JPH0514600A - Original reader - Google Patents

Abstract

PURPOSE:To improve the accuracy and sensitivity of reading. CONSTITUTION:The original reader consists of a light source 1, plural lenses 2 arranged linearly at a prescribed interval, plural semiconductor chips 3 having lots of photoelectric conversion elements 3a arranged linearly to be correspondent with each lens 2 one by one and a light shield plate 4 arranged among the semiconductor chips 3. Reflecting light from an original 5 is divided into plural blocks by the lenses 2 and radiates to the semiconductor chip 3 while being reduced, the length of each semiconductor chip 3 is reduced and the distance between a cut-out part and the photoelectric conversion element 3a in the vicinity of the cut-out part is extended. As a result, production of distortion due to exertion of a stress at cut-out to the photoelectric conversion element 3a in the vicinity of the cut-out part is avoided and the accuracy and sensitivity of original reading are enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type document reading apparatus used for a facsimile or the like.

[0002]

2. Description of the Related Art In recent years, document reading devices such as contact image sensors have been actively developed.

In such a conventional document reading apparatus, as shown in FIG. 5, a light source 11 such as a fluorescent lamp, a rod lens array 12 of an erecting equal-magnification optical system, and a large number of photoelectric conversion elements 1 are usually used.
3a and a semiconductor chip 13 having a semiconductor chip 13a. The light source 11 projects light on the original 15, and the reflected light is applied to each photoelectric conversion element 13a of the semiconductor chip 13 via the rod lens array 12 and each photoelectric conversion element 13a. Conversion element 1
The image of the document 15 is read by causing photoelectric conversion corresponding to the light applied to the light 3a.

[0004]

However, in this conventional document reading apparatus, the rod lens array 12 that irradiates the photoelectric conversion element 13a on the semiconductor chip 13 with the reflected light from the document 15 is an erecting equal-magnification optical system, The photoelectric conversion elements 13a on the semiconductor chip 13 have substantially the same length as the original 15 at a predetermined interval (for example, 216 mm in the case of A4 size) because the reflected light from 15 is directly applied to the photoelectric conversion elements 13a. It is necessary to arrange the photoelectric conversion elements 13a linearly, and there is a drawback that the arrangement of the photoelectric conversion elements 13a becomes extremely long.

The long semiconductor chip 13 in which the photoelectric conversion elements 13a are arranged at a predetermined interval is extremely difficult to manufacture in the present semiconductor manufacturing technology, and therefore, generally, a semiconductor substrate having a fixed size is usually used. By cutting out a good semiconductor chip 13 having a short length, and arranging a plurality of semiconductor chips 13 having a short length in a straight line, the photoelectric conversion elements 13a are arranged in substantially the same length as the original 15.

However, when the non-defective semiconductor chip 13 is cut out from the semiconductor substrate, a large number of photoelectric conversion elements 13a are formed over the entire area of the semiconductor chip 13, so that the stress at the time of cutting out causes the photoelectric conversion element 13a to be near the cut-out portion. There is a drawback in that distortion is generated by being added to the conversion element 13a, and as a result, the photoelectric conversion element 13a cannot be caused to perform accurate photoelectric conversion, and the reading accuracy of the original document deteriorates.

In order to solve the above-mentioned drawbacks, the area of each photoelectric conversion element 13a formed on the semiconductor chip 13 is reduced so that the distance between the semiconductor chip cutout and the photoelectric conversion element 13a adjacent to the cutout is reduced. It is possible to keep it long.

However, when the area of each photoelectric conversion element 13a is narrowed, the amount of converted electricity in each photoelectric conversion element 13a becomes small, which causes a defect that the sensitivity of reading an original is lowered.

[0009]

A document reading apparatus according to the present invention comprises a light source, a plurality of lenses linearly arranged at predetermined intervals, and a linear shape so that each lens has a one-to-one correspondence. It is characterized by comprising a plurality of semiconductor chips having a large number of photoelectric conversion elements arranged in a matrix and a light shielding plate arranged between the respective semiconductor chips.

Further, in the document reading apparatus of the present invention, at a position where it is equidistant from each lens between two adjacent lenses,
In addition, the light source is arranged in parallel with the arrangement direction of the lenses.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing an embodiment of the document reading apparatus of the present invention, and FIG. 2 is a side view of the document reading apparatus shown in FIG. 1 viewed from the direction R. In FIG. Is a lens, 3 is a semiconductor chip having a large number of photoelectric conversion elements 3a, 4 is a light blocking plate, and 5 is an original.

The light source 1 is composed of a light emitting diode, a fluorescent lamp or the like, and is arranged obliquely below the original 5 so as to be parallel to the original 5.

