JP2006058691A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-accuracy image reading apparatus free from the positional deviation of a mirror. <P>SOLUTION: Regarding the image reading apparatus provided with a 1st carriage having an exposure lamp for illuminating an original surface and a 1st mirror for receiving the reflected light from the original surface, and a 2nd carriage having a 2nd mirror and a 3rd mirror for changing the optical path direction of the light reflected from the 1st mirror, and wherein the original surface is exposed/scanned by moving the 1st carriage and the 2nd carriage at a velocity ratio of 2:1 in a sub scanning direction, the housing of the 2nd carriage is constituted by joining three members, that is, a front arm, a rear arm and a stay in a U-shape, and a sliding member sliding on a rail is constituted of a total of six sliding members, that is, four members arranged in four U-shaped corners, one member in the center part of the front arm, and one member in the center part of the rear arm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus such as a copying machine, a FAX, or a scanner.

For example, in the prior art disclosed in Patent Document 1, an exposure lamp that illuminates a document surface and a first carriage that has a first mirror that receives reflected light from the document surface, and an optical path direction of light reflected from the first mirror are described. A second carriage having a second mirror and a third mirror for changing, and exposing the document surface by moving the first carriage and the second carriage in the sub-scanning direction at a speed ratio of 2: 1. In the scanning image reading apparatus, the second carriage is configured such that the members of the arm portion (front and rear) and the stay portion are integrally formed in a substantially U shape, and sliding members are attached to the four corners thereof.
However, since the arm portion is long, there is a problem that the mirror position shifts due to some external force or its own weight. In addition, this also causes a problem that the scanner output image is not formed correctly.
JP 2002-328436 A

As described above, in the conventional image reading apparatus, there is a problem in that the member constituting the carriage that supports the mirror is deformed by some external force or its own weight and the mirror position is shifted and the scanner output image is not formed correctly. .
Accordingly, the present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a highly accurate image reading apparatus that is free from mirror position deviation.

In order to solve the above-described problems, according to the first aspect of the present invention, the housing of the second carriage includes a stay extending in the sub-scanning direction, and a front arm and a rear arm extending from both ends of the stay in the main scanning direction. It is configured by connecting two members in a U-shape, and sliding members for sliding on the rail are provided at the four corners of the U-shaped housing and at the central portion of the front arm, and at the central portion of the rear arm. One, a total of six, is arranged.
According to a second aspect of the present invention, there is provided an image forming apparatus that obtains an image obtained by developing an image read by the image reading device according to the first aspect by an electrophotographic method, transferring the image onto a sheet, and fixing the image. Main features.

According to the present invention, the exposure lamp for illuminating the document surface, the first carriage having the first mirror for receiving the reflected light from the document surface, and the second for changing the optical path direction of the light reflected from the first mirror. An image reading apparatus comprising: a second carriage having a mirror and a third mirror, wherein the document surface is exposed and scanned by moving the first carriage and the second carriage in a sub-scanning direction at a speed ratio of 2: 1 The housing of the second carriage is configured by connecting a stay 9A extending in the sub-scanning direction, and three members of a front arm 9b and a rear arm 9b extending from both ends of the stay 9A in the main scanning direction in a U-shape. A total of six sliding members for sliding on the rail are arranged, one at the four corners of the U-shaped housing and the central portion of the front arm, and one at the central portion of the rear arm. Therefore, it is possible to provide a highly accurate image reading apparatus that is free from mirror position deviation.
According to the present invention, since the image read using the image reading apparatus according to claim 1 is visualized by an electrophotographic method, transferred to a sheet, and fixed, the image is formed to obtain an image. Therefore, it is possible to provide a highly accurate image forming apparatus that is free from mirror position deviation.

