JPH09294190A - Image scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To markedly enhance read precision of a color image and image quality by preventing deterioration in an image contrast. SOLUTION: A lamp 10 and a light source lens 14 are arranged to an inner side of a aperture 3 of a main body case 2 so as to be directed toward the aperture 3. A CCD sensor 16 that receives a light emitted on a prescribed original arranged in the vicinity of the aperture 3 via the light source lens 14 and reflected in the original via a lens unit 17 so as to read the image of the original is arranged at an opposite end of the aperture (3), and an aperture 20 is arranged in the inside of the lens unit 17. An aperture 21 to make the optical path of the line received by the lens unit 17 is formed to the aperture member 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner, and more particularly to an image scanner which reads an image by irradiating a desired document with light and reading the reflected light with a CCD sensor.

[0002]

2. Description of the Related Art Conventionally, an image scanner has been widely used which reads an image by irradiating a desired document with light and reading the reflected light.

FIG. 6 shows such a conventional image scanner. The image scanner 31 has a main body case 32 having a rectangular box shape, and one end face in the longitudinal direction of the main body case 32. Has a substantially rectangular opening 33 facing a predetermined document (not shown) from which an image is read. The opening 33 has a length dimension that extends to almost both sides of the main body case 32,
In the inner portion of the opening 33 of the main body case 32,
The holding plate 34 is integrally formed so as to project inward. Further, a cylindrical lamp 35 is disposed inside each of the holding plates 34, and when the lamp 35 is turned on, light emitted from the lamp 35 is transmitted through a light source lens (not shown) to the main body case. Irradiation is performed to the outside from the opening 33 of 32, and the document placed near the opening 33 is irradiated.

A CC for image reading is provided inside the main body case 32 at an end opposite to the opening 33.
The D sensor 36 is disposed so that its detection surface faces the opening 33, and a cylindrical lens unit 37 is provided on the detection surface side of the CCD sensor 36.
They are integrally arranged so as to surround the detection surface of the sensor 36.

In the conventional image scanner 31 described above, a desired document is set near the opening 33 of the image scanner 31, and in this state, the image scanner 31 or the document is moved relatively to each other. By turning on the lamp 35, the light emitted from the lamp 35 is emitted from the opening 33 to the document through the light source lens. Then, the light reflected by the original document is again made incident on the inside of the main body case 32 through the opening 33, and the CCD sensor 3 through the lens unit 37.
The image sensor 6 receives the light, and the CCD sensor 36 reads the image information of the document.

[0006]

However, in the conventional image scanner 31, the lens unit 3 is used.
Since the inner surface of 7 is formed into a smooth flat surface, the lens unit 37 is reflected by the document and passes through the opening 33.
There is a problem that the light incident on the inside of the lens is irregularly reflected by the inner surface of the lens unit 37.

Therefore, if the light diffusedly reflected by the inner surface of the lens unit 37 is received by the CCD sensor 36, it is greatly affected by light other than the light that should be received, and the contrast of the original image is lowered. However, there is a problem that the reading accuracy is significantly reduced.

Conventionally, since the image scanner 31 is of a type that binarizes an image of an original and reads it as a monochrome image, even if the image contrast is slightly poor, there is no problem. In this case, it has become possible to obtain color image information by reading an image of a document in multi-value gradations such as 256 gradations. As described above, unnecessary reflected light is irradiated to form an image. If the contrast is lowered, the color image cannot be read with high accuracy, and the quality of the read image is deteriorated.

The present invention has been made in view of the above points, and an object of the present invention is to provide an image scanner capable of preventing a decrease in image contrast and significantly improving the reading accuracy and image quality of a color image. It is a thing.

[0010]

In order to achieve the above object, an image scanner according to the invention of claim 1 has an opening formed on one end surface of the main body case, and an inner portion of the opening of the main body case. A lamp and a light source lens are arranged so as to be directed to the opening, and the lamp and the light source lens are located inside the main body case, at an end opposite to the opening, near the opening from the lamp through the light source lens. An image scanner comprising a CCD sensor for irradiating a predetermined document placed on the document and receiving light reflected by the document through a lens unit to read an image of the document. A diaphragm member is provided inside the diaphragm, and a diaphragm portion for narrowing the optical path of light entering the lens unit is formed in the diaphragm member.

According to the first aspect of the present invention, the diaphragm member is arranged inside the lens unit, and the diaphragm portion of the diaphragm member narrows the optical path of the light entering from the lens unit. Therefore, when the light incident on the inside of the lens unit is diffused and reflected by the inner surface of the lens unit, the diaphragm portion of the diaphragm member prevents excess reflected light passing near the inner surface of the lens unit. Since the light is shielded, it is possible to prevent the CCD sensor from receiving extra reflected light from the inner surface of the lens unit, and as a result, to be affected by the reflected light from the inner surface of the lens unit. The image contrast can be significantly improved by preventing it.

The invention described in claim 2 is the first invention.
In, forming a minute unevenness on the surface of the diaphragm member,
It is characterized in that the minute irregularities are formed so that the light applied to the diaphragm member is not reflected.