The light source 1 projects light obliquely to the lower surface of the original 5 and irradiates the photoelectric conversion element 3a with the reflected light, thereby transmitting the image information of the original 5 to the photoelectric conversion element 3a.

A plurality of lenses 2 are linearly arranged below the original document 5 projected by the light source 1 at a predetermined distance X from the original document 5 with a predetermined adjacent distance Y. Each lens 2 reflects the light of the light source 1 reflected by the original 5 from A to
It has a function of dividing into H blocks and reducing the reflected light of each divided block to the photoelectric conversion element 3a on the semiconductor chip 3.

The lens 2 is made of a transparent convex material such as glass or resin, and has a focal length (fl) of f.
l. = 3.429 mm is preferably used.

Further, since the lens 2 does not use an expensive rod lens array as in the prior art, but an extremely inexpensive transparent convex body is used, the original reading device as a product can be made inexpensive.

Below the linearly arranged lens 2, a semiconductor chip 3 having a large number of photoelectric conversion elements 3a on the upper surface is separated by a predetermined distance Z and is linearly arranged by a number corresponding to the lens 2 in a one-to-one correspondence. It is arranged in a shape.

The photoelectric conversion element 3a formed on the upper surface of each semiconductor chip 3 is an original document 5 which is irradiated through the lens 2.
The function of converting the reflected light in the above into an electric signal is converted, whereby the image information of the document 5 is converted into an electric signal.

In this case, since the reflected light from the original 5 is divided by the lens 2 into blocks A to H and reduced, the photoelectric conversion element 3 is formed on the upper surface.
The semiconductor chip 3 having a may have a short shape in each shape, and it is not necessary that the semiconductor chips 3 are arranged linearly in a long shape by contacting one end thereof. Therefore, it is not necessary to arrange a plurality of semiconductor chips 3 linearly in a long length so that the photoelectric conversion element 3a has the same length as the original 5 as in the conventional case.

At the same time, since the semiconductor chip 3 having the photoelectric conversion elements 3a on the upper surface does not need to be in contact with one end and arranged in a straight line in order to make all the photoelectric conversion elements 3a uniform, the semiconductor substrate is cut out. When obtaining the semiconductor chip 3 having a large number of photoelectric conversion elements 3a on the upper surface by the cutout portion and the photoelectric conversion element 3a near the cutout portion
It is possible to increase the distance between the photoelectric conversion element 3a and the photoelectric conversion element 3a in the vicinity of the cutout portion, and the stress at the time of cutting is hardly generated to cause distortion. It is also possible to significantly improve the reading accuracy of the document 5 by causing the error.

Further, the photoelectric conversion element 3 on the semiconductor chip 3
Since the reflected light from the document 5 irradiated on a is reduced by the lens 2, the converted amount of electricity can be large even if the area of the photoelectric conversion element 3a is narrowed.
The sensitivity of reading the original can be made high.

The semiconductor chip 3 having a large number of photoelectric conversion elements 3a on the upper surface is fixed on an insulating substrate such as glass or ceramic with an adhesive, and each electrode of each semiconductor chip 3 is on the substrate. Is electrically connected via a bonding wire to a conductor pattern made of aluminum, gold, or the like, which is connected to the external drive circuit formed in the above.

A light-shielding plate 4 is disposed between the semiconductor chips 3 adjacent to each other. The light-shielding plate 4 irradiates each semiconductor chip 3 with unnecessary light so that the photoelectric conversion element 3a of each semiconductor chip 3 is illuminated. The photoelectric conversion element 3a of each semiconductor chip 3 can be made to perform accurate photoelectric conversion corresponding to the image information of the document 5 by effectively acting to prevent unnecessary photoelectric conversion. Becomes

The light shielding plate 4 may be made of any material as long as it blocks light.

Thus, in the above-described document reading apparatus, the light source 1 projects the light on the document 5, and the reflected light is applied to the photoelectric conversion element 3a formed on the upper surface of the semiconductor chip 3 through the lens 2 and each photoelectric conversion element. It functions as a document reading device by causing photoelectric conversion corresponding to the light applied to 3a.

Since the lens 2 has a convex shape in the above-mentioned document reading apparatus, when the reflected light from the document 5 enters the lens 2 at an angle of θ as shown in FIG.
As the value of θ becomes larger, the amount of reflected light that has passed through the lens 2 is reduced to cause unevenness, and accordingly, the accuracy of reading the image information of the original 5 on the photoelectric conversion element 3a on the semiconductor chip 3 is reduced. There is a risk of doing it.

However, in this case, the above-mentioned problem is solved by disposing the light source 1 between two adjacent lenses 2 at a position equidistant from each lens 2 and parallel to the arrangement direction of the lenses 2. be able to.

