JP2001144897A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the positions of carriages by adjusting the positions of driving pulleys with respect to a driving shaft in a scanner for driving a full rate carriage and a half rate carriage by the two driving pulleys provided on the single driving shaft. SOLUTION: Two driving pulleys of a large diameter driving pulley 20 and a small diameter driving pulley 25 are arranged on a driving shaft 7 respectively driving a full rate carriage 11 and a half rate carriage 15, and belts 8 and 9 are arranged at the respective pulleys. The two pulleys 20 and 25 are attachably and detachably supported by the shaft 7 by using fixing screws 23 and 28. After loosening the screws, the carriages are moved and after rotating the pulleys by a portion equivalent to the length of the belts moved with respect to the shaft 7, the carriages can be fixed to the driving shaft with the screws again to be set in an operating state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for two carriages arranged in a scanning section of an image reading apparatus, and more particularly, to adjusting a stop position of a pulley on which a belt for driving a carriage is mounted with respect to a driving shaft. It relates to a device that can be easily performed.

[0002]

2. Description of the Related Art In an image reading apparatus provided in combination with an image forming apparatus such as a facsimile apparatus or a copying machine, a scanning apparatus is arranged along the lower surface of a platen on which an original is set, and the scanning apparatus is moved in a sub-scanning direction. It is provided as possible. The scanning device includes a full-rate carriage (first scanning body) provided with a lamp as a light source and a first mirror;
A half-rate carriage (second scanning body) provided with two mirrors (second and third mirrors) is configured to move the half-rate carriage at half speed following the movement of the full-rate carriage. ing. Then, the light of a lamp provided on the full-rate carriage is irradiated on the image surface of the original, the reflected light is reflected via a plurality of mirrors and the like, and the image is formed by a lens toward photoelectric conversion means such as a CCD. The optical signal is converted into an electric signal, and the CCD outputs an image signal as a digital signal. In addition to using the digital signal as a transmission signal of a facsimile machine, in a copying machine, an image recording unit transmits the digital signal to a writing unit to use the photoconductor to write optical information.

[0003]

The two carriages arranged in the scanning device are slid on guide rail members provided in the main body frame so as to be movable at the time of reading an image of a document. In order to transmit the drive to the carriage, a drive transmission means such as a wire or a timing belt is used. In an example in which a timing belt is used as the driving unit, it may be necessary to adjust the position of the two carriages. In this case, the position adjustment is performed by adjusting the belt gripping and fixing position of the carriage. Adjusting the position of the carriage is performed, for example, when a slight deviation occurs in the optical path length between the two carriages. Fine adjustment is performed to clarify the image quality of the read image. Is required. However, after releasing the fixing of the belt gripping means provided on the carriage, the operation of moving the carriage and fixing it again at the adjusted position needs to be performed with the platen glass removed, and the delicate position of the carriage is required. When making adjustments,
There is a drawback that a heavy burden is imposed on maintenance workers.

In order to adjust the position of the carriage as described above, the present invention can be easily performed by adjusting the fixed position of the pulley on which the belt is wound with respect to the drive shaft, and the drive transmission of the pulley to the belt is adjusted. It is an object of the present invention to provide a device that can improve reliability.

[0005]

SUMMARY OF THE INVENTION The present invention relates to driving means provided in a scanning device of an image reading device. According to a first aspect of the present invention, there is provided a movable first scanning body having a light source for irradiating light to a document, a mirror for guiding light reflected from the document in a predetermined direction, A movable second scanning member having a mirror for receiving the light and guiding the image to the image reading means, wherein each of the scanning members is driven via a large and small pulley provided on one shaft, and Are independently fixed to the drive shaft. Therefore, the position of each carriage can be adjusted by adjusting the fixed position of each pulley with respect to the drive shaft.

According to a second aspect of the present invention, the pulley includes a first pulley that drives a full-rate carriage as the first scanning body and a second pulley that drives a half-rate carriage as the second scanning body. A second pulley, wherein the second pulley comprises a base for fixing to a shaft, and a belt hooking portion for hanging a belt for driving a half-rate carriage with a smaller diameter than the base, the first pulley; The belt is not detached from the base of the second pulley. By mounting only the pulley on the drive shaft without using a separate auxiliary member to perform belt hanging on the pulley, the belt can be supported so as not to come off from the pulley.

