JP2002247293A - Image reading device - Google Patents

Abstract

(57) Abstract: The present invention provides an inexpensive image reading apparatus capable of appropriately reading a document surface regardless of the insertion direction of the document regardless of whether the image surface of the document is front or back. An image reading device (1) rotates a rotary document reading unit (7) by pressing a reading direction change key on an operation unit (1) depending on whether the curl direction of a document (2) and the document image surface are inward or outward. The reading direction is changed so that the curled document 2 can be inserted into the document insertion opening between the document table 3 and the insertion guide plate 4 with the curl direction of the leading end of the curled document 2 facing the document table 3. Insertion can be performed easily and quickly.

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, and more particularly, to an inexpensive image reading apparatus capable of properly reading a document surface regardless of the direction in which the document is inserted, regardless of whether the image surface of the document is front or back. It relates to a reading device.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus such as a copying machine, a facsimile machine and a scanner, a CCD is generally used.
(Charge Coupled Device) An image reading unit using a sensor or the like scans one side of a conveyed document or a document set on a contact glass, and reads an image of one side of the document, for example, a position below the document. In most cases, the image is fixed at a position where an image on the side surface or the upper surface is read (see Japanese Patent Publication No. 2941295).

[0003]

However, in such a conventional image reading apparatus, if the image reading section is provided only at a position where one side of the document is read, the document may be curled. However, if the insertion direction of the original is not necessarily the one suitable for the curl direction of the original, and if the insertion direction of the original and the curl direction of the original are opposite to each other, it takes time to insert the original, When the original is transported, there is a problem that the probability that the original is transported obliquely increases.

In this case, for example, Japanese Patent Publication No. 2950962
As described in Japanese Patent Application Laid-Open Publication No. H10-209, two sets of image reading units are provided so that the original can be read in either the upper direction or the lower direction, and the original is inserted in an insertion direction suitable for the curl direction of the original, It is conceivable to reduce the insertion time of the original or to reduce the probability that the original is skewed when the original is transported.

However, when two sets of image reading units are provided, there are problems in that the number of components increases, the size of the image reading apparatus increases, and the price of the image reading apparatus increases.

Therefore, according to the present invention, the original inserted in the original insertion slot is conveyed to the reading position by the original conveying mechanism, and the original at the reading position is irradiated with light from the light source of the reading unit. When the reflected light from the original is incident on the photoelectric conversion unit by the scanning optical system and the incident light is photoelectrically converted by the photoelectric conversion unit to read the image of the original, the reading unit operates the front or back surface of the original at the reading position. By selectively reading the document, if the document is curled, regardless of the curl direction of the document, the document can be inserted into the document insertion slot with ease so that the image forming surface of the inserted document is displayed. One reading unit selectively reads the front side and the back side, which are the image forming surfaces of the original, with a single reading unit. Properly transport the original And its object is to provide an image reading apparatus capable of.

According to a second aspect of the present invention, the reading means is rotated in the front and back directions of the original at the reading position to selectively read the front or back surface of the original, thereby inserting the original into the original insertion opening in a state where it can be easily inserted. The light source for illuminating the document, the scanning optical system, and the photoelectric conversion means, which are particularly related to the reading characteristics, are integrated as a single reading unit depending on whether the image forming surface of the read document is on the front side or the back side. Rotate without changing the position to prevent the change and deterioration of the reading characteristics, improve the image quality of the read image, and reduce the size, inexpensiveness, the efficiency of document feeding, and the conveyance of the document after feeding. It is an object of the present invention to provide an image reading apparatus that can appropriately perform the image reading.

According to a third aspect of the present invention, the reading direction of the reading unit is either the front side or the back side of the document.
An image reading apparatus that can efficiently and inexpensively use an image signal without using an additional function when using an output image signal by switching a reading start position in the main scanning direction. It is intended to be.

