JPH06152860A - Optical original reader - Google Patents

Abstract

PURPOSE:To obtain a picture signal with high gradation and high accuracy by using a slit member so as to allow a photoelectric conversion element to receive only a ray effective to reading. CONSTITUTION:An LED array 5 fitted to an inside of a base 3 of a board 1 with a photoelectric conversion element 2 mounted thereon is used to emit a light to an original 7 and its reflected light is collected by a rod lens array 4 and passes through a slit 8 and a slit 10 of a member 9 and is received by a photoelectric conversion element array 2, in which the light is converted into an electric signal. In this case, the width of the slit of the member 9 is made narrower than the width of the slit of a base 3 and equal to the light collection angle C to shut a stray light. Thus, only the ray valid to original reading is introduced to the photoelectric conversion element 2 and the original reading with high accuracy is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical document reading device for optically reading document information.

[0002]

2. Description of the Related Art In recent years, an optical document reading device has been widely used as a reading device for small facsimiles, bar code readers and the like.

An example of the above-mentioned conventional optical document reading apparatus will be described below with reference to the drawings.

FIG. 7 shows the structure of a conventional optical document reading apparatus. In FIG. 7, reference numeral 41 is a substrate. 42 is a photoelectric conversion element array. 43 is a base. Reference numeral 44 is a rod lens array. 45 is an LED array. 46 is a glass plate. Reference numeral 47 is a manuscript. Reference numeral 48 is a slit provided on the base 43 as an optical path. The operation of the optical document reading apparatus configured as described above will be described below.

First, the photoelectric conversion element array 42 is mounted on a wiring board 41 and attached to a base 43. Inside the base 43, a rod lens array 44 and an LED array 45 serving as a light source are attached, and a manuscript 47 positioned on the lower surface of the glass plate 46 by the LED array 45.
And the reflected light was collected by the rod lens array 44, passed through the slit 48, received by the photoelectric conversion element array 42, and converted into an electric signal.

[0006]

However, in the above-described structure, the light rays reflected by the original 47 and condensed by the rod lens array 44 include reflected light other than the original necessary light containing the original information. Since the light is condensed and guided to the photoelectric conversion element array 42, the photoelectrically converted electric signal becomes an electric signal with poor accuracy, the image quality is poor, and high gradation reading is not possible.

In view of the above-mentioned problems, the present invention provides an optical original reading apparatus which can guide only an effective light ray originally required to a photoelectric conversion element array and can obtain a highly accurate image signal.

[0008]

In order to solve the above-mentioned problems, an optical document reading apparatus of the present invention comprises a base having an optical path, and a light beam which is provided on the base and located outside the base. A light source for irradiating the document, a transparent glass plate in contact with the surface of the document, a rod lens array provided inside the base for condensing light rays emitted from the light source and reflected on the document, and the base. The photoelectric conversion element is provided and receives a light beam condensed by the rod lens array and converts it into an electric signal. Only the effective light beam in the light beam condensed by the rod lens array can be taken into the photoelectric conversion element. Through a member having a slit that can be formed, the slit of the member is wide on the rod lens array side and narrow on the photoelectric conversion element side, or the optical path between the rod lens array inside the base and the document surface is Widely head lens array side, those having a structure that a narrow slit in the original surface.

[0009]

According to the present invention, the stray light guided to the photoelectric conversion element array is blocked by the above-described structure to obtain a highly accurate image signal.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical document reading apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of an optical document reading apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged view of a part of FIG. In FIG. 1, 1 is a substrate. 2 is a photoelectric conversion element array. 3 is a base.
4 is a rod lens array. 5 is an LED array. 6 is a glass plate. Reference numeral 7 is a manuscript. 8 is the base 3
It is a slit provided as an optical path. Reference numeral 9 is a member having a slit 10 capable of blocking stray light. The operation of the optical document reading apparatus configured as described above will be described below with reference to FIGS. 1 and 2.

First, the photoelectric conversion element array 2 is mounted on the wired substrate 1 and attached to the base 3. In addition, inside the base 3, the rod lens array 4 and an LE serving as a light source are provided.
The D array 5 is attached, the original 7 positioned on the lower surface of the glass plate 6 is illuminated by the LED array 5, and the reflected light thereof is condensed by the rod lens array 4 and passes through the slit 8 and the slit 10 of the member 9. The photoelectric conversion element array 2 receives the light and converts it into an electric signal. However, the slit width a of the member 9 is narrower than the slit width b of the base 3 and is equal to or almost equal to the converging angle c of the rod lens array 4 to block stray light. And As described above, according to this embodiment,
The slit width a of the member 9 is narrower than the slit width b of the base 3 and is equal to or almost equal to the light collection angle c collected by the rod lens array 4, so that it is originally necessary. Only the light beam containing the document information to be guided is guided to the photoelectric conversion element array 2 to block unnecessary stray light,
A highly accurate image signal can be obtained.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a structural diagram of an optical document reading device showing a second embodiment of the present invention. In the figure, 11 is a glass substrate. Reference numeral 12 is a photoelectric conversion element array. 13 is a base. 14 is a rod lens array. Reference numeral 15 is a slit. Reference numeral 16 is a thick film printing pattern. The operation will be described below with reference to FIG.

