JP2001135812A - Solid-state image pick-up device and its drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correspond to high resolution readout and high sensitivity readout by a single solid-state image pick-up device. SOLUTION: A solid-state image pick-up device comprising a plurality of sensor lines 1, 2, has a different pitch in each of sensors 10, 20 in the sensor lines 1, 2. This drive method sequentially transfers electric charges fetched in by the sensor line provided with the pitch of the sensor preselected. Furthermore, this drive method sequentially transfers the electric charges fetched in by each of the sensors 10, 20 in the plurality of sensor lines 1, 2 in sensor unit of the different sensor lines 1, 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a solid-state imaging device having a plurality of sensor arrays each including a plurality of sensors and a driving method thereof.

[0002]

2. Description of the Related Art FIG. 9 is a configuration diagram illustrating a conventional solid-state imaging device. This solid-state imaging device is composed of a linear sensor, and includes one sensor row 1 'in which a plurality of sensors 10' are arranged in a row. In this solid-state imaging device, each sensor 1
After transferring the line-by-line charge taken in at 0 'to the charge transfer unit 12 via the readout gate 11, the charge transfer unit 12 transfers each charge to the output gate 30 side.
Each charge is sent to the charge-voltage converter 31 via the output gate 30, and is changed to a voltage corresponding to the charge amount and output.

FIG. 10 is a configuration diagram illustrating another conventional solid-state imaging device. This solid-state imaging device is a linear sensor in which two sensor rows 1 "and 2" are arranged substantially in parallel. The two sensor rows 1 ″, 2 ″
0 'and 20' are arranged in a state shifted by a half pitch. In such a solid-state imaging device, each sensor row 1 ″,
After the charges taken in by the 2 ″ sensors 10 ′ and 20 ′ are transferred to the charge transfer units 12 and 22 via the readout gates 11 and 21, the charges are alternately transferred to the output gate 30 by the charge transfer units 12 and 22. As a result, the charges captured by the two sensor rows are alternately output from the charge-voltage converter 31 for each pixel.

[0004]

However, such a solid-state imaging device has the following problems. That is, in the solid-state imaging device as shown in FIG. 9, the MTF (Modulation Transfer Functio) in reading at the highest resolution is used.
Although n) is sufficient, there is a problem that the sensitivity is reduced due to the narrow sensor aperture at the time of reading at half the maximum resolution.

On the other hand, in the solid-state image pickup device shown in FIG. 10, the sensitivity is sufficient because the aperture area of one sensor is four times as large as that in the solid-state image pickup device shown in FIG. The MTF characteristic at the resolution is lower than that of the solid-state imaging device shown in FIG.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a solid-state imaging device and a driving method for solving the above-mentioned problems. That is, in the solid-state imaging device according to the present invention, in a solid-state imaging device including a plurality of sensor rows in which a plurality of sensors are arranged at a predetermined pitch, the pitch of each sensor is different among the plurality of sensor rows.

In such a solid-state imaging device according to the present invention, since the pitch of each sensor is different between a plurality of sensor rows, it is sufficient to capture by a sensor row having a fine sensor pitch for capturing at high resolution. Can be secured,
In the case of capturing at low resolution, sufficient sensitivity can be obtained by capturing with a sensor row having a coarse sensor pitch.

The driving method for a solid-state imaging device according to the present invention is the method for driving an individual imaging device in which a plurality of sensor rows have different sensor pitches. This is a method of sequentially transferring the charges taken in by the sensor array having the pitch of. further,
There is also a method of sequentially transferring the charge taken in by each sensor in a plurality of sensor rows in units of sensors in different sensor rows.

In such a driving method, a single solid-state imaging device selectively uses a sensor array capable of securing a sufficient MTF as needed and a sensor array capable of obtaining a sufficient sensitivity. Will be able to In addition, by sequentially transferring the electric charge in units of sensors of different sensor rows, it becomes possible to select an output signal in units of sensors for a part requiring sufficient MTF and a part requiring sufficient sensitivity.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a solid-state imaging device and a method of driving the same will be described below with reference to the drawings. FIG. 1 is a configuration diagram illustrating a solid-state imaging device according to the present embodiment. That is, this solid-state imaging device includes a plurality of sensor rows 1 and 2 in which a plurality of sensors are arranged at a predetermined pitch. In particular, the pitch of each sensor 10 and 20 in each sensor row 1 and 2 is different. It is different in that it is unique.

In this solid-state imaging device, the pitch of the sensors 10 in the first sensor row 1 composed of Line-1 is equal to that of Line-2.
Are smaller than the pitch of the sensors 20 in the second sensor row 2 composed of For example, the pitch of the sensors 10 in the first sensor row 1 is の of the pitch of the sensors 20 in the second sensor row 2.

That is, the first sensor row 1 is suitable for reading a high-resolution image, and the second sensor row 2 has high sensitivity (S / S).
(Good N).

A read-out gate (Read-out Gate) 11 is formed in parallel with the first sensor row 1, and a charge transfer section (CCD Register) 12 is formed in parallel with the read-out gate. On the other hand, a read-out gate (Read-out Gate) 21 is formed in parallel with the second sensor row 2, and a charge transfer section (CCD Register) 22 is formed in parallel with the read-out gate 21.

