JPH04239869A - Image sensor unit - Google Patents

Abstract

PURPOSE:To make the constitution of the complete contact type image sensor unit used for such as a facsimile equipment simple. CONSTITUTION:A wiring board, a supporting board, etc., which are matched to a conventional image sensor unit are omitted and a sensor board 14 and flexible wiring 18 are direct-connected electrically. Besides, the outer surface of a cover glass 20 is made to lower than the outer surface of the flexible wiring 18.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor unit used in a document reading section of a facsimile, an image scanner, a digital copying machine, etc., and more particularly to a completely contact type image sensor unit that does not use a lens array.

0002

[Prior Art] Conventionally, a charge coupled device (charge coupled device) is used in a document reading section of a facsimile machine or the like.
Image sensors with a reduction optical system using a CCD (device; CCD) have been used, but in recent years, image sensors with a same-magnification optical system have been used. An image sensor with a same-magnification optical system is generally called a contact image sensor, and reads an image on a document by focusing it on a photoelectric conversion element made of amorphous silicon a-Si or the like at the same magnification. Here, a lens array is usually used to form an image on a document at the same magnification on a photoelectric conversion element, but in recent years, complete contact type image sensors that do not use a lens array have also begun to be used. These image sensors are incorporated into a housing together with a driving element, an LED array, etc. for reading signals from a photoelectric conversion element, and are provided as an image sensor unit.

As shown in FIG. 5, a conventional fully contact type image sensor unit 100 includes a housing 102 made of aluminum or the like, a sensor substrate 104 on which a plurality of photoelectric conversion elements are formed for reading images, and a sensor. A wiring board 106 patterned with wiring for inputting or outputting signals to the board 104 , a support board 108 made of glass or the like and supporting the sensor board 104 and the wiring board 106 , and image signals from the sensor board 104 in time series A processing circuit board 110 for reading data is attached to the memory. Furthermore, the wiring board 106
is processed by the flexible wiring 112 on the circuit board 11
A cover glass 114 is attached to cover the entire sensor board 104 and a part of the wiring board 106. Here, the sensor board 10
4 is a transparent substrate 11 such as glass, as shown in FIG.
6 A plurality of photoelectric conversion elements 11 made of a-Si or the like on top
8, and a matrix wiring 120 that allows the signals of these photoelectric conversion elements 118 to be read out in time series in block units. Also,
The processing circuit board 110 is provided with driving elements for reading out signals from the photoelectric conversion elements 118 in time series, and is also provided with a light source 122 such as an LED array.

[0004] This image sensor unit 100 is used by being incorporated into a facsimile machine, etc., and is used as a light source 122.
The light emitted from the supporting substrate 108 and the transparent substrate 11
6 and the cover glass 114 and are conveyed by the platen roller 124.
irradiate. Then, the light reflected by the original 126 passes through the cover glass 114 again and enters the photoelectric conversion element 118. Here, a light entrance window 128 is provided near the photoelectric conversion element 118 so that the light emitted from the light source 122 reaches the document 126 without being hindered and is promptly incident on the photoelectric conversion element 118. ing. In this way, the original 12
6 Light corresponding to the above image is made incident on the photoelectric conversion element 118 , and an electric signal corresponding to the amount of light is arranged on the processing circuit board 110 through the matrix wiring 120 , the wiring on the wiring board 106 , and the flexible wiring 112 . The data is read out in time series by a driving element.

On the other hand, as shown in FIGS. 7 and 8, in order to connect the matrix wiring 120 of the sensor board 104 and the wiring of the wiring board 106, electrode portions 130, 132 are formed at the ends of these wirings. has been done. These electrode parts 130, 132 are arranged to face each other, and a conductive paste 134 is placed between these electrode parts 130, 132.
The sensor board 104 and the wiring board 106 are electrically connected. For example, A4
In the case of a matrix-driven image sensor unit with a plate size and resolution of 8 dots/mm, 172
Eight photoelectric conversion elements (pixels) are required, and these photoelectric conversion elements are divided into 54 blocks of 32 each, and the number of electrode parts 130 and 132 is 86 each.
There are (32+54) pieces. Therefore, the sensor board 10
4 and the wiring board 106 and the wiring board 106 and the flexible wiring 112 are each electrically connected at 86 points. Furthermore, this wiring board 106
and the aforementioned processing circuit board 110 and the flexible wiring 1
12 electrically connected.

[0006]

SUMMARY OF THE INVENTION As described above, the conventional image sensor unit has a complicated structure made up of many parts, and therefore has the problem of requiring a large number of assembly steps. For this reason, the yield associated with assembly is low, which is also a cause of lowering the reliability of the image sensor unit. Moreover, there is a problem in that both the parts cost and the assembly cost are high.