Hereinafter, embodiments of a scanner device of the present invention will be described in detail with reference to the drawings. The present embodiment shows an application example to a flat bed type (original fixed type) scanner apparatus.
FIG. 1 is a longitudinal side view schematically showing an embodiment of a scanner device of the present invention.
First, the overall configuration of the scanner device will be schematically described. The scanner device 1 includes a housing-shaped scanner housing 3 having a contact glass 2 for placing a document on the upper surface. In the scanner housing 3, a xenon lamp (hereinafter referred to as an Xe lamp) 4 as a lamp and a first carriage 6 on which a first mirror 5 inclined at 45 ° is mounted, the angles formed by the reflecting surfaces at an inclination of 45 ° are orthogonal to each other. Then, a second carriage 9 on which a second mirror 7 and a third mirror 8 are mounted to invert the reading optical axis by 180 ° is provided.
The first and second carriages 6 and 9 are arranged with the main scanning direction (direction orthogonal to the paper surface in FIG. 1) as the longitudinal direction, and 2: 1 along the sub-scanning direction (left and right direction in FIG. 1). It is provided so that it can reciprocate at the speed ratio. The first and second carriages 6 and 9 when waiting for the reading of the document image are positioned at the home position at the left end portion in FIG. The Xe lamp 4, the first mirror 5, the second mirror 7, and the third mirror 8 are optical systems that scan along the original surface.
The Xe lamp 4 is provided with a reflector 18 that covers the side away from the contact glass 2 with the light reflecting surface in the axial direction so that a slit (aperture) is formed at a position facing the contact glass 2. . Thus, the light emitted from the Xe lamp 4 can be effectively used to improve the recycling efficiency of the light irradiated toward the contact glass 2. In the scanner housing 3, a sensor board on which a drive motor 10 by a stepping motor for reciprocating the first and second carriages 6 and 9 along the sub-scanning direction and a linear CCD 11 as a reading element are mounted. A lens block stay 14 and the like on which the unit 12 and the lens block 13 are mounted are provided. In addition, a width sensor 15 and a length sensor 16 that detect the size of the document placed on the contact glass 2 are provided on the bottom plate 3 a of the scanner housing 3.

Next, each part with which the scanner apparatus 1 is provided is demonstrated. 2 is a horizontal sectional view showing the internal structure of the scanner device 1, FIG. 3 is a longitudinal side view thereof, FIG. 4 is a perspective view showing each part provided in the scanner housing 3, and FIG. 5 is a perspective view showing a part thereof. FIG. 6 is an explanatory view schematically showing the direction of the force applied by locking and fixing the belt, and FIG. 7 is an explanatory view schematically showing the principle of the moving pulley regarding the moving operation of the first and second carriages 6 and 9. FIG.
Rail members 17 are attached to a pair of left and right side walls 3b (see FIG. 2) raised along the sub-scanning direction of the scanner housing 3. These rail members 17 have a U-shaped cross section, and as a result, rails 17a and 17b that face each other in the vertical direction are formed as a two-stage rail structure as shown in FIG. Hereinafter, the upper pair of rails will be referred to as a first rail 17a for the first carriage 6, and the lower pair of rails will be referred to as a second rail 17b for the second carriage 9.
In this way, by dividing the traveling sliding surfaces of the first and second carriages 6 and 9 as rails 17a and 17b, the positions of the first and second carriages 6 and 9 (in the home position state) can be brought closer, This is useful for reducing the overall size of the scanner device 1 to a necessary minimum.
As shown in FIG. 2, the wall 3c on the home position side raised in the main scanning direction of the scanner housing 3 is for restricting the movement of the second carriage 9 positioned at the home position in the vertical direction. The stopper 17c is integrally formed by a part of the wall 3c. These stoppers 17c are formed at positions corresponding to L-shaped arm portions 9c (see FIG. 5) formed on a mirror stay 9a (described later) of the second carriage 9. Sliders (not shown) are provided at the four corners of the lower surface of the first carriage 6, and these four sliders are brought into contact with the upper surface of the first rail 17a so that they can reciprocate along the sub-scanning direction. ing.