[0009]

According to a first aspect of the present invention, there is provided an image reading apparatus, comprising: a light source for irradiating a document at a reading position with light;
A reading unit including: a photoelectric conversion unit that photoelectrically converts incident light; and a scanning optical system that causes the reflected light reflected by the original to enter the photoelectric conversion unit; and A document transport mechanism for transporting the document to the reading position, wherein the document inserted into the document insertion port is transported to the reading position by the document transport mechanism, and the light source of the reading unit is transferred to the document at the reading position. In the image reading device that irradiates light from the original and irradiates the reflected light on the original with the scanning optical system to the photoelectric conversion unit, and photoelectrically converts the incident light by the photoelectric conversion unit to read an image of the original, The reading unit achieves the above object by selectively reading the front or back surface of the document at the reading position.

According to the above construction, the original inserted into the original insertion slot is transported to the reading position by the original transport mechanism, and the original at the reading position is irradiated with light from the light source of the reading unit and reflected by the original. When light is incident on the photoelectric conversion unit by the scanning optical system and the photoelectric conversion unit photoelectrically converts the incident light to read the image of the document, the reading unit selectively selects the front or back surface of the document at the reading position. Since the original is curled, the original can be inserted into the original insertion slot easily regardless of the curl direction of the original, regardless of the curl direction of the original. The one reading unit selectively reads the front side and the back side, which are the image forming surfaces of the original, with a single reading unit, thereby appropriately performing the original feeding efficiency and properly conveying the original after the feeding. Image reading device It can be an inexpensive and small-sized ones.

In this case, for example, as set forth in claim 2, the reading means rotates in the front and back direction of the document at the reading position to selectively read the front or back surface of the document. You may.

According to the above construction, the reading means is rotated in the front and back directions of the original at the reading position to selectively read the front or back side of the original, so that the original inserted in a state where it can be easily inserted into the original insertion slot. The relative position of each member is changed as an integrated reading unit, including a light source for illuminating the original, a scanning optical system, and a photoelectric conversion unit, which are particularly relevant to the reading characteristics, depending on whether the image forming surface is the front or the back. It is possible to rotate the document without any change, prevent the change and deterioration of the reading characteristics, improve the image quality of the read image, and perform the document feeding efficiency and appropriately carry the document after feeding. The image reading apparatus that can be used can be made inexpensive and small.

Further, for example, in the image reading apparatus, the image reading device may be configured to read in the main scanning direction according to whether the reading direction of the reading unit is the front side or the back side of the document. The start position may be switched.

According to the above configuration, the reading start position in the main scanning direction is switched according to whether the reading direction of the reading unit is the front side or the back side of the document. Without the need for
The image signal can be used efficiently and inexpensively.

[0015]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 7 show an embodiment of the image reading apparatus of the present invention. FIG. 1 shows an image reading apparatus 1 to which the embodiment of the image reading apparatus of the present invention is applied. It is a main part front schematic structure diagram.

In FIG. 1, an image reading apparatus 1 includes an original 2
A document table 3 on which the document is placed, an insertion guide plate 4 for guiding the leading end of the document on the document table 3, an inserted document sensor 5 for detecting the document 2 inserted between the document table 3 and the insertion guide plate 4, a document A document feed roller pair 6, which feeds the documents 2 on the table 3 one by one, a rotary document reading unit 7, and transport guide plates 8, 9 for guiding the document 2 sent from the document feed roller pair 6 to the rotary document reading unit 7. A registration sensor 10 for detecting the original 2 conveyed to the rotary original reading section 7, an original discharge roller pair 11 disposed downstream of the rotary original reading section 7, and completion of reading by the rotary original reading section 7. Transport guide plates 12 and 13 for guiding the document 2 to the document discharge roller pair 11, and a document receiving tray 14 on which the document 2 discharged from the document discharge roller pair 11 is placed.

The rotary original reading section (reading unit) 7
Is formed in a substantially symmetrical shape in the transport direction of the original 2,
Linear sensor (photoelectric conversion means) 20, selfoc lens array 21 as a scanning optical system, contact glass 2
2, the document illumination light sources 23 and 24, the rear roller 25 disposed at a position facing the contact glass 22, the transport guide plates 26 to 29, the document transport rollers 30 to 33, and the like. By the mechanism 40, the upper surface and the lower surface of the document 2 can be selectively read by rotating by 180 ° in the direction indicated by the arrow in FIG.