According to the invention of claim 2, since minute irregularities are formed on the surface of the diaphragm member so that the surface of the diaphragm member is not made smooth, the light reflected by the inner surface of the lens unit is shielded. Therefore, when the diaphragm member is irradiated with light, it is possible to prevent the light from being reflected by the surface of the diaphragm member.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 show an embodiment of an image scanner according to the present invention. The image scanner 1 of this embodiment has a main body case 2 having a rectangular box shape. An opening 3 is formed on one end surface of the main body case 2 in the longitudinal direction so as to face a predetermined document (not shown) for reading an image. The opening 3 is formed so as to have a width dimension reaching both sides of the main body case 2, but the opening 3 irradiates light only in a range necessary for reading the original. It is formed to have a length dimension that allows it.

In addition, holding plates 4 and 4 extending along both side surfaces of the body case 2 are integrally formed on the inner side of the opening 3 of the body case 2 so as to project inward. Each of the holding plates 4 has an inner wall 5 formed so that its inner edge extends in the direction of the opening 3.
have. A concave lamp accommodating portion 6 having an opening toward the opening 3 is formed between the inner wall 5 of the holding plate 4 and the inner side surface of the main body case 2. On the inner surface of the inner wall 5 of the plate 4 and the inner surface of the main body case 2, a lamp locking recess 7 and a lens locking recess 8 located on the opening side of the lamp housing 6 with respect to the lamp locking recess 7 are formed. Has been done. further,
The holding plate 4 is formed with a slit 9 extending along the side surface of the body case 2.

A cylindrical lamp 10 is provided in the inner portion of the lamp housing portion 6, and the lamp 10 is provided on the outer peripheral surface of the lamp housing portion 6 inside the lamp housing portion 6. A fixing plate 11 having an arcuate cross-sectional shape for fixing is attached. Further, locking projections 12 are formed on both sides of the outer peripheral surface of the fixing plate 11. By engaging the locking projections 12 with the lamp locking recesses 7, the lamp 10 is housed in the lamp. It is designed to be fixed to the portion 6. Further, terminals 13 connected to both ends of the lamp 10 are drawn out from the slit 9 into the main body case 2, and the terminals 13 are formed on the inner side surface of the main body case 2 of the holding plate 4. Is electrically connected to a wiring board (not shown) arranged in the.

Further, a light source lens 14 having an arcuate cross-section is arranged in the opening portion of the lamp housing portion 6 so that the arcuate portion projects from the opening portion. A locking claw 15 is formed on the edge. The light source lens 14 is fixed by engaging the locking claws 15 with the lens locking recesses 8.

Then, by energizing each of the lamps 10 to turn on the lamp 10, the light emitted from the lamp 10 is emitted to the outside from the opening 3 of the main body case 2 via the light source lens 14. The document placed in the vicinity of the opening 3 is irradiated with the light.

A CCD sensor 16 for image reading having a resolution of about 1/600 inch, for example, is mounted on a substrate (not shown) inside the main body case 2 at the end opposite to the opening 3. Is arranged so that its detection surface 16a faces the opening 3, and the CCD
A cylindrical lens unit 17 is integrally arranged on the detection surface 16a side of the sensor 16 so as to surround the detection surface 16a of the CCD sensor 16.

The lens unit 17 includes the lamp 1
The lens unit 17 has a light entrance portion 18 for entering the light emitted from 0 and reflected by the document. The light entered from the light entrance portion 18 is introduced into the CCD sensor 16 inside the lens unit 17. A plurality of imaging lenses 19 for focusing so as to form an image are arranged with a predetermined interval.
Furthermore, in the present embodiment, the lens unit 1
7, the imaging lens 19 and the CCD sensor 1
An annular diaphragm member 20 is disposed between the diaphragm unit 6 and the lens unit 6 so as to be in close contact with the inner surface of the lens unit 17, and the inner peripheral surface of the diaphragm member 20 receives light from the light incident portion 18. A diaphragm 21 for narrowing the optical path of the light is formed so as to project inward in the radial direction. In addition, minute unevenness 22 is formed on the entire surface of the diaphragm member 20 by subjecting it to so-called embossing.

The shape of the diaphragm portion 21 of the diaphragm member 20 is, for example, as shown in FIG. 3, formed so that the axial center portion of the diaphragm member 20 has a convex cross-section protruding inward. Alternatively, as shown in FIG. 4, the diaphragm member 20
The axial center part of the may be formed in a taper shape that protrudes inward, or as shown in FIG. 5, the thread may be formed in a female screw shape that protrudes inward. Any shape may be used as long as it can narrow the optical path of the light incident from the light incident portion 18.

Next, the operation of the present embodiment will be described.

In the present embodiment, first, a desired document is placed near the opening 3 of the image scanner 1,
In this state, each of the lamps 10 is turned on while moving the image scanner 1 or the document relatively.
As a result, the light emitted from the lamp 10 is emitted to the original from the opening 3 through the light source lens 14, and the light reflected by the original is again emitted from the opening 3 into the main body case 2. The light is made incident and passes through between the holding plates 4 and enters the light entering portion 18 of the lens unit 17.