At both ends of the lower surface of the first carriage 6, endless type timing belts 21 extending along the sub-scanning direction are disposed over almost the entire length of the scanner housing 3. A part of the timing belt 21 is locked to the lower surface on the end side of the first carriage 6 by a belt clamp 6a (see FIGS. 3, 5 to 7) together with a part of a flat belt 30 described later. At this time, the shape of the belt clamp 6a is determined so that the heights of the locking portions of the timing belt 21 and the flat belt 30 with respect to the first carriage 6 are the same (horizontal state) (see FIG. 5). ).
When the timing belt 21 and the flat belt 30 are simultaneously locked in the same plane with respect to one belt clamp 6a, the first timing belt 21 and the flat belt 30 can be pressed against the rail 17a. Is slightly lifted and fastened to the first carriage 6 (see FIG. 6 schematically).
By doing so, the sliders attached to the lower four corners of the first carriage 6 can reliably contact and scan on the rail 17a, which is effective in preventing jitter in the read image. The first carriage 6 pulls the second carriage 9 in the scanning direction via the flat belt 30. Since the timing belt 21 and the flat belt 30 are fixed on the same plane, the first carriage 6 is attached to the first carriage 6. There is no rotational moment.
A part of each timing belt 21 is bridged over drive timing pulleys 23 fixed to both ends of the drive shaft 22 extending along the main scanning direction. The other part of each timing belt 21 is stretched over a driven timing pulley 24 attached to the scanner housing 3. The driven timing pulley 24 is urged in a direction away from the driving timing pulley 23 by a tension spring (not shown) spanned between the driven timing pulley 24 and the scanner housing 3. As a result, tension is applied to each timing belt 21 in the sub-scanning direction.
A drive transmission timing pulley 25 a is attached to one end of the drive shaft 22. The drive motor 10 described above is disposed on the side of the drive transmission timing pulley 25a. As shown in FIG. 3, a helical gear 10b is fixed on the drive shaft 10a of the drive motor 10, and meshes with the reduction gear 25b to rotate. A transmission timing pulley 25c is provided coaxially with the reduction gear 25b, and an endless type drive timing belt 26 is bridged between the transmission timing pulley 25c and the drive transmission timing pulley 25a. .
As a result, the driving force of the driving motor 10 is transmitted to the driving timing pulley 23 via the driving shaft 22. An iron disk is fixed to the drive shaft 10a on the rear side of the drive motor 10 in order to stabilize the rotation. A rubber damper for vibration isolation is arranged between the disturbance motor 10 and the motor bracket on the helical gear 10b side. The motor bracket is slidable to adjust the tension of the drive timing belt 26 described above, and is screwed after a predetermined tension is applied by a spring.
The second carriage 9 has a pair of mirror stays 9a that support both ends of the second and third mirrors 7 and 8, and an arm 9b that extends from both outer sides of the mirror stay 9a toward the first carriage 6 side. is doing. The extension length of the arm 9b is a length corresponding to the amount of movement of the second carriage 9 in the sub-scanning direction. Therefore, the second carriage 9 of the present embodiment is substantially U-shaped when viewed in plan. In such a second carriage 9, a flat pulley 27 that is rotatable along the surface direction of the mirror stay 9a is provided outside the mirror stay 9a. A bracket 28 for rotatably holding the flat pulley 29 is attached, and a flat belt 30 is bridged between the flat pulleys 27 and 29.