As shown in FIG. 2, the rotating mechanism 40 detects a stepping motor 41, a small gear 42, a large gear 43, a filler 44 for detecting a rotational position that rotates together with the rotary original reading section 7, and a filler 44. The center of the large gear 43 is connected so as to coincide with the rotation center of the rotary original reading unit 7. The rotation mechanism 40 is configured such that the stepping motor 41 rotates the small gear 42 to rotate the large gear 43,
The rotary document reader 7 connected to the large gear 43 is rotated, and the filler 4 is rotated together with the rotary document reader 7.
The position 4 is detected by the rotation position sensor 45, and the rotary document reading unit 7 is rotated to a position suitable for reading the upper or lower surface of the document 2.

The image reading apparatus 1 has a circuit block configuration as shown in FIG. 2, and includes the linear sensor 20, the inserted document sensor 5, the registration sensor 10, and the rotation position sensor 4.
5, a stepping motor 41, etc., an analog processing circuit 50, an A / D converter 51, a shading correction circuit 52, a memory 53, and a timing generation circuit 5.
4, a control unit 55, a memory 56, an operation unit 57, and the like.

The analog processing circuit 50 includes the linear sensor 2
The A / D converter 51 includes a sample and hold circuit 61 that samples and holds a signal section of an analog image signal from 0, a level adjustment circuit 62 that performs DC reproduction and level adjustment, and an amplifier 63. An analog image signal is converted to an 8-bit digital image signal and output to a shading correction circuit.

The timing generation circuit 54 supplies a clock, a gate signal, an address signal, and the like to each circuit block to the control unit 5.
5. Output under the control of 5.

The shading correction circuit 52 is used to vary the distribution of the light amounts of the original illumination light sources 23 and 24 in the main scanning direction and the variation in the image signal in the main scanning direction due to the characteristics from the linear sensor 20 to the output of the A / D converter 51. Is corrected. As shading data used for shading correction in the shading correction circuit 52, data obtained by multiply-averaging the output value of the A / D converter 51 for each of 128 pixels in the main scan is stored in the memory 56 as shading data. .

The memory 53 has a memory capacity for two main scanning lines, and the memory for one line repeats input and output for each main scanning line. At the time of output by a control signal from the operation unit 57 via the control unit 55, switching is performed between output in the same order as the reading order of the linear sensor 20 in the main scanning direction or output from the reverse.

The operation unit 57 designates a document surface reading direction, that is, whether the upper surface of the document 2 conveyed to the rotary document reader 7 is the reading direction or the lower surface of the document 2 is the reading direction. A reading direction change key is provided, and the specification of the reading direction by the reading direction change key is performed before reading a document image for capturing shading data.

The shading data uses 128 main scanning signals read by the linear sensor 20 using the surface around the back roller 25 as a white reference surface when there is no original on the back roller 25. In pixel units,
The shading correction circuit 52 calculates the following equation and stores it in the memory 56.

Shading data = (7 × pre-shading data + current reading signal) The pre-shading data at the time of the first calculation is
It is set to “0”.

The original image signal obtained when the original 2 is read is subjected to shading correction represented by the following equation in the shading circuit 26 in pixel units.

Original image signal after correction = Original image signal × 2
40 ° shading data In the case of a document having the same density as the rear roller 25 in pixel units, the output value after shading is 240. (2
(The value of 40 is changed depending on the density and reading characteristics of the back roller 25.) Next, the operation of the present embodiment will be described. Image reading device 1
Switches the reading direction of the rotary document reading unit 7 upward and downward depending on whether the document image surface of the document 2 is the upper surface or the lower surface. With the image side facing up,
It is possible to appropriately select whether to insert between the insertion guide plate 4 and the image guide or to insert with the image surface facing downward.

