JPS62159458A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To eliminate an external switch circuit in which an output signal is replaced even if an interlacing operation is executed in an image pickup element for reading out a signal charge of two lines by two horizontal CCDs. CONSTITUTION:A signal charge stored in a photoelectric converter 2 is transferred by vertical CCDs 11-1N to horizontal CCDs 3, 3', and simultaneously read out in two lines by CCDs 3, 3'. A gate connected with a terminal M2 and a storage unit connected with a terminal M2 are provided between the vertical CCDs and the horizontal CCD3'. Two lines of signal charges are transferred to the CCDs 3, 3' without using the storage unit at first field reading time. The order of the lines to be transferred to the CCDs 3, 3' are replaced to be transferred by utilizing the storage unit at second field reading time. Then, even if the combination of the lines to be read simultaneously is altered at every field to be interlaced in a single plate color image pickup element using a mosaiclike color filter, the horizontal CCDs 3, 3' always output the same color signals, thereby eliminating an external switch circuit.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a solid-state imaging device, particularly a structure of a charge transfer solid-state imaging device that simultaneously reads two-dimensionally stored information charges in two rows per horizontal period. and its driving method and circuit.

[Conventional technology]

Figure 2 shows the already proposed patent application No. 49-11746.
This figure shows the circuit configuration of a charge transfer type solid-state imaging device capable of simultaneous readout of two rows, which is detailed in No. 4.

2 is a group of photoelectric conversion elements that convert incident light into signal charges. 11.12...IN is a charge-coupled device (CCD) for transferring the charge accumulated in the photoelectric conversion element section in the direction of the vertical arrow, and terminal V 1 .

The transfer pulse φv1g φv2 added to V2 is synchronized with the horizontal synchronizing signal of the television signal.

The signal charge accumulated in the photoelectric conversion unit 2 is transferred to the adjacent CCD in the vertical direction by a switch pulse φvo applied to the terminal Vo during the vertical retrace period.

The transferred signal charge is generated by a pulse φv1. synchronized with the horizontal synchronization signal of the television signal. φv2, Vt.

(2) By adding the data to 2, two lines are sequentially transferred upward (towards the CCD in the horizontal direction) in the horizontal period.

3 and 3' are CCDs that transfer charges in the horizontal direction. Signal charges for two lines transferred from the vertical CCD in synchronization with the horizontal synchronizing signal of the television signal, for example, the signal charges Q1 for the first and second lines. J and Qx+J (j is Q 1
, J represents the number of the vertical CCD to be transferred,
11,12. ...IN is left) Nonouchi, QIJ is CCD
3 niQ xi are independently transferred and stored in the CCD 3'. Fig. 3 shows a timing chart of each driving pulse during this period. This is done by adding to.

Note that the timing in FIG. 3 is shown for the case where each electrode indicated by a square in the ccD section of FIG. 1 has the structure shown in FIG. 4.

The signal charge transferred to the CCD 3.3' in the horizontal direction is applied to the terminals H1 and H2 in a pulse train φl1l during the subsequent horizontal video period.
s φH2 is added, and the signal charges Q 114 @Qt, J are output as video signals from the output terminals 4 and 4', respectively.

In the next field, 2
Change the combination of lines (for example, 2.

and Q 31JI Q4? J and Q fl, J...) are used to perform interlace operation.6 To make a single-chip color imaging device using the elements shown in Figure 2,
On the upper layer of the photoelectric conversion section 2, there is a mosaic color filter as shown in FIG. This indicates that it is a color filter.Hereinafter, the signal charges obtained by transmitting light r will also be indicated by the same symbol).

As a result, in the first field, the output signal from the output terminal 4 is S 1 = ・= + W + Cy + W + C
The output signal 5z==-+G+Y e +G+Y e +- is output from the output terminal 4'. However, in the second field, the combination of two lines to be read at the same time changes for interlace operation, so
Contrary to the first field, 81 is from the output terminal 4', s2
is output from output terminal 4.

FIG. 6 shows a block diagram of a signal processing circuit that converts this output signal S 1 t S x into an NTSC signal. 1 is an image sensor, 9 is a drive circuit, 1o is an output signal 81,
Problems to be Solved by the Invention with a Signal Processing Circuit that converts S2 into an NTSC signal] By the way, in the single-plate color element using the element shown in FIG. 2, as described above, the output signal S1. Since Sx is output from different output terminals for each field, a switch circuit 8 switches the two signals from the elements so that the same signal (for example, Sz to the input terminal 51) is always input to the input terminal of the signal processing circuit. is required, making the circuit complex. Furthermore, even if the output signal SL is the same, the path it passes through differs from field to field, so its magnitude changes, resulting in flicker.

