JPH04336855A - Driver for scanner - Google Patents

Abstract

PURPOSE:To form a margin in the inside of a frame of the scanner and to prevent the effect of load fluctuation from being caused in the driver for driving two carriages by arranging a photoelectric conversion means to a lower part of a home position of the full rate carriages. CONSTITUTION:A wire 41 is provided to a scanning member comprising a full rate carriage 10 and a half rate carriage 20, the full rate carriage 10 is fixed to the wire 41 and the half rate carriage 20 is arranged thereto via pulleys 56, 56a. The end of the wire 41 is connected to a support bracket 45 is a resistance provision guide 43 and a spring 42, the bracket 45 is arranged at the outside of the driver to adjust the wire tension. The wire 41 is tensed to an idler pulley 52 and a capstan pulley 51 arranged at both sides of the driver and a drive shaft 50 is driven to move the carriage in a scanning direction X and a return direction Y.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device such as an electronic copying machine, and more particularly, the present invention relates to an image reading device such as an electronic copying machine, and more particularly, a photoelectric conversion means is disposed at the home position of a full rate carriage, and a half rate transducer is positioned upstream in the scanning direction of the full rate carriage. The present invention relates to a scanning device configured to use a rate carriage to reflect scanning light from a full rate carriage toward photoelectric conversion means.

0002

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a scanning device consisting of a full rate carriage and a half rate carriage is arranged along the lower surface of a platen on which a document is placed. Then, the light scanned by the full rate carriage is condensed through a lens and irradiated onto a photoreceptor drum etc. through another mirror to form an electrostatic latent image on the photoreceptor drum. ing. As an image forming apparatus provided with the above-mentioned scanning means, for example, an apparatus such as that disclosed in Japanese Patent Application Laid-Open No. 64-72178 is used. In the conventional scanning device, wires are arranged on both sides of the full rate carriage and the half rate carriage, and the scanning member is moved by interlocking and driving the wires, as in the case of a general image forming device. An image of a document placed on a platen is scanned, and the scanned light is irradiated toward a photoreceptor drum to form an electrostatic latent image on the photoreceptor drum.

In addition to the apparatus that uses the method of directly irradiating the scanning light onto the photoreceptor drum as shown in the above-mentioned conventional example, there is also an apparatus that uses the method of directly irradiating the photoreceptor drum with scanning light, as shown in Japanese Utility Model Application Publication No. 35365/1983, etc. In some cases, a means for inputting the signal into a photoelectric conversion means and outputting it as an electric signal from the photoelectric conversion means may be used. Then, using the image signal output from the photoelectric conversion means, a laser beam is output from a digital writing device to write an image on the photoreceptor drum.

[0004] Also, in the scanning device used in the digital image forming apparatus, as in the case of the optical scanning device, a half-rate carriage is used as opposed to a full-rate carriage that moves along the lower surface of the platen. The drive mechanism is configured to move in the same direction at half the speed. Therefore, in both of the above two methods, the half-rate carriage forming the scanning system moves in a state downstream of the full-rate carriage in the scanning direction, and follows the full-rate carriage in the scanning direction; The light that scans the original is reflected by a large number of mirrors provided on each carriage, and is transmitted toward the photosensitive drum or photoelectric conversion means.

Furthermore, in the case of the above-mentioned scanning device, while the full-rate carriage scans the entire surface of the document placed on the platen, the half-rate carriage only moves back and forth in half of that area. In addition to the two carriages, a lens device is arranged in the center of the optical path, and a mirror, photoelectric conversion means, etc. are arranged in a portion out of the movement area of the half-rate carriage. Therefore, inside the frame of the scanning device, all the constituent members are arranged in a uniformly distributed state, so that maintenance and the like of each member can be easily performed.

[0006] In the scanning device, a driving device as shown in FIG. 8, for example, may be used to drive the two carriages. In the drive device 40 shown in FIG. 8, one wire 41 is used, and the wire 4
1 is fixed to a full rate carriage 10, wound around a pulley provided on a half rate carriage 20, and the wire is driven via a capstan pulley 51. Further, the wire is wound around idler pulleys 52 and 53 arranged at both ends in the scanning direction of the carriage, one end of the wire is fixed via a spring 42, and the other end is attached to the frame. It is fixed to the provided support member. By driving the capstan pulley 51 in the forward and reverse directions, the carriage is driven in the scanning direction There is.

