JP2002064678A - Reader, image processing system with reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a distortion in read image to a minimum in an image processing system, by preventing oscillation of a running body on one guide rail side with a larger influence of oscillation out of a pair of guide rails at acceleration. SOLUTION: A carriage 30 is supported on a pair of guide rails 33a and 33b with guiding members 32a and 32b on four corners. On the assumption that one out of four points may be floated, the guiding member 32a on a driving system side, to which the driving force is transmitted faster, (when the guiding member on the reference side of drive is floated, large distortion of image is caused) is prevented from floating. A light emitting driving circuit board (including an inverter) 12 is mounted on a carriage, and the position thereof is put nearer to the driving motor side from the optical center and for achieving the purpose, the center of gravity is dislocated to the driving motor side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading apparatus which can be used in copying machines (analog and digital copying machines), scanners, and the like. And a reading device configured to slide the reading device.

[0002]

2. Description of the Related Art A reading device provided in a conventional image scanner device places a document on a platen, and scans the placed document surface by a reading means mounted on a carriage, and displays the document on the document surface. Reads image information such as graphics and characters. In such an apparatus, a lens and a photoelectric conversion unit (consisting of a CCD reading and an output processing circuit) among the elements constituting the photoelectric reading means are fixedly installed on the frame side of the apparatus, and the surface of the document to be scanned is fixed. An optical system such as a light source (lamp) and a mirror for transmitting an image to a lens and a photoelectric conversion unit is separately mounted on two carriages that slide on a guide surface of a guide rail, and the first carriage is mounted on a document surface. In general, a two-carriage system is used in which scanning is performed at a scanning (scanning) speed and the second carriage is moved at half the speed. The relationship between the speeds of the first and second carriages is a condition for keeping the distance (conjugate length) from the document surface to the CCD constant (see FIG. 1 described later).

In the above-mentioned image scanner, as means for driving two carriages,
Conventionally, a method using a wire is known (see FIG. 2). In this drive mechanism of the wire system, a wire is wound around a drive pulley attached to a drive shaft driven by a motor, and the drive force is transmitted. After being wound around the driving pulley a plurality of times, each end of the wire is wound around and fixed to the pulley of the second carriage via driven pulleys provided on both left and right sides. The first carriage is fixed to the wire crawled in this manner, and the fixed first carriage is driven at the linear speed of the wire in accordance with the input from the drive shaft, moves, and travels for reading and scanning. Also, the second
The carriage moves accurately at half the linear speed of the wire because the pulley serves as a moving pulley. Each carriage driven by the wire method is supported by sliding members provided at both ends of the carriage on guide rails provided on both sides of the read image with the read image interposed therebetween. A system corresponding to each guide rail via a transmission mechanism (a wire or the like) transmits the driving force, that is, each end of the carriage is pulled through a wire wound around a drive pulley provided at each end of the drive shaft. The drive is performed by transmitting the driving force to the carriage while being divided into the wire drive systems described above, and slides on the guide rail. At this time, the sliding member supports the carriage at three points and travels along the plane of the guide rail, so that correct operation is theoretically guaranteed. However, in actuality, the sliding force is generated by the driving force of the wire and the sliding member. When an acceleration acts, such as during running acceleration, when a resistance force acts on the carriage, a rotational moment acts on the carriage to generate a run-out such as an inclination of the carriage at one point.

[0004]

In order to prevent the occurrence of run-out occurring at the time of traveling, a sliding member is provided at four places, and the sliding member is designed to be supported at four points. By selecting the position where the force acts, the moment generated by the driving force and the rotational moment by the resistance force generated by the sliding member are balanced to cancel the rotational moment, so that the occurrence of runout can be prevented to some extent. it can. However, in practice, it is not possible to design as calculated, and in practice, it is not possible to completely eliminate vibration. The present invention provides a guide rail provided on both sides of an object to be read, a traveling body equipped with reading means that slides on the guide surface of the guide rail, and a driving force from a driving source applied to the traveling body via a transmission mechanism. The present invention has been made in view of the above-described problems in a conventional reading device including a traveling body driving unit that separately transmits a system corresponding to a guide rail. Even when run-out occurs, the guide rail on the side where the effect of the run-out greatly appears in the reading result,
That is, a reading device and an image provided with the reading device, in which the guide rail on the drive system side to which the driving force is transmitted earlier is prevented from swaying and distortion of a read image can be minimized. An object of the present invention is to provide a processing device.

[0005]

According to a first aspect of the present invention, there is provided a traveling body having a guide rail provided on both sides of an object to be read, a sliding member in contact with a guide surface of the guide rail, and having a reading means, A driving unit that slides the traveling body by transmitting a driving force from a driving source to a traveling body by dividing the driving force into a system corresponding to each guide rail via a transmission mechanism; A plurality of drive rails are provided for each guide rail along the moving direction, and the running body is supported on the guide surface by the sliding member, and the center of gravity of the running body is transmitted to the driving system from the driving source more quickly. A reading device, which is biased toward the guide rail.