The object of the present invention is to have two or more horizontal CCDs,
Using this, in a single-chip color field imaging device using a charge transfer layer solid-state image sensor that reads out two rows simultaneously, there is no need for an external switch circuit to switch two or more output signals even when performing interlace operation, and there is no flicker. It is an object of the present invention to provide a structure of a solid-state image sensor and a driving circuit thereof that do not cause this phenomenon.

[Means for solving problems]

In order to achieve the above object, the present invention changes the CCD structure in the horizontal direction of the device structure shown in FIG. Alternatively, a new storage section is provided between the vertical CCD and the horizontal CCD. This storage section or horizontal CCD
Using this, the order of the two rows of signal charges transferred by the vertical CCD is switched within the element for each field and transferred to the horizontal CCD. A feature is that signal charges of the same type (for example, W and Cy) are always read out to the outside through the same horizontal CCD.

[Effect]

According to the configuration of the present invention as described above, two or more horizontal CCDs are provided, and the signal charges accumulated in two rows of photodiode columns are read out simultaneously in each horizontal period using the CCDs. In a single-chip color imaging device using a layered solid-state imaging device, the same color signal can always be output from the same output terminal even when interlace operation is performed. Therefore, an external switch circuit for switching two output signals for each field, which was necessary in an imaging apparatus using conventional elements, is no longer necessary, and the circuit can be simplified. Furthermore, since each output signal can pass through the same circuit for each field, a flicker-free image can be obtained.

[Embodiments of the invention]

FIG. 1 is a block diagram of an embodiment of a solid-state image pickup device according to the present invention, which allows the same type of signal charge to be always read out through a CCD in the same horizontal direction regardless of the field even if an interlace operation is performed.

This device has a terminal M adjacent to the electrode connected to the terminal T1.
This device differs from the device shown in FIG. 1 in that a gate connected to terminal M1 and a storage section connected to terminal M1 are provided.

In this device, the first field keeps terminal M2 in the off state. Similarly to the device shown in FIG. 2, the terminal V1. V2
By adding the driving pulse shown in Fig. 3 to ~Ht, Hz, the signal charges of two rows, for example, Q1+a*QxeJ, are changed to C0D3 in the horizontal direction.
．． 3' and output from output terminals 4 and 4'.

On the other hand, in the second field, driving is performed according to the timing chart of driving pulses shown in FIG. That is, two rows of signal charges 02pt are transferred simultaneously.

Q82. Q z , t which is sent first is the terminal Ml.

Once transferred to the storage section by pulses 21 and 22 applied to M2, the gate connected to M2 is kept in an off state. and a pulse 23. applied to the terminal Vll Vat T 1 v Ht. 26, the signal charge Qaj sent later is first transferred into the CCD in the horizontal direction. Thereafter, the gate connected to the terminal M2 is turned on again by the pulse 27, and the signal charge Qza in the M product section is returned to the bottom of the electrode connected to the terminal T1.

Thereafter, pulses 28 and 29 are applied to the terminals H1 and T2, and the signal charge Q37 is transferred to the CCD 3 in the horizontal direction, and the signal charge Q2J is transferred to the CCD 3' in the same horizontal direction as in the first field. In addition to this, data is read from the output terminals 4 and 4' during the horizontal video period.

If, for example, the color filter shown in FIG. 5 is arranged on this element to make a single-chip color imaging device, the same signal as in the first field will be outputted from the output terminal 4 in the second field S1=...1 w+c y +w+c y+. ··but,
Also, from the output terminal 4', S 2 = -+ G + Y e + G + Y e
+ - is output.

Therefore, the signal processing circuit of a single-chip color imaging device using this element does not require the switch circuit 8 required in the circuit of FIG. 6, as shown in FIG. 8, and the circuit becomes simpler.

Also, since the two output signals Sz+82 always pass through the same circuit regardless of the field, there is no variation in gain.
A flicker-free image can be obtained.

FIG. 9 is a diagram showing another embodiment according to the present invention. This device differs from the devices shown in FIGS. 2 and 1 in the following three points. In other words, each electrode of the CCD in the horizontal direction can be controlled independently as shown in FIG.
(The structure shown in the figure is fine) and the structure in which each electrode that controls the two horizontal CCDs is connected to an electrode that is shifted by two electrodes from each other in the horizontal direction, and that the electrodes that control the horizontal CCDs are The electrodes located between the same two vertical CCDs and connected to each other (the electrodes connected to the terminal Hz in Figure 9) are kept in the OFF state while the signal charge is transferred from the vertical CCD to the horizontal CCD. The point is to keep it.

In addition, in FIG. 9, the electrodes connected to the terminals Tr and Tx are also connected to the 10th electrode.
As shown in the figure, each device will be described below as having one electrode.6 FIG. 11 shows a drive pulse timing chart of the device shown in FIG. 9. Terminal T2. The pulses applied to H4 vary depending on the field; the pulses for the first field are shown by solid lines, and the pulses for the second field are shown by broken lines.

