JPH08225182A - Sheet material conveying device and image forming device - Google Patents

Abstract

PURPOSE: To suppress interference of a conveying roller with another member and to shorten the length of the conveying roller so as to accomplish compactification by arranging an engaging part, which is provided with an axial direction pressing face and a diametral direction pressing face, in the end part of the conveying roller and locking a spring member, which energizes the two pressing faces in the engaging part at the same time, in a fixed part of a device main body. CONSTITUTION: An end part of a conveying roller 10 is provided with a groove 30 serving as an engaging part having an axial direction pressing face 30a and a diametral direction pressing face 30b, and a non-coil type wire spring 17, which energizes the two pressing faces 30a, 30b in the groove 30 at the same time, is locked in a fixed part 39 in a device main body. In this way, a backlash in the axial direction and in the diametral direction of the conveying roller 10 can be eliminated by means of the single spring member 17, and consequently, not only a shift in the lateral direction but also a shift in the conveying direction are reduced in a recording sheet material, so that a recording position to the recording sheet material is decided, and printing precision can be improved. Therefore, the conveying roller 10 can be shortened in length, and a member projecting from the conveying roller 10 is dispensable, and as a result, compactification can be accomplished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material conveying device for conveying a sheet material such as an original or a copy sheet by using a conveying roller, which is integrally attached to a portable computer, a word processor or the like. Printers and copiers
It can be applied to an image forming apparatus such as a facsimile.

[0002]

2. Description of the Related Art Conventionally, in a sheet material conveying apparatus for conveying a recording sheet material in a printer as an information output device such as a computer, friction is caused by bringing the outer peripheral surface of a rotating conveying roller into contact with the sheet material. A method of conveying a sheet material by force is generally adopted.

When the conveying roller does not merely convey the sheet material in a fixed direction, but rotates the sheet material back and forth during the recording operation to detect the front end of the sheet material and perform overprinting, to reciprocate the sheet material. There is. Therefore, it is desirable to reduce not only the axial play but also the radial play due to the play of the shaft of the bearing and the conveying roller.

In this conventional example, a coil spring provided coaxially with the carrying roller is used as a means for suppressing the play in the axial direction of the carrying roller.

FIG. 7 is a diagram in which only the conveying roller portion of the sheet material conveying device is taken out and illustrated for the sake of explanation.

Reference numeral 101 denotes a side plate of the chassis of the apparatus body, 102
Is a conveying roller for conveying the recording sheet material to the recording means, 103 is the conveying roller 102, and the side plate 101 of the chassis.
Bearing 107 for receiving by, a groove 107 provided on the outer periphery near the shaft end of the carrying roller 102, a spring 104 located on the shaft of the carrying roller 102 by hooking a plurality of claws 108 on the groove 107 provided on the carrying roller 102. Receiving 105 is bearing 103
Alternatively, it is a coil spring provided between the side plate 101 of the chassis and the spring receiver 104. The coil spring 105 urges the conveying roller 102 in the direction of the arrow in FIG. 7 via the claw 108 of the spring receiver 104 and the groove 107, and presses it against a chassis or the like on the opposite side not shown. As a result, the play in the axial direction of the transport roller 102 is suppressed.

[0007]

However, in such a conventional example, the axial length occupied by the coil spring 105 and the spring receiver 104 on the shaft of the conveying roller 102 becomes large.

That is, the range in which the coil spring 105 and the spring receiver 104 are on the shaft of the conveying roller 102 is
Since the sheet material cannot be placed, it is an invalid length, and the chassis width must be made larger than the sheet material width by at least that amount.

In addition, in order to install the printer apparatus incorporated in a portable computer or the like in an area of a very limited size, the carrying roller is close to the carriage on which the recording head as a recording means is mounted, and the carrying roller is The presence of the protrusions on the outer periphery hinders the carriage from moving in the lateral direction. Therefore, the presence of the spring 105 and the spring receiver 104 also limits the movement of the carriage.