According to a second aspect of the present invention, in the reading device according to the first aspect, the sliding member is provided at four corners of the traveling body.

According to a third aspect of the present invention, in the reading device according to the first or second aspect, a lamp and a driving circuit board for the lamp are mounted on the traveling body, and the deviation of the center of gravity of the traveling body is driven by the lamp. The method is characterized in that it is performed by disposing a circuit board.

According to a fourth aspect of the present invention, there is provided an image processing apparatus comprising the reading device according to any one of the first to third aspects.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on the following embodiments shown in the accompanying drawings. FIG. 1 is a diagram illustrating a schematic configuration of an image reading apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an image reading apparatus main body.
On the upper surface of the image reading device 1, a contact glass 20 on which a read document is placed is provided. Contact glass 2
The image surface of the original placed on the
Is exposed and scanned from the lower surface side of the. For exposure scanning, a pair of guide rails 33a and 33b are provided in the image reading apparatus 1 on both sides of the document in parallel with the contact glass 20, and the first guide rails 33a and 33b are provided on the guide surfaces of the guide rails 33a and 33b.
The traveling body 23 and the second traveling body 25 are slid. For this purpose, the first carriage 30 of the first traveling body 23 and the second carriage 31 of the second traveling body 25 are provided with sliding members 32a and 32b which are in sliding contact with the guide surfaces. Sliding member 32
The guide rails a and 32b are provided at two places along the running direction with respect to the guide rails 33a and 33b, that is, at four corners of each carriage. Further, the lamp 21 and the first mirror 22 are mounted on the first carriage 30 of the first traveling body 23,
The first mirror 22 is mounted on the second carriage 31 of the second traveling body 25.
And the second and third mirrors 24 that turn back the reflected light of the second direction. The first carriage 30 is provided with a light emission drive circuit board 12 for driving the lamp 21. An optical imaging lens 26 that converges the reflected light and forms an image on the optical path of the reflected light from the original folded by the second and third mirrors 24.
At the image forming position, a photoelectric conversion element 27 composed of, for example, a CCD for reading the image of the formed document is provided.

Next, a description will be given of a driving mechanism of a traveling body which is slid to perform exposure scanning. FIG. 2 is a diagram illustrating a driving mechanism of the traveling body (carriage) of the present embodiment. FIG.
The example shown in the figure shows a drive mechanism using a wire system.
Driving wire 15 with both ends of the carriage stretched individually
a, 15b. However,
The drive wires 15a and 15b are driven by a single drive motor 11 in synchronization via a common drive shaft 14. Further, since the input of the driving force from the driving motor 11 is performed from one end of the driving shaft 14, each driving wire 15
The transmission of the driving force to the motors a and 15b is delayed. That is, each carriage 30,
The driving force is transmitted to 31. Each drive wire 15a, 15
b is wound around the drive pulleys 17a, 17b attached to both ends of the drive shaft 14 driven by the drive motor 11 a plurality of times, respectively, and then driven pulleys 19a, 19a, 1 fixed to the left and right of the moving range of the carriage, respectively.
Wrap around 9b, 19b. Further, the second carriage 3
After each end of the drive wire is wound around each of the pulleys 16a and 16b provided at both ends of
3a and 13b, and the other end is tensioned by springs 18a and 18b, respectively. The driving wires 15a, 15 thus stretched around
b, the end of the first carriage 30 is fixed, and the fixed first carriage 30 moves and runs at the linear velocity of the drive wires 15a and 15b according to the input from the drive shaft 14. The second carriage 31 is provided with pulleys 16 provided at both ends.
a, 16b serve as a pulley, so that the drive wire 15
It moves accurately at 1/2 of the linear velocity of a, 15b. By moving each of the carriages 30 and 31 at such a speed, the distance (conjugate length) from the document surface to the photoelectric conversion element 27 is obtained.
Is constant, and a constant read image accuracy can be secured.

Next, details of the first traveling body 23 of this embodiment will be described. FIG. 3 is a diagram illustrating a schematic configuration of the first traveling body (carriage) 23 of the present embodiment. Referring to FIG. 3, a sliding member 3 is provided on a pair of guide rails 33a and 33b.
2a, 32b, the first carriage 30 (normally 15 carriages).
0-300 g). Since the guide surfaces of the guide rails 33a and 33b are positioned with respect to the optical center, the geometrical optical conditions of the lamp 21 and the first mirror 22 on the first carriage 30 are three points by the sliding members 32a and 32b. If supported, optimal conditions should be obtained, but as described above, there is a problem that the one-point support side of the carriage is inclined during acceleration traveling. Therefore, four-point support is employed. In this embodiment, as shown in FIG. 3, sliding members 32a and 32b are provided at four corners of the first carriage 30, and the carriage is supported at four points. In the case of four-point support, it is assumed that one of the four points rises due to the moment applied during acceleration running. In this embodiment, when it is assumed that such a floating occurs, the sliding member 32a on the drive system side (hereinafter referred to as “drive motor side”) to which the driving force from the drive motor 11 is transmitted more quickly does not float. To do.
The reason why the sliding member 32a on the drive motor side is prevented from floating is that the drive motor side is a reference for driving, and if the sliding member 32a on this side floats, it greatly affects image distortion. Because.