As shown in FIG. 9, the characteristic structure of the present invention is that the housing of the second carriage has a stay 9A extending in the sub-scanning direction, and a front arm 9b and a rear arm 9b extending from both ends of the stay 9A in the main scanning direction. The three members are combined in a U-shape, and there are one sliding member for sliding on the rail at the four corners of the U-shaped housing and the center of the front arm, and the center of the rear arm. There is a point where a total of six parts are arranged, one in each part. Therefore, it is possible to provide a highly accurate image reading apparatus that is free from mirror position deviation.
At this time, the flat pulleys 27, 29 and the like are arranged so that the flat belt 30 is slightly separated from the timing belt 21 in parallel when viewed in plan. The bracket 28 that supports the flat pulley 29 is slidable with respect to the arm 9b, and is attached with a predetermined tension from a spring (not shown). That is, the flat belt 30 does not need to transmit a driving force unlike the timing belt 21, so basically, if there is no slack between the flat pulleys 27 and 29, no tension is required. In order to prevent this from occurring, a weak tension of about several hundred gr is applied. Since the tension is weak as described above, the rotational load between the flat pulleys 27 and 29 and the shaft (the drive shaft 22 or the like) that rotatably supports the flat pulleys 27 and 29 is very small even without using the main bearing.

In addition, a total of six sliders (sliding members) are provided on the lower surface of the second carriage 9, one at each of the four corners and the central portion of the arm that are diagonal positions of the entire second carriage 9 ( 9), these six sliders are brought into contact with the upper surface of the second rail 17b so that they can reciprocate along the sub-scanning direction. As a result, the deformation of the arm is prevented, the mirror position is not displaced, and a highly accurate scanner image can be output.
The second carriage 9 is arranged so that each arm 9b is positioned on the inner peripheral side of the timing belt 21 (between the upper and lower timing belts 21 arranged substantially in parallel). At this time, the pair of flat belts 30 is positioned inside the pair of timing belts 21 in the main scanning direction.
A part of each flat belt 30 is fixed in position by being locked to a fixing member 31 fixed to the bottom plate 3 a of the scanner housing 3. The fixing position of the flat belt 30 by the fixing member 31 is set so as to be different from the position where the belt clamp 6a is engaged with the flat belt 30 of the first carriage 6 by substantially a half circumference. Since a portion of the flat belt 30 is fixed by the fixing member 31 as described above, the white of the flat belt 30 rotates even if the flat belt 30 is moved by following the timing belt 21 at the locking position by the belt clamp 6a. Without moving, it moves in the sub-scanning direction together with the flat pulleys 27 and 29 according to the principle of the moving pulley. Accordingly, the second carriage 9 that supports the flat pulleys 27 and 29 and the flat belt 30 also moves in the sub-scanning direction.
As described above, since the upper side of the flat belt 30 is locked to the first carriage 6 in a slightly lifted state, a force that can be lifted by the first carriage 6 acts on the second carriage 9. Yes. However, the lower side of the flat belt 30 is fixed at a slightly lower position by a fixing member 31 attached to the bottom plate 3a, and a force that pulls the second carriage 9 downward acts by the fixing member 31. (See FIG. 6 schematically).

In the present embodiment, the force by which the second carriage 9 is pulled upward by the first carriage 6 and the force by which the second carriage 9 is pulled downward by the fixing member 31, that is, the force acting up and down are made substantially equal. Thus, the second carriage 9 can scan while reliably contacting the rail 17b. As a result, it is possible to apply a downward urging force to the second carriage 9, and during reciprocation, the lower surface of the second carriage 9 is stably brought into contact with the second carriage 17 without being lifted from the second rail 17 b. And can be moved.
The scanning means 32 that scans the Xe lamp 4, the first mirror 5, the second mirror 7, and the third mirror 8 as an optical system along the document surface is a first unit on which the Xe lamp 4 and the first mirror 5 are mounted. A carriage 6, a second carriage 9 on which a second mirror 7 and a third mirror 8 are mounted, a rail 17 that slidably supports these carriages 6 and 9, a timing belt 21 driven by a drive motor 10, and a flat surface. The belt 30 and the fixing member 31 are used.
In such a scanner device 1, when reading a document image, the drive motor 10 is driven to reciprocate the first and second carriages 6 and 9 at a speed ratio of 2: 1, and the Xe lamp 4 is turned on. Then, the original image is exposed and scanned. As a result, the light emitted from the Xe lamp 4 is reflected by the original surface via the contact glass 2 and reaches the first mirror 5, and then is sequentially reflected by the second and third mirrors 7 and 8, and the lens. The original image is read by being condensed on the CCD 11 via the block 13.
Accordingly, it is possible to provide an image reading apparatus that can obtain a stable image without a change in illuminance of the original surface with time, and to provide an inexpensive image reading apparatus that is small and has high assembly work efficiency.