[0007]

However, in the drive device shown in FIG. 8, when the wire stretches, the two carriages move toward each other, and the There is a problem in that the length of the optical path changes. In addition, with the wire arrangement shown in the conventional example, when the carriage returns, a large force is instantaneously applied to the half-rate carriage, stretching the spring and applying pressure to the motor that drives the capstan pulley. Load torque may fluctuate. Then, as the load torque on the drive motor fluctuates, the motor is likely to step out, and the movement speed of the carriage fluctuates, causing problems such as disturbances in the read image.

Furthermore, in the drive mechanism of the conventional scanning device, the spring disposed at one end of the wire is
When fixed to the end of the frame of the scanning device, it was placed inside the frame and fixed to the locking member. Therefore, when adjusting the elongation of the wire, it is necessary to remove the platen installed at the top of the scanning device and put your hand inside the frame to adjust the wire, which is relatively difficult. The problem was that it was troublesome. In addition, when the wire is stretched several millimeters, it is very difficult to adjust the length of the wire minutely in order to keep the wire tension constant.

[0009] Furthermore, in the conventional scanning device as described above, it is difficult to perform maintenance from above, for example, on the constituent members of the copying machine body located below the scanning device, especially the writing device, etc. There is a problem that. For example, when performing maintenance on the writing device of the copying machine main body, it is necessary to remove the scanning device from the copying machine main body, open the upper frame of the copying machine, and perform other troublesome tasks. Further, in the case of a digital type electronic copying machine, maintenance is often required for the motor that drives the polygon mirror of the writing device, and such work is troublesome. However, in conventional image forming apparatuses using digital methods, there are problems such as the need to move the upper scanning means when performing maintenance on the writing device.

0010

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the conventional scanning means as described above, and aims to reduce fluctuations in the relative position of two carriages due to wire elongation, etc. It is an object of the present invention to provide a device that can prevent a drive motor from being affected by load fluctuations due to tension of a spring.

[0011]

[Means for Solving the Problems and Effects] The present invention scans the image of the original by moving a scanning means composed of a full-rate carriage and a half-rate carriage along the lower surface of a platen on which an original is placed. a scanning means for carrying out;
The half-rate carriage constituting the scanning means is disposed below the home position of the full-rate carriage, and is provided with a means for outputting image information as an electrical signal using a photoelectric conversion means. It is configured to be moved upstream. Further, in the present invention, means is provided for reflecting the light scanned by the scanning means to the photoelectric conversion means via a mirror provided on the half-rate carriage, and the two carriages are driven using wires on both sides. , one end of the wire is connected to a fixed position on the home position side, and the other end is attached via a spring and means for providing resistance to the wire. Furthermore, means for fixing one end of the wire that drives the carriage of the present invention via a support bracket outside the frame of the scanning device is provided, and by finely adjusting the attachment position of the support bracket, the elongation of the wire can be avoided. It will be possible to make it correspond.

With the configuration described above, in the drive device of the scanning device of the present invention, it is possible to suppress fluctuations in the load on the drive motor when the carriage returns, so that the scanning speed may be reduced due to motor loss of synchronization, etc. can be prevented from fluctuating. Furthermore, by arranging the member that supports the end of the wire outside the frame, it becomes possible to easily adjust the wire tension and the like. Furthermore, by using the driving method of the present invention, the conjugate length of the optical path set by the mirrors provided on the two carriages does not change, so it is possible to maintain good image quality of the read image.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A driving device for a scanning device according to the present invention will be described with reference to the illustrated example. In the present invention, as shown in FIGS. 1 and 2, two carriages, a full rate carriage 10 and a half rate carriage 20, are
It is configured to be driven by one wire 41,
The wires are placed on both sides of the two carriages of the scanning device.
They are arranged in parallel and are provided to be driven in conjunction with each other. The wire 41 has one end fixed to a support member 58 and the other end fixed to a support bracket 45 via a spring 42.
It is attached to. The wires 41 are arranged in the direction of movement (scanning) of the carriage on both sides of the frame of the scanning device.
A capstan pulley 51 provided on the drive shaft 50 and supported by idler pulleys 52 and 53 arranged at its front and rear ends.
Driven through. Also, full rate carriage 10
For the half-rate carriage 20, it is fixed by a fixing part 57, and for the half-rate carriage 20, it is wound around pulleys 56 and 56a. By driving the capstan pulley 51 in the forward and reverse directions, the two carriages are
They are driven in conjunction with each other in the scanning direction X and the return direction Y to scan the image of the original.