That is, the document 2 may be rounded and curled as shown in FIG.
The document 2 is spread and inserted from a document insertion opening between the document table 3 and the insertion guide plate 4. In the case of FIG. 4, the image reading apparatus 1 is positioned inside the curled original 2 (inward curl direction) of the original image.
If the reading direction of the document 2 is upward, when the document 2 is inserted into the document insertion port, the document 2 is inserted with the curl direction of the leading end of the document 2 facing upward, as shown in FIG. If the reading direction of the image reading device 1 is downward, when inserting the original 2 into the original insertion slot, as shown in FIG. 6, the original 2 may be inserted with the curl direction of the leading end of the original 2 facing downward. become. In FIG. 4, when the reading direction of the image reading apparatus 1 is upward on the outside (outside of the curl) of the original 2 on which the original image surface is curled, as shown in FIG. The original 2 is inserted in a state where the curl direction of the leading end is downward. If the reading direction of the image reading apparatus 1 is downward, the curl direction of the leading end of the original 2 is set to upward as shown in FIG. It will be inserted in the state where it became.

That is, a curled original 2 as shown in FIG.
It is necessary to insert the original 2 into the original insertion opening while holding down the curl of the original and correcting the roundness of the original 2. However, the original 2 needs to be inserted in a state where the curl of the original 2 is curled upward. In the case shown in FIG. 6 in which the curl tip of No. 2 is curled in the downward direction on the original platen 3 side, the original 2
Insertion operability is good.

That is, in the case of FIG. 6, the original document curl is directed downward and the original document is almost in contact with the original document table 3, so that the original document 2 is slid along the flat original document table 3. The document 2 can be inserted into the document insertion opening between the document table 3 and the insertion guide plate 4 by simply performing
In the case of FIG. 5, the curl of the document leading edge is upward,
Not only is the operator required to insert the entire leading edge of the document 2 under the insertion guide plate 4, but also after the leading edge of the document 2 enters under the insertion guide plate 4,
Since the plane is different from that of the platen 3, the smoothness of insertion is impaired, which may cause oblique conveyance.

Therefore, the image reading apparatus 1 of the present embodiment
The operation unit 57 determines whether the curl direction of the document 2 and the document image surface are inward or outward with respect to the curl direction.
By pressing the reading direction change key of the
Is rotated to change the reading direction, so that the curl direction of the leading end of the curled document 2 is oriented in the direction of the platen 3.
The document 2 can be easily and promptly inserted by inserting the document 2 into the document insertion opening between the document and the insertion guide plate 4.

That is, in the initial state of the image reading apparatus 1, as shown in FIG. 1, the linear sensor 20 is located on the upper side and the back roller 25 is located on the lower side, and the reading direction is downward. When the reading direction change key of the operation unit 57 is pressed, the control unit 55
The stepping motor 41 is rotated. When the stepping motor 41 rotates, the filler 44 also rotates, and the rotational position sensor 45 that detects the filler 44 recognizes that the rotary original reading unit 7 has deviated from the initial position.
The control unit 55 rotates the stepping motor 41 until the rotary document reading unit 7 rotates by 180 degrees, and then stops, and sets the reading direction of the rotary document reading unit 7 to the lower side.

When the reading direction is downward,
The control unit 55 sets the reading direction of the memory 53 in a direction opposite to that in the upper reading direction, that is, the linear sensor 2.
Reading is performed from the direction opposite to the reading s of 0 to obtain an image output signal.

When the reading direction of the rotary original reading unit 7 is downward and the reading direction is to be upward, the reading direction change key of the operation unit 57 is pressed again. The control unit 55 outputs a signal for rotating the stepping motor 41 in the opposite direction according to a signal from the operation unit 57, and the stepping motor 41 rotates, and the rotary original reading unit 7 rotates the rotation position sensor 45 to the filler 35. When rotated to the position where
The rotation of the stepping motor 41 is stopped.

When the reading direction is upward,
The control unit 55 reads the image data from the memory 53 in the forward direction (the same direction as the reading of the linear sensor 20).
And an image output signal.

Therefore, regardless of whether the image surface of the document 2 is inward or outward with respect to the curl direction, the reading direction of the rotary document reading unit 7 is switched so that the document 2 is always displayed in FIG. And the document table 3 and the insertion guide plate 4
The document 2 can be inserted quickly, and the operation for inserting the document 2 can be simplified and quickly performed, and the document 2 can be prevented from being skewed.