Next, an embodiment of a copying machine to which the present invention is applied will be described with reference to FIG. FIG. 8 is a longitudinal sectional side view schematically showing an embodiment of a copying machine. The copying machine 40 includes a scanner device 1 configured as described in the above-described embodiment, and a printer device 41 that forms an image of a document read by the scanner device 1 on a sheet.
In the printer device 41, paper from a paper feed tray 42 that stacks and holds sheet-like paper or a manual feed tray 43 that accepts manual paper to a discharged paper stacker unit 46 via a printer engine 44 and a fixing unit 45. A conveyance path 47 is formed.
In the present embodiment, an electron having a photoconductor (organic photoconductor in the present embodiment) 48 and a charger (not shown), an exposure device 50, a developing device 51, and a transfer device 52 provided around the photoconductor 48. A photographic printer engine 44 is used. In the printer device 41, a paper reversing mechanism 53 for reversing the paper on which an image is formed on one side is provided.
In such a configuration, the original image read by the scanner device 1 is imaged and developed on the photoconductor 48 by the printer device 41, transferred to the paper fed from the paper feed tray 42 or the manual feed tray 43, and The toner image transferred to the paper is fixed by the fixing unit 45. In these embodiments, application examples to a digital scanner including the CCD 11 as the scanner device 1 have been described. For example, the original image light reflected by the third mirror 8 is passed through an imaging lens, a reflection mirror, and the like. The present invention can also be applied to an analog copying machine that directly exposes a photosensitive member.

It is a vertical side view which shows roughly one Embodiment of a scanner apparatus. 2 is a horizontal sectional view showing an internal structure of the scanner device 1. FIG. It is a vertical side view of FIG. FIG. 4 is a perspective view showing each part provided in the scanner housing 3. It is a perspective view which shows a part of FIG. It is explanatory drawing which shows roughly the action direction of the force by latching and fixation of a belt. It is explanatory drawing which shows schematically the principle of the moving pulley about the movement operation | movement of the 1st, 2nd carriages 6 and 9. FIG. 1 is a longitudinal side view schematically showing an embodiment of a copier. FIG. FIG. 5 is an explanatory diagram illustrating a configuration of a housing of a second carriage 9.

Explanation of symbols

  6 First carriage, 7 Second mirror, 8 Third mirror, 9 Second carriage, 9A Stay in sub-scanning direction, 9a Mirror stay, 9b Arm in main scanning direction, 27 Flat pulley, 28 Bracket, 29 Flat pulley , 30 flat belt

Claims (2)

  A first carriage having an exposure lamp for illuminating the original surface and a first mirror for receiving light reflected from the original surface; a second mirror and a third mirror for changing the optical path direction of the light reflected from the first mirror; In an image reading apparatus that exposes and scans the document surface by moving the first carriage and the second carriage in a sub-scanning direction at a speed ratio of 2: 1, The case is composed of a stay extending in the sub-scanning direction, and a front arm and a rear arm extending in the main scanning direction from both ends of the stay in a U-shape, and is a slide for sliding on the rail. An image reading apparatus, wherein six moving members are arranged, one at the four corners of the U-shaped casing and the central portion of the front arm and one at the central portion of the rear arm.   An image forming apparatus characterized in that an image read using the image reading apparatus according to claim 1 is visualized by an electrophotographic method, transferred to a sheet, and then fixed to obtain an image.

Images