[0007]The inventors of the present invention have made intensive studies to simplify the configuration of the image sensor unit without degrading its performance, and have finally arrived at the present invention.

[0008]

[Means for Solving the Problems] The gist of the image sensor unit according to the present invention is that a plurality of photoelectric conversion elements and wiring for inputting and outputting signals to the photoelectric conversion elements are provided on a transparent substrate. the formed sensor substrate, a processing circuit board including a circuit element for driving the plurality of photoelectric conversion elements and reading out the output signals, and a flexible board for electrically connecting the sensor board and the processing circuit board. The present invention is an image sensor unit in which a wiring is attached to a housing, and the sensor board and the flexible wiring are directly electrically connected.

Another aspect of the image sensor unit according to the present invention is that a plurality of photoelectric conversion elements and wiring for inputting and outputting signals to and from the photoelectric conversion elements are formed on a transparent substrate. A sensor board, a processing circuit board including circuit elements for driving the plurality of photoelectric conversion elements and reading output signals, and flexible wiring for electrically connecting the sensor board and the processing circuit board. An image sensor unit that is attached to a housing and in which the sensor board and the flexible wiring are directly electrically connected, the cover glass being attached to the document reading surface of the sensor board to protect the sensor board. The outer surface is lower than the outer surface of the flexible wiring that is adjacent to the cover glass and electrically connected directly to the sensor substrate.

0010

[Operation] In such an image sensor unit, the sensor board is directly connected to the flexible wiring for electrical connection to the processing circuit board, and the wiring board, support board, and associated parts that were in the conventional image sensor unit are not included. reduced. Therefore, production efficiency is improved by reducing the number of steps for assembling the image sensor unit, and the number of wiring connections is reduced, which further improves product yield.

Furthermore, by configuring the outer surface of the cover glass to be lower than the outer surface of the flexible wiring, documents brought in from the flexible wiring side can quickly reach the top surface of the cover glass without getting caught on the edge of the cover glass. transported.

0012

Embodiments Next, embodiments of the image sensor unit according to the present invention will be described in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 10 indicates an image sensor unit according to the present invention. The image sensor unit 10 includes a housing 12 made of aluminum or the like, a sensor board 14 for reading images, and a processing circuit board 1 for reading out image signals from the sensor board 14 in time series.
6, and flexible wiring 18 that electrically connects the sensor board 14 and the processing circuit board 16. Further, a cover glass 20 is attached to cover a part of the sensor substrate 14.

In the sensor substrate 14, a plurality of photoelectric conversion elements such as photodiodes (not shown) are formed one-dimensionally on a transparent substrate 15 made of glass, resin, etc.
Wiring for driving the plurality of photoelectric conversion elements and wiring for reading signals photoelectrically converted by the photoelectric conversion elements are formed. This photoelectric conversion element is mainly formed of an amorphous silicon-based semiconductor layer having electrode layers on both sides, and this amorphous silicon-based semiconductor layer includes amorphous silicon a-Si, hydrogenated amorphous silicon a-Si:H, and hydrogenated amorphous silicon carbide. a-SiC:H, amorphous silicon nitride, etc., silicon and carbon, germanium,
Pi refers to amorphous, microcrystalline, or polycrystalline amorphous silicon semiconductors made of alloys with other elements such as tin.
Those deposited in an n type, nip type, ni type, pn type, MIS type, heterojunction type, homozygous type, Schottky barrier type, or a combination of these types are used. This photoelectric conversion element may be made of other non-silicon semiconductors, and is not limited in any way by the present invention. Further, a light entrance window is provided adjacent to the photoelectric conversion element, and the document is irradiated with light transmitted through the light entrance window.

The photoelectric conversion element formed on the sensor substrate 14 is, for example, A4 size and has a resolution of 8 dots/mm.
In the case of a matrix drive type image sensor unit, 1728 photoelectric conversion elements are required as described above. In order to speed up signal processing, these photoelectric conversion elements are divided into 54 blocks in total, with one block consisting of, for example, 32 photoelectric conversion elements. Therefore, in this example, in order to drive the photoelectric conversion elements in block units in a time-series manner and read out signals from the photoelectric conversion elements, there are five
Four wires are formed on the read side, and 32 matrix wires are formed on the read side. Furthermore, blocking diodes, TFTs, and the like are formed in correspondence with photoelectric conversion elements as necessary. These wirings are led out to the long sides of the transparent substrate 15, and electrode portions 22 are formed at the ends thereof.