Like the previous two elements, when this element enters the horizontal retrace period, pass/L/passes 23' and 24' are applied to the terminals Vz+Vz to transfer the signal charges in the CCD in the vertical direction. At this time, in the first field, the terminal TI is simultaneously applied.

By adding pulses 31 to 34 to Ht+ Tz and Hs, for example, the signal charge Q 1 of the first row transferred at the beginning
．． j is transferred horizontally to within CCDa.

After that, when terminal T2 is turned off, terminal H2,.

Since the electrode connected to H4 is in the OFF state, the signal charges Qxesxe QxexztQ 1 are located within the horizontal CCDa and are transferred to different vertical CCDs.
, 1 s... are accumulated under the electrodes all to alN connected to the terminal H8 without mixing with each other in the horizontal direction.

Next, pulses 23' and 24' are applied to the terminals Vx and Vz again, and the signal charges Q21 sent later are converted into vertical C
When transferring from CD to horizontal CCD, terminal Tx,
Pulses 31' and 32' are applied only to H1 and H numbers.

35 and terminal T2. Keep H2 in the OFF state.

And Q 1 , a is the terminal H in the CCD 3 in the horizontal direction
While accumulating under the electrode connected to terminal H8, Qz and J are connected under the electrode bzt of CCD 3' in the horizontal direction connected to the same terminal H8.
...Move to bl, N. Thereafter, in the following horizontal video period, the contents of the CCD in the horizontal direction are sequentially transferred and read out from the output terminal 4°4'.

On the other hand, in field 2, when the signal charge Q 1 * tz is transferred to the horizontal CCD by pulses 23' and 24', terminal T2 is kept off, and instead, pulse 35' is applied to terminal H4 to turn it on. do.

Then, the same pulses 31, 32, and 34 as in the first field are applied to the terminals Txr Hl and Hs, and the signal charge Q22 that is transferred first is transferred to the terminal H8 of the CCD 3' in the horizontal direction, bxz~bIN under the connected electrodes. To accumulate 0, pulse 33 is applied to terminal T2 while terminal H4 is kept off.
’ to turn it on, and the terminals Vg Vxp Tl, H
l pulses 23', 24'.

Add 30' and 32'. Then, the signal charge Q a J transferred later is transferred to the terminal H of the CCD 3 in the horizontal direction.
It is transferred and accumulated under the electrodes connected to δ all to axN (electrodes connected to the electrode where Qza is accumulated).

Then, in the subsequent horizontal image period, the horizontal CCD
The contents are transferred and read from output terminals 4 and 4'.

In this way, with the device shown in Figure 9, the signal charges in two rows can be exchanged for each field and transferred to the CCD in the horizontal direction for readout. After making the device, the first step is to create the device. In both the second field, the signal Sz =...+W + Cy + W +
Cy+... can be output from the output terminal 4, and the signal Sx=.=+G+Ye +G+Ye+- can be output from the output terminal 4'.

Therefore, the signal processing circuit of a single-chip color imaging device using this element does not require the switch circuit 8 as in FIG. 8, and can obtain flicker-free images.

FIG. 12 is a diagram showing still another embodiment of the present invention. 6 Generally, in a solid-state image pickup device, such as the device shown in FIG. 1, charges are generated under the photodiode 2 by incident light. This generated charge is absorbed and accumulated in the photodiode, and the signal charge Q11. However, some of the generated charges diffuse and directly enter the CCD in the vertical direction. Then, a white band-like smear appears in the vertical direction of the screen centered on the point where strong light hits, degrading the image quality. The device in Figure 12 independently outputs not only the signal charge for two lines, but also the charge that causes this smear (hereinafter referred to as smear charge), and by subtracting the smear signal from the output two lines of video signal. It attempts to create a smear-free television signal.

In order to output three types of signal charges (two rows of signal charges and smear charges) independently, this device divides the vertical CCD electrodes into four groups of electrodes controlled by terminals v1 to v4. This is done by sequentially turning on the terminals v4 to v1 as schematically shown in FIG. Also, horizontal CCD
Three CCDs are provided, and these three charges are transferred and output independently.6 However, the electrodes that control the three horizontal CCDs are connected to electrodes that are offset by two electrodes from each other, similar to the element in Figure 9. In addition to the structure, the electrodes (
In FIG. 12, there is an electrode connected to the terminal H2.

