JPH07140565A - Image reader - Google Patents

Abstract

PURPOSE:To accurately and easily correct an optical path length with a simple configuration without increasing the movable part of a general image reader, and to always obtain a stable good image even in the case of reading the image of a book document. CONSTITUTION:The image reader is provided with a 1st optical carriage driving part 102 for driving a 1st optical carriage 101, a 2nd optical carriage driving part 104 for driving a 2nd optical carriage 103, an operating part 105 for selecting whether the original is a sheet like document or a bound document such as a book and a control part 107 for controlling the driving part 102 and the driving part 104 at the time of scanning near the bound part of the book by the 1st optical carriage 101 and changing the speed of the 2nd optical carriage 103 with respect to the speed of the 1st optical carriage 101 in the case the bound document such as the book is selected by the operating part 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention scans an original with a first optical carriage and a second optical carriage that moves in the same direction as the first optical carriage at a speed half that of the first optical carriage. More specifically, the present invention relates to an image reading apparatus that changes the speed of the second optical carriage according to the type of a document.

[0002]

2. Description of the Related Art Conventionally, a slit exposure type image reading apparatus used in a copying machine is provided with a fluorescent lamp for illuminating a document and a mirror for guiding the reflected light of the light illuminating the document in a predetermined direction. The first optical carriage and the second optical carriage having a pair of mirrors for guiding the reflected light guided by the first optical carriage in a predetermined direction are configured to move at a fixed speed ratio of 2: 1. ing. Therefore, it is general that the relative positional relationship between the first optical carriage and the second optical carriage can hardly be changed.

For this reason, in such an image reading apparatus, when it is possible to correct the optical path length, for example, when a variable magnification function such as enlargement / reduction is provided, a pair of roof mirrors are further provided in the third optical carriage. As well as
A driving means for moving the third optical carriage according to the magnification change is required.

FIG. 7 shows an image reading apparatus having a conventional first optical carriage and a second optical carriage, showing an example of the scanning unit of the image reading apparatus viewed from above. As shown in the figure, the first optical carriage 101 and the second optical carriage 103 include one drive motor 701 to the drive pulley 7
Reciprocate through 02. The drive pulley 702 is configured by a combination of two large and small pulleys coaxially having a pitch diameter ratio of 1: 2, drives the first optical carriage 101 via the large pulley, and drives the second optical carriage via the small pulley. By driving 103, a speed ratio of 2: 1 is obtained.

FIG. 8 is an explanatory view showing an example of a conventional image reading apparatus having a third optical carriage in which magnification is changed. Here, the positions of the third optical carriage 801 and the lens 802 shown by the broken line indicate the positions at the same magnification, and the third optical carriage 801 shown by the solid line.
The position of the lens 802 indicates the position at the time of zooming. In this way, by changing the position of the third optical carriage 801, the entire optical path length is extended and the lens 80
By moving 2 as appropriate, a predetermined scaling factor is obtained. That is, an image with a predetermined magnification is formed on the photoconductor 803.

Further, as an apparatus that enables high-quality reading even in a raised portion of a set document, Japanese Patent Application Laid-Open No. 61-278839 “exposure scanning apparatus” has been proposed. In this exposure scanning device, the speed of the optical carriage for scanning the original is controlled in relation to the distance or the angle between the original placed on the original glass and the original glass, so that the original may be lifted. Also, a good image can be obtained.

Further, as a device for facilitating the reading of bound originals such as books, Japanese Patent Laid-Open No. 60-168131, "Copier" has been proposed. In this copying machine, the platen glass on which the original is placed is configured to have a substantially V shape, and the relative speed of the second optical carriage with respect to the first optical carriage is controlled at a ratio according to the opening angle of the V shape. However, a good image can be obtained even in the original document.

[0008]

However, according to the conventional image reading apparatus described above, when the optical path length is corrected when the variable magnification function is used, it is necessary to provide a movable mirror dedicated to the optical path length correction. Since the number of drive parts increases, the mounting angle of the mirror may become inaccurate.
There is a problem that a good image cannot be obtained.

In the vicinity of the binding portion of this type of document, the reading surface is separated from the platen glass, and the reflected light of the light emitted from the illuminating portion to the reading surface is weakened to cause background stain. In other words, there is a problem that a good image cannot be obtained.

