JP2573432Y2 - Image sensor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor used in a document reading section such as a facsimile, an image scanner, a digital copying machine, and an electronic blackboard. Related to sensors.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made regarding the form of a completely close contact type image sensor. However, the present inventors have already proposed an image sensor 2 using a wide cover glass 1 as shown in FIG. Proposal (Japanese Utility Model Application No. 3-522)
No. 97).

The image sensor 2 has a sensor substrate 3 on which a number of photoelectric conversion elements 3a are arranged in a straight line, and a COG (Chip on Glass) on which a signal processing IC 4a and the like are mounted.
Substrate 4 and supporting glass 5 for supporting and fixing them
And a cover glass 1 stuck over the sensor substrate 3 and the COG substrate 4. The image sensor 2 is mounted on a frame 7 together with a printed circuit board 6 on which an LED array 6a, a driving IC 6b, a connector 6c and the like are mounted, and is used as an image sensor unit 8.

In this image sensor 2, the width of the sensor substrate 3 in the sub-scanning direction should be as narrow as possible because the wide cover glass 1 secures a width sufficient to smoothly transport the original. As a result, the manufacturing cost of the image sensor 2 was significantly reduced.

[0005]

However, the image sensor 2 has a four-layer structure consisting of a sensor substrate 3, a COG substrate 4, a support glass 5, and a cover glass 1, so that the image sensor 2 can be used in a lamination (bonding) process. There was a problem that the alignment was complicated. In addition, since the large supporting glass 5 is used and the ICs 4a and 6b are separately mounted on the printed board 6 and the COG board 4,
There was also a problem that it was complicated and expensive.

Accordingly, the present inventors have studied diligently to provide an inexpensive and high-performance image sensor while maintaining a structure in which the width of the sensor substrate in the sub-scanning direction can be made as small as possible. As a result, the present invention was achieved.

[0007]

SUMMARY OF THE INVENTION The gist of the image sensor according to the present invention includes a sensor board on which a plurality of photoelectric conversion elements are arranged in parallel and a circuit board for operating the sensor board. In the image sensor, the sensor board is provided on the circuit board, and a support member having the same thickness as the sensor board is provided adjacent to the sensor board, and the width of the sensor board in the sub-scanning direction is provided. That is, a translucent thin plate wider than that is disposed over the sensor substrate and the support member.

In this image sensor, a document conveyed on the translucent thin plate on one or both of the circuit board and the sensor board is illuminated from the circuit board side. The light-shielding film is provided in a portion other than the light guide path for performing the light-shielding.

[0009]

According to such an image sensor, since the supporting member is disposed adjacent to the sensor substrate and the wide translucent thin plate is disposed across the supporting member, the original is not covered by the translucent thin plate. It can be transported smoothly on the top. That is, a sufficient width for smoothly transporting the document is ensured by the light-transmitting thin plate. Therefore, the width of the sensor substrate in the sub-scanning direction can be made as small as possible,
The manufacturing cost of such an image sensor can be significantly reduced. Further, since the sensor board is provided on the circuit board, the sensor board is supported and fixed by the circuit board. That is, this circuit board has both a function of operating the sensor board and a function of supporting and fixing the sensor board. This simplifies the alignment in the laminating process and further reduces the manufacturing cost.

The document is illuminated from the circuit board side via a light guide path. Since a light shielding film is provided on a portion other than the light guide path, extra light passes through the sensor board and the like. Never. Therefore, light other than the light reflected from the original does not enter the photoelectric conversion element, and the reading accuracy is improved. In addition, the position where the light-shielding film is provided may be on the surface of the circuit board, on the surface of the sensor substrate, or on the surface of both the circuit substrate and the sensor substrate as long as it is a portion other than the light guide path. There may be.

[0011]

Next, an embodiment of the image sensor according to the present invention will be described in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 10 denotes an embodiment of the image sensor according to the present invention. The image sensor 10 includes a sensor substrate 12 for reading a document.
And a circuit board 14 for operating the sensor board 12
And a cover glass (light-transmitting thin plate) 16 for protecting the sensor substrate 12 and a support member 18 for supporting the cover glass 16.

The sensor substrate 12 is made of glass, on which a number of photoelectric conversion elements 20 made of a thin film semiconductor such as amorphous silicon a-Si and CdS-CdSe are linearly formed. Although not shown, drive wirings for applying a drive voltage to these photoelectric conversion elements 20 and signal wirings for deriving signals from the photoelectric conversion elements 20 are also formed. Note that a light guide window (not shown) is formed near the photoelectric conversion element 20 to illuminate a document conveyed over the cover glass 16 by a light source provided on the circuit board 14 side.