According to a third aspect of the present invention, the two pulleys are:
It is characterized by being fixed to the drive shaft with a stopper. Therefore, each pulley is supported so as to be adjustable with respect to the drive shaft, and the labor of the adjustment operation can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an image reading apparatus according to the present invention will be described with reference to the illustrated example. The example shown in FIG.
FIG. 2 is a side view of the image reading apparatus 1, showing an apparatus applicable to a multifunction peripheral with a copying machine or a facsimile apparatus or an image reading apparatus used as a scanner for a personal computer. In the image reading apparatus 1, a platen 5 is arranged on an upper part of a main body frame 2, and an image of a document set on the platen 5 is scanned by a scanning device 10 that reciprocates in a sub-scanning direction along a lower surface of the platen 5. It is configured to read. For the original set on the platen 5, the elastic body 4 of the platen cover 3 positioned on the upper surface thereof
Is pressed so that the image surface of the original is brought into close contact with the platen 5 to enable reading.

A scanning device 10 in which the platen 5 is disposed inside a frame in which the platen 5 is disposed is a first scanning member in which a lamp 12 and a mirror m1 are disposed, similarly to a conventional image reading device. A full-rate carriage 11 and a half-rate carriage 15 as a second scanning body on which two mirrors m2 and m3 are arranged are movably provided along a guide rail 19. 2 above
Drive 6 for driving the two carriages 11, 15
The two carriages 11 and 15 are connected to belts 8 and 9 wrapped around pulleys 20 and 25 provided on the drive shaft 7 via fixed portions 13 and 16, respectively. By forming the diameters of the two pulleys 20 and 25 at a ratio of 2: 1, the half-rate carriage 15 is driven at half the speed of the full-rate carriage 11.

In the image reading apparatus 1, a full-rate carriage 11 that moves at a constant speed in the length direction of a document,
The half-rate carriage 15, which is moved at half the speed of the full-rate carriage 11, is reciprocally moved in conjunction with the half-rate carriage 15, and the light of the lamp 13 irradiates the image surface of the document set on the platen 5. Then, the reflected light of the light illuminating the original is reflected via mirrors m1, m2 and m3 provided on the two carriages 11 and 15, respectively.
Is reflected on the CCD 18 through the lens 17,
A digital signal obtained by converting optical information into an electric signal is output to a device combined with an image reading device. The CCD 1
The image information as a digital signal obtained by 8 can be used as a transmission signal in a facsimile machine. When the image reading apparatus is used in combination with a copying machine or a multifunction machine including a facsimile machine and a copying machine, the image information can be transmitted to a recording unit and printed on a recording sheet. Further, when the image reading device is used in combination with a computer or the like, the image reading device is also used to create a document or the like combined with other arbitrary information using the image information.

In order to move the full-rate carriage 11 and the half-rate carriage 15 in the sub-scanning direction, there is provided a driving device 6 configured as shown in FIGS. Using the large-diameter drive pulley 20 as a first pulley and the small-diameter drive pulley 25 as a second pulley, the carriages 11 and 15 are driven in accordance with the moving speeds of the respective carriages 11 and 15. A full-rate carriage 11 is fixed to the belt 8 wound around the large-diameter drive pulley 20 via a fixed portion 13, and a half-rate carriage is fixed to the belt 9 driven by the small-diameter drive pulley 25 via a fixed portion 16. The carriage 15 is fixedly supported. The two belts 8 and 9 are also arranged on the other side of the frame of the image reading device, and are attached to one drive shaft 7 on the front side and the rear side in the scanning direction of the frame of the image reading device. Driving is performed via the pulleys arranged respectively, and FIG. 2 shows only one side of the driving mechanism. Further, a tension adjusting mechanism 30 is arranged on the other side of the frame in the sub-scanning direction with respect to the two belts 8 and 9, so that the tension of the belts can be adjusted. The tension adjusting mechanism 30 will be described later with reference to FIG.

Pulleys 20 and 25 arranged on the drive shaft 7
Is formed as described with reference to FIGS.
The drive shaft 7 is fixed to the drive shaft 7 using a screw. When the position of the carriage is adjusted, the screw is loosened so that the adjustment operation can be easily performed. The large-diameter drive pulley 20 is formed by integrally molding a large-diameter belt hook portion 21 and a small-diameter stopper 22, and is fixed to the drive shaft 7 using screws 23 arranged on the stopper 22. A tapered surface 24 for regulating the belt at a belt hooking portion 26 of the small-diameter drive pulley 25 is integrally provided on the side of the stopper 22 of the large-diameter drive pulley 20, in a state combined with the small-diameter drive pulley 25. Thus, tapered surfaces 24 and 24a as flanges are formed on both sides of the belt hanging portion 26.