Further, according to Japanese Patent Laid-Open No. 61-278839, although a good image can be obtained with respect to the floating of the original, the original is floated when a bound original such as a book is set. There is a problem in that it is impossible to correct the increase in the optical path length caused by this.

According to Japanese Patent Laid-Open No. 60-168131, although it is effective for bound originals such as books, it is generally frequently used because the original placing table is V-shaped. There is a problem that it is difficult to set the single-cut sheet, and the automatic document feeding mechanism is particularly difficult to realize.

When reading a bound document such as a book, an increase in the optical path length caused by the document rising from the contact glass in the vicinity of the binding portion is corrected.
If the third optical carriage is configured to move during scanning of the original in the image reading apparatus shown in FIG. 1, the mirror vibrates with the movement of the third optical carriage, and the imaging performance is significantly deteriorated. It was virtually impossible to perform optical path length correction during scanning.

The present invention has been made in view of the above, and corrects the optical path length accurately and easily with a simple structure without increasing the number of movable parts of a general image reading apparatus, and also in this type document. The purpose is to always obtain a stable and good image.

[0014]

In order to achieve the above object, the present invention provides illumination means for irradiating an original placed on an original placing glass with light and reflected light reflected by the original. The first optical carriage includes a first optical carriage configured to guide in a predetermined direction and a pair of mirrors configured to guide the reflected light emitted from the first optical carriage in a predetermined direction. First at a speed of / 2
In an image reading apparatus including a second optical carriage that moves in the same direction as the second optical carriage, a first driving unit for driving the first optical carriage and a second optical carriage are driven. Second driving means for selecting, a selection means for selecting whether the original is a sheet-like original or a bound original such as a book, and the bound original such as a book is selected by the selecting means. In this case, when the first optical carriage scans the vicinity of the binding portion of the book, the first drive means and the second drive means are controlled so as to control the second speed with respect to the speed of the first optical carriage. An image reading apparatus including a control unit that changes the speed of an optical carriage.

The control means controls the amount of light emitted from the illuminating means when scanning a bound portion of a bound document such as a book.

In order to achieve the above-mentioned object, the present invention guides the illuminating means for irradiating the original placed on the original placing glass with light and the reflected light reflected by the original in a predetermined direction. A first optical carriage including a mirror and a pair of mirrors that guide the reflected light emitted from the first optical carriage in a predetermined direction, and have a speed half that of the first optical carriage. A second optical carriage that moves in the same direction as the first optical carriage,
An image reading apparatus comprising: an automatic document feeder that conveys a document onto the document placing glass; and a document detector that detects whether a document is placed on a document placing table of the automatic document feeder. When the first drive unit for driving the first optical carriage, the second drive unit for driving the second optical carriage, and the document detection unit detect a document, the first drive unit An image reading apparatus comprising: a control unit that controls the second drive unit to bring the movement start position of the second optical carriage closer to the movement start position of the first optical carriage by a predetermined amount. Is.

In order to achieve the above-mentioned object, the present invention guides the illuminating means for irradiating the original placed on the original placing glass with light and the reflected light reflected by the original in a predetermined direction. A first optical carriage including a mirror and a pair of mirrors that guide the reflected light emitted from the first optical carriage in a predetermined direction, and have a speed half that of the first optical carriage. In an image reading apparatus including a first optical carriage and a second optical carriage that moves in the same direction, first driving means for driving the first optical carriage, and the second optical carriage Second driving means for driving the image forming apparatus, variable magnification designating means for designating enlargement or reduction of the original image, and second enlargement or reduction by the variable magnification designating means. And controlling means, by changing the movement start position of the second optical carriage, there is provided an image reading apparatus and control means for changing the optical path length.

[0018]

In the image reading apparatus of the present invention, when a bound original such as a book is selected, when the first optical carriage scans in the vicinity of the bound portion of the book, the first optical carriage is operated with respect to the speed of the first optical carriage. Change the speed of the optical carriage of 2.

Further, the image reading apparatus of the present invention adjusts the light emission amount of the illumination means when scanning the bound portion of a bound original such as a book.