That is, the adjacent lenses 2 as shown in FIG.
If the light source 1 is arranged at a position equidistant from each lens 2 between them, the reflected light from the document 5 corresponding to the portion of the light source 1 having a large amount of light is incident on the lens 2 at a large angle θ, and the light source 1 The reflected light from the original 5 corresponding to the portion having a small amount of light is incident on the lens 2 at a small angle θ.
As a result, the unevenness in the amount of light generated depending on the incident angle of the reflected light entering the lens 2 is complementarily canceled by the amount of the reflected light entering the lens 2, so that the photoelectric conversion element 3a on the upper surface of the semiconductor chip 3 is substantially compensated. It is possible to improve the accuracy of reading image information of a document by causing each photoelectric conversion element 3a to perform accurate photoelectric conversion by being uniformly irradiated with uniform light.

In the present invention, the read pixel density of the original 5 can be changed by changing the distance between the original 5 and the lens 2 and the distance between the lens 2 and the semiconductor chip 3. For example, the focal length of the lens 2 can be changed. (Fl) to f.
l. = 3.429 mm, the distance X between the original 5 and the lens 2 is 12 mm, and the distance Z between the lens 2 and the semiconductor chip 3
Is 4.8 mm, the reading pixel density of the original 5 is 8d.
When the distance X between the original 5 and the lens 2 is 7.715 mm and the distance Z between the lens 2 and the semiconductor chip 3 is 6.172 mm, the read pixel density of the original 5 is 1.
It becomes 6 dots / mm. Therefore, by using the same lens and the same semiconductor chip as they are, it is possible to change and select the reading pixel density of the document to a predetermined arbitrary value by changing the distance between the document and the lens and the distance between the lens and the semiconductor chip. .

[0031]

The document reading apparatus of the present invention includes a light source,
A plurality of lenses linearly arranged at a predetermined interval, a plurality of semiconductor chips having a large number of photoelectric conversion elements linearly arranged so that each lens has a one-to-one correspondence, and each semiconductor chip Since it is formed with a light-shielding plate arranged between them, the reflected light from the document is divided into a plurality of blocks by the lens and is irradiated to the semiconductor chip having the photoelectric conversion element on the upper surface in a reduced state. The semiconductor chips may be small ones each of which has a short length, and it is not necessary for the respective semiconductor chips to be arranged linearly in a long shape by contacting one end thereof.

Further, since the reflected light from the original which is irradiated on the photoelectric conversion element formed on the upper surface of each semiconductor chip is reduced by the lens, even if the area of the photoelectric conversion element is reduced, the converted electricity amount is large. And as a result,
The sensitivity of reading the original can be made high.

Further, since the photoelectric conversion element formed on the upper surface of the semiconductor chip has a large amount of converted electricity even if it has a small area, when the area of the photoelectric conversion element is narrowed, the semiconductor substrate is cut out and the photoelectric conversion element is formed on the upper surface. When obtaining a semiconductor chip having a large number of photoelectric conversion elements, the distance between the cutout portion and the photoelectric conversion element near the cutout portion becomes long, and as a result, the stress at the time of cutting is added to the photoelectric conversion element near the cutout portion. Almost no distortion is generated, so that accurate photoelectric conversion can be caused in all photoelectric conversion elements to significantly improve the reading accuracy of the original.

Further, since the light shielding plate is arranged between the semiconductor chips adjacent to each other, each semiconductor chip is irradiated with unnecessary light and unnecessary photoelectric conversion is performed on the photoelectric conversion element formed on the upper surface of the semiconductor chip. It is possible to effectively prevent the conversion, and it is possible to cause the photoelectric conversion element of each semiconductor chip to perform accurate photoelectric conversion corresponding to the image information of the document.

Furthermore, in the document reading apparatus of the present invention, since the expensive rod lens array is not used, the cost of the entire apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a document reading apparatus of the present invention.

FIG. 2 is a side view seen from the R direction in FIG.

FIG. 3 is a diagram showing the relationship between the incident angle of light incident on a lens and the amount of light.

FIG. 4 is a diagram showing a light amount of light passing through a lens when a light source and a lens are arranged at predetermined positions.

FIG. 5 is an exploded perspective view showing a configuration of a conventional document reading apparatus.

[Explanation of symbols]

1 ... Light source 2 ... Lens 3 ... Semiconductor chip 3a ... Photoelectric conversion element 4 ... Light shield 5 ... manuscript

Claims (2)

[Claims] 1. A plurality of light sources, a plurality of lenses linearly arranged at a predetermined interval, and a plurality of photoelectric conversion elements linearly arranged so that each lens has a one-to-one correspondence. Document reading apparatus including the semiconductor chip of 1 above and a light shielding plate arranged between the semiconductor chips. 2. The document reading apparatus according to claim 1, wherein a light source is arranged between two adjacent lenses at a position equidistant from each lens and in parallel with the lens arrangement direction.