A spring 42 supporting one end of the wire 41 is engaged with a support bracket 45 disposed outside the frame of the scanning device.
The wire 41 whose end is locked is connected to the resistance imparting guide 43
It is guided in a bent state through the. The two members supporting the ends of the wire are configured as shown in FIGS. 3 and 4. The resistance imparting guide 43 shown in FIG. 3 has a V-shaped groove 44 provided in its main body.
As illustrated in FIG.
so that it slides. The frictional resistance between the wire and the guide prevents the spring from being strongly pulled by the wire even if a large tension is applied to the wire.

A support bracket 45 for locking the end of the wire 41 guided through the resistance applying guide 43 via a spring 42 is a locking bracket protruding from the main body as shown in FIG. Claws 47, 47a are provided, and the end of the spring 42 is engaged with the claws. Further, the main body of the bracket 45 is provided with a long hole 46, and the bracket 45 is fixedly held on the outside of the main body frame using a screw member or the like through the long hole 46. Therefore, if the wire stretches during use of the device, the extension of the wire can be adjusted simply by slightly moving the support bracket 45, and the length of the wire can be adjusted. Work can easily be done outside the frame.

[0016] When scanning an image of a document in the driving device of the scanning device of the present invention configured as described above,
The capstan pulley 51 is driven counterclockwise in the figure, and the full rate carriage 10 and the half rate carriage 20 are moved.
and are set to respective predetermined moving speeds and driven in the scanning direction X. Furthermore, when driving the capstan pulley 51 clockwise in the figure, the two carriages are moved in the return direction Y. Therefore, when driving the carriage in the return direction, even if a large tension is applied to the portion of the wire held by the spring 42, resistance is applied by the resistance applying guide 43, so that the wire is Rather than pulling the spring strongly, the spring can be stretched only a little. In addition, when the wire is stretched as shown in the drawings of the present invention, even if the wire stretches, the stretch of the wire moves the full rate carriage and the half rate carriage in the same direction. Therefore, there is little change in the conjugate length of the optical path.

In the carriage of the present invention constructed as described above, the full rate carriage is constructed as shown in the front view of FIG. 5 and the side view of FIG. 6. In the full rate carriage 10 shown in FIGS. 5 and 6,
A lamp 12 and two reflectors 13, 13a are arranged on the upper part of the frame 11, and a mirror 15 is supported by a lower frame 16 projecting from the lower part of the frame 1. The light from which the image of the document is scanned by the lamp 12 is transmitted to the mirror 15 through the slit 14 provided in the frame 11, and is transmitted to the mirror 15 of the half-rate carriage disposed upstream in the direction of movement of the carriage during scanning. It forms an optical path that reflects light. Further, wire connecting members 17, 17 are arranged at the lower part of the frame 11 of the full rate carriage 10 on both sides of the lower frame 16, and the wire 41 is fixed to these members.

The rail member 30 for guiding the full-rate carriage 10 is formed by bending a sheet metal, and is formed by integrally forming an upper rail 31 and a lower rail 32. Then, the slide protrusion 35 is slid on the upper part of the upper rail 31, and the leaf spring 36 is arranged on the lower surface of the rail 31, and the full rate carriage is guided while pressing the rail from above and below. The lower rail member 32 of the rail member 30 guides the bracket 23 which is arranged to protrude from the side of the half-rate carriage 20, and slides the slide protrusion 24 which protrudes from the lower part of the bracket 23. That's what I do. In addition, in the scanning device of the present invention, the two carriages are moved in the same direction, but even at the end of the scan, the two carriages move in the same direction. is in a state where a certain interval is left. Therefore, even if the guide surfaces of the rail members for moving the two carriages are very close to each other, the carriages will not come into contact with each other.

The carriage of the present invention having the above-described configuration can be applied to a scanning device as shown in FIG. The scanning device 5 shown in FIG. 7 is disposed at the top of the digital type electronic copying machine 1, and converts light from an image of a document placed on a platen 7 into a photoelectric conversion means 26.
The signal is output as an electrical signal and transmitted to the control device of the electronic copying machine 1 via the connecting wire 9. In the electronic copying machine 1, the image signal is transmitted to the laser beam output means of the writing device 3, and the light from the writing device 3 is outputted toward the photosensitive drum 2. In addition,
Around the photoreceptor drum 2 of the electronic copying machine 1, in addition to devices such as a charging device, a developing device, and a cleaning device, there are also devices such as a charging device, a developing device, a cleaning device, etc., as well as a toner image formed on the photoreceptor drum, as in the case of a general electronic copying machine. A device capable of making a copy is constructed by providing means for transferring it to paper, but the copy making mechanism is omitted in FIG. 7.