Further, a cover glass 2 is attached to the sensor substrate 14.
0 is attached on top of the photoelectric conversion element, drive side wiring, matrix wiring, blocking diode, etc., excluding the electrode portion 22, in order to protect them. here,
From the top surface of the sensor substrate 14 to the outer surface L of the cover glass 20
If the distance to 1 is too large, the image will be blurred, so for example, for an image sensor unit with a resolution of 8 dots/mm, this distance is usually 150 μm.
be done within. This cover glass 20 and sensor substrate 14
The distance is set by adjusting the thickness of the cover glass 20 and the thickness of the adhesive layer.

After the sensor board 14 having such a configuration is arranged and fixed at a predetermined position of the housing 12, the sensor board 14 is
Electrode part 2 of the drive side wiring and readout side matrix wiring
One end of the flexible wiring 18 is directly connected to 2 and wound around the outer periphery of the housing 12, and the other end is connected to an electrode portion of the processing circuit board 16. Since the cover glass 20 is attached to the sensor substrate 14 adjacent to the electrode section 22 to which the flexible wiring 18 is directly connected, a step is created between the flexible wiring 18 and the cover glass 20. Therefore,
The thickness of the flexible wiring 18 and the thickness of the adhesive layer are set such that the height of the outer surface L1 of the cover glass 20 is lower than the height of the outer surface L2 of the flexible wiring 18. Flexible wiring 1 is connected to the electrode section 22 of the sensor board 14.
8 is generally connected by sandwiching an anisotropic conductive film between the electrode part 22 and the flexible wiring 18 and by thermocompression bonding. A common method for connecting the parts 18 is to press them together using a support member. Here, the housing 12 supports and fixes the sensor board 14, and
It is formed into a shape sufficient to guide the light from the light source 24 to the light incidence window of the sensor substrate 14, and is configured to prevent the sensor substrate 14 from being broken by the pressing force of a platen roller or the like.

On the other hand, the processing circuit board 16 drives the photoelectric conversion elements in time series, and also includes circuit elements such as switch ICs and driving ICs for reading out signals from the driven photoelectric conversion elements, and LEDs. Light source 2 such as array
4 are arranged on a printed circuit board. The switch IC is equipped with a shift register for sequentially selecting photoelectric conversion elements in blocks, and the driving IC is equipped with a shift register and the like for sequentially reading out signals from the photoelectric conversion elements driven for each block. It is equipped with an amplifier circuit that amplifies the read signal. Note that the light source 24 is turned on when reading starts, and turned off when reading ends.

The image sensor unit 10 has a wiring board 1 that is in the conventional image sensor unit 100.
06, the number of support substrates 108 is reduced, and the structure is simple with a small number of parts. Therefore, the number of assembly steps is reduced, the assembly yield is improved, and the reliability of the image sensor unit 10 is also improved. Furthermore, both component costs and assembly costs are reduced. Further, since the sensor board 14, the processing circuit board 16, etc. are configured in the same manner as the conventional one, the performance of the image sensor unit 10 is not inferior to that of the conventional one. Furthermore, it is also possible to downsize the image sensor unit as in this example.

[0020] Furthermore, such an image sensor unit 10
is used by being incorporated into a document reading device such as a facsimile machine, and as shown in FIG.
is used so as to be conveyed from the flexible wiring 18 side, that is, from the right side to the left side in the figure, while being pressed against the surface of the cover glass 20 on the reading section of the sensor board 14 by the platen roller 28. Therefore, cover glass 2
The outer surface L1 of the flexible wiring 18 is lower than the outer surface L2 of the flexible wiring 18, so that the document 26 can be quickly attached to the cover glass 20 without getting caught on the edge 30 of the cover glass 20.
0, and there is no possibility of transport failure.

Although one embodiment of the present invention has been described above in detail, the present invention is not limited to the above-described embodiment, and can be implemented in other embodiments.

For example, as shown in FIG. 4, the flexible wiring 32 may pass through a slit 36 provided in the housing 34 and be connected to the processing circuit board 40 by a connector 38 or the like. The method of connecting the wiring and the processing circuit board is not limited at all. Similarly, the method of connecting the flexible wiring and the sensor board is not limited in any way, and the present invention suffices as long as the flexible wiring and the sensor board are directly connected without using another wiring board or the like. Further, the shape, structure, material, etc. of the casing 34 are not particularly limited, and the casing 34 may be an unsealed cylindrical one or may be composed of a plurality of members. Furthermore, the light source 42 does not need to be disposed on the processing circuit board 40 and may be attached to the housing 34. The light source may be a xenon lamp, a halogen lamp, a cold cathode tube, a fluorescent lamp, etc., and is not limited to an LED array. Furthermore, the light source does not have to be integrated into the image sensor unit. In the case of an image sensor unit that does not include a light source, it is sufficient that the image sensor unit is configured so that the sensor board is irradiated with a light source that is already installed in the main body of the facsimile machine or the like.

