JPH04185162A - Image sensor and information processor mounted with this sensor - Google Patents

Abstract

PURPOSE:To obtain excellent photoelectric conversion outputs by setting the substantial size of the picture elements existing at the ends of plural optical sensor chips which are adjacent to each other at the size large than the substantial size of other picture elements. CONSTITUTION:These sensor chips 1, 2 are formed with the plural picture elements on a single crystal Si. The reading width in the main scanning direction of the picture elements 1-1, 2-1 at the ends of the chips are set wider than the picture elements 1-2, 1-3, 2-2, 2-3 exclusive of the end parts. The width in the sub-scanning direction is the same for all the picture elements and the area of the picture elements 1-1, 2-1 is set larger. Then, the insufficiency of the crosstalk quantity when the outputs of e picture elements at the ends of the chips and the outputs of the picture elements exclusive of the end are compared is made up and the output signal levels of the entire picture elements are eventually uniformized. The output signal levels of the joint part of the chips are uniformized in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-chip image sensor in which a plurality of image sensor chips are arranged on a substrate, and an information processing device equipped with the image sensor.

[Conventional technology]

Linear image sensors are widely used in facsimiles, scanners, etc. Linear image sensors, which have traditionally been used as reading devices, are created using single-crystal silicon wafers, so the sensor length is limited by the wafer size, making it difficult to create a linear image sensor chip with the same length as the original. It is. For this reason, the reflected light from the document is reduced using an optical system, and the image is read by projecting the reduced light onto a linear image sensor. However, a reading device using such a reduction optical system requires a large space for the optical system and does not have sufficient resolution. To solve this problem, a multi-chip close-contact image sensor in which a plurality of linear image sensor chips are arranged in a straight line is used.

FIG. 2 is a schematic plan view showing the conventional contact type image sensor mentioned above. Here, the reading width is widened by arranging sensor pixels or arranging a plurality of near image sensor chips in a straight line.

In Fig. 2, 1 and 2 are image sensor chips, 3 is a mounting board, and 1-1, l-2, 1-(n-1), 1
-n, 2-1, 2-2.2-(n-1), and 2-n indicate each pixel.

Here, only two adjacent image sensor chips are illustrated.

[Problem that the invention is trying to solve]

However, in the above conventional example, the outputs of the pixels 1-n, 2-1 at the edges of each image sensor chip are converted to the outputs of the pixels 1-2, . . . 1-(n-1), 2-2, .・・２
-(n-1), the output signals sometimes differed from each other.

As a result of repeated numerous experiments and studies, the inventor found that
The cause was found to be as follows. In other words, the cause is that pixels 1-2,...1-(n-1), 2-
In 2,...2-(n-1), since pixels are arranged on both sides, crosstalk components from adjacent pixels are added to the output, whereas in the case of end pixels 1-1.1-n, 2 -1.2-n
In this case, since there are adjacent pixels only on one side, the crosstalk component is approximately halved.

In a multi-chip image sensor, the above problem appears as discontinuity in the output signal at the chip joint.

〔the purpose〕

The present invention has been made in view of the above-mentioned technical problems, and an object of the present invention is to provide an image sensor and an information processing device that can obtain a photoelectric conversion output superior to the conventional ones.

Another object of the present invention is to provide an image sensor and an information processing device with a simple configuration that can obtain uniform borrowing signals including the joints between optical sensor chips.

[Means to solve the problem]

An object of the present invention is to provide an image sensor in which a plurality of optical sensor chips each having a plurality of pixels arranged in the main scanning direction are arranged in the main scanning direction, in which a plurality of optical sensor chips located at ends of the plurality of adjacent optical sensor chips are arranged in the main scanning direction. It is an object of the present invention to provide an image sensor characterized in that the substantial size of a pixel is larger than the substantial size of other pixels, and to provide an information processing device equipped with the sensor.

[Effect]

According to the present invention, the size of the edge pixel of the sensor chip is made thicker than the size of the pixels other than the edge (by doing so, the output signal levels of the edge pixel and the pixels other than the edge are made equal). This is what I did.

By doing so, the levels of the output signals can be made uniform using an extremely simple method.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments described below.