In the solid-state imaging device shown in FIG. 1, the charge transfer section 12 corresponding to the first sensor row 1 and the charge transfer section 13 corresponding to the second sensor row 2 join at the multiplex section 29. The electric charges taken in by the two sensor rows 1 and 2 can be output from one output terminal.

That is, one output gate 30, a charge-voltage converter 31, a reset gate 32, and a reset drain 33 are connected to the rear end of the multiplex section 32.

FIG. 2 is a configuration diagram illustrating the multiplex unit. That is, the charge transfer section 12 corresponding to the first sensor row 1 is provided with the first electrodes 42a and the second electrodes 42b alternately, and a transfer pulse composed of φ1 ′ and φ2 ′ is applied to these. In the charge transfer section 22 corresponding to the second sensor row 2, first electrodes 41a and second electrodes 41b are provided alternately, and a transfer pulse composed of φ1 and φ2 is applied to these. Further, the multiplex section 29 is provided with first electrodes 43a and second electrodes 43b alternately, and a transfer pulse composed of φ3 and φ4 is applied to these.

The transfer of the charge taken in by the first sensor row 1 and the charge taken in by the second sensor row 2 are controlled by the application timing of these transfer pulses.

Next, a method of driving the solid-state imaging device will be described. 3 and 4 are timing charts for explaining a driving method in the solid-state imaging device according to the present embodiment. 3 is a timing chart in the case where the charge captured by the first sensor array 1 of the solid-state imaging device in FIG. 1 is transferred. FIG. 4 is a timing chart in the second sensor array 2 of the solid-state imaging device in FIG. 6 is a timing chart in the case of transferring a captured charge.

In this example, when reading at a high resolution, a mode is selected in which the charges captured by the first sensor array 1 (see FIG. 1) are transferred and output. In this case, a drive pulse composed of φ1 ′ and φ2 ′ is applied to the first electrode 42a and the second electrode 42b (see FIG. 2) of the charge transfer unit 12 corresponding to the first sensor row 1 at the timing shown in FIG. Apply
The driving pulse composed of φ3 and φ4 is supplied to the multiplex unit 29.
To the first electrode 43a and the second electrode 43b (see FIG. 2). Note that φRS is a reset pulse applied to the reset gate 32 shown in FIG. 1, and Vout is an output signal.

Thus, only the charge of the high-resolution image captured by the first sensor array 1 can be transferred by the charge transfer unit 12 and the multiplex unit 29 and output as a voltage from the charge-voltage conversion unit 31. become.

When reading with high sensitivity, the second
The mode in which the charge captured by the sensor array 2 (see FIG. 1) is transferred and output is selected. In this case, the drive pulse composed of φ1 and φ2 is applied to the first electrode 41 of the charge transfer unit 22 corresponding to the second sensor row 2 at the timing shown in FIG.
a, applied to the second electrode 41b (see FIG. 2),
Is applied to the first electrode 43a and the second electrode 43b (see FIG. 2) of the multiplex section 29. Note that φRS is a reset pulse applied to the reset gate 32 shown in FIG. 1, and Vout is an output signal.

Thus, only the charge of the high-sensitivity image captured by the second sensor array 2 can be transferred by the charge transfer unit 22 and the multiplex unit 29 and output as a voltage from the charge-voltage conversion unit 31. become.

By such mode switching, 1
Even with one solid-state imaging device, a high-resolution image output and a high-sensitivity image output can be obtained.

Next, another driving method will be described with reference to the timing chart of FIG. The driving method described here is different from the driving method in which the charge captured by the first sensor row 1 (see FIG.
And alternately transferring and outputting the charge taken in the sensor array 2 (see FIG. 1) in sensor units.

That is, in this driving method, the first electrode 42a of the charge transfer section 12 corresponding to the first sensor row 1 and the first electrode 4a of the charge transfer section 22 corresponding to the second sensor row 2
1a and drive pulses φ1 ′ and φ1 in phase with each other,
The second electrode 42 of the charge transfer unit 12 corresponding to the sensor row 1
Drive pulses φ2 ′ and φ2 having the same phase are applied to b and the second electrode 41a of the charge transfer unit 22 corresponding to the second sensor row 2.

The first electrode 4 of the multiplex section 29
Drive pulses φ3 and φ4 of opposite phases are applied to 3a and the second electrode 43b.
Is applied. As a result, charges are alternately transferred from the charge transfer row 12 corresponding to the first sensor row 1 and the charge transfer row 22 corresponding to the second sensor row 2 to the multiplex unit 29 in units of sensors, and the charge-voltage conversion unit 31 causes the signal to be output alternately.

In this operation, the electric charge taken in the first sensor array 1 and the second sensor array 2 is alternately transferred and output in sensor units, so that the second sensor having the smaller number of pixels is used. The charges are alternately output until the transfer of the charges taken in column 2 is completed.
The rest of the charge taken in by the sensor row 1 is output.