The small-diameter drive pulley 25 is formed by integrally forming a small-diameter belt hook portion 26 and a large-diameter stopper 27, and one end of the pulley is provided on the belt hook portion 26 side of the stopper 27. Is provided with a tapered surface 24a as a flange. A screw 28 is arranged on the stopper 27 so that the small-diameter drive pulley 25 is fixed to the drive shaft 7 by the screw 28. As shown in FIG. 2, in a state where the small-diameter drive pulley 25 is combined with the large-diameter drive pulley 20 and attached to the drive shaft 7, the belt hooking portion 21 of the large-diameter drive pulley 20 has flanges on both sides of the belt 8. In the belt hooking portion 26 of the small-diameter drive pulley 25, the taper surface 24 of the stopper 27 is attached to one side of the belt 9.
a plays the role of a flange, and on the other side a stop 22
Are positioned. Each pulley 2
The reason why the flanges are provided at 0 and 25 is that when the toothed belt is used as the drive transmission means, the pulley side portion hits the teeth of the toothed belt and generates abnormal noise. By guiding the teeth of the toothed belt so as to contact the pulley via the flange, generation of abnormal noise can be prevented. Therefore, for the belt 9 that drives the half-rate carriage 15,
The flange means of the two pulleys regulate the belt so that the belt 9 is guided and driven.

A tension adjusting mechanism 30 for adjusting the tension of the two belts 8 and 9 on the side opposite to the drive side.
Arranges separate pulleys 31, 35 for each belt as shown in FIGS. 2, 4, and 5, and each pulley 31,
35 can be adjusted using another adjusting mechanism. Large diameter pulley 31 disposed on the tension adjusting mechanism 30
Is supported by the bracket 32, and the tension of the belt 8 can be set using tension setting means such as a spring 33. A small-diameter pulley 35 corresponding to the belt 9 is supported by a bracket 36, and a tension setting means such as a spring 37 is provided.

As shown in FIGS.
The pulley 35 is supported by a shaft 35 a provided on a bracket 36, and a spring 37 is locked on a locking portion provided on the bracket 36 to apply tension. A large number of long holes 38, 38a, 39,... Are arranged on the side plate 2a of the main body frame of the apparatus with respect to the brackets 32, 36 respectively supporting the two pulleys 31, 35, and provided on each bracket. The position of the screw mounted in the screw hole is provided so as to be adjustable. For example, two screw holes 32a and 32b are arranged in the bracket 32 that supports the pulley 31, and the screw holes are slid into the long holes 39 and 39a provided in the main body frame 2a to be provided with position adjustment screws 41. , 41a are mounted. Also,
Screw hole 3 of bracket 36 supporting small diameter pulley 35
6a, 36b are elongated holes 38, 38a of the main body frame 2a.
The screws 40 and 40a are attached to each of the above.

The bracket 32 of the tension adjusting mechanism 30;
The spring engaging projections 42 and 43 are provided on the main body frame 2a so as to project from the elongated holes 44 and 45, respectively. Also,
The two spring locking projections 42 and 43 and the body frame 2
a between springs 33,
37 is provided so that a predetermined value of tension can always be set for the two pulleys 31 and 35. The mounting positions of the brackets 32 and 36 with respect to the belts 8 and 9 for driving the two carriages and the support means of the two pulleys 31 and 35 of the tension adjusting mechanism 30 with respect to the side plates 2a of the main body frame. , The tension on the belts 8 and 9 can be set. As a means for setting the tension on the belts 8 and 9, a mechanism conventionally used for setting a tension on a belt or the like can be provided, and a mechanism using a spring and a screw member can be used. , And other arbitrary mechanisms are arranged so that the adjustment can be performed by an adjustment screw (not shown) arranged at the end 2a of the frame.

