JPS62285569A - Reader - Google Patents

Abstract

PURPOSE:To contrive miniaturization and low cost by providing a light source support member having a long recess to the 2nd plate face side of a base and arranging a light source in the recess. CONSTITUTION:A long recess 18 is formed to a base support 17 in parallel with a photodetector array substantially, and plural LED chips 19 are arranged at the bottom face of the recess 18 at a prescribed interval in the direction of main scanning. A printed board 20 is provided to the base support 17 and a wiring pattern to drive the LED chip 19 is formed to the printed board 20. In selecting the interval between th LD chip 19 and the original 1 to nearly 6mm, since the original 1 can be irradiated by a sufficient lightness, the thickness of the entire reader is made to nearly 10mm or below even if the thickness of the printed board 20 and a metal plate for radiation 21 is taken into account.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention aims at downsizing, for example, a facsimile machine, and the present invention is aimed at miniaturizing a facsimile machine, for example, by making the facsimile machine substantially correspond to a document in dimensionally 1=1. The present invention relates to a reading device, such as a contact type image sensor, in which a photoelectric conversion element array is arranged.

[Prior art and its problems]

Recently, the development of contact image sensors has become more active.
Other types of this sensor have been developed, including a type that detects the reflected light from the document via a focusing rod lens array, and a type that achieves excellent light transmission rate and miniaturization without using this array.

FIG. 4 is a schematic diagram showing a close-contact reading system that does not use a focusing rod lens array, in which a light detection section 2 that corresponds to the document 1 in a substantially 1:1 dimension is brought into close contact with the document 1. death,
The light emitting diode 3 emits light onto the original 1, and the light detecting section 2 receives the reflected light.

5 and 6 show a reading device corresponding to the photodetector 2, and FIG. 6 is a sectional view taken along the section line XX in FIG.

That is, a transparent substrate 4 made of glass or the like is attached to a substrate support 5 made of a metal frame or the like, and common electrodes 6a, 6 are formed by vapor-depositing Cr, Aff, etc. on the substrate 4.
b... are formed, and a photoelectric conversion section 7 made of amorphous silicon or the like is formed on the common electrodes 6a and 6b.
Then, a transparent electrode 8 made of a transparent material such as ITO is formed on each photoelectric conversion section 7 by sputtering or vapor deposition. Further, extraction electrodes 9 are individually connected by vapor depositing Cr%A42 or the like so as to cover a part of the transparent electrode 8, and a transparent protective layer IO made of glass or the like is formed on the top. ,
Light passing holes 11 are formed in the common electrodes 6a and 6b, the photoelectric conversion section 7, and the transparent electrode 8. A light emitting diode 3 is arranged behind the substrate support 5 . And, HojIJiIO
An original 1 is arranged above, and the light emitted from the light emitting diode 3 illuminates the original l through the substrate 4, the light passage hole 11, and the protective layer 10, and the reflected light is reflected near the light passage hole ll. The light passes through the transparent electrode 8 and is received by the photoelectric conversion section 7. In addition, the light passage hole 11 is arranged in the width direction of the original 1 (main scanning direction).
That is, the light emitting diodes 3 are arranged at intervals along the axial direction, and a drive circuit 12 such as a shift register is mounted on the substrate 4.

Further, FIG. 7 shows the light emitting diode 3. As shown in FIG.

That is, a plurality of LED chips 1 are mounted on the LED mounting board 13.
4 are arranged in a line at a predetermined interval, and on top of this LED chip array, a cylindrical rod lens 15 is mounted with a lens support member 16 such that the central axis of the cylinder is parallel to the LED chip array. installed by.

Since this rod-shaped lens 15 can condense the light irradiated by the LED chip 14, when the original 1 is positioned near its focal length, the illuminance to the original 1 can be significantly increased.

However, according to this reading device, the distance between the original l and the rod-shaped lens 15 needs to be equal to the focal length of the rod-shaped lens 15 (usually about 6 mm), and the height of the light emitting diode 3 is about 10 mm. As a result, the thickness of the reading device composed of the photodetector 2 and the light emitting diode 3 must be at least about 16 mm.
As a result, it has become difficult to further reduce the size of reading devices.

[Purpose of the invention]

Accordingly, an object of the present invention is to provide a reading device that achieves miniaturization by not using a condensing lens for an LED light source.

Another object of the present invention is to provide a reading device that achieves cost reduction by eliminating the need for a condensing lens for an LED light source.

[Means for solving problems]

According to the present invention, a photoelectric conversion element array is formed on a first plate surface of a substrate, a light source is provided at a portion corresponding to the element array on the second plate side of the substrate, and the light source is provided on the first plate surface. In a reading device in which light is emitted from the object to be detected on the side, the reflected light is received by a photoelectric conversion element array, and read signals are sequentially obtained from this element array in chronological order. A reading device is provided, comprising a light source support member having an elongated recess, and the light source is disposed within the recess.

〔Example〕

Next, an embodiment of the present invention will be explained with reference to FIG.

FIG. 1 shows a reading device corresponding to the photodetector shown in FIG. 4, but is a sectional view taken along the section line XX in FIG. 5 in place of FIG. 6. Note that the same parts as in FIG. 6 are given the same reference numerals.