Further, with such a coil spring, only the play in the axial direction can be eliminated, and the conveying roller 10
The radial play between the second shaft and the bearing 103 is not taken into consideration at all, and it is not intended to eliminate the eccentric eccentricity of this radial play due to the rotation of the conveying roller 102, and the sheet The pressing force on the material changes slightly, and the carry amount changes.

Further, since a spring receiver is required in addition to the spring, the number of parts is increased and the assemblability is not good, which causes a cost increase.

The present invention has been made to solve the above-mentioned problems of the prior art, and its object is to improve the spring structure for eliminating the play in the axial direction and the radial direction of the conveying roller. , The conveyance roller is restrained from interfering with other members, the length of the conveyance roller is shortened, and the conveyance device or the image forming apparatus incorporating the conveyance device is made compact, and the assembling property and the cost are improved. An object of the present invention is to provide a sheet material conveying device with good performance.

[0013]

In order to achieve the above object, according to the present invention, in a sheet material conveying apparatus provided with a conveying roller for conveying a sheet material, at least one bearing of the conveying roller or the conveying roller. An engaging portion having an axial pressing surface and a radial pressing surface is provided at the end portion, and a spring member for simultaneously urging the two pressing surfaces of the engaging portion is locked to the fixing portion of the apparatus main body. Characterize.

The spring member uses a non-coil type wire spring or a leaf spring, and includes a locking portion which is locked to the fixed portion of the apparatus main body, and a biasing portion which biases the engaging portion. Between the locking portion and the urging portion in the axial direction and the radial direction.
It is characterized in that it has a bending allowance in the direction.

It is also preferable that the one bearing is movably held in the apparatus main body in the axial direction of the carrying roller and has an abutting portion for urging the carrying roller in the other bearing direction.

It is also preferable that the spring member is a conductive member.

Further, an image forming apparatus for forming an image on a sheet material is provided with an engaging portion having a radial pressing surface and an axial pressing surface at the bearing of at least one of the conveying rollers or the end of the conveying roller. It is also effective to provide a sheet material conveying device in which a spring member for urging the two pressing surfaces of the joining portion at the same time is locked to the fixing portion of the apparatus main body.

[0018]

In the present invention constructed as described above, one spring member presses the engaging portion having the axial pressing surface and the radial pressing surface provided at the end of the bearing or the conveying roller. Eliminates play in the axial and radial directions of the transport roller.

Since the spring member is a non-coil type wire spring or a leaf spring, its axial dimension is reduced, and there are two directions, an axial direction and a radial direction, between the engaging portion and the urging portion. The bending allowance serves as a spring force that urges the axial pressing surface and the radial pressing surface.

Since the bearing moves in the axial direction, if the spring member is applied to the engaging portion of the bearing, the spring member and the conveying roller do not come into direct contact with each other, and the play in the axial direction and the radial direction of the conveying roller is eliminated as described above. .

Since the spring member is electrically conductive, the charge on the conveying roller is removed.

If the above-mentioned conveying roller is incorporated into the image forming apparatus, the space between the both side plates of the apparatus holding the conveying roller can be narrowed, so that the width of the apparatus main body can be made small and compact. You can Further, in this case, the lateral movement of the carriage is not disturbed.

[0023]

First Embodiment A first embodiment of the present invention is shown in FIGS. 1 to 4. In the present embodiment, the present invention is applied to a printer unit as an image forming apparatus of a type incorporated in a portable computer, a word processor or the like.

First, the overall structure of the recording apparatus will be described with reference to FIG. This recording apparatus has a serial type recording means, in which a recording head moves laterally together with a carriage to record one line and is conveyed by a conveying means which is a recording sheet conveying device. The predetermined recording is performed on the recording sheet material.