In the driving device constructed as described above, the two carriages are fixedly supported on the belts 8 and 9 by using the fixing portions 13 and 16, respectively. The carriages 11 and 15 are reciprocated. When adjusting the positional relationship between the two carriages, for example, the carriage 1 that needs to be adjusted
Then, the fixing screw 23 of the drive pulley 20 to the drive shaft 1 is loosened to release the fixed state to the drive shaft 7, and the carriage 11 is adjusted to an accurate position. When the carriage 11 is moved, the large-diameter drive pulley 20 idles with respect to the drive shaft 7. After the carriage 11 is positioned, the screw 23 of the stopper 22 is screwed into the drive shaft 7. The large-diameter drive pulley 20 is fixed. Similarly, when adjusting the position of the half-rate carriage 15, the small-diameter drive pulley 25 is released from the fixed state of the drive shaft 7, and the half-rate carriage 15 is moved. Can be fixed. The operation of opening and fixing the drive pulley to the drive shaft 7 can be performed by removing the platen 5 from the main body frame 2. In addition, an opening is provided on the other side plate of the main body frame 2. For example, it is also possible to adjust the fixing position of the drive pulleys 20 and 25 with respect to the drive shaft 7, and in this case, it is not necessary to remove the platen 5.

In the two pulleys 20, 25, the flange of the small diameter drive pulley 25 at the belt hooking portion 26 uses the stopper 22 of the large diameter drive pulley 20 as one flange. Of course, it is also possible to form a flange integrally on both sides with respect to the part 26. Further, a plurality of screw holes can be formed in the stoppers 22 and 27 for the two drive pulleys 20 and 25, and screws can be mounted on arbitrary screw holes. When the fixing work is performed, it may be possible to easily cope with the work.

[0019]

Since the image reading apparatus of the present invention is constructed as described above, it has two carriages (scanning members), a full rate carriage and a half rate carriage.
Is driven through large and small pulleys provided on one shaft,
Since the two pulleys are independently fixed to the drive shaft, the position of the two carriages can be adjusted by adjusting the fixed position of each pulley with respect to the drive shaft. By providing an opening in the side plate of the main body frame, it is also possible to adjust the fixing position of the drive pulley with respect to the drive shaft. In this case, it is not necessary to remove the platen to perform the operation. Also, a base for fixing a first pulley for driving the full-rate carriage, a second pulley for driving the half-rate carriage to a shaft, and a belt for driving the half-rate carriage with a smaller diameter than the base. In the state where the two pulleys are combined,
Since the belt is not attached to or detached from the small-diameter drive pulley, no separate auxiliary member is required to hook the small-diameter drive pulley, and only the pulley is mounted on the drive shaft. The belt can be supported so that it does not come off. Further, since the two pulleys are fixed to the drive shaft using the stoppers, each pulley is supported so as to be adjustable with respect to the drive shaft, so that the work of the adjustment operation can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of an image reading device.

FIG. 2 is an explanatory diagram of a driving device.

FIG. 3 is an explanatory diagram of two drive pulleys arranged on a drive shaft.

FIG. 4 is an exploded perspective view showing a configuration of a tension adjusting mechanism.

FIG. 5 is an explanatory view of the tension adjusting mechanism of FIG. 4 in an assembled state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image reading apparatus, 2 Body frame, 5
Platen, 6 drive device, 7 drive shaft, 8.9
Belt, 10 scanning device, 11 full rate carriage, 15 half rate carriage, 17
Lens, 18 CCD, 20 large-diameter drive pulley, 21 belt hook, 22 stopper, 24
Tapered surface, 25 Small diameter drive pulley, 26
Belt hook, 27 stopper, 30 tension adjustment mechanism, 31 large diameter pulley, 32/36 bracket, 33/37 spring, 35 small diameter pulley, 38/39/44/45 long hole, 40, 41
Screw member, 42, 43 Spring retaining projection, 46
Locking member.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/31

Claims (3)

[Claims] 1. A movable first scanning body having a light source for irradiating light to a document, a mirror for guiding light reflected from the document in a predetermined direction, and receiving a light guided in the predetermined direction. A movable second scanning member having a mirror for guiding the scanning member to the image reading means, wherein each of the scanning members is driven via a large and small pulley provided on one shaft, and the two pulleys are independently provided. An image reading device fixed to a drive shaft. 2. The pulley includes a first pulley that drives a full-rate carriage as the first scanning body, and a second pulley that drives a half-rate carriage as the second scanning body, The second pulley includes a base portion for fixing to a shaft, and a belt hooking portion for hanging a belt for driving a half-rate carriage with a smaller diameter than the base portion. The first pulley and the second pulley The image reading device according to claim 1, wherein the belt is configured not to be attached to or detached from a base. 3. The two pulleys are fixed to a drive shaft with a stopper.
The image reading device according to claim 1.