FIG. 1 is a schematic plan view showing one embodiment of a contact type image sensor according to the present invention. In Figure 1, 1
, 2 are sensor chips in which a plurality of pixels are formed on single-crystal Si, and two are shown here. 1-1.
1-2.1-3.2-1.2-3 indicates the pixel at the chip connection part among all the pixels. As shown in the figure, for the pixel 1-1.2-1 at the edge of the chip, the reading width in the main scanning direction is for the pixel 1-2.1-3.2-2 at the edge other than the edge.
．． It is wider than 2-3. The width in the sub-scanning direction is the same for all pixels, and the area of pixel 1-1.2-1 is larger. According to this embodiment, the shortfall in the amount of crosstalk when comparing the output of the pixel at the end of the chip with the output of the pixel other than the end is compensated for, and the output signal levels of all the pixels are made equal.

In this example, the size of each pixel was defined as the area of the opening provided in the light shielding layer A, 1, etc.

FIG. 3 is a schematic plan view showing the opening.

In this example, the openings do not have a closed shape, but two light shielding layers are used as shown in FIG. 3, so the openings defining each pixel communicate with each other. Here, specifically
75μm, x2, X3 7゜11m, yISY2
125. czm, Z to 200. czm. Therefore, in this example, the size of pixel 2-1 is X.

×Zμ The size of the door pixel 2-2 is defined as X2XZμ.

Area 52-1 of end pixel 2-1 and other pixels 2-
2 to the area 52-2 may be selected as desired, but preferably 52-1/52-2=1.
07 more preferably 52-1/S2-2=1.
It is IO.

FIG. 4 is an equivalent circuit diagram corresponding to one pixel of this embodiment.

PS is a bipolar transistor forming a pixel, SWl
is an NMOS transistor, SW, which connects the emitter to the reference voltage source VR5 and serves as a switch means for resetting.
2 is a PMOS transistor as a switching means for connecting the base to the reference voltage source VBH and performing reset;
SW3 is an NMO as a switch means for signal charge transfer.
The S transistor, CT, is a quantitative load on which a signal voltage is generated. Its operation will be briefly explained.

<Reset Operation> First, a negative pulse voltage is applied to the gate of the PMOS transistor SW2, and the base is clamped to the voltage V B B.

Next, a positive pulse voltage is applied to the gate of the NMOS transistor SWr, and the emitter is connected to the voltage source V. connected to 5,
A current flows between the base and emitter to eliminate photogenerated carriers remaining in the base.

Accumulation Operation> Both NMOS transistors SW1 and SW3 are turned off, their emitters and bases are both in a floating state, and an accumulation operation is started.

<Reading operation> Next, a positive pulse voltage is applied to the gate of NMO3) transistor SW3 to turn it on, the emitter and capacitor CT are connected, and the signal voltage is read to capacitor CT.

The basic structure of such an image sensor is disclosed in U.S. Patent No. 4. 686°554
In the specification, etc., the output circuit including the capacitive load is bipolar.
It is described as a charge storage type photoelectric conversion device with high sensitivity and low noise, in which the emitter of a transistor is connected.

[Other Examples]

[Second Embodiment] FIG. 5 shows an image sensor according to a second embodiment of the present invention.

The basic configuration of this example is the same as the first example described above, but the pixel 1-2.2- adjacent to the end pixel 1-1.2-1
2 shape to other pixels 1-3.1-4.2-3.2-
The difference is that the shape is different from No. 4.

Here, the relationship between pixel widths is X, -3, X, -4, Xl-
3. Xl-4 was set to the same 70 μm, Xl-2 and Xl-2 were narrower <60 μm, and x r-+ and Xl-1 were set to the largest 75 μm in order to increase the area.

Similarly, the pitch between pixels is also different from the first embodiment, specifically, P is 1.0 μm, P+ is 09 μm, and P2 is 1.0 μm.
1μm5P3 is 1.4μm and pitch deviation is 0.1.
It becomes gentle at 0.2.0.3. Of course, regarding the area of the pixels, only the pixels 1-1, 2-1 are larger than the other pixels. Therefore, pixel 1-2.2-2 has an area equal to that of pixels 1-3, ■-4, 2-3, and 2-4 by increasing the length in the public scanning direction where the pixel width has become smaller due to pitch adjustment. are doing.

According to this embodiment, the problem of chip joints is further improved.

In the first and second embodiments described above, a charge accumulation/amplification type image sensor using a bipolar transistor has been described, but the present invention uses a photodiode as a light receiving section and an M
It can also be preferably applied to a type of sensor that transfers signal charges using an OS switch, a charge-coupled device (CCD), or the like.