Although the invention made by the inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

[0040]

According to the image reading apparatus of the first aspect of the present invention, the original inserted into the original insertion slot is transported to the reading position by the original transport mechanism, and the original at the reading position is transferred from the light source of the reading unit to the original. When the light is irradiated and the reflected light from the original is incident on the photoelectric conversion means by the scanning optical system, and the photoelectric conversion means photoelectrically converts the incident light to read the image of the original, the reading unit operates at the reading position. Selectively scans the front or back side of the original, so if the original is curled, the original can be inserted into the original insertion slot easily regardless of the curl direction of the original. 1 depending on whether the image forming surface of the original
An inexpensive and compact image reading device that can selectively read the front and back sides of an image on a document with two reading units, and perform document feeding efficiency and properly transport the document after feeding. It can be.

According to the image reading apparatus of the present invention, the reading means is rotated in the front and back directions of the document at the reading position to selectively read the front or back side of the document. A reading unit that integrates a light source for illuminating a document, a scanning optical system, and a photoelectric conversion unit, which is particularly relevant to reading characteristics, depending on whether the image forming surface of a document inserted in an easily accessible state is front or back. As it can be rotated without changing the relative position of each member, it can prevent the change and deterioration of the reading characteristics, improve the image quality of the read image, and improve the efficiency of document feeding and after feeding. An image reading apparatus capable of appropriately carrying the original document can be made inexpensive and small.

According to the image reading apparatus of the third aspect, the reading start position in the main scanning direction is switched in accordance with whether the reading direction of the reading unit is the front side or the back side of the document. When using a signal, an image signal can be used efficiently and inexpensively without requiring an additional function.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a main part of an image reading apparatus to which an embodiment of the image reading apparatus of the present invention is applied.

FIG. 2 is a schematic configuration diagram of a rotation mechanism of the rotary original reading unit in FIG. 1;

FIG. 3 is a circuit block diagram of the image reading apparatus of FIG. 1;

FIG. 4 is a side view of a document in a curled state.

FIG. 5 is a schematic front view showing a state in which a document curled upward is inserted between a document table and an insertion guide plate.

FIG. 6 is a schematic front view showing a state in which an original curled downward is inserted between an original platen and an insertion guide plate.

FIG. 7 is a schematic front view of a main part of the image reading apparatus in a state where the rotary document reading unit of FIG. 1 is rotated by 180 ° and the reading direction is on the lower side;

[Description of Signs] 1 Image reading device 2 Document 3 Document table 4 Insert guide plate 5 Insert document sensor 6 Document feed roller pair 7 Rotary document reading unit 8, 9 Conveyance guide plate 10 Registration sensor 11 Document discharge roller pair 12, 13 Transport guide plate 14 Document receiving tray 20 Linear sensor 21 Selfoc lens array 22 Contact glass 23, 24 Document illumination light source 25 Back roller 26-29 Transport guide plate 30-33 Document transport roller 40 Rotating mechanism 41 Stepping motor 42 Small gear 43 Large Gear 44 Filler 45 Rotational position sensor 50 Analog processing circuit 51 A / D converter 52 Shading correction circuit 53 Memory 54 Timing generation circuit 55 Control unit 56 Memory 57 Operation unit 61 Sample hold circuit 62 Level adjustment circuit 63 Amplifier

Claims (3)

[Claims] A light source for irradiating a document at a reading position with light; a photoelectric conversion unit for photoelectrically converting incident light; and a scanning optical system for entering reflected light reflected by the document to the photoelectric conversion unit. A reading unit, and a document transport mechanism for transporting the document inserted in the document insertion port to the reading position, and the document inserted in the document insertion port is moved to the reading position by the document transport mechanism. The scanning optical system conveys and irradiates the original at the reading position with light from the light source of the reading unit, and the reflected light from the original enters the photoelectric conversion unit by the scanning optical system, and is incident by the photoelectric conversion unit. An image reading apparatus for reading an image of the document by photoelectrically converting light, wherein the reading unit selectively reads a front surface or a back surface of the document at the reading position. 2. The image reading apparatus according to claim 1, wherein said reading means rotates in the front and back directions of said document at said reading position to selectively read the front side or back side of said document. 3. The image reading apparatus according to claim 1, wherein the reading unit switches the reading start position in the main scanning direction according to whether the reading direction of the reading unit is the front side or the back side of the document. The image reading device according to claim 1.