Further, the image reading apparatus of the present invention brings the movement start position of the second optical carriage closer to the movement start position of the first optical carriage by a predetermined amount when a document is set on the automatic document feeder.

Further, the image reading apparatus of the present invention changes the optical path length by changing the movement start position of the second optical carriage when the magnification change for reading the image by enlarging or reducing the image is designated. .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image reading apparatus of the present invention will be described in detail below in the order of [First Embodiment], [Second Embodiment], and [Third Embodiment] with reference to the drawings, taking a copying machine as an example. .

[Embodiment 1] FIG. 1 is an explanatory diagram showing a configuration of a main part of Embodiment 1, in which a first optical carriage 101 forming an optical system for reading an original and a first optical carriage 101 are driven. First optical carriage drive unit 1 for
02, a second optical carriage 103 forming an optical system for reading a document together with the first optical carriage 101, a second optical carriage drive unit 104 for driving the second optical carriage 103, and a document binding for a book or the like. Operation unit 1 for selecting whether or not the original and inputting various settings
05, a document size detection unit 106 for detecting the size of the document, and a control unit 107 for controlling the above units.

The first optical carriage 101 is composed of an illuminating section 101a for irradiating the original with light, and a mirror (not shown) for guiding the reflected light of the light illuminating the original from the illuminating section 101a in a predetermined direction. Has been done. The second optical carriage 103 is composed of a pair of roof mirrors (not shown) that guide the reflected light guided by the first optical carriage 101 in a predetermined direction.

The operation of the above configuration will be described.
First, with reference to FIG. 2, the operation of reading a bound original such as a book, which is a feature of the present invention, will be described. Figure 2
Shows an example of reading a bound original such as a book. In the figure, 201 indicates a book-type original, and 202 indicates a platen glass for placing the original. When the first optical carriage 101 is at the first position indicated by the broken line in FIG. 2, the reading surface of the original 201 of this type is in close contact with the platen glass 202. Further, when the first optical carriage 101 is at the second position shown by the solid line in FIG. 2, the second position is near the binding portion of the original 201, and therefore the original 201 Reading surface is platen glass 20
It is located at a position away from 2 by Δl.

Here, when the original document 201 is in close contact with the platen glass 202, the original document 20 is
When the distance from the reading surface of 1 to the lens (not shown) is l, when the original 201 of this type is located at a position away from the platen glass 202, the lens (not shown) of the original 201 of this type is read. The distance to () is l + Δl. In this case, when Δl becomes a distance that exceeds the depth of field of the lens, the original image is not formed and a good image cannot be obtained.

In the present invention, when reading the original 201 of this type, the second optical carriage drive unit 104 is controlled to
First optical carriage 101 and second optical carriage 103
The distance between and is reduced by Δ1 / 2 so that the distance from the document surface to the lens is constant. Therefore, a good image can be obtained even when reading a bound original such as a book.

Next, referring to FIG. 3, the control amount in the control of the above-mentioned second optical carriage driving section 104 will be described. Now, as shown in FIG. 3, the x-axis in the scanning direction,
The orthogonal coordinate system is set so that the y axis is in the vertical direction, and the shape of the part where the original 201 of this type is floating (away from) the platen glass 202 is represented by a function f (x) of x. At this time, if the speed of the first optical carriage 101 is dx / dt, the relative distance between the first optical carriage 101 and the second optical carriage 103 during the minute time Δt is as follows (1)
If it changes by Δh shown in the equation, the distance l from the reading surface of the original 201 of this type to the lens is always constant. Δh = f ′ (x) · dx × 1/2 (1)

That is, while the first optical carriage 101 is passing through the floating portion of the original 201 of this type, the second optical carriage 103 is accelerated by the acceleration α shown in the following equation (2).
You can move it with. α = f ′ (x) · Δx / (Δt) ² × 1/2 (2)

As can be seen from FIG. 3, f (x) is discontinuous at the binding portion of the book-shaped original 201, so that in practice, for several millimeters near the binding portion of the book-shaped original 201. When scanning is performed, it is necessary to make f (x) a constant.

