JP2000250146A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader capable of preventing the lowering of light quantity on an image reading surface without using a side reflector. SOLUTION: The image reader is provided with an original platen 2 and a light source 8 which are arranged in a fixed state, 1st and 2nd carriages 6 and 7 for scanning the original placed on the original platen 2 with the light emitted from the light source 8 with a fixed optical path length, and also, guiding the light reflected by the original at optical scanning in a prescribed direction, and a CCD line sensor 14 for receiving the light guided by the 1st and 2nd carriages 6 and 7 and reading the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus provided in, for example, an electrophotographic copying machine for optically reading an image on a document.

[0002]

2. Description of the Related Art An image reading apparatus of this type scans a document placed on a document table with light emitted from a light source, and receives light reflected from the document by a light receiving element by this scanning. To read.

In this image reading apparatus, there is an image reading apparatus in which a document table and a light source are fixedly provided, and light emitted from the light source is reflected by a reflecting member to move the reflecting member, thereby scanning the document with light. .

However, in the prior art, since the optical path length until the light emitted from the light source reaches the document reading surface changes with the movement of the reflecting member, the light quantity on the image reading surface decreases. However, there is a disadvantage that the reading accuracy is reduced.

Therefore, conventionally, a side reflector is provided along the moving direction of the reflection member to prevent a light amount from being reduced on the image reading surface.

[0006]

However, when the side reflector is used, the structure becomes complicated, the cost is increased, and the size is increased.

[0007] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide an image reading apparatus capable of preventing a decrease in light amount on an image reading surface without using a side reflector.

[0008]

According to a first aspect of the present invention, there is provided an original mounting table and a light source which are fixedly arranged, and a light emitted from the light source being fixed on the original. Optical scanning means for scanning with an optical path length of, an optical system for guiding light reflected from the document by the optical scanning means in a predetermined direction, and reading for reading an image by receiving light guided by the optical system Means.

According to a second aspect of the present invention, there is provided a document table and a light source which are fixedly arranged, and first and second carriages which move along the document table and mount a mirror,
Light scanning means for scanning the document with a fixed optical path length through the mirrors of the first and second carriages with light emitted from the light source; and light reflected from the document by the light scanning of the light scanning means. An optical system for guiding light in a predetermined direction, and reading means for receiving light guided by the optical system and reading an image are provided.

According to a third aspect of the present invention, there is provided a document table and a light source which are fixedly disposed, and first and second carriages which move along the document table and mount a mirror,
Light for scanning the document with a constant optical path length by using light emitted from the light source via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. A scanning unit; an optical system that guides light reflected from the document by the optical scanning unit in a predetermined direction; and a reading unit that receives light guided by the optical system and reads an image.

According to a fourth aspect of the present invention, there is provided a document table and a light source which are fixedly arranged, and first and second carriages which move along the document table and mount a mirror,
Light for scanning the document with a constant optical path length by using light emitted from the light source via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. Scanning means, an optical system for guiding light reflected from the original by the optical scanning means in a predetermined direction, a light receiving element for receiving light guided by the optical system, and light receiving by the light receiving element. Reading means for reading an image of the document.

According to a fifth aspect of the present invention, there is provided a document table and a light source which are fixedly arranged, and first and second carriages which move along the document table and mount a mirror,
Light for scanning the document with a constant optical path length by using light emitted from the light source via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. Scanning means, an optical system for guiding light reflected from the document by the optical scanning by the optical scanning means in a predetermined direction, an imaging lens for forming an image of the light guided by the optical system, and an image forming lens. A light receiving element for receiving light to be imaged; and reading means for reading an image of the document based on the light received by the light receiving element.

According to a sixth aspect of the present invention, there is provided a document table and a light source which are fixedly arranged, and first and second carriages which move along the document table and mount a mirror,
Light for scanning the document with a constant optical path length by using light emitted from the light source via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. Scanning means, an optical system for guiding light reflected from the document by the optical scanning by the optical scanning means in a predetermined direction, an imaging lens for forming an image of the light guided by the optical system, and an image forming lens. A light receiving element for receiving light to be imaged; and reading means for reading an image of the document based on the light received by the light receiving element, wherein the light source is provided near the imaging lens.

According to a seventh aspect of the present invention, there is provided a document table and a light source which are fixedly disposed, and first and second carriages which move along the document table and mount mirrors,
The light emitted from the light source is scanned with a constant optical path length on the original document via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. Light scanning means for guiding light reflected from the original in a predetermined direction via mirrors of the first and second carriages; reading means for receiving light guided by the light scanning means and reading an image; Is provided.