The sensor board 12 is attached to a predetermined position on the circuit board 14 with an adhesive or the like. The circuit board 14 is also made of glass, on which a wiring pattern (not shown) is formed, and driving ICs 24 a and 24 b for driving the photoelectric conversion element 20 and a signal for processing a signal from the photoelectric conversion element 20. A processing IC 26 is mounted. That is, the circuit board 14 is provided with a COG (Chip on Gla
ss). The driving ICs 24a and 24b are provided at two locations near both ends of the sensor substrate 12, and
Each terminal of these three ICs 24a, 24b, 26 is directly connected to a lead terminal of each wiring formed on the sensor substrate 12 by wire bonding or the like. The wiring pattern is formed of a thin film of chromium Cr, aluminum Al, or the like, or a thick film of gold Au, silver Ag, copper Cu, or the like. Further, a light-shielding film 28 having a slit-shaped opening only in a portion serving as a light guide path is provided on a portion of the circuit board 14 where the sensor substrate 12 is mounted. Here, the light guide path is a traveling path of light for illuminating the original conveyed on the cover glass 16 from the circuit board 14 side. Note that the light-shielding film 28 is preferably formed simultaneously with the wiring pattern and the like.

The support member 18 is also made of glass and has the same thickness as the sensor substrate 12. The support member 18 is disposed adjacent to the sensor board 12 and is attached on the circuit board 14 with an adhesive or the like. Further, a cover glass 16 wider than the width D of the sensor substrate 12 in the sub-scanning direction is attached to the sensor substrate 12 and the support member 18 with an adhesive or the like. The thickness of the cover glass 16 is 100 μm or less, preferably 50 μm. The sensor substrate 12, the support member 18, the cover glass 16
As the adhesive for adhering the resin, a thermosetting epoxy resin-based adhesive is mainly used, but a UV-curable epoxy resin-based adhesive or a silicone resin-based adhesive may be used.

The image sensor 10 is, for example, shown in FIG.
Is mounted on a resin frame 30 and used as an image sensor unit 32 as shown in FIG. A connector 34 is embedded in the frame 30,
A printed circuit board 38 having a light source 36 such as an LED array or a xenon lamp is provided. This connector 34
Is for inputting a power supply or a control signal from the outside or outputting an image signal or the like from the inside. The circuit board 14 is connected to the connector 34 via a flexible wiring 40. Further, a stainless steel cover 42 is attached in order to smoothly send out the document 41 onto the sensor substrate 12. Although the connector 34 can be directly mounted on the circuit board 14, it is embedded in the frame 30 in consideration of reliability and the like. The frame 30 may be formed by cutting, drawing, or die-casting a metal material such as aluminum or zinc.

According to the image sensor unit 32, the document 41 is sequentially conveyed while being pressed onto the cover glass 16 by the platen roller 43. Further, the original 41 is emitted from the light source 36 and
4 and the sensor substrate 12 are illuminated by the light transmitted therethrough. Then, the reflected light corresponding to the density of the document 41 enters the photoelectric conversion element 20 and the document 41 is read.

As described above, the image sensor 1 according to the present invention is provided.
In the case of 0, a width sufficient to smoothly transport the document 41 by the cover glass 16, for example, a width of 6 mm or more is secured, so that the width D of the sensor substrate 12 in the sub-scanning direction is set to 6 mm or less as much as possible. Of about 2 to 4 mm. Therefore, a large number of sensor substrates 12 can be manufactured at once, and the manufacturing cost is greatly reduced. In addition, since the circuit board 14 itself is also used as the supporting glass 5 in the conventional image sensor 2 and the sensor substrate 12 and the supporting member 18 are adhered thereon, compared with the conventional image sensor 2, The sticking area is small. Therefore, the work of attaching glass and the like becomes very simple, and the amount of glass used is reduced overall, so that the material cost is reduced.

Since the light-shielding film 28 is provided to prevent extra light from passing through the sensor substrate 12 and the like, the reading accuracy is high. Moreover, since it is not necessary to provide a slit for guiding light on the frame 30, the structure becomes extremely simple, and the overall size of the image sensor unit 32 is greatly reduced. Further, since the frame 30 is also made of resin, the cost is greatly reduced.

Further, the height of the ICs 24a, 24b, 26, etc. is lower than that of the prior art, so that even if a protective resin or the like is coated, they do not protrude above the cover glass 16, and handling during actual use is very simple. It is. Further, not only the signal processing IC 26 but also the driving IC 24
Since a and 24b are also mounted on the circuit board 14 and all the circuits are concentrated on the circuit board 14, the structure is extremely simple. In addition, since one driving IC is usually mounted in two parts, the width occupied by the driving wiring on the sensor substrate 12 is reduced to about half.