In order to prevent the sliding member 32a on the drive motor side from rising, the present invention is configured such that the center of gravity of the carriage is biased toward the drive motor side, that is, on the guide rail 33a side. As a method of shifting the center of gravity, it is possible to add a weight to the drive motor side. However, the method is performed without adding new components, that is, by considering the arrangement of existing elements. In this embodiment,
As shown in FIG. 3, an example applied to the first carriage 30 is shown. The first carriage 30 has a lamp 21 and a first mirror 22 (not shown in FIG. 3) mounted thereon, but these elements are provided over the entire width of the reading area. Deviation cannot be performed by these factors. Therefore, the light emission drive circuit board 12 that drives the lamp 21 is used as an element that functions to change the center of gravity. That is, the light emission drive circuit board 12 is mounted on the first carriage 30, and its arrangement is shifted toward the drive motor side from the optical center, so that the center of gravity of the carriage is brought to the drive motor side.
The light emission drive circuit board 12 includes an inverter (ballast) and usually has a weight of 50 to 150 g, and thus can have a function of changing the center of gravity. By arranging the light-emitting drive circuit board 12 in this way, the above-described function can be realized, and additional components such as weights (balancers) are not required for the first carriage again, so that component costs can be reduced.

[0013]

(1) Effects corresponding to the first and second aspects of the invention: a traveling body having guide rails provided on both sides of an object to be read, and reading means for sliding on a guide surface of the guide rail; In a reading device having traveling body driving means for transmitting a driving force from a driving source to a body through a transmission mechanism in a system corresponding to each guide rail, a plurality of sliding members (traveling The traveling body is supported on the guide rails via sliding members provided at the four corners of the body, and the center of gravity of the traveling body is biased toward the drive system to which the driving force from the driving source is transmitted more quickly. When the sliding member is lifted during acceleration running, the sliding member on the side serving as the drive reference is not lifted, and the other sliding member is lifted. Etc.) to a minimum Door can be. (2) Effects corresponding to the third aspect of the invention In addition to the effects of the above (1), a lamp and a driving circuit board for the lamp are mounted on the traveling body, and the deviation of the center of gravity of the traveling body is adjusted by the By performing the positioning, the lamp and the driving circuit board of the lamp, which are necessary elements for the reading apparatus using the optical reading means, do not need to design the structure of the traveling body in order to shift the position of the center of gravity. The invention of claim 1 or 2 can be carried out easily and without increasing the cost by selecting the arrangement. (3) Effects corresponding to the invention of claim 4 By using the reading device according to any one of claims 1 to 3 as a component of an image processing device, the effects of the above (1) and (2) can be obtained by a scanner. This can be realized in an image processing apparatus such as a copying machine and a facsimile, and the performance of the apparatus can be improved.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a driving mechanism of a traveling body (carriage) in the image reading apparatus according to the embodiment.

FIG. 3 is a diagram illustrating a schematic configuration of a first traveling body (carriage) in the image reading apparatus of the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image reading device, 11 ... Drive motor, 1
2 ... light emission drive circuit board 14 ... drive shaft 15 ...
Drive wire, 16 pulley, 17 drive pulley, 19 driven pulley, 20 contact glass, 21 lamp, 22 first mirror, 23 first traveling body, 25 second traveling body, 30 first Carriage, 31 ... second
Carriage, 32a, 32b ... sliding member, 3
3a, 33b ... guide rails.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5B047 AA01 BA02 BB02 BC01 BC04 BC11 CA07 5C051 AA01 BA03 DB01 DB04 DB22 DB24 DB28 DC01 DC05 DC07 DE09 FA01 5C072 AA01 BA13 BA17 CA09 DA02 DA04 DA21 EA05 MA02 MA05 MA06 XA01

Claims (4)

[Claims] 1. A traveling body having a guide rail provided on both sides of an object to be read, a sliding member in contact with a guide surface of the guide rail, and having a reading unit, and a driving force from a driving source through a transmission mechanism. And a driving unit that slides the traveling body by transmitting the traveling member to the traveling body in a system corresponding to each guide rail, wherein the sliding member is moved along the moving direction with respect to each guide rail. A plurality of the sliding members support the traveling body on the guide surface by the sliding member, and the center of gravity of the traveling body is biased toward the guide rail side of the drive system to which the driving force from the driving source is transmitted more quickly. Reading device. 2. The reading device according to claim 1, wherein the sliding member is provided at four corners of a traveling body. 3. The reading device according to claim 1, wherein a lamp and a driving circuit board for the lamp are mounted on the traveling body, and the deviation of the center of gravity of the traveling body is adjusted by an arrangement of the driving circuit board for the lamp. A reading device. 4. An image processing apparatus comprising the reading device according to claim 1. Description: