JPH04334284A - Traverse transfer fit system ccd solid-state image pickup element - Google Patents

Abstract

PURPOSE:To reduce the traverse frame shift frequency. CONSTITUTION:Transfer channels 106A, 106B are formed at the upper and lower sides of the sensor column in the horizontal direction. A channel stop 105 is formed on the opposite side of the side of sensors SEa, SEb of the channels 106A and 106B. The channel stop 105 is formed between the sensors SEa and SEb and on the sides of the channels 106B and 106A of the sensors SEa and SEb, respectively. A pair of transfer electrode 101-103 is distributed to a pair of sensor SEb and SEa bearing odd and even number and the three- phase drive is performed with transfer pulses phi1-phi3. The charge is read from the sensor SEb with a pulse PRD of a transfer pulse phi1 at the channel 106B (Arrow 1, 2), the charge is read from the sensor SEa with a pulse PRD of transfer pulse p3 at the channel 106A and (Arrow 3) and each charge is transferred in the horizontal direction with the transfer pulses phi1-phi3 (Arrow 4). As the two horizontal picture element pitch transfer can be performed with a frequency of the transfer pulses phi1-phi3. The traverse frame shift frequency is reduced by half.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lateral transfer FIT (frame inter transfer) type CCD solid-state imaging device.

0002

2. Description of the Related Art Hitherto, a lateral transfer FIT type CCD solid-state image sensing device has been proposed in which storage areas are arranged horizontally with respect to the imaging area (see Japanese Patent Laid-Open No. 125077/1983). FIG. 8 shows the configuration of a lateral transfer FIT type CCD solid-state image sensor.

In the figure, 1 is an imaging area, and SE
12 is a sensor consisting of a photodiode, and 12 is a horizontal shift register. One horizontal shift register 12 is arranged corresponding to each sensor row in the horizontal direction.

[0004] The signal charges accumulated in each sensor SE are read out to a horizontal shift register 12 and transferred at high speed to a light-shielded accumulation region 2. Thereafter, the data is transferred vertically one line at a time and supplied to the horizontal shift register 3. Then, the charge from each sensor is transferred to the horizontal shift register 3.
The signals are sequentially transferred to the signal detecting section 4 in accordance with the horizontal scanning speed, and the imaging signals are taken out from the signal detecting section 4.

FIG. 9 shows the pixel structure of the imaging area 1. In the figure, reference numerals 101 to 103 are transfer electrodes made of poly-Si electrodes, and transfer pulses φ1 to φ are provided respectively.
3 is supplied and three-phase drive is performed. 106 is a transfer channel constituting the horizontal shift register 12, and 105 is a channel stop.

FIG. 10 shows transfer pulses φ1 to φ3, and the transfer pulses φ1 to φ3 during the transfer period are at potentials VL and VM.
Although it is a binary pulse of (VL<VM), a readout pulse PRD of potential VH (VH>VM) is added to the transfer pulse φ3 in the read period.

By pulse PRD of transfer pulse φ3,
Transfer channel 10 corresponding between transfer electrodes 101 and 102
6, the signal charge is read out from the sensor SE (arrow a
reference). Then, the signal charges are transferred in the horizontal direction by transfer pulses φ1 to φ3 (see arrow b). in this case,
One horizontal pixel pitch is transferred in one period T of transfer pulses φ1 to φ3.

[0008]

[Problem to be solved by the invention] By the way, imaging area 1
The transfer from to the storage area 2 is performed, for example, during a horizontal blanking period in order to reduce smear. In this case, for example, when there are 768 horizontal pixels, the horizontal frame shift frequency is as high as about 1.6 MHz, which is disadvantageous in terms of driver driving ability and power consumption. In addition, regarding the characteristics of the element itself, transfer deterioration caused by the high horizontal frame shift frequency cannot be ignored.

Therefore, it is an object of the present invention to reduce the horizontal frame shift frequency.