Further, the sensor board 12, the circuit board 14,
Since the cover glass 16 and the support member 18 are made of glass having substantially the same coefficient of thermal expansion, they are excellent in reliability such that they do not warp or peel due to temperature changes.

As described above, one embodiment of the image sensor according to the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, but can be implemented in other modes.

For example, in the above-described embodiment, the light shielding film 28
Is provided on one side of the circuit board 14, but may be provided on both sides. Further, it may be provided only on the back side of the sensor board 12, or may be provided on both the circuit board 14 and the sensor board 12. That is, the light-shielding film is preferably provided on the entire surface as much as possible so that extra light does not enter the photoelectric conversion element 20.
Any portion other than the portion serving as the light guide path may be provided. Further, a conventional frame with a slit may be used without providing a light-shielding film.

The circuit board may not be made of transparent glass. For example, as shown in FIG. 4, a circuit board 4 using a printed board in which an oblong slit 44 is opened.
6 is acceptable. The slit 44 is for illuminating the document from behind the sensor substrate 12. It is preferable to use a hard printed board made of glass epoxy, ceramic, metal, or the like. Also, the circuit board 46
It is also possible to provide a suitable reinforcing material or the like so as not to bend by the pressure of the platen roller.

Alternatively, only one of the signal processing IC and the driving IC may be mounted on a circuit board, and the remaining ICs may be mounted on a printed board 38 on which the light source 36 is mounted. . Further, one or three or more driving ICs may be mounted, and usually one signal processing IC
May be implemented two or more.

The support member is not particularly limited to glass, but may be resin or metal, and the material is not limited at all. However, when a metal is used, it is necessary to provide an appropriate insulating coat or the like so as not to short-circuit the wiring pattern on the circuit board. In the case where an insulator such as glass or resin is used for the support member, an ITO or metal film may be formed on the surface for shielding.

Further, instead of the cover glass 16, a resin or the like whose surface is hard-coated may be used. Further, not all of the cover glass need be transparent, and it is sufficient that at least a portion for reading a document is transparent.

In addition, the present invention can be implemented in various modified, modified, and modified forms based on the knowledge of those skilled in the art without departing from the gist of the present invention, such as the drive system of the image sensor is not limited at all. What you get.

[0029]

According to the image sensor of the present invention, a support member having the same thickness as the sensor substrate is disposed adjacent to the sensor substrate, and a light-transmitting thin plate wider than the width of the sensor substrate in the sub-scanning direction is provided. The translucent thin plate secures a width sufficient to smoothly transport the document because the translucent thin plate is provided so as to straddle the sensor substrate and the support member. Therefore, the width of the sensor substrate in the sub-scanning direction can be made as small as possible, and the manufacturing cost of the image sensor can be significantly reduced. In addition, since the sensor board is provided on the circuit board, the sensor board is supported and fixed by the circuit board. For this reason, the structure is extremely simple as compared with the conventional image sensor, the alignment in the laminating step is easy, and the number of components is small, so that the cost can be further reduced.

Further, on the surface of one or both of the circuit board and the sensor board, a portion other than the light guide path for illuminating the original conveyed on the translucent thin plate from the circuit board side. Since the light shielding film is provided, light other than the light reflected from the original does not enter the photoelectric conversion element. Therefore, a high-performance image sensor with good reading accuracy can be provided at low cost. In addition, when the image sensor unit is mounted on a frame and used as an image sensor unit, a frame having a simple structure may be used.

[Brief description of the drawings]

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

FIG. 2 is a sectional side view of the image sensor shown in FIG.

FIG. 3 is a cross-sectional side view showing an example of an image sensor unit using the image sensor shown in FIGS. 1 and 2.

FIG. 4 is a perspective view showing another embodiment of a circuit board used for the image sensor according to the present invention.

FIG. 5 is a sectional side view showing an example of an image sensor unit using a conventional image sensor.

[Explanation of symbols]

 Reference Signs List 10; image sensor 12; sensor boards 14, 46; circuit board 16; cover glass (light-transmitting thin plate) 18; support member 20; photoelectric conversion element 28;

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/335

Claims (2)

(57) [Scope of request for utility model registration] 1. An image sensor comprising: a sensor board on which a plurality of photoelectric conversion elements are arranged in parallel; and a circuit board for operating the sensor board, wherein the sensor board is disposed on the circuit board. A support member having the same thickness as the sensor substrate is disposed adjacent to the sensor substrate, and a light-transmitting thin plate wider than the width of the sensor substrate in the sub-scanning direction is provided between the sensor substrate and the support member. An image sensor, wherein the image sensor is disposed over the image sensor. 2. A light guide path for illuminating a document conveyed on the transparent thin plate from the circuit board side on one or both of the circuit board and the sensor board. The image sensor according to claim 1, wherein a light-shielding film is provided in a portion other than the portion.