The light entering the lens unit 17 is imaged by the imaging lens 19 of the lens unit 17, then passes through the diaphragm member 20 and the CCD sensor 1
The light is received by the image sensor 6, and the CCD sensor 16 reads the image information of the document.

In this case, in this embodiment, an annular diaphragm member 20 is provided inside the lens unit 17, and the diaphragm portion 21 of the diaphragm member 20 allows light to enter from the light incident portion 18. Since the light path of the light is narrowed, when the light entering the lens unit 17 from the light entering portion is diffused by the imaging lens 19 and reflected by the inner surface of the lens unit 17. In addition, the diaphragm unit 21 of the diaphragm member 20 allows the lens unit 1
The unnecessary reflected light that passes near the inner surface of 7 is shielded, and as a result, the CCD sensor 16 and the lens unit 17
It is possible to prevent excessive reflected light from being received by the inner surface of the.

Moreover, since the minute irregularities 22 are formed on the surface of the diaphragm member 20, when the diaphragm member 20 is irradiated with light in order to shield the reflected light, the surface of the diaphragm member 20. Therefore, it is possible to prevent the light from being reflected.

The image information read in this way is output to an image control circuit (not shown) composed of, for example, a CPU, a memory, etc.
For example, an image is displayed on a CRT based on the image information for image processing, or printing based on the image information is performed.

Therefore, in this embodiment, the optical path of the light entering the lens unit 17 from the light entering section 18 is narrowed by the diaphragm section 21 of the diaphragm member 20. When the light entering the inside is diffused by the imaging lens 19 and reflected by the inner surface of the lens unit 17, the extra portion passing near the inner surface of the lens unit 17 by the aperture portion 21 of the aperture member 20. Such reflected light is blocked, and as a result, it is possible to prevent the CCD sensor 16 from receiving extra reflected light from the inner surface of the lens unit 17. Moreover, since the minute irregularities 22 are formed on the surface of the diaphragm member 20, when the diaphragm member 20 is irradiated with light to shield the reflected light, the surface of the diaphragm member 20 emits light. It can also be prevented from being reflected.

As a result, the influence of the reflected light from the inner surface of the lens unit 17 can be prevented, and the image contrast can be remarkably improved. As a result, in reading a color image in recent years, for example, 256 gradations It is possible to read with multi-value gradation such as
The quality of the read image can be improved.

In the present invention, for example, fine irregularities 22 may be formed on the entire inner surface of the lens unit 17 by graining. In such a case, the light generated by the inner surface of the lens unit 17 may be used. It is possible to prevent the reflection of.

Further, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made if necessary.

[0033]

As described above, in the image scanner according to the present invention, when the light entering the lens unit is diffused by the diaphragm portion of the diaphragm member and reflected by the inner surface of the lens unit. In addition, since the extra reflected light passing near the inner surface of the lens unit is shielded, it is possible to prevent the extra reflected light from the inner surface of the lens unit from being received by the CCD sensor. Moreover, since minute irregularities are formed on the surface of the diaphragm member, when the diaphragm member is irradiated with light in order to shield the reflected light, light is reflected by the surface of the diaphragm member. Can be prevented. As a result, the image contrast can be remarkably improved, and in the recent color image reading, multi-value gradation reading can be performed with high accuracy, and the quality of the read image can be improved. Play.

[Brief description of drawings]

FIG. 1 is a half sectional plan view showing an embodiment of an image scanner of the present invention.

FIG. 2 is a half sectional side view of the image scanner of FIG.

FIG. 3 is a longitudinal sectional view showing another embodiment of the diaphragm member of the present invention.

FIG. 4 is a vertical cross-sectional view showing another embodiment of the diaphragm member of the present invention.

FIG. 5 is a longitudinal sectional view showing another embodiment of the diaphragm member of the present invention.

FIG. 6 is a half cross-sectional side view showing a conventional image scanner.

[Explanation of symbols]

 1 Image Scanner 2 Body Case 3 Opening 4 Holding Plate 5 Inner Wall 10 Lamp 14 Light Source Lens 16 CCD Sensor 17 Lens Unit 20 Aperture Member 21 Aperture Part 22 Unevenness

Claims (2)

[Claims] 1. An opening is formed in one end surface of a main body case, and a lamp and a light source lens are arranged inside the opening of the main body case so as to be directed to the opening. At the end opposite to the opening, a light is emitted from the lamp through the light source lens to a predetermined document arranged in the vicinity of the opening, and the light reflected by the document is received through the lens unit. And an image scanner having a CCD sensor for reading the image of the original document, in which a diaphragm member is arranged inside the lens unit, and the light incident on the lens unit is incident on the diaphragm member. An image scanner characterized by forming a diaphragm for narrowing the optical path of the. 2. The surface of the diaphragm member is formed with minute irregularities, and the minute irregularities are formed so that the light irradiated to the diaphragm member is not reflected. Image scanner.