FIG. 14 shows a drive pulse timing chart for the device shown in FIG. 12. In the figure, reference numeral 41 denotes a series of operations for transferring three charge positions in the CCD in the vertical direction, one stage each, by the driving method shown in FIG. That is, while applying this series of pulses, the terminals Tl, T2 . T3. H
When pulses 42 to 48 and 34 are applied to l, H3° H4, the smear charge that was under the electrode leading to the top terminal V4 of the vertical CCD, e.g. Q n ! HJ is Crs ~ under the electrode connected to terminal H8 of CCD3 in the horizontal direction.
Transferred to CIN. Also, the signal charge Q that was under the electrode connected to the terminal Vs*Vz at the top of the CCD in the vertical direction
3. Je Q4#J are each raised one stage and transferred under the electrodes connected to terminals v4 and Vδ. Thereafter, while keeping the terminals H2 and T3 in the OFF state, the same operation as driving the element in FIG. 9 (FIG. 11) is performed.

Even in this operation, the smear charge is always horizontal CC:
The signal charges in the two rows can be exchanged field by field and transferred to the CCDs 3' and 3' in the horizontal direction and read out through the D3.For example, by arranging the color filters shown in FIG. If you make , the first. In both the second field, the smear signal is from the output terminal 4, and the signal S1=...+W+Cy+W+Cy+...
・ is the signal S2. from the output terminal 4'. =...+G+Y e +G'+Y e +- can be output from the output terminal 4''.

Therefore, the signal processing circuit of a single-chip color image pickup device using this element does not require a switch circuit and eliminates flicker.
You can get an image without.

〔Effect of the invention〕

As explained above, according to the present invention, two or more horizontal CCDs are provided, and the signal charges that are TJ multiplied in the previous diode column of two rows are read out simultaneously in each horizontal period. In a single-chip color imaging device using a transfer type solid-state imaging device, the same color signal can always be output from the same output terminal even if interlace operation is performed. Therefore, in imaging devices using conventional elements, 2
This eliminates the need for an external switch circuit that switches two output signals for each field, and the circuit can be simplified. Furthermore, since each output signal can pass through the same circuit for each field, it is possible to obtain both flicker-free images.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a solid-state imaging device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a conventional charge transfer solid-state imaging device with simultaneous two-row readout, and FIGS. Driving method, filter arrangement, and signal processing circuit, Figures 7 and 8 are
Examples of the structure and driving method of the solid-state imaging device and its signal processing circuit shown in the figure, FIGS. 9 to 11 show the structure and driving method of the solid-state imaging device according to other embodiments, and FIGS. 12 to 14 show further A circuit diagram of a solid-state imaging device according to another embodiment and its explanatory diagram. Figure 1. 1 Figure 8 Figure 9 Fast-spoken 10th/l Figure 3s' 12th H3 75th Inv-74 National Proceedings Amendment (Method) % Formula % Indication of Case 1985 Patent Application No. 000539 Invention name
Relationship with the case of a person who corrects solid-state imaging devices Patent applicant name (510)
New type manufactured by Hitachi Co., Ltd.
person

Claims (1)

[Claims] A plurality of photoelectric conversion elements arranged in one or two dimensions and a plurality of charge-coupled devices (hereinafter referred to as vertical CCDs) that vertically transfer signal charges accumulated in each photoelectric conversion element. ) and a charge-coupled device (hereinafter referred to as horizontal CCD) that reads out the signal charge received from the vertical charge-coupled device in the horizontal direction in one horizontal period. In a solid-state imaging device that has a structure in which signal charges can be read out, even if the combination of rows to be read out simultaneously is changed by performing an interlacing operation, the signal charges in the same row are always output from the same output terminal for both the first and second fields. A solid-state imaging device characterized by: 2. In the solid-state imaging device according to claim 1, a signal storage section is provided between the vertical CCD and the horizontal CCD, and the signal is transferred within the vertical CCD using this storage section. 1. A solid-state imaging device characterized in that the order of signal charges is switched. 3. In the solid-state imaging device according to claim 1, two or more horizontal CCDs are provided, and the electrodes for controlling the CCDs are connected to one horizontal CCD of the vertical CCD.
A solid-state imaging device characterized in that it has a configuration in which four or more electrodes are provided per period, and the four electrodes of the CCD in different horizontal directions are connected to electrodes that are shifted by two electrodes from each other. 4. In the solid-state imaging device according to claim 3, at least one of the four electrodes of the CCD in different horizontal directions
A solid-state imaging device characterized in that the electrodes are connected to each other between two CCDs in the same vertical direction. 5. In the solid-state imaging device according to claims 3 and 4, the order of the two rows of signal charges transferred from the vertical CCD in each horizontal period is changed within the horizontal CCD. A solid-state imaging device featuring: 6. In the solid-state imaging device according to claim 4, at least one electrode of a series of electrodes connected between the same two CCDs in the vertical direction is A solid-state imaging device characterized in that it is always kept in an OFF state while transferring signal charges from a CCD to a horizontal CCD and changing the order of the signal charges.