and removed until near the end of the subsequent horizontal retrace period, and then the horizontal zoom is performed. The signal charge corresponding to the pixel to be transferred is transferred at a charge detection unit (hereinafter abbreviated as output unit) at a speed of 1 / n of the normal horizontal transfer speed, and then the remaining signal charge is transferred from the vertical transfer unit It is transferred and removed during the period until it is transferred to the horizontal transfer unit. The output of the solid-state imaging device driven as described above is such that signals in 1 / n vertical and horizontal scanning periods in a normal case are output for one vertical scanning period for every n horizontal scanning lines. Then, the signal is zoomed n times in both the vertical and horizontal directions without increasing the maximum operating frequency of the solid-state imaging device by simply interpolating the signal to the horizontal scanning line portion where no signal is output using the delay line. Can be obtained.

The present invention uses the output of the solid-state imaging device driven by the above-described driving method to easily increase the image in the vertical and horizontal directions by n times without increasing the maximum operating frequency of the solid-state imaging device. Because you can get the signal
Without using a zoom lens with a complicated mechanism,
In addition, it is possible to instantaneously obtain an n-fold zoom effect.

Embodiment Hereinafter, a driving method of a solid-state imaging device having a 2 × zoom function of a center portion of a screen using the present invention will be described in detail with reference to the drawings using an embodiment.

FIG. 1 is a configuration diagram of an interline type CCD solid-state imaging device used in one embodiment of the present invention, wherein 1 is a photoelectric conversion device, 2 is a vertical transfer unit, 3 is a horizontal transfer unit, and 4 is a charge detection unit. is there.

FIG. 2 is a timing chart of a driving signal according to an embodiment of the present invention for driving the solid-state imaging device of FIG.
FIG. 2 is a timing chart in which the time steal of the AA ′ portion of FIG. 2 is enlarged, (a) is a composite blanking signal, and (b) is a signal from one photoelectric conversion element (hereinafter abbreviated as pixel). The readout signal for reading out the signal charge to the second vertical transfer unit is referred to as a first charge transfer unit. (C) is a vertical drive signal comprising second, third and fourth charge transfer means for driving two vertical transfer units, and (d) is a fifth and fifth drive signal for driving three horizontal transfer units.
6, a horizontal drive signal comprising the seventh charge transfer means, (e)
Is an output signal output from the signal charge detector 4.

By applying the first charge transfer means 5 during the vertical blanking period, signal charges are transferred from the pixel 1 to the vertical transfer section. Then, during the period from after the first charge transfer means 5 to the vicinity of the end of the same vertical retrace period, unnecessary signal charges corresponding to 1/4 of the total pixels in the vertical direction are transferred at high speed and removed. Charge transfer means 6 is applied to remove signal charges corresponding to a quarter of the total pixels in the vertical direction. During the subsequent vertical scanning period, the signal charges corresponding to half of the total pixels in the vertical direction at the center of the screen to be zoomed are intermittently leveled every other horizontal scanning period at any time during the horizontal scanning period. The charges are sequentially transferred in the direction of the transfer unit 3 by the third charge transfer means 7. Then, the signal charges corresponding to the remaining 1/4 of the total pixels in the vertical direction are transferred from the vicinity of the beginning of the subsequent vertical retrace period to the time when the next first charge transfer means is applied, by the fourth charge transfer. It is removed by means 8. By driving the vertical transfer unit 2 as described above, the signal charges for the pixels in the center 1/2 of the vertical screen are transferred to the horizontal transfer unit 3 every other horizontal scanning period over one vertical scanning period.

The signal charge corresponding to 1/4 of the total pixels in the horizontal direction is transferred by the fifth transfer means 9 from the time when the charge transfer means 7 shown in FIG. Transfer and remove. Thereafter, during the subsequent horizontal scanning period, the signal charge corresponding to 1/2 of the total pixels in the horizontal direction is applied to the charge detection unit 4 at a speed 1/2 of the normal speed by applying the sixth charge transfer means 10. Then, the signal is transferred through the horizontal transfer unit 3 and taken out as an output signal. After that, the signal charge corresponding to 1/4 of the remaining total pixels in the horizontal direction is supplied from the vicinity of the beginning of the subsequent horizontal retrace period to the time when the next third charge transfer means 7 is applied.
The removal is performed by applying the seventh charge transfer means 11.