0010

[Means for Solving the Problems] The present invention arranges horizontal shift registers on both sides of each horizontal sensor row, and transfers signal charges from odd-numbered and even-numbered sensors of the sensor row to one and the other horizontal shift registers, respectively. It is read out and transferred to the shift register.

[0011]

[Operation] The signal charges from the odd-numbered and even-numbered sensors in the horizontal sensor row are read out and transferred to one side and the other, respectively, so the signal charges are transferred by two horizontal pixel pitches in one period T of the transfer pulse. . Therefore, it is possible to reduce the horizontal frame shift frequency by half compared to the conventional method.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 8 are designated by the same reference numerals.

In the figure, 1 is an imaging area, and SE
are sensors consisting of photodiodes, 12A, 12B
is a horizontal shift register. Horizontal shift registers 12A and 12B are arranged above and below each horizontal sensor row.

The signal charges accumulated in the odd-numbered sensors SE in the horizontal sensor row are transferred to the horizontal shift register 12.
A (see solid arrow), while the signal charges accumulated in even-numbered sensors SE are read out to horizontal shift register 1.
2B (see dashed arrow).

The signal charges read out to the horizontal shift registers 12A and 12B are transferred to the light-shielded accumulation region 2 at high speed, for example, during the vertical blanking period. Thereafter, the data is transferred one line at a time in the vertical direction. In this case, the same vertical shift register is used with the signal charges from the odd-numbered sensors SE and the signal charges from the even-numbered sensors SE arranged alternately, and the signal charges from the even-numbered sensors SE are
Transferred step by step.

One line of signal charges from even-numbered sensors SE is supplied to a horizontal shift register 3A, and further supplied to a horizontal shift register 3B via a horizontal transfer gate 5. On the other hand, the odd-numbered sensor SE
The signal charge for one line from is transferred to the horizontal shift register 3A.
is supplied to

The signal charges for one line from the odd-numbered and even-numbered sensors SE supplied to the horizontal shift registers 3A and 3B during each horizontal blanking period are sent to the signal detection unit in accordance with the horizontal scanning speed during the subsequent horizontal period. It is sequentially transferred to 4A and 4B. Imaging signals related to odd-numbered and even-numbered sensors SE are then extracted in parallel from the signal detection units 4A and 4B, respectively.

FIG. 2 shows an example of the pixel structure of the imaging area 1. In the figure, SEa and SEb are odd-numbered and even-numbered sensors in the horizontal sensor row, respectively. Sensor SEa of each horizontal sensor row,
Horizontal shift registers 12A are provided above and below SEb, respectively.
, 12B extending horizontally.
6A and 106B are formed.

A channel stop 10 is provided on the opposite side of the transfer channels 106A and 106B from the sensors SEa and SEb.
5 is formed. Channel stops 105 are also formed between sensors SEa and SEb, on the transfer channel 106B side (lower side) of sensor SEa and on the transfer channel 106A side (upper side) of sensor SEb. As a result, the signal charge from sensor SEa is transferred only to transfer channel 106A, while the signal charge from sensor SEb is transferred to transfer channel 106A.
The read direction is restricted so that the data is read only to 06B.

Further, 101 to 103 are transfer electrodes made of poly-Si electrodes and extending in the vertical direction.
They are repeatedly arranged in the horizontal direction in the order of 02→103→101→... In this case, a pair of sensors SEa, SEb
A set of transfer electrodes 103 to 101 is arranged corresponding to the transfer electrodes 103 to 101, and portions of the transfer electrodes 101 to 103 corresponding to the sensors SEa and SEb are cut out.

Transfer electrodes 101 to 103 are supplied with transfer pulses φ1 to φ3, respectively, and are driven in three phases.

FIG. 3 shows the transfer pulses φ1 to φ3, and the transfer pulses φ1 to φ3 during the transfer period are at the potentials VL, VM(
Although the pulses are binary pulses with VL<VM), a readout pulse PRD with a potential VH (VH>VM) is added to the transfer pulses φ1 and φ3 in the read period.