That is, a transparent substrate 4 is attached to a substrate support 17 composed of a metal frame or the like, and on the substrate 4 are provided common electrodes 6a, 6b, . 9 and a protective layer 10 are sequentially formed. Substrate support 1
7 has an elongated recess 18 formed substantially parallel to the light-receiving element array, and a plurality of LEDs are arranged on the bottom surface of this recess 18.
Chips 19 are arranged in the main scanning direction at predetermined intervals (pitch). A printed circuit board 20 is attached to the substrate support 17 and forms the bottom surface of the recess 18, and a wiring pattern for driving the LED chip 19 is formed on this printed circuit board 20. Furthermore, a heat dissipation metal plate 21 is attached to the printed circuit board 20 to dissipate heat generated as the LED chip 19 is driven.

According to this reading device, the light detection section 2 shown in FIG.
and a light emitting diode 3 are integrated, and according to experiments by the inventors, if the distance between the LED chip 19 and the document 1 is set to about 6 mm, the document 1 can be illuminated with sufficient brightness. Printed circuit board 20 and heat dissipation metal plate 21
Even considering the thickness of the reader, the overall thickness of this reader is approximately 1
It becomes possible to set it to 0 mm or less.

In addition, the reading device used in this example was
It has been found through experiments conducted by the inventors that when the resolution capability is set to ot/mm, the size of the recess and the pitch of the LED chips should be set within the following ranges.

That is, the width W of the recess shown in FIG. 1 is preferably set within the range of 0.5 to 3 mm, preferably 1 to 2 fflIl+, and if this width W is less than 0.5 mm, the LED chip It becomes difficult to implement the common electrodes 6a, 6b and
... cannot completely block light, causing stray light.

Further, as is clear from FIG. 2, the depth d of the recessed portion has a significant difference in illuminance depending on its size. In other words, A in the figure,
B and C each have d of 2.0 mm.

LE when set to 3.0mm and 5.0mm
It shows the illuminance relative to the distance from the D chip, where d =
In the case of 2.0 mm (A), the highest illuminance is shown near the installation of the LED chip, but the illuminance decreases significantly as the distance from the LED chip increases. On the other hand, d = 3
．． 0 mm (B) and then d = 5.0 mm (C), and as d increases, the illuminance near the LED chip installation decreases, but on the other hand, even if the LED chip is far away, the illuminance remains relatively small. Maintained.

Therefore, the present inventors set the pitch P of the LED chips to 5 mm.
When the illuminance distribution in the main scanning direction was measured when d was set in three ways as described above, the results shown in FIG. 3 were obtained.

In Fig. 3, a, b, and c each have d of 2.0 mm, 3,
This is the illuminance distribution when set to 0 mm and 5.0 mm, and as is clear from the figure, as d increases, the illuminance decreases, but the illuminance distribution becomes uniform over the main scanning direction.

Therefore, based on the above-mentioned experimental results, the inventors set the depth d of the recess and the pitch P of the LED chips from 3 to 8 m, respectively.
It has been found that it is sufficient to set the depth d to 4 to 5 mm and the pitch P to 2 to 5 mm. If the depth d is less than 3 mm, the variation in illuminance distribution will increase, making it impossible to obtain uniform output signal strength for each light receiving element.
If it exceeds mm, the illumination intensity will become small and the output signal intensity of the light receiving element will become small. Furthermore, if the pitch P of the LED chips exceeds 8 mm, the variation in the illuminance distribution of the chip array itself becomes significant, making it impossible to obtain uniform output signal strength for each light receiving element.

〔Effect of the invention〕

As described above, according to the reading device of the present invention, the rod-shaped lens (condensing lens) of the LED array is not required, and the amount of chips used can be reduced by maintaining the pinch size of the LED chip to a certain degree. As a result, further miniaturization and lower cost than before have been achieved.

Furthermore, when a reading device is equipped with an LED array equipped with a rod-shaped lens, it is impossible due to current mass production technology to accurately arrange the LED chip array in a straight line and set all of the chips to the focal point of the rod-shaped lens. As a result, an even illuminance distribution cannot be obtained in the main scanning direction. On the other hand, according to the reading device of the present invention, since no rod-shaped lens is used, accurate focusing is not required, so the LE
The manufacturing of the D-chip array is simplified, thereby providing a high quality and reliable reader.

Note that the present invention is not limited to the above embodiments,
Various changes, improvements, etc. may be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the reading device of the present invention, FIG. 2 is a diagram showing the relationship between the depth of the recess shown in this embodiment, the distance from the LED chip, and the illuminance, and FIG. A diagram showing the LED chip and illumination distribution based on the results shown in Figure 2, Figure 4 is a schematic diagram showing a reading system related to a four-temple reading device, and Figure 5 is a perspective view of a conventional reading device. Figure 6 is the 5th
FIG. 7, a cross-sectional view taken along the section line XX in the figure, is a schematic diagram showing a light emitting diode used in a conventional reading device. 1... Original document 2... Light detection unit 3... Light emitting diode 5.17... Substrate support 14.19... LED chip 15... Rod-shaped lens 18... Concave portion Patent applicant (
663) Kyocera Corporation Figure 1 Figure 2

Claims (1)

[Claims] A photoelectric conversion element array is formed on the first plate surface of the substrate, and a light source is provided at a portion corresponding to the element array on the second plate side of the substrate, and this light source detects the object to be detected on the first plate side. A reading device in which light is emitted, the reflected light is received by a photoelectric conversion element array, and read signals are sequentially obtained from this element array in chronological order, and the reader has an elongated recess on the second plate surface side of the substrate. A reading device comprising a light source support member and the light source disposed within the recess.