Further, the processing circuit board may be attached to the housing so as to be perpendicular to the sensor board, and the position of the processing circuit board is not limited at all. Further, the processing circuit board may be of any type as long as it has a function of reading signals from the photoelectric conversion elements, and its circuit configuration is not limited in any way.

Furthermore, the number of flexible wirings may be one or more. Additionally, the outer surface of the flexible wiring and the outer surface of the cover glass may be at the same height, or if the document is fed from the cover glass side to the flexible wiring side, the outer surface of the cover glass may be at the same height as the outer surface of the cover glass. Preferably, it is configured to be higher than the outer surface of.

In addition, the present invention is not limited to a matrix drive type image sensor unit, but can also be applied to an individual drive type image sensor unit in which signals from each photoelectric conversion element are individually read out. Various improvements, modifications, and variations may be made based on the knowledge of those skilled in the art without departing from the above.

[0026]

Effects of the Invention The image sensor unit according to the present invention is different from conventional image sensors because the sensor board is directly connected to the flexible wiring for electrical connection to the processing circuit board, and no other wiring board is used. It has a simple structure, without the wiring board, support board, and related parts that were found in the unit. Therefore, the number of assembly steps is reduced, the assembly yield is improved, and the reliability of the image sensor unit is also improved. Additionally, both component costs and assembly costs are reduced. Moreover, the performance of the image sensor unit is not inferior to conventional ones.

Furthermore, by configuring the cover glass so that the outer surface thereof is lower than the outer surface of the flexible wiring, the document sent from the flexible wiring side is quickly conveyed to the upper surface of the cover glass. Therefore, even if no other guide member or the like is used, there will be no failure in conveyance of the document.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of an image sensor unit according to the present invention.

[Fig. 2] Fig. 2 is a diagram showing the image sensor unit shown in Fig. 1, in which (a) is a partially fragmented plan view, and Fig. 2 (b) is a partially fragmented plan view.
is a side view.

FIG. 3 is an enlarged side view of main parts for explaining how to use the image sensor unit shown in FIGS. 1 and 2. FIG.

FIG. 4 is a partially exploded perspective view showing another embodiment of the image sensor unit according to the present invention.

FIG. 5 is a perspective view showing an example of a conventional image sensor unit.

6 is a side view for explaining how to use the image sensor unit shown in FIG. 5. FIG.

7 is a diagram showing the image sensor unit shown in FIGS. 5 and 6, where (a) is a plan view and (b) is a plan view.
) is a side view.

8 is an enlarged view of a part of the image sensor unit shown in FIGS. 5 to 7; FIG. 8(a) is a plan view and FIG. 8(b) is a side sectional view;

[Explanation of symbols]

10; Image sensor unit 12, 34; housing 14; Sensor board 15; Transparent substrate 16,40; Processing circuit board 18, 32; Flexible wiring 20; cover glass

Claims (2)

[Claims] 1. A sensor substrate having a plurality of photoelectric conversion elements and wiring for inputting and outputting signals to and from the photoelectric conversion elements formed on a transparent substrate, and a sensor substrate for driving and outputting the plurality of photoelectric conversion elements. The image sensor unit includes a processing circuit board equipped with a circuit element for reading out the sensor signal, and flexible wiring for electrically connecting the sensor board and the processing circuit board, which are attached to a housing. An image sensor unit characterized in that a substrate and flexible wiring are directly electrically connected. 2. A sensor substrate having a plurality of photoelectric conversion elements and wiring for inputting and outputting signals to and from the photoelectric conversion elements formed on a transparent substrate, and a sensor substrate for driving and outputting the plurality of photoelectric conversion elements. A processing circuit board equipped with a circuit element for reading out a signal, and a flexible wiring that electrically connects the sensor board and the processing circuit board are attached to a housing, and the sensor board and the flexible wiring are connected to each other. The image sensor unit is directly electrically connected, and the outer surface of a cover glass that is attached to the original reading surface of the sensor board and protects the sensor board is adjacent to the cover glass and is electrically connected to the sensor board. An image sensor unit characterized by being lower than the outer surface of the flexible wiring to which it is directly connected.