Next, a specific control operation will be described with reference to FIG. The control unit 107 firstly operates the operation unit 10
It is determined whether or not the set original is a book type original based on the type of original selected in step 5 (whether or not the original is a bound original such as a book) (S401), and the set original is a book. If the original is a mold, the original size detection unit 106 is controlled to detect the size of the original (S402). continue,
Based on the detected size of the original, the position of the binding portion of the original 201 of this type is obtained, and based on the obtained position of the binding portion,
The speed variation range of the second optical carriage 103 is determined (S403). When the speed variation range of the second optical carriage 103 is determined, the control unit 107 starts reading (S
404).

When the reading is started, the control unit 107
The first optical carriage drive unit 102 is controlled to drive (scan) the first optical carriage 101 at a constant speed (S).
405a). In parallel with this, the control unit 107 controls the second optical carriage driving unit 104 to drive (scan) the second optical carriage 103 (S405b).
That is, when the position of the first optical carriage 101 is at a position where the reading surface of the original is in close contact with the platen glass 202, the second optical carriage 103 is driven at a speed half that of the first optical carriage 101. Control to
When the position of the first optical carriage 101 is at a position where the reading surface of the document is floated (away from) the platen glass 202, the second optical carriage 103 is moved at a speed half that of the first optical carriage 101. From the above, the control is performed so as to drive with the acceleration of α described above. When all lines of the original are read, the reading ends (S406).

On the other hand, in S401, when the original is not the original document, the control unit 107 causes the first optical carriage drive unit 10 to operate.
2 and the second optical carriage driving unit 104 is controlled,
First optical carriage 101 and second optical carriage 1
03 is controlled to be driven at a constant speed (S407), and when all lines of the original are read, the reading is completed (S40).
6). In S407, the speed of the second optical carriage 103 is half the speed of the first optical carriage 101.

In addition, in consideration of the fact that the reflected light of the light emitted from the illumination unit 101a is weakened due to the reading surface and the platen glass 202 being separated from each other in the vicinity of the binding portion of the original 201 of this type, In addition to the above-described control (operation of the flowchart of FIG. 4), the control unit 107 includes the illumination unit 10
It controls so that the light emission amount of 1a may be adjusted. That is, the control shown in FIG. 5 is performed. In FIG. 5, the operations other than S405a in FIG. 4 are the same as those in FIG. In S501, S4 in FIG.
In addition to the operation of 05a, the light emission amount (illuminance) of the illumination unit 101a is adjusted. That is, when the first optical carriage 101 is driven (scanned) at a constant speed, and the position of the first optical carriage 101 is at a position where the reading surface of the document is floating (away from) the platen glass 202, The light emission amount (illuminance) of the illumination unit 101a is adjusted. In this case, the adjustment amount may be adjusted based on the function of f (x), like the control amount of the second optical carriage 103.

As described above, according to the copying machine of the first embodiment, the first optical carriage 101 and the second optical carriage 1
Since the relative position with respect to 03 is changed in the middle of scanning (reading) and the optical path length is automatically corrected, it is possible to perform good reading in focus even if the original is a book type. Further, since the light amount of the illumination unit 101a can be adjusted (increased) when scanning the vicinity of the binding portion of the book-shaped original 201, it is possible to obtain a good image without scumming.

[Embodiment 2] In Embodiment 2, when the original is set by using the automatic original feeder, the second optical carriage 10 at the start of reading is considered in consideration of the floating of the original.
The control for changing the reading start position of No. 3 is performed. FIG. 6 is an explanatory view showing the configuration of the main part of the second embodiment, and 601 is an automatic document feeder (ADF or R).
The document detecting section for detecting that a document is set in (DH) is shown. The same reference numerals as those in FIG. 1 are given in the same manner as in the first embodiment, and the description is omitted.

The operation of the above configuration will be described.
When the document detection unit 601 detects that a document is set in the automatic document feeder, the control unit 107 sets the reading start position of the second optical carriage 103 to the reading start position of the first optical carriage 101 before starting reading. It is moved so that the distance from the position is reduced, and after the movement is completed, normal reading operation is started. The amount of movement of the second optical carriage 103 is determined by the performance of the automatic document feeder, and is determined based on the distance between the document and the platen glass when the document is set using the automatic document feeder. .