According to an eighth aspect of the present invention, there is provided a document table and a light source which are fixedly disposed, and first and second carriages which move along the document table and mount a mirror,
The light emitted from the light source is scanned with a constant optical path length on the original document via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage. An optical scanning unit that guides light reflected from the original in a predetermined direction via mirrors of the first and second carriages; an imaging lens that forms an image of the light guided by the optical scanning unit; A light receiving element for receiving light formed by the imaging lens; and reading means for reading an image of the document based on the light received by the light receiving element; and the light source is provided near the imaging lens. .

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 1 shows an image reading apparatus.

The image reading apparatus includes an original mounting table 2 on which an original is mounted on the upper surface of the apparatus main body 1 and an original pressing plate 3 for pressing the original G mounted on the original mounting table 2. A scanner 4 is provided in the apparatus main body 1 as an optical scanning unit for scanning the original G with light.

The scanner 4 includes first and second carriages 6 and 7, and a light source 8 such as a fluorescent lamp. The first and second carriages 6 and 7 are provided movably along the document table 2, and the light source 8 is fixedly provided. First
The carriage 6 has a first mirror 9 mounted thereon, and the second carriage 7 has second and third mirrors 10 and 11 mounted thereon.

In the moving direction of the second carriage 10, an imaging lens 13 for converging the reflected light from the third mirror 11 and the reflected light condensed by the imaging lens 13 are received and photoelectrically converted. And a CCD line sensor 14 as a light receiving element. The imaging lens 13 is movably provided in a plane including the optical axis of the light deflected by the third mirror 11, and is moved by a driving mechanism (not shown) to form reflected light at a desired magnification. It is an image. The CCD line sensor 14 photoelectrically converts incident reflected light.

The CCD line sensor 14 is connected to an image processing circuit 16 for reading an image from the photoelectrically converted signal. The image processing circuit 16 includes an amplification circuit, an AD converter,
And a shaving correction circuit. Image processing circuit 1
6 is connected to a CPU 18, and a memory 1 is connected to the CPU 18.
9, a drive circuit 21 of a motor 20 for performing a scanning operation, and an operation panel 22 are connected.

FIG. 2 is a front view showing a drive system of the first and second carriages 6 and 7, and FIG. 3 is a plan view thereof.

On both sides of the second carriage 7, first and second movable pulleys 25 and 26 are rotatably mounted. Both sides of the first carriage 6 are fixed to a toothed scan belt 28 by bolts and nuts (not shown). One end of the toothed scan belt 28 is the first
Of the second carriage 7, the first moving pulley 25, the first fixed gear 30, the second fixed gear 31, and the second carriage 7
And the other end is a second fixture 33
It is fixed to. The first fixed gear 30 has a shaft 3
A drive motor 35 that rotates in the forward and reverse directions is connected via the switch 4.

Next, the image reading operation will be described.

First, the original G is placed on the original placing table 2, the original G is pressed by the original holder 3, and a copy button (not shown) is pressed. Thus, light is emitted from the light source 8 and the drive motor 35 is driven. The light emitted from the light source 8 is sent to the first mirror 9 of the first carriage 6 via the third and second mirrors 11 and 12 of the second carriage 7 and is reflected by the first mirror 9. Then, the original G on the original table 2 is irradiated.

The driving of the drive motor 35 causes the first
Of the first carriage 6 is moved while the second carriage 7 is traveling along the original placing table 2.
The document G is scanned at a speed of 2 and light is scanned. By this scanning, the light reflected from the document G is reflected by the first mirror 9 of the first carriage 6 and then reflected and combined by the second and third mirrors 10 and 11 of the second carriage 7. The image is sent to the image lens 13, condensed by the image forming lens 13, and an original image is formed on the CCD line sensor 14. As a result, the image signal is processed by the image signal processing circuit 16, and the laser beam is scanned from the semiconductor laser (not shown) to the photosensitive member, thereby forming an image corresponding to the original image.

When the optical scanning of the original G is completed, the drive motor 35 is rotated in the reverse direction, and the first and second carriages 6, 7 are moved in the opposite directions to return to the initial position.

As described above, the light emitted from the light source 8 fixedly provided in the vicinity of the imaging lens 13 is supplied to the second carriage 7 which travels at half the speed of the first carriage 6. Since the original G is scanned via the mirrors 11 and 10 and the mirror 9 of the first carriage 6, light is scanned over the original G with a constant optical path length. Therefore, the amount of light on the image reading surface of the document can be made constant, so that it is not necessary to use a side reflector or the like as in the related art.