A signal charge is read out from sensor SEb to transfer channel 106B corresponding to transfer electrode 101 by pulse PRD of transfer pulse φ1 (see arrow ■). This signal charge is transferred in the horizontal direction by transfer pulses φ1 to φ3. When this signal charge is transferred to the position corresponding to the transfer electrode 103 (see the arrow ■), the signal charge is read out from the sensor SEa to the transfer channel 106A corresponding to the transfer electrode 103 by the pulse PRD of the transfer pulse φ3 (arrow ■ reference). As a result, sensor S
Signal charges from Ea and SEb are transferred to the transfer electrode 10, respectively.
3, and the reading is completed.

[0024] After that, these sensors SEa, SEb
The signal charges from are transferred in parallel in the horizontal direction by transfer pulses φ1 to φ3 (see arrow ■). in this case,
Two horizontal pixel pitches are transferred in one period T of transfer pulses φ1 to φ3.

Next, FIG. 4 shows another example of the pixel structure of the imaging area 1. In the figure, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this example, the transfer electrodes 101 (shown with a dashed line) and 102 (shown with a solid line) are formed of second-layer and first-layer poly-Si electrodes, respectively. These transfer electrodes 101
, 102 are formed to extend in the vertical direction as a whole, and are repeatedly arranged in the horizontal direction in the order of electrodes 101→102→101→....

The transfer electrode 102 is connected to the sensors SEa, SE
Transfer channels 106A, 106 corresponding to each of b
It is arranged in a crank shape to cover part B. The transfer electrode 101 is crank-shaped like the transfer electrode 102,
It is arranged so as to cover a portion of the transfer channels 106A, 106B corresponding to the middle between the sensors SEa and SEb.

Further, the transfer electrode 103 (indicated by a broken line) is composed of a third layer of poly-Si electrode. This transfer electrode 103 is arranged so as to extend in the horizontal direction so as to cover both transfer channels 106A and 106B.

Furthermore, for each sensor row, the transfer channel 106B side (lower side) and transfer channel 1 of sensor SEa are
Channel stops 105 are formed alternately on the 06A side (upper side), and the transfer channel 106A side (upper side) and transfer channel 10 of sensor SEb are formed every sensor row.
Channel stops 105 are alternately formed on the 6B side (lower side). As a result, signal charges from sensor SEa are transferred to transfer channels 106A and 106B for each sensor column.
In addition, the readout direction is regulated so that signal charges from sensor SEb are read out only to transfer channels 106B and 106A for each sensor column.

This example is configured as described above, and the other configurations are the same as the example shown in FIG.

FIG. 5 shows the transfer pulses φ1 to φ3, and the transfer pulses φ1 to φ3 during the transfer period are at the potentials VL, VM(
Although it is a binary pulse of VL<VM), a readout pulse PRD of potential VH (VH>VM) is added to the transfer pulse φ2 in the read period.

Transfer channels 106A and 106 corresponding to transfer electrode 102 are activated by pulse PRD of transfer pulse φ2.
B, sensors SEa and SEb (or SE
The signal charges are simultaneously read out from SEa) and accumulated (see arrow ■), and the readout is completed.

[0033] After that, these sensors SEa, SEb
The signal charges from are transferred in parallel in the horizontal direction by transfer pulses φ1 to φ3 (see arrow ■). In this case, as in the example of FIG. 2, two horizontal pixel pitches are transferred in one period T of transfer pulses φ1 to φ3.

Next, FIG. 6 shows still another example of the pixel structure of the imaging area 1. In the figure, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this example, 101 to 104 are poly-Si
A vertically extending transfer electrode consisting of electrodes, electrode 1
They are repeatedly arranged in the horizontal direction in the order of 01→102→103→104→101→... Transfer electrodes 101 to 104
are respectively supplied with transfer pulses φ1 to φ4 and driven in four phases.