The difference from FIGS. 1 and 2 is that the slit 10 provided by the member 9 in FIG. 1 is provided on the glass substrate 11 by the thick film printing pattern 16.

As described above, by forming the slit for blocking stray light by thick film printing, it is possible to integrate it with the glass substrate without requiring a new member.

A third embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a structural diagram of an optical document reading device showing a third embodiment of the present invention.

FIG. 5 is an enlarged view of a part of FIG. In the figure, reference numeral 21 is a substrate. 22 is a photoelectric conversion element array. 23 is a base. 24 is a rod lens array. 25 is an LED array. Reference numeral 26 is a document surface glass. Reference numeral 27 is a manuscript. Reference numeral 28 is a slit provided on the base 23 as an optical path. 29 is a slit that can block stray light. The operation of the optical document reading apparatus configured as described above will be described below with reference to FIGS. 4 and 5.

The difference from FIG. 1 is that the rod lens array 2
That is, the slit 29 is provided between the No. 4 and the document surface glass 26. However, the slit width A of the slit 29 on the original surface glass 26 side is narrower than the slit width B on the rod lens array 24 side, and is equal to or almost equal to the converging angle C condensed by the rod lens array 24. The structure is such that only the original information that is originally necessary is irradiated and the light is condensed. As described above, according to the present embodiment, the slit width A of the slit 29 on the document surface glass 26 side is narrower than the slit width B on the rod lens array 24 side, and the rod lens array 2 is used.
By setting the light collecting angle C to be equal to or almost equal to the light collecting angle C to irradiate only original document information and collecting light, unnecessary stray light is blocked and a highly accurate image signal is obtained. Can be obtained.

A fourth embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is a structural diagram of an optical document reading device showing a fourth embodiment of the present invention.

What is different from FIG. 5 is that the slits 29 are formed on the original surface glass by thick film printing.

[0021]

As described above, according to the present invention, a slit having a light-collecting angle on the rod lens array side is provided on a member or a photoelectric conversion element side or a document surface side according to a thick film printing pattern, or both of them can achieve high efficiency. An accurate image signal can be obtained and high gradation reading can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical document reading device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a slit portion for explaining the operation in the embodiment.

FIG. 3 is an enlarged view of a slit portion of an optical document reading device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an optical document reading device according to a third embodiment of the present invention.

FIG. 5 is an enlarged view of a slit portion for explaining the operation in the embodiment.

FIG. 6 is an enlarged view of a slit portion of an optical document reading device according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view of an optical document reading device in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Photoelectric conversion element array 3 Base 4 Rod lens array 5 LED array 6 Original surface glass 7 Original 8 Slit 9 Member 10 Slit a, b Slit width c Condensing angle 11 Glass substrate 12 Photoelectric conversion element array 13 Base 14 Rod Lens Array 15 Slit 16 Thick Film Printing Pattern 21 Glass Substrate 22 Photoelectric Conversion Element Array 23 Base 24 Rod Lens Array 25 LED Array 26 Original Surface Glass 27 Original 28 Slit 29 Slit A, B Slit Width C Focusing Angle 31 Slit 41 glass substrate 42 photoelectric conversion element array 43 base 44 rod lens array 45 LED array 46 document surface glass 47 document 48 slit

Claims (6)

[Claims] 1. A base having an optical path, a light source that is provided on the base and irradiates a document located outside the base with a light beam, a transparent glass plate that contacts the surface of the document, and an inside of the base. A rod lens array that is provided on the light source and collects the light rays that are reflected by the original from the light source; and photoelectric conversion that is provided on the base and receives the light rays that are collected by the rod lens array and converts the light rays into an electrical signal. An element and a substrate on which the photoelectric conversion element is mounted, through a member having a slit capable of taking in only the effective light beam among the light rays condensed by the rod lens array into the photoelectric conversion element, the slit of the member Is an optical original reading device characterized in that it is wide on the side of the rod lens array and narrow on the side of the photoelectric conversion element. 2. The optical original reading device according to claim 1, wherein the slit width of the member for taking in only the effective light beam is equal to or substantially equal to the converging angle of the rod lens array. 3. The optical original reading device according to claim 1, wherein the substrate on which the photoelectric conversion element is mounted is a transparent glass substrate, and the member is provided on the glass substrate by printing. 4. A base having an optical path, a light source provided on the base to irradiate a light beam on a document located outside the base, a transparent glass plate abutting on the document surface, and an inside of the base. A rod lens array that is provided on the light source and collects the light rays that are reflected by the original from the light source; and photoelectric conversion that is provided on the base and receives the light rays that are collected by the rod lens array and converts the light rays into an electrical signal. An element and a substrate on which the photoelectric conversion element is mounted, and a slit is provided between the rod lens array and the document surface to allow the photoelectric conversion element to take in only an effective ray of the rays condensed by the rod lens array. An optical document reading device, wherein the slit has a structure that is wide on the rod lens array side and narrow on the document surface side. 5. The optical original reading device according to claim 4, wherein the width of the slit is equal to or substantially equal to the light collecting angle of the rod lens array. 6. The optical document reading device according to claim 1, wherein the slit is provided by printing on the document surface glass.