JPS61198981A - Image pickup device - Google Patents

Abstract

PURPOSE:To prevent field after image by storing respective picture information in the same direction from the line sensors of an image pickup part in the first and second storing parts, and by independently reading the respective picture information from said storing part. CONSTITUTION:Of the electric charges accumulated in the image pickup part 1, those in odd-number lines are transmitted to a storing part 2 and those in even-number lines to a storing part 3 by means of high-speed transmission pulses of phiI, phiS1, and phiS2. The charges of the odd-number lines transmitted to the storing part 2 are fetched in a vertical shift register 4 by a vertical transmission pulse phiP1, and those of the even-number lines transmitted to the storing part 3 are taken in a horizontal shift register 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an improvement in an imaging device including a plurality of horizontally arranged line sensors.

[Prior Art] Conventionally, in an imaging device, it has been considered to use an interline transfer type CCD or a MOS type sensor in order to convert, for example, information of one image into sequential signals of two fields.

However, these sensors have the disadvantage that a transfer path, a gate, etc. are provided within the light-receiving surface, resulting in a small aperture ratio and a reduction in sensor sensitivity.

Furthermore, from the perspective of semiconductor manufacturing technology, it requires a high degree of integration, resulting in poor yields, and also has the disadvantage that it is not possible to increase the number of pixels.

On the other hand, if a frame transfer type CCD is used, these drawbacks can be eliminated, but it has been said that the frame transfer type cannot convert one image into a two-field sequential signal.

In response to this, the applicant proposed an imaging device capable of eliminating such drawbacks in Japanese Patent Application No. 138551/1982.

That is, we have proposed an imaging device in which interlaced two-field signals can be obtained by one imaging process by configuring the imaging device using a plurality of horizontally arranged line sensors.

[Objective] The object of the present invention is to further improve the imaging device disclosed in the above-mentioned Japanese Patent Application No. 138551/1982, and to provide an imaging device that can obtain an interlaced two-field video signal by one imaging operation suitable for still images. The goal is to provide equipment.

Another object of the present invention is to obtain an interlaced two-field video signal suitable for moving images without deteriorating sensitivity.

[Example] The present invention will be described in detail below based on Examples.

FIG. 1 is a diagram showing an example of the configuration of an image sensor according to the present invention, in which 1 is an image pickup section, 2 and 3 are storage sections, 4 and 5 are CCD structure shift registers as readout means, 6 and 7 are output amplifiers for the shift registers 4 and 5, respectively, and are shielded from light except for the imaging section l.

The imaging unit l is arranged at the focal point of the optical lens system,
It also has a plurality of line sensors with a transfer function arranged so that the length direction is in the horizontal direction. Each line sensor has a transfer electrode provided on a semiconductor substrate via an insulating layer, and a voltage pulse φ to be described later is applied to this transfer electrode.
By adding (2), the charges in each line sensor are simultaneously transferred in the line direction. A voltage pulse is applied to the transfer electrode in each line sensor so that the signal charges on the odd lines (indicated by odd numbers in the figure) in Figure 1 are transferred to the left, and the signal charges on the even lines are transferred to the right. .

FIGS. 2(a) and 2(b) are cross-sectional views of the imaging unit for explaining the transfer direction, with FIG. 2(a) showing odd lines and FIG. 2(b) showing even lines. In the figure, 8 is a semiconductor substrate made of P-type silicon, ! 3.11.12゜20
．． Reference numerals 21 and 22 are implanted donor ion regions, and 13 and 14 are insulating layers made of 5i02. 15 and 1B are transparent electrodes made of polysilicon, electrically connected by aluminum wiring,
A voltage pulse φ■ for transfer is applied.

In FIG. 2(a), when a high level voltage is applied to the electrodes 15 and 18, the potential level within the substrate 8 changes as indicated by 17 in the figure.
0 is relatively lower than other regions when viewed from electrons, a well is formed, and charges are collected under each electrode.

Further, when the voltage applied to the electrodes 15 and 16 is set to a low level, a potential level as shown by the dotted line 18 in the figure is obtained in the substrate 8, and the regions 11 and 16 not covered by the electrodes 15 and 16 are A well is formed at 12, and the charges that had been collected under electrodes 15 and 16 are transferred to the left in the figure.

On the other hand, similarly for even-numbered lines, as shown in FIG. When a level voltage is applied, the signal is transferred to the right in the figure.

In the unimplemented example, a single-phase drive type C is used as a line sensor.
Although a CD structure is shown, such a single-phase drive method is described in detail in, for example, Japanese Patent Laid-Open No. 11394/1983.

Accumulators 2 and 3 are composed of a plurality of linear CCs arranged in parallel.
It has D. This CCD has horizontal transfer electrodes that transfer accumulated charges horizontally and vertical transfer electrodes that transfer accumulated charges vertically. These storage units 2 and 3 transfer and accumulate the horizontally transferred charges from the imaging unit l by applying voltage pulses φSl and φS2 to the horizontal transfer electrodes in the same way as in the imaging unit 1, and then vertically transfer and accumulate the charges from the imaging unit l. Voltage pulse φPI is applied to the transfer electrode.

By applying φP2, one row (horizontal direction)
By applying voltage pulses φold and φH2 to the transfer electrodes of each horizontal shift register, the voltage pulses φold and φH2 are vertically transferred downward and transferred to the horizontal shift registers 4 and 5 composed of line-shaped CCDs. A horizontal line video signal is read out. That is, an odd line video signal is obtained from the amplifier 6, and an even line video signal is obtained from the amplifier 7.

Next, the operation of obtaining an interlaced two-field video signal by one imaging operation according to the present invention will be explained in detail with reference to FIG.

First, from time t1 to t2, the imaging section 1 and the storage section 2
and 3, horizontal transfer pulses φ■, φS1°φS2 are supplied at high speed to remove unnecessary charges in the imaging unit 1 and storage units 2 and 3. During time 0 t2 to t3, the imaging unit 1 is charged with charges according to the optical information. This is the accumulation time for accumulating , and is set to a desired length. The accumulated charges are transferred from time t3 to t4 by high-speed transfer pulses φ■, φS1 and φS2, so that the charges on the odd lines are transferred to the accumulation section 2, and the charges on the even lines are transferred to the accumulation section 3.
Transfer to.

Therefore, the number of high-speed transfer pulses φ■, φS1, and φS2 at time tl-t2 and time t3-t4 corresponds to the number of pixels in 1 horizontal line in storage section 1.

P? The charge of the odd line transferred to the product group 2 is at time t4
~t5, the vertical transfer pulse φP1 vertically transfers the vertically downward one line at a time, and the line is taken into the horizontal shift register 4. From this horizontal shift register 4, the horizontal transfer pulse φold sequentially reads out the odd numbered lines as shown by Sl. A first field video signal is output from the output amplifier 6 as the video signal. Similarly, the charges of the even lines transferred to the storage section 3 are vertically transferred downward by l lines by the vertical transfer pulse φP2 from time t5 to t8, and taken into the horizontal shift register 5, and from this horizontal shift register 5. The second field video signal is sequentially read out by the horizontal transfer pulse φH2, and is outputted from the output amplifier 7 as an even line video signal as shown as S2.

As explained above, by one imaging (at the same time),
Two interlaced field video signals are obtained, and a continuous two-field video signal can be easily obtained by adding these two field video signals or switching a switch.

FIG. 4 shows drive timings for explaining an embodiment in which the present invention is used as a continuous so-called movie camera instead of a single frame video signal.

The charges accumulated in each horizontal line of the imaging section l are accumulated over time tl
At -t2, the odd lines are transferred to the storage section 2 and the even lines are transferred to the storage section 3 by the transfer pulses φ■, φSl, and φS2. Then, from time t2 to t3, the vertical transfer pulses φS1 and φS2 simultaneously vertically transfer one line at a time, and the horizontal transfer pulses φold and φH2 read out the signals to obtain field video signals St and S2.

Therefore, in the first field, from the field video signals S1 and S2, the first line (indicated by corresponding symbols in the waveforms of St and S2, the same applies hereinafter), the second line,
3rd line and 4th line... N-1st line and Nth line
The video signals of each line are obtained simultaneously.

Next, in the second field, vertical transfer pulse φP2
By delaying the vertical transfer pulse φP1 by one line, the third and second lines, the fifth and fourth lines,
...The line signals of the m-t line and the N-2 line are obtained simultaneously.

Therefore, by adding each field video signal St and S2, it is possible to obtain an interlaced video signal in each field, and although the accumulation time of each field is shorter than the period of the previous field, there is no deterioration in sensitivity, and even if the number of odd Since the line accumulation time and the even-numbered line accumulation time are completely synchronized, no field afterimage occurs.

[Effects] As explained above, according to the imaging device of the present invention, two lines of information can be read out every other line by one imaging to generate a two-field video signal, and the two lines of information can be added. do! A field video signal can also be used, and in either case, information on each line is obtained at the same time, so a clear video signal without field afterimages can be obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an imaging device according to the present invention, FIGS. 2(a) and (b) are sectional views of an imaging section showing the horizontal transfer direction, and FIG. 3 is an imaging device according to the present invention. FIG. 4 is a diagram showing an example of the driving timing of the device. FIG. 4 is a diagram showing another example of the driving timing. l...Imaging section. 2.3...Storage section, 4.5...Horizontal shift register, 6.7...Output amplifier.

Claims (1)

[Scope of Claims] An imaging section having a plurality of line sensors, in which the directions of transferring pixel information in each line sensor are sequentially reversed for each line, and the same transfer of pixel information of each line sensor of the imaging section. An imaging device comprising: first and second storage sections that accumulate pixel information in each direction; and readout means that independently reads each pixel information from the first and second storage sections. .