JPH03210872A - Picture reader - Google Patents

Abstract

PURPOSE:To absorb a stress due to a difference of a thermal expansion between a line sensor and a support and to prevent crack of the line sensor by specifying the hardness of an adhesives in a picture reader in which one side face among side faces of the line sensor in the lengthwise direction is in contact with the support and the adhesives exists between the other side face and the support. CONSTITUTION:The hardness of an adhesives is selected in a range of AO to 80 according to the JIS, preferably in a range of 5-60, and more preferably in a range of 10-40. A complete contact line sensor 101 (thickness is usually 1-2mm) is adhered to a support 103 with a light source 102 integrated thereto by using an adhesives 106. RSiO2/3, R2SiO, R3SiO1/2 and SiO2 are used as a constitution unit for composition of a polymer in a silicon resin in use. Thus, crack of the sensor is completely prevented.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to an image reading device.

[Prior art]

Line sensors are built on quartz glass, pyrex glass, etc. On the other hand, the support that holds the line sensor is made of metal such as aluminum. Conventionally, general-purpose adhesives such as epoxy and acrylic adhesives have been used to fix the line sensor to the support.

However, these completely contact type line sensors sometimes develop cracks, and a solution to this problem has been sought.

According to research conducted by the present inventors, it has been found that these cracks are caused by stress caused by the difference in thermal expansion between glass and metal such as aluminum when the line sensor is fixed to a support. In particular, it has been found that when the environmental temperature changes suddenly, stress accumulates and a failure occurs in which the fully contact type line sensor cracks.

Therefore, as a result of examining the adhesives that are conventionally used, we found that conventionally, general-purpose adhesives such as epoxy and acrylic adhesives have been used, and these adhesives have relatively high hardness (shear hardness D40~ 90) had low flexibility.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure for an image reading device that overcomes the above-mentioned drawbacks, is highly reliable because it does not cause cracks, and can ensure a large S/N ratio.

〔composition〕

The image reading device of the present invention is an image reading device in which one side surface in the longitudinal direction of a line sensor is in contact with a support, and an adhesive is present between the other side surface and the support. The hardness of the agent is in the range of JIS A O to 80,
Preferably from 5 to 60, more preferably from 10 to 40
It is characterized by being in the range of

The above-mentioned adhesive has high flexibility and is suitable for line sensor 101.
It becomes possible to absorb stress due to the difference in thermal expansion between the support body 103 and the support body 103, and there is no fear that the line sensor will break.

Since conventionally used adhesives are not flexible, JIS
A cannot be evaluated, JIS A evaluates the shrinkage of the spring that presses the pressure rod when the pressure rod sinks into the adhesive surface (
Evaluate using (load conversion). According to JISA, a value of 100 means that the pressure rod does not dent, and with conventional adhesives,
All of them are displayed as JIS A 100, and are too hard to be evaluated by JIS A.

In particular, it is preferable that the adhesive described above is made of silicone resin.

Usually, highly flexible adhesives include natural rubber and silicone resin, but silicone resin in particular is
It is easy to obtain a high-purity product with reduced impurities such as , K", CI-, etc. Therefore, when silicone resin is used, there is no fear of accelerating electrolytic corrosion of the fully contact type line sensor, and long-term reliability is high.

Further, it is preferable that the aforementioned adhesive exhibits a color of black, brown, brown, gray, or orange. By using these colored adhesives, it is possible to reduce light scattering on the side surfaces of the line sensor. This makes it possible to secure a large S/N ratio.

〔Example〕

A configuration diagram of an embodiment of the present invention is shown in FIG.

A completely contact type line sensor 101 (usually 1 to 2 cm thick) is attached with an adhesive 10 to a support 103 that integrates a light source 102.
Fix it at 6.

In addition, in FIG. 1, 105 is a metal guide for paper passing;
104 is a reading PCB (mounted printed circuit board)
The reading PCB 104 is connected to a fully contact type line sensor by flexible wiring or an anisotropic conductive film (not shown).

Figures 2.3, 4.5 and 6 show block diagrams of other embodiments of the invention.

2.3.5 and 6 are examples in which a metal guide for sheet passing is provided, and FIG. 4 is an example in which it is not provided.

In each of FIGS. 2.3, 4.5, and 6, the reading PCB and the complete contact type line sensor are connected in the same way as in FIG. 1.

FIG. 6 shows an example in which a completely contact type line sensor 601 is placed on a line sensor holding transparent substrate 607 and fixed with an adhesive 606. The silicone resins used in this example were R51o, 73, R, SiO, R3S l ol/,
, S I Oa is a constituent unit of the polymer (R is a methyl group or a phenyl group).

〔effect〕

According to the present invention, cracking of the sensor can be completely prevented and reliability has improved. Furthermore, the coloring of the adhesive suppressed stray light and improved the S/N ratio.

[Brief explanation of drawings]

FIG. 1 shows a configuration diagram of an embodiment of the present invention. 2.3, 4.5 and 6 are block diagrams of other embodiments of the present invention. 101.201,301,401,501,601...
・Complete contact type line sensor 102.202, 302, 4
02,502,602...Light source 103.203,30
3,403,503,603...Support 104.20
4,304,404,504,604...Reading PCB105.205,305. 505,605・
・・Metal guide for paper passing 106.206, 306, 40
6,506,606... Adhesive 1 Figure 3 Figure O5 4 Figure 02 Figure 5 Figure 6

Claims (1)

[Claims] 1. In an image reading device in which one of the longitudinal side surfaces of the line sensor is in contact with a support and an adhesive is present between the other side and the support, the adhesive An image reading device characterized in that the hardness of the agent is in the range of JISA 0 to 80. 2. The image reading device according to claim 1, wherein the adhesive is made of silicone resin.