In this case, a pair of sensors SEa, SEb
A set of transfer electrodes 104 to 101 are arranged corresponding to the transfer electrodes 104 to 101, and portions of the transfer electrodes 104 to 101 corresponding to the sensors SEa and SEb are cut out.

This example is configured as described above, and the other configurations are similar to the example shown in FIG.

FIG. 7 shows the transfer pulses φ1 to φ4, and the transfer period of the transfer pulses φ1 to φ4 is at the potentials VL, VM(
Although the pulses are binary pulses with VL<VM), a readout pulse PRD with a potential VH (VH>VM) is added to the transfer pulses φ1 to φ4 in the read period.

Transfer channel 1 corresponding to transfer electrodes 101 and 102 by pulse PRD of transfer pulses φ1 and φ2
At 06B, signal charges are read out from sensor SEb (
(See arrow ■). This signal charge is transferred in the horizontal direction by transfer pulses φ1 to φ4. When this signal charge is transferred to the position corresponding to the transfer electrodes 103, 104 (see arrow ■), the transfer channel 1 corresponding to the transfer electrodes 103, 104 is
Signal charges are read out from sensor SEa at 06A (
(See arrow ■). As a result, signal charges from sensors SEa and SEb are accumulated in transfer channels 106A and 106B corresponding to transfer electrodes 103 and 104, respectively, and reading is completed.

[0040] After that, these sensors SEa, SEb
The signal charges from are transferred in parallel in the horizontal direction by transfer pulses φ1 to φ4 (see arrow ■). In this case as well, two horizontal pixel pitches are transferred in one period T of the transfer pulses φ1 to φ4, as in the example of FIG.

As described above, according to this example, the transfer pulse φ1
Since 2 horizontal pixel pitches are transferred in one cycle T of ~φ3 (φ1 to φ4), the horizontal frame frequency is reduced by 1 compared to the example in FIG.
/2. This is advantageous in terms of driving ability and power consumption of the driver, and also reduces transfer deterioration of the element itself.

Furthermore, according to the four-phase drive as in the example shown in FIG. 6, the signal charges from the sensors SEa and SEb are
Transfer channels 106 each corresponding to two transfer electrodes
A, 106B can be read and stored, so the data in Figures 2 and 4 can be read and stored.
The amount of charge handled by lateral transfer increases by 50% compared to the case of three-phase driving as in the example shown in FIG.

[0043]

According to the present invention, horizontal shift registers are arranged on both sides of each horizontal sensor row, and signal charges from odd-numbered and even-numbered sensors in the sensor row are transferred to one and the other horizontal shift registers, respectively. Since the signal charge is read out and transferred to
The horizontal pixel pitch can be transferred, and the horizontal frame shift frequency can be halved compared to the conventional method. This is advantageous in terms of driving ability and power consumption of the driver, and also reduces transfer deterioration of the element itself.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment.

FIG. 2 is a diagram showing a pixel structure of an imaging area.

FIG. 3 is a diagram showing transfer pulses.

FIG. 4 is a diagram showing a pixel structure of an imaging area.

FIG. 5 is a diagram showing transfer pulses.

FIG. 6 is a diagram showing a pixel structure of an imaging area.

FIG. 7 is a diagram showing transfer pulses.

FIG. 8 is a diagram showing the configuration of a conventional example.

FIG. 9 is a diagram showing a pixel structure of an imaging area.

FIG. 10 is a diagram showing transfer pulses.

[Explanation of symbols]

1 Imaging area 2 Accumulation area 3A, 3B, 12A, 12B Horizontal shift register 4
A, 4B Signal detection unit 5 Horizontal transfer gates 101 to 104 Transfer electrode 105 Channel stop 106A, 106B Transfer channel SE, SEa, SEb Sensor

Claims (1)

[Claims] 1. Horizontal shift registers are arranged on both sides of each horizontal sensor row, and signal charges from odd-numbered and even-numbered sensors in the sensor row are read out and transferred to one and the other horizontal shift register, respectively. A lateral transfer FIT type CCD solid-state image pickup device.