The recording means records the recording sheet material conveyed by the conveying means on the platen 4 by a recording head (not shown). This recording head has a guide rail 5
The carriage 6 is mounted on a carriage 6 which can reciprocate right and left along the right and left, and a timing belt 8 spanning between left and right pulleys 7, 7 provided near the left and right side walls of the chassis 3 is connected to the carriage 6. A carriage motor 9 is connected to one of the pulleys 7, and the carriage 6 is reciprocally moved left and right along the guide rail 5 via the timing belt 8 by the forward and reverse rotation driving of the carriage motor 9.

The recording head in the embodiment of the present invention uses an ink jet recording head which discharges ink for recording. That is, this recording head generates a fine liquid discharge port (orifice), a liquid passage, and an energy acting portion provided in a part of this liquid passage, and a droplet forming energy that acts on the liquid in the acting portion. And energy generating means.

As an energy generating means for generating such energy, a recording method using an electric converter such as a piezo element, electromagnetic waves such as laser are irradiated to generate heat, and droplets are ejected by the action of the heat generation. There is a recording method using an energy generating means.

Among them, a recording head used in an ink jet recording method for ejecting a liquid by thermal energy has a high density of liquid ejection ports (orifices) for ejecting recording liquid droplets to form ejection liquid droplets. Since they can be arranged, high resolution recording is possible. Among them, the recording head using the electrothermal converter as the energy generating means can easily be made compact, and has the advantages of the IC technology and the microfabrication technology, which have been remarkably improved in technology and reliability in the recent semiconductor field. This is advantageous because it can be used in two parts, high-density mounting is easy, and the manufacturing cost is low.

Next, the sheet material conveying device is configured to convey the recording sheet material fed from the automatic feeding device (the pressure plate 1, the feeding rotating body 2). That is, the transport roller 10
1 is rotationally driven in the direction of arrow A1 in FIG. 1, and the recording sheet material is sandwiched by the pinch rollers 11 that are driven to rotate and conveyed forward.

Next, a method of holding the transport roller 10 on the chassis 3 will be described with reference to FIGS. FIG. 2 is a front view of the state where the conveying roller 10 is held by the chassis 3, FIG.
FIG. 3 is a detailed view of a main part in which the left end of the transport roller 10 is held by the chassis 3. FIG. 4 is a component diagram of the bearing B13 and the non-coil type wire spring 17, which is a feature of the present invention.

The conveying roller 10 has bearings A1 at both ends.
2. Bearings B13 are rotatably held on both side plates of the chassis 3. A transport gear 14 is attached near the right end of the transport roller shaft 10, and the transport gear 14 is connected to a transport motor (not shown) by sequentially meshing transmission gears. Therefore, the rotational force of the carry motor is transmitted to the carry roller 10 via the gear train, and the carry roller 10 rotates in the direction of arrow A1 in FIGS. 1 and 3 to carry the recording sheet material forward.

A rubber roller 15 is provided at the left end of the carrying roller 10.
Are urged by a spring to come into contact with each other, and the rotational force of the transport roller 10 is transmitted to the paper discharge roller 16. As a result, the recording sheet material recorded by the recording head is ejected outside the apparatus by the paper ejection roller 16.

The right end of the conveying roller 10 is rotatably held on the side plate of the chassis 3 by a bearing A12 made of plastic or the like. The bearing A12 has a bag-like shape having a bottomed hole. At the time of assembly, the bearing A12 is covered on the end of the conveying roller 10 and fitted and fixed in the hole of the side plate of the chassis 3. The fitting of the bearing A12 and the side plate of the chassis 3 is provided with unevenness as a rotation stopper to prevent the bearing A12 from rotating together when the transport roller 10 rotates.

Similarly, the left end of the conveying roller 10 is also rotatably held on the side plate of the chassis 3 by a bearing B13 made of plastic or metal. The bearing B13 also has a bottomed hole and is fitted with the conveying roller 10, and during assembly,
First, with the right end side of the conveying roller 10 assembled to the chassis 3, the bearing B13 is attached to the chassis 3 from the outside.
The holes are formed in the side plates of the sheet and the outer circumference of the end of the conveying roller 10. Similarly to the right end, the left end side is provided with a rotation stopping shape between the bearing B13 and the side plate of the chassis 3.