As described above, according to the copying machine of the second embodiment, when a document is set by using the automatic document feeder, the reading start position of the second optical carriage 103 is changed, so that the focus is caused by the floating of the document. The deviation is corrected and a good image can always be obtained.

[Third Embodiment] In the third embodiment, when the variable magnification is designated, the second optical carriage 103 is moved to perform the variable magnification by correcting the optical path length, and the movable portion during the variable magnification is reduced. It is what makes me. The configuration of the main part of the third embodiment is the same as that of the first embodiment, and the description is omitted. Further, the scaling is designated by the operation unit 105.

The operation of the above configuration will be described.
When magnification is designated via the operation unit 105, the control unit 1
Reference numeral 07 controls the second optical carriage driving unit 104 before the start of reading to move the second optical carriage 103 to a position according to the designated scaling ratio, and after the movement ends,
Start normal read operation. By this control, the optical path length from the original to the lens is changed, and the magnification can be changed. Therefore, it becomes unnecessary to provide a pair of roof mirrors for moving the lens or driving the zoom function only.

As described above, according to the copying machine of the third embodiment, the optical path length correction at the time of zooming is performed by moving the second optical carriage 103.
Compared with the method of moving the third optical carriage, the number of movable parts is reduced, the accuracy of the mounting position of the mirror can be improved, and the vibrating part can be reduced, so that the image quality is greatly improved. Further, the second optical carriage drive unit 104
Since the positioning can be performed by using, it is not necessary to use a driving means used only for the positioning, and the device can be simplified.

[0042]

As is apparent from the above, according to the image reading apparatus of the present invention, the illumination means for irradiating the original placed on the original placing glass with light and the reflected light reflected by the original are provided. The first optical carriage includes a first optical carriage configured to guide in a predetermined direction and a pair of mirrors configured to guide the reflected light emitted from the first optical carriage in a predetermined direction. In an image reading apparatus provided with a second optical carriage that moves in the same direction as the first optical carriage at a speed of / 2, a first drive means for driving the first optical carriage, and the first drive means for driving the first optical carriage. Second driving means for driving the second optical carriage; selecting means for selecting whether the original is a sheet-like original or a bound original such as a book; and the selecting means for selecting a book or the like. Bound If the document has been selected, the first
When the second optical carriage scans the vicinity of the binding portion of the book, the first driving unit and the second driving unit are controlled to change the speed of the second optical carriage with respect to the speed of the first optical carriage. Since the optical path length is accurately and easily corrected with a simple configuration without increasing the number of movable parts of a general image reading device, a stable and good image is always obtained even in the original document. Can be set.

Further, according to the image reading apparatus of the present invention, the control means controls the light emission amount of the illumination means when scanning the bound portion of a bound original such as a book. ， It is possible to obtain a good image without background stains.

Further, according to the image reading apparatus of the present invention, an illuminating means for irradiating the original placed on the original placing glass with light, and a mirror for guiding the reflected light reflected by the original in a predetermined direction. A first optical carriage composed of
A pair of mirrors for guiding the reflected light emitted from the first optical carriage in a predetermined direction, and moving in the same direction as the first optical carriage at a speed half that of the first optical carriage. 2, an optical carriage, and an automatic document feeder for feeding a document on the document placing glass,
In an image reading apparatus including a document detecting unit that detects whether or not a document is placed on a document placing table of the automatic document conveying unit, a first driving unit for driving the first optical carriage, A second drive means for driving the second optical carriage, and the second drive means for controlling the movement of the second optical carriage when the document detection means detects a document. Since the control means for controlling the start position to approach the movement start position of the first optical carriage by a predetermined amount is provided, it is possible to accurately and accurately determine the optical path length without increasing the number of movable parts of a general image reading apparatus. It can be easily corrected, and a good image can be obtained even when a document is set using the automatic document feeder.