The image sensor shown in Figure 1 is assembled integrally with a light source such as an LED array and an imaging optical system such as a short-focus imaging element array in a housing made of AI etc. to produce a close-contact image. Configure the sensor unit.

FIG. 6 shows an example of a facsimile having a communication function as an image information processing apparatus configured using the sensor unit according to this example. Here, 102 is a feeding roller serving as a feeding means for feeding the original PP toward the reading position, and 104 is a separation piece for reliably separating and feeding the original PP one by one. A platen roller 106 is provided at a reading position with respect to the sensor unit, and serves as a conveying means for regulating the surface to be read of the document PP and conveying the document PP.

In the illustrated example, P is a recording medium in the form of a roll paper,
Image information read by the sensor unit or, in the case of a facsimile device, image information transmitted from the outside is reproduced here. Reference numeral 110 denotes a recording head as a recording means for forming the image, and various types such as a thermal head and an inkjet recording head can be used.

Also, this recording head is a serial type,
It may also be a line type. 112 is the recording head 11
The platen roller serves as a conveying means for conveying the recording medium P to the recording position according to zero and regulating the recording surface of the recording medium P.

Reference numeral 120 denotes an operation panel on which are arranged switches and messages for receiving operation input as input/output means, and a display section for notifying the status of the apparatus.

130 is a system control board as a control means, and is provided with a control unit (controller) for controlling each part, a drive circuit (driver) for the photoelectric conversion element, an image information processing unit (processor), a transmitting/receiving unit, etc. It will be done. 1
40 is a power source for the device.

As the recording means used in the information processing device of the present invention,
For example, U.S. Pat. No. 4,723,129, U.S. Pat.
Preferably, the typical configuration and principle thereof are disclosed in the specification of No. 0796. In this method, at least one electrothermal transducer that corresponds to the recorded information and that causes a rapid temperature rise exceeding nucleate boiling is applied to an electrothermal transducer placed corresponding to the sheet holding the liquid (ink) or the liquid path. By applying a drive signal, the electrothermal transducer generates thermal energy and causes a film to boil on the heat-active surface of the recording head, resulting in a one-to-one response to the drive signal that causes bubbles in the liquid (ink) to be removed. It is effective because it can be formed.

Due to the growth and contraction of these bubbles, liquid (
ink) to form at least one droplet.

Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above requirements or a configuration as a single recording head formed integrally may be used.

In addition, there are also replaceable chip-type recording heads that can be installed on the device body to enable electrical connection to the device body and supply of ink from the device body, or an ink tank integrated into the recording head itself. The present invention is also effective when a cartridge type recording head is used.

〔Effect of the invention〕

As described above, by changing the size of the pixels between the end pixels and the pixels other than the end of each image sensor chip, it is possible to make the output signal levels of the chip joints the same.

[Brief explanation of the drawing]

FIG. 1 is a schematic top view of a contact type image sensor according to a first embodiment of the present invention, FIG. 2 is a schematic top view of a conventional contact type image sensor, and FIG. 3 is a schematic top view of a contact type image sensor according to the present invention. FIG. 4 is a circuit diagram of one pixel of an image sensor according to the present invention; FIG. 5 is a schematic top view of a contact type image sensor according to a second embodiment of the present invention; FIG. FIG. 1 is a schematic cross-sectional view of an information processing device according to the invention. 1.2... Image sensor chip 3... Mounting board 1-1.1-2.1-3.1-(n-1), 1-n, 2
-1.2-2.2-3.2-(n-1), 2-n...
Sensor pixel Figure 3 Figure 4

Claims (5)

[Claims] (1) In an image sensor in which a plurality of optical sensor chips having a plurality of pixels arranged in the main scanning direction are arranged in the main scanning direction, the substance of the pixels located at the ends of the plurality of adjacent optical sensor chips An image sensor characterized in that the actual size of the pixels is larger than the actual size of other pixels. (2) The image sensor chip has a pixel made of a bipolar transistor, and an output circuit including a capacitive load is provided at the emitter of the bipolar transistor, and the photoelectrically converted signal is read out as a voltage at the capacitive load. The image sensor according to claim 1, characterized in that: (3) An information processing device comprising: the image sensor according to claim (1); and document holding means for holding a document at a reading position by the image sensor. (4) The information processing apparatus according to claim (3), wherein the information processing apparatus has a recording means for recording image information. (5) The information processing apparatus according to claim (4), wherein the recording means is a recording head that discharges ink and performs recording using thermal energy.