However, the bearing B13 is movably held in the axial direction with respect to the hole of the side plate of the chassis 3. Therefore, if the bearing B13 is moved to the right end side, the bearing A1 is moved.
2 and the bearing B13 at the bottoms of the two fitting holes of the conveying roller 10
It is possible to suppress the play in the axial direction of the transport roller 10 by sandwiching both end faces of the. Further, on the outer periphery of the bearing B13 protruding to the inside of the side plate of the chassis 3, there is provided a groove 30 as an engaging portion for locking the non-coil type wire spring 17.

The groove 30 has an axial pressing surface 30a and a radial pressing surface 30b. When the axial pressing surface 30a is urged, the axial play is eliminated, and the radial pressing surface 30b.
If you press, the radial play is eliminated.

The non-coil type wire spring 17 is bent to have the shape shown in FIG. 4, and the center line X of the bent portion.
-It is almost symmetrical to the X-ray. Further, the centrally bent end portion 32 and the two end portions 34 and 35 are locking portions that are locked to the fixing portion on the apparatus main body side, and the two end portions 36 bent inward in an arc shape. Reference numeral 37 is a biasing portion that engages with the groove 30.

When the wire spring 17 is assembled to the apparatus, the axial pressing surface 30a extends in the axial direction indicated by the arrow T1.
And a bending margin for urging the radial pressing surface 30b in the radial direction indicated by the arrow T2. Therefore, the legs extending from the two inner ends 36, 37 to the three outer ends 32, 34, 35 are
It is slightly bent to the side plate side. Further, both fixing portions 39, 39 and the end portions 36, 37 of the side plates of the chassis 3 are also bent in a mountain shape for the purpose of urging the radial pressing surface 30b.

When assembling, the end portions 36, 3
The two arcuate inner sides of 7 are locked in the groove 30 on the outer periphery of the bearing B13 protruding to the inner side of the side plate of the chassis 3, and the three outer end portions 32, 34, 35 abut on the inner side of the side plate of the chassis 3. In particular, the two end portions 34 and 35 are hooked and held by the two fixing portions 38 and 39 provided inside the side plate of the chassis 3.

By incorporating in this way, first of all, since the leg portions of the non-coil type wire spring 17 are bent from the side toward the side plate of the chassis 3 from the beginning, the three outer end portions 3 are formed.
When abutting on the inside of the side plate of the chassis 3, the members 2, 34, 35 are stretched by the initial shape and elastic force on the side plate of the chassis 3 to form two arc-shaped inner end portions 36, 37 and the groove 30. The bearing B13 is urged toward the right end side in the axial direction via the axial pressing surface 30a, and the bearing B13 is moved in that direction. As a result, the transport roller 10 is
13 is urged toward the right end side in the axial direction (in the direction of arrow A2 in FIG. 3) through the bottom of the fitting hole and the shaft end face, and is moved in that direction, and both end faces of the bearing A12 and the bearing B13 are separated. It is sandwiched between the bottoms of the two fitting holes, and the play in the axial direction of the transport roller 10 is suppressed. In this case, the two arc-shaped inner ends 36, 37 of the non-coil-shaped wire spring 17 are inside the triangle having the three outer ends 32, 34, 35 as vertices, and thus the three outer ends. The parts 32, 34, and 35 can stably urge the bearing B13 like the legs of a tripod.

Secondly, when the outer ends 34, 35 of the non-coil type wire spring 17 are hooked and held by the two fixing portions 38, 39 provided inside the side plate of the chassis 3, the outer ends 34, 35 have the initial shape. The inner ends 36 and 37 of the two arcs are formed as a reaction against the inner end parts 36 and 37, which are wider than the inner end parts 36 and 37.
Is pressed against the radial pressing surface 30b of the groove 30, and urges the bearing 13 and the conveying roller 10 in the direction of arrow A3 in FIG. 3, suppressing radial backlash and the inner end portion 36, The engagement between the groove 37 and the groove 37 does not come off.