FIG. 6 is a timing chart for explaining another driving method. This driving method includes a first sensor row 1 and a second sensor row 2 as in the driving method described above.
, The charge captured by the first sensor row 1 having the larger number of pixels is transferred by two sensors, and the second sensor row 2 having the smaller number of pixels is transferred.
And the transfer of the charge taken in by one sensor is alternately repeated.

That is, during one cycle of the driving pulses φ1 and φ2 having opposite phases applied to the first electrode 41a and the second electrode 41b of the charge transfer section 22 corresponding to the second sensor row 2, The first of the charge transfer units 12 corresponding to the sensor row 1
The drive pulses φ1 ′ and φ2 ′ having opposite phases applied to the electrode 42a and the second electrode 42b are applied twice.

Thus, the transfer of the charge taken in by the first sensor row 1 for two sensors and the transfer of the charge taken in by the second sensor row 2 for one sensor are alternately repeated,
From the charge-voltage converter 31, a signal output for two pixels corresponding to the first sensor row 1, that is, high-resolution image capturing, and a second sensor row 2, that is, one corresponding to high-sensitivity image capturing, from the charge-voltage converter 31. The signal output for the pixels is performed alternately.

Here, when the charges captured by the first sensor row 1 and the second sensor row 2 are alternately transferred and signal output is performed at the timings shown in FIGS. 5 and 6, a captured image of one line is captured. Among them, the captured image of the first sensor array 1 corresponding to the high resolution is applied only to the portion requiring a high resolution, and the second sensor array 2 corresponding to the high sensitivity is applied to the other portions.
May be switched by a subsequent processing circuit to apply the captured image.

In the solid-state imaging device shown in FIG.
Although the charge taken in by the sensor row 1 and the charge taken in by the second sensor row 2 are multiplexed by the charge transfer register, they may be multiplexed by the charge-voltage converter 31.

FIG. 7 is a configuration diagram (part 1) for explaining another example of the solid-state imaging device. This solid-state imaging device
Read-out gates (Read-out Gates) 11a and 11b are formed on both sides corresponding to the first sensor row 1 corresponding to high resolution. This makes it possible to transfer the charge captured by the first sensor array 1 at a high speed when the mode for capturing a high-resolution image is selected.

FIG. 8 is a configuration diagram (part 2) for explaining another example of the solid-state imaging device. This solid-state imaging device
An output circuit is provided independently for each of the charge transfer unit 12 corresponding to the first sensor row 1 and the charge transfer unit 22 corresponding to the second sensor row 2. That is, the charge transfer unit 12 corresponding to the first sensor row 1 has the output gate 30a,
A charge-voltage converter 31a, a reset gate 32a, and a reset drain 33a are provided. The charge transfer unit 22 corresponding to the second sensor row 2 includes an output gate 30b, a charge-voltage converter 31b, a reset gate 32b, and a reset drain 33b. Is provided.

Such an independent output circuit may be provided as long as the circuit scale is allowed.

In each of the above-described embodiments, the solid-state imaging device having two sensor rows has been described as an example. However, the present invention is not limited to this, and may include three or more sensor rows. It is also applicable.

[0037]

As described above, the solid-state imaging device and the driving method of the present invention have the following effects. That is, even a single solid-state imaging device can support both high-resolution image capturing with sufficient MTF characteristics and high-sensitivity (good S / N) image capturing. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a solid-state imaging device according to an embodiment.

FIG. 2 is a configuration diagram illustrating a multiplex unit.

FIG. 3 is a timing chart (part 1) for explaining a driving method.

FIG. 4 is a timing chart (part 2) for explaining a driving method.

FIG. 5 is a timing chart illustrating another driving method.

FIG. 6 is a timing chart illustrating another driving method.

FIG. 7 is a configuration diagram (part 1) illustrating another example of the solid-state imaging device.

FIG. 8 is a configuration diagram (part 2) illustrating another example of the solid-state imaging device.

FIG. 9 is a configuration diagram illustrating a conventional solid-state imaging device.

FIG. 10 is a configuration diagram illustrating another conventional solid-state imaging device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st sensor row, 2 ... 2nd sensor row, 10 ... sensor, 11 ... output gate, 12 ... charge transfer part, 20 ... sensor, 21 ... readout gate, 22 ... charge transfer part, 29 ...
Multiplex unit, 30 output gate, 31 charge-voltage converter

Claims (3)

[Claims] 1. A solid-state imaging device comprising a plurality of sensor rows in which a plurality of sensors are arranged at a predetermined pitch, wherein the plurality of sensor rows have different pitches of the respective sensors. 2. A method of driving an individual imaging device in which a plurality of sensor rows have different sensor pitches, wherein a charge captured by a sensor row having a sensor pitch selected in advance among the plurality of sensor rows. Are sequentially transferred to the solid-state imaging device. 3. A method of driving an individual imaging device in which a plurality of sensor rows have different sensor pitches, wherein electric charges taken in by each sensor in the plurality of sensor rows are sequentially transferred in sensor units of different sensor rows. A method for driving a solid-state imaging device.