Further, according to the image reading apparatus of the present invention, the illumination means for irradiating the original placed on the original placing glass with light, and the mirror for guiding the reflected light reflected by the original in a predetermined direction. A first optical carriage composed of
A pair of mirrors for guiding the reflected light emitted from the first optical carriage in a predetermined direction, and moving in the same direction as the first optical carriage at a speed half that of the first optical carriage. An image reading apparatus including a second optical carriage, a first driving unit for driving the first optical carriage, a second driving unit for driving the second optical carriage, and an original document. Magnification specifying means for specifying enlargement or reduction of an image, and when enlargement or reduction is specified by the magnification specifying means, the second driving means is controlled to start the movement of the second optical carriage. Since the control means for changing the optical path length by changing the position is provided, the optical path length can be corrected accurately and easily with a simple structure without increasing the number of movable parts of a general image reading apparatus. Rukoto can.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of a first embodiment.

FIG. 2 is an explanatory diagram showing an example of reading a bound original such as a book.

FIG. 3 is an explanatory diagram showing how to obtain a control amount of a second optical carriage driving unit.

FIG. 4 is a flowchart showing a control operation of the first embodiment.

FIG. 5 is a flowchart showing a control operation of the first embodiment.

FIG. 6 is an explanatory diagram showing a configuration of a main part of the second embodiment.

FIG. 7 is an explanatory diagram showing an example of a scanning unit of an image reading apparatus having a first optical carriage and a second optical carriage of the related art viewed from above.

FIG. 8 is an explanatory diagram showing an example of a case in which a conventional image reading apparatus having a third optical carriage is used to perform zooming.

[Explanation of symbols]

 101 First Optical Carriage 101a Illumination Unit 102 First Optical Carriage Drive Unit 103 Second Optical Carriage 104 Second Optical Carriage Drive Unit 105 Operation Unit 106 Document Size Detection Unit 107 Control Unit 601 Document Detection Unit

Claims (4)

[Claims] 1. A first optical carriage comprising an illuminating means for irradiating an original placed on an original placing glass with light, and a mirror for guiding the reflected light reflected by the original in a predetermined direction. , A pair of mirrors for guiding the reflected light emitted from the first optical carriage in a predetermined direction, and the first optical carriage is operated at a speed half that of the first optical carriage.
In an image reading apparatus including a second optical carriage that moves in the same direction as the second optical carriage, a first driving unit for driving the first optical carriage and a second optical carriage are driven. Second driving means for selecting, a selection means for selecting whether the original is a sheet-like original or a bound original such as a book, and the bound original such as a book is selected by the selecting means. In this case, when the first optical carriage scans the vicinity of the binding portion of the book, the first drive means and the second drive means are controlled so as to control the second speed with respect to the speed of the first optical carriage. An image reading apparatus comprising: a control unit that changes a speed of an optical carriage. 2. The control means controls the light emission amount of the illuminating means when scanning a bound portion of a bound original such as a book.
The image reading device described. 3. A first optical carriage comprising an illuminating means for irradiating a document placed on a document placing glass with light, and a mirror for guiding the reflected light reflected by the document in a predetermined direction. , A pair of mirrors for guiding the reflected light emitted from the first optical carriage in a predetermined direction, and the first optical carriage is operated at a speed half that of the first optical carriage.
Second optical carriage that moves in the same direction as the optical carriage of No. 1, an automatic document feeder that conveys an original on the original placing glass, and whether or not an original is placed on the original placing table of the automatic original feeding unit. In an image reading apparatus provided with a document detecting means for detecting whether the first optical carriage is used, a first driving means for driving the first optical carriage and a second driving means for driving the second optical carriage. When the document detection unit detects a document, the second drive unit is controlled to bring the movement start position of the second optical carriage closer to the movement start position of the first optical carriage by a predetermined amount. An image reading apparatus comprising: a control unit that performs control. 4. A first optical carriage comprising an illuminating means for irradiating a document placed on a document placing glass with light and a mirror for guiding the reflected light reflected by the document in a predetermined direction. , A pair of mirrors for guiding the reflected light emitted from the first optical carriage in a predetermined direction, and the first optical carriage is operated at a speed half that of the first optical carriage.
In an image reading apparatus including a second optical carriage that moves in the same direction as the second optical carriage, a first driving unit for driving the first optical carriage and a second optical carriage are driven. For controlling enlargement or reduction of the original image, and when the enlargement or reduction is designated by the scaling designation unit, the second driving unit is controlled. An image reading apparatus comprising: a control unit that changes the optical path length by changing the movement start position of the second optical carriage.