The result of the construction of the first embodiment as the spring structure for suppressing the play in the axial direction of the conveying roller 10 is clearly the axial dimension as compared with the case of using the conventional coil spring shown in FIG. Can be small.
As a result. As a matter of course, the sheet material conveying device having such a conveying roller can also reduce the width of a computer or the like incorporating the sheet material conveying device, and with respect to a recording sheet material of the same size, or A computer or the like can be downsized for the same amount of reciprocation of the recording head in the left-right direction.

Further, since the non-coil type wire spring 17 is made of metal, the grounding of the conveying roller 10 can be dropped to the chassis 3 by making the bearing B13 a conductive material.

In order to remove the play of the conveying roller 10 in the axial direction by urging the bearing B13 in the axial direction, the bearing (both A and B) and the conveying roller 10 are brought into surface contact in the axial direction. However, it is not limited to a bearing having a bottomed fitting hole as in the first embodiment.

As shown in FIG. 5 (a), the bearing 41 may have a stepped hole so that the stepped portion of the hole and the shaft end surface are in contact with each other.

A transport roller 52 as shown in FIG.
May have a stepped end, and the end surface of the bearing 51 and the stepped portion of the shaft may come into contact with each other.

(Second Embodiment) The spring member for urging the bearing B13 is not limited to the shape of the non-coil type wire spring 17 of the first embodiment. For example, as shown in FIG. 63
A wire spring having such a shape also belongs to the scope of the present invention. In this case, the radial play of the bearing 61 is held at the center of the fixed portions 64a, b, c by the elasticity of the wire spring 63.

Further, the spring member is not limited to the wire spring but may be a leaf spring, for example, 73 in FIG. 6 (b).
A wire spring having such a shape also belongs to the scope of the present invention.

The method of locking the end of the spring to the bearing or the side plate of the chassis is not limited to the first embodiment. As a means for locking the bearing, for example, in FIG. 6 (b), the forked portion 73 a of the leaf spring 73 is formed in a two-face cut groove provided on the outer diameter of the bearing 71.
Is locked.

As the locking means on the chassis side plate side, for example, the wire spring 63 is stopped by a pin 64a in FIG. 6A, and the plate spring 73 is stopped by a screw 74 in FIG. 6B. .

In the first and second embodiments described above, the spring member engages the bearing to urge the bearing, but it goes without saying that the end portion of the conveying roller does not go through the bearing. It is also within the scope of the present invention to provide the engaging portion with and press the engaging portion.

[0052]

As described above, the present invention has the above-described structure and operation, and can eliminate the play in the axial direction and the radial direction of the conveying roller by one spring member. Therefore, as a result of suppressing the play of the conveying roller, not only the lateral displacement of the recording sheet material but also the deviation in the conveying direction are reduced, so that the recording position on the recording sheet material is determined and the printing accuracy is improved.

Further, since the spring structure is improved and the conventional coil spring is changed to a non-coil type spring or a leaf spring, the length of the conveying roller is shortened and the constituent members protruding from the conveying roller are eliminated. Thus, it is possible to reduce the width and height of the sheet material conveying device or the image forming apparatus incorporating the sheet conveying device, thereby realizing compactness.

Further, the spring member of the present invention can be assembled separately from the conveying roller, and the assembling property can be improved.

By making the spring member conductive, it is possible to eliminate the charging of the conveying roller.

[Brief description of drawings]

FIG. 1 is a perspective view of a printer unit according to a first embodiment of the invention.

FIG. 2 is a view showing a state in which a carrying roller according to the first embodiment of the present invention is held by a chassis.

FIG. 3 is a detailed perspective view of a left end of the transport roller according to the first embodiment of the present invention.

FIG. 4 is a component diagram of a bearing B13