By driving the vertical transfer unit 2 and the horizontal transfer unit 3 of the solid-state imaging device as described above, the signal charges for the pixels in the center part 画面 of the screen are changed every other horizontal scanning period for one vertical scanning period. As the output of Then, only by interpolating the signal during the horizontal scanning period without signal charge, without increasing the maximum operating frequency of the solid-state imaging device,
A double zoom effect can be easily obtained.

As described above, according to the present embodiment, the zoom effect can be instantaneously doubled by an electronic method without using mechanical or optical means and without increasing the maximum operating frequency of the solid-state imaging device. Can be easily obtained. Further, even when it is desired to obtain an n-times zoom effect and a zoom effect of an arbitrary point on the screen, it is possible to realize the same method as in this embodiment. In the present embodiment, the interline CCD is used as the solid-state imaging device. However, the same effect can be obtained when the frame interline CCD and the frame accumulation type CCD are used as the solid-state imaging device.

Advantages of the Invention As is clear from the above description, the present invention can easily increase the maximum operating frequency of the solid-state imaging device electronically by n times compared to the conventional mechanical and optical zoom functions. It is easy to obtain a zoom effect, and the effect is large.

[Brief description of the drawings]

FIG. 1 is a block diagram of a solid-state imaging device used in one embodiment of the present invention, FIG. 2 is a timing chart of one embodiment of the present invention for driving the solid-state imaging device of FIG. 1, and FIG. 3 is FIG. 3 is a timing chart of the partial enlargement. 1 ... photoelectric conversion element, 2 ... vertical transfer section, 3 ... horizontal transfer section, 4 ... charge detection section.

Claims (1)

(57) [Claims] 1. A photoelectric conversion unit in which a plurality of photoelectric conversion elements are two-dimensionally arranged, a vertical transfer unit for vertically transferring signal charges accumulated in the photoelectric conversion unit, and a transfer from the vertical transfer unit. A solid-state imaging device having at least a horizontal transfer unit that transfers the received signal charge in the horizontal direction, and a signal charge detection unit that converts the signal charge transferred from the horizontal transfer unit into a signal voltage or a signal current and outputs the signal voltage or signal current. A solid-state imaging device, comprising: first charge transfer means for reading a signal charge from the photoelectric conversion element to the vertical transfer unit at an arbitrary position within a vertical flyback period; and a time when the first charge transfer means is generated. Until near the end of the same vertical retrace period, a part of the signal charges corresponding to the photoelectric conversion elements is transferred at a high speed at a transfer frequency higher than a normal vertical transfer frequency and removed from the solid-state imaging device. Charge transfer means, and in the subsequent vertical scanning period, a part of the signal charge corresponding to the remaining photoelectric conversion elements is intermittently transferred from the vertical transfer unit once at an arbitrary time in an n horizontal scanning period. A third charge transfer means for transferring toward the horizontal transfer unit; and a third charge transfer means corresponding to the remaining photoelectric conversion elements during a period from near the beginning of a subsequent vertical retrace period to before the occurrence of the first charge transfer means. A fourth charge transfer means for transferring the signal charges at a higher speed than a normal vertical transfer frequency and removing the signal charges from the solid-state imaging device; and wherein the vertical transfer unit transfers the signal charges from the vertical transfer unit to the horizontal transfer unit once every n horizontal scanning periods. A part of the signal charge transferred to the horizontal transfer unit during a period from the time when the signal charge is transferred by the third charge transfer means to the end of the subsequent horizontal retrace period is equal to the normal horizontal transfer frequency or That's it Fifth charge transfer means for transferring the solid-state image sensor at a low frequency and removing the remaining part of the signal charges transferred to the horizontal transfer unit during one horizontal scanning period later than a normal horizontal frequency Sixth charge transfer means for transferring at a frequency, and from the vicinity of the beginning of the subsequent horizontal retrace period until the time when the next signal charge is transferred by the third charge transfer means from the vertical transfer section to the horizontal transfer section. And a seventh charge transfer unit for transferring the remaining charge of the signal charge transferred to the horizontal transfer unit during an arbitrary period of time.