The scanning device 5 disposed at the top of the copying machine main body has a platen 7 disposed at the top of the frame 6, scans the image of the document set on the platen 7 with a full rate carriage 10, and converts the light into half. The two mirrors provided on the rate carriage 20 reflect the light toward the lens 25 . Then, the light collected by the lens is
The light is made incident on a photoelectric conversion means 26 constituted by a CD, and outputted as an electrical signal. In the embodiment described above, since the photoelectric conversion means 26 is disposed below the home position of the full rate carriage 10, the cooling air sent from the fan 4 disposed on the side of the copying machine main body 1 can be used for photoelectric conversion. Means 26 and full rate carriage 1
0 can be cooled at the same time, and the configuration of the cooling system can be simplified. Furthermore, since the frame of the scanning device 5 is mounted on the upper part of the copying machine main body 1 via elastic leg members 8, vibrations generated in each of the two devices are transmitted to the other device. can be prevented from being
It is possible to prevent the effects of vibrations from other devices from exerting influence when performing the respective operations of reading and writing images of a document.

Further, as shown in FIG. 7, in the scanning device 5 of the present invention, the half-rate carriage 10
is moved from the center inside the frame toward the right side in the figure, and the full-rate carriage 10, which moves over the entire lower surface of the platen 7, never comes into contact with the half-rate carriage 20. Then, when the full rate carriage 10 is returned to the home position, the half rate carriage 20 will be located approximately in the center of the frame, so the right half area of the frame will be left as a space. Become. Therefore, for example,
When performing maintenance on the writing device 3 of the copying machine main body, the upper parts of the electronic copying machine can be easily inspected from the top of the device by removing the platen 7 of the scanning device and removing the upper cover of the writing device 3. You can do it.

[0022]

[Effects of the Invention] By providing a wire-based drive system configured as described above, the present invention can suppress fluctuations in the load on the drive motor when the carriage returns, and reduce the scanning speed due to motor loss of synchronization. can be prevented from fluctuating. Further, by arranging the member that supports the end of the wire and the spring outside the frame, it becomes possible to easily adjust the elongation of the wire. Furthermore, by using the drive method of the present invention,
Since there is little change in the conjugate length of the optical path set by the mirrors provided on the two carriages, it is possible to maintain good image quality of the read image.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a drive system of a scanning device according to the present invention.

FIG. 2 is a perspective view showing the configuration of a drive system of the scanning device of the present invention.

FIG. 3 is a side view of the resistance imparting guide of the present invention.

FIG. 4 is a perspective view of the support bracket of the present invention.

FIG. 5 is a front view of the full rate carriage.

FIG. 6 is a side view of the full rate carriage.

FIG. 7 is an explanatory diagram of an image forming apparatus to which the scanning device of the present invention can be applied.

FIG. 8 is an explanatory diagram of a drive system in a conventional scanning device.

[Explanation of symbols]

1 copying machine, 3 writing device, 5
Scanning device, 6 frames, 7
platen, 10 full rate carriage,
12 lamp, 17 wire connection member,
20 Half-rate carriage, 23
Bracket, 24 Slide protrusion, 25
Lens, 26 Photoelectric conversion means, 30
Rail member, 31 Upper rail, 3
2 Lower rail, 35 Slide protrusion, 37
Presser, 40 Drive device, 41
Wire, 42 Spring, 43
resistance imparting guide, 45 support bracket,
50 Drive shaft, 51 Capstan pulley, 52.
53 Idler pulley.

Claims (1)

[Claims] 1. Scanning means for scanning an image of a document by moving a scanning device consisting of a full rate carriage and a half rate carriage along the lower surface of a platen on which a document is placed, and a home for the full rate carriage. A means for outputting image information as an electric signal is provided at a lower position of the position, using a photoelectric conversion means, and the half-rate carriage constituting the scanning means is moved upstream in the scanning direction with respect to the full-rate carriage. A means is provided for reflecting the light scanned by the scanning means to the photoelectric conversion means via a mirror provided on the half-rate carriage, and the two carriages are driven using wires on both sides, and A driving device for a scanning device, characterized in that one end of the wire is connected to a fixed position on the home position side, and the other end is attached via a spring and means for applying resistance to the wire.