[0029]

As described above, according to the present invention, since the light emitted from the fixed light source is scanned over the original with a constant optical path length, the amount of light on the image reading surface of the original can be made constant.

Therefore, it is not necessary to use a side reflector or the like as in the prior art, and it is possible to prevent an increase in size.
This has the effect of reducing costs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a front view showing a drive system of the image reading apparatus.

FIG. 3 is a plan view showing a driving system of the image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Document mounting plate 3 ... Document holder 4 ... Scanner 6 ... 1st carriage 7 ... 2nd carriage 8 ... Light source 9 ... 1st mirror 10 ... 2nd mirror 11 ... 3rd mirror 11 ... Screw hole 13 ... Imaging lens 14 ... CCD sensor (image reading means) 16 ... Image processing circuit 18 ... CPU 19 ... Memory 20 ... Drive motor 21 ... Drive circuit 22 ... Operation panel 25 ... First moving pulley 26 ... First 2 movable pulley 28 ... toothed scan belt 29 ... first fixture 30 ... first fixed gear 31 ... second fixed gear 33 ... second fixture 34 ... shaft 35 ... drive motor

Claims (8)

[Claims] An original mounting table and a light source which are fixedly arranged; optical scanning means for scanning light emitted from the light source on the original with a constant optical path length; and optical scanning by the optical scanning means. An image reading apparatus, comprising: an optical system that guides light reflected from the document in a predetermined direction; and a reading unit that receives light guided by the optical system and reads an image. 2. A light source, comprising: a document table and a light source fixedly disposed; and first and second carriages that move along the document table and mount mirrors. Scanning means for scanning the document with a constant optical path length via mirrors of the first and second carriages, and an optical guide for guiding light reflected from the document by the optical scanning of the document in a predetermined direction. An image reading apparatus, comprising: a system; and reading means for receiving light guided by the optical system and reading an image. 3. A light source emitted from the light source, comprising: a document table and a light source fixedly disposed; and first and second carriages that move along the document table and mount a mirror. Optical scanning means for scanning the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage; An image reading device, comprising: an optical system for guiding light reflected from the document by a light scanning means in a predetermined direction; and reading means for receiving the light guided by the optical system and reading an image. . 4. A light source emitted from the light source, comprising: a document table and a light source fixedly disposed; and first and second carriages that move along the document table and mount a mirror. Optical scanning means for scanning the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage; An optical system for guiding light reflected from the document in a predetermined direction by means of optical scanning, a light receiving element for receiving the light guided by the optical system, and reading for reading an image of the document based on the light received by the light receiving element And an image reading device. 5. A light source, comprising: a document table and a light source fixedly arranged; and first and second carriages that move along the document table and mount mirrors. Optical scanning means for scanning the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage; An optical system that guides light reflected from the document by a light scanning unit in a predetermined direction, an imaging lens that forms an image of the light guided by the optical system, and receives light that is formed by the imaging lens. An image reading apparatus comprising: a light receiving element; and reading means for reading an image of the document based on light reception of the light receiving element. 6. A light source emitted from the light source, comprising: a document table and a light source fixedly disposed; and first and second carriages that move along the document table and mount mirrors. Optical scanning means for scanning the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage; An optical system that guides light reflected from the document by a light scanning unit in a predetermined direction, an imaging lens that forms an image of the light guided by the optical system, and receives light that is formed by the imaging lens. An image reading device, comprising: a light receiving element; and reading means for reading an image of the document based on light received by the light receiving element, wherein the light source is provided near the imaging lens. 7. A light source emitted from the light source, comprising a document table and a light source fixedly disposed, and first and second carriages that move along the document table and mount mirrors. Scans the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage, and reflects light from the original. Light scanning means for guiding light in a predetermined direction via mirrors of the first and second carriages; and reading means for receiving light guided by the light scanning means and reading an image. Image reading device. 8. A light source emitted from the light source, comprising: a document table and a light source fixedly disposed; and first and second carriages that move along the document table and mount mirrors. Scans the original with a constant optical path length via a mirror of the first carriage and a mirror of a second carriage moving at half the speed of the first carriage, and reflects light from the original. Scanning means for guiding the light guided in a predetermined direction via mirrors of the first and second carriages; an imaging lens for imaging the light guided by the optical scanning means; and an imaging lens formed by the imaging lens. A light receiving element for receiving light from the light receiving element, and reading means for reading an image of the document based on the light received by the light receiving element, wherein the light source is provided near the imaging lens. Reader.