JPH05191560A - Sold image pickup element having plural charge transfer path - Google Patents

Abstract

PURPOSE:To constitute adjacent light receiving part rows to be close by preventing the concentration of circuit parts in a linear image sensor device, and prevenling the concentration of heat generating sources. CONSTITUTION:Light receiving part columns 22 and 25 are arranged to be in parallel in two rows.on a semiconductor substrate 21, and two phase CCD 24 and 27 being the charge transfer paths are provided to be adjacent to the light receiving part rows 22 and 25. A charge is transferred to output terminals 28 and 29 while the transfer direction of the CCD 27 is used as an X positive direction, and the transfer direction of the CCD 24 is used as the opposite direction, and outputted through output buffets 31 and 30 arranged at the both sides. The transfer directions of the two CCD are made to be opposite, and the output buffers 31 and 30 are arranged at the both sides of the device, so that the circuit parts being the heat generating sources can be separated, and the concentration of the heat generating sources can be prevented. Thus, the device can be constituted so that the two CCD sensor parts can be adjacent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device having a plurality of charge transfer paths.

[0002]

2. Description of the Related Art Conventionally, a charge transfer section has a CC
In the linear image sensor D, as shown in FIG. 3, a solid-state image sensor device 1 having two light-receiving section arrays 2 and 5 in which charge transfer paths 4 and 7 transfer signal charges in the same direction. Are known. One of the plurality of charge transfer paths transfers a bright / dark (luminance) signal read by the light receiving section array, and the other charge transfer path transfers a color signal such as an imprint (red) read by the light receiving section. Used to

The light receiving section rows 2 and 5 are composed of a plurality of cells and generate electric charges according to incident light. The shift gates 3 and 6 transfer the charges to the charge transfer paths 4 and 7, and transfer the charges to the charge transfer paths associated with the respective light receiving section rows 2 and 5. That is, the charges generated in the light receiving section array 2 are sent to the charge transfer path 4 by the shift gate 3, and the charges generated in the light receiving section array 5 are sent to the charge transfer path 7 by the shift gate 6. The transfer is
This is performed by the charge read pulse voltage applied to the input terminal 16.

The charge transfer paths 4 and 7 are specifically 2
It is a phase CCD and is arranged parallel to the shift gates 3 and 6. In this transfer path, the charges transferred from the light-receiving section columns 2 and 5 by the shift gates 3 and 6 are converted into two-phase charge transfer drive pulses (hereinafter referred to as transfer clock pulses) shown in FIG. Among them, the transfer clock 1 is input to the terminal 14 and the transfer clock 2 is input to the terminal 15 to transmit to the charge-voltage converters 8 and 9 on the output side. The output terminals 8 and 9 serving as the charge-voltage converter are
Basically, it has a function of converting charges into electric signals, and supplies the converted signals to the output buffers 10 and 11. The output buffers 10 and 11 are generally output circuits,
It adjusts the output impedance and the function that amplifies and processes signals.

As described above, when the charge transfer paths 4 and 7 transfer signal charges in the same direction, the buffers 10 and 11 associated with the output section are concentrated on one side of the sensor. In this case, the circuit portion which is a heat generation source is concentrated in a part of the device, thermal noise is easily generated in the device, and as a result, the S / N of the output signal is deteriorated.

Further, in the linear image sensor, the width of the output circuit portion is larger than the total width of the light receiving portion and the charge transfer portion. Therefore, when the circuits are concentrated, the size in the width direction of the device (length in the Y direction in the figure). Is determined at this portion, which is an obstacle especially when the two light receiving unit rows 2 and 5 are attempted to be brought close to each other.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a linear image sensor in which the adjacent light receiving section rows can be brought close to each other by avoiding the concentration of the heat generating source by avoiding the concentration of the circuit section in the linear image sensor device. Is in the point of providing.

[0008]

A solid-state image sensor having a plurality of photosensors arranged in a straight line on the same device, and parallel charge transfer paths corresponding to the respective photosensors. In the above, the output parts are arranged at both ends of the image pickup device, and the transfer direction of the signal reaching the final output part is inverted and transferred for each transmission path or each light receiving part row.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, an example of a CCD linear image sensor in which light receiving portion rows arranged in parallel are arranged as in the conventional example will be described. FIG. 1 is a block circuit diagram of a first embodiment of a linear image sensor of the present invention. On the semiconductor substrate 21, the light receiving section array 22 including the photosensor diode arrays
And 25 are arranged in parallel in two rows, and a pair of shift gates 23 and 26 and a pair of charge transfer paths 24 and 27 are arranged in parallel to each light receiving section row.

The light-receiving section rows 22 and 25 are composed of a plurality of cells and generate electric charges according to incident light. The shift gates 23 and 26 transfer charges to the charge transfer paths 24 and 2.
7, and the charges are transferred to the charge transfer paths associated with the respective light-receiving section arrays 22 and 25. That is, the charges generated in the light receiving section array 22 are sent to the charge transfer path 24 by the shift gate 23, and the light receiving section array 2
The charges generated in 5 are sent to the charge transfer path 27 by the shift gate 26. The transfer is performed by the charge read pulse voltage applied to the input terminal 36.

The charge transfer paths 24 and 27 are specifically two-phase CCDs, and are arranged parallel to the shift gates 23 and 26. This transfer path is connected by the shift gates 23 and 26 to the light receiving section rows 22 and 25.
Of the electric charges transferred from the transfer clock 1 to the terminal 34 among the two-phase transfer clock pulses shown in FIG.
The transfer clock 2 is input to the terminal 35 and transmitted to the output side. The output terminals 28 and 29 serving as the charge-voltage converters are
Basically, it has a function of converting electric charges into electric signals, and supplies the converted signals to the output buffers 30 and 31. The output buffers 30 and 31 are generally output circuits,
It adjusts the output impedance and the function that amplifies and processes signals.

In general, this portion consumes electric power and serves as a heat generation source. Further, the physical width (length in the Y direction in the figure) tends to be larger than that of the CCD sensor section (light receiving section array, shift gate, charge transfer path). The charge transfer path is configured so that the charge transfer path to the output portion is the positive transfer direction of the charge transfer path 27 and the negative transfer direction of the charge transfer path 24. The output terminals 28 and 2 are created at the end of each charge transfer path.
9, output buffers 30 and 31 are provided.

In the solid-state image pickup device having the above-mentioned structure, the output buffer sections 30 and 31 are located at both ends of the device, and the circuit section which is the heat generation source is separated. This makes it possible to avoid concentration of heat generation sources due to concentration of circuits. In addition, the circuit portion that has determined the length of the device in the Y direction will be separated.
It is possible to obtain a device in which two CCD sensor units can be brought close to each other without being affected by the circuit unit.

Next, a double-sided readout type CCD linear image sensor according to a second embodiment of the present invention will be described with reference to FIG. A light receiving section array 42 is provided on a semiconductor substrate 41, and shift gates 43 and 44 are arranged in parallel on both sides of the light receiving section array 42. The first and second charge transfer paths 45 are provided for the respective shift gates. And 46 are placed. The shift gates 43 and 44 are for transferring the charges generated in the light receiving section array 42 to the charge transfer paths 45 and 46, and the transfer is performed by applying a charge read pulse voltage to the input terminal 57. ..

At this time, the charges generated in the light-receiving portion array 42 have different transfer directions between the even-numbered and odd-numbered portions of the light-receiving portion array, and one of the charges is transferred to the positive Y shift gate 43 in the drawing. The charges are transferred to the first charge transfer path 45, and the other charges are transferred to the second charge transfer path 46 by the negative shift gate 44 of Y in the figure. The charge transfer paths 45 and 46 are composed of two-phase CCDs and charge-voltage converters 47 and 4 are provided.
8 to transfer the charge. Charge transfer is performed by the two-phase CCD 4
6 to the terminal 53 and the terminal 55 of the two-phase CCD 45, the transfer clock 1 shown in FIG.
The transfer clock 2 shown in FIG. 4 (B) is input to the terminal 54 of 6 and the terminal 56 of the two-phase CCD 45.

Here, the repetition frequency of the transfer clock pulse is halved unlike the first embodiment and the conventional example. This is because the transfer rate for reading one line is halved and the data rates are the same.

As described above, like the first embodiment, the direction of this charge transfer is set to the opposite direction between the first charge transfer path and the second charge transfer path, and the charge-voltage conversion section becomes an output terminal at each end. 47 and 48 and output buffers 49 and 50 are provided. With such a configuration, the output buffer unit can be separated, and the adverse effect due to the circuit concentration can be avoided.

[0018]

By using the present invention, it is possible to avoid local concentration of the circuit portion in the device and avoid concentration of the heat generation source, so that the temperature distribution of the device can be made uniform. Further, in a device having a plurality of light receiving section arrays, it becomes possible to bring adjacent light receiving section arrays close to each other due to the dispersion of the circuit section.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a first embodiment of the present invention.

FIG. 2 is a block circuit diagram of a second embodiment of the present invention.

FIG. 3 is a block circuit diagram of a conventional example.

FIG. 4 is a diagram showing transfer clock pulses.

[Explanation of symbols]

22 and 25..Light receiving section array 23 and 26..Shift gates 24 and 27..Charge transfer path 28 and 29..Charge / voltage conversion section 30 and 31..Output buffer

Claims (3)

[Claims] 1. A solid-state image sensor having a plurality of light-receiving section rows in which a plurality of photosensors are linearly arranged on the same device, and parallel charge transfer paths corresponding to the respective light-receiving section rows. A solid-state image pickup device, wherein output parts are arranged at both ends of the solid-state image pickup device, and a transfer direction of a signal reaching a final output part is inverted and transferred for each transfer path or each light-receiving part row. 2. A solid-state image sensor having a plurality of photosensors arranged in a line on the same device, and a plurality of charge transfer paths arranged in parallel corresponding to the photosensors. A solid-state image pickup device, wherein parts are arranged at both ends of the solid-state image pickup device, and a transfer direction of a signal reaching a final output part is inverted and transferred for each transfer path. 3. The solid-state image pickup device according to claim 2, wherein the charge transfer paths are arranged in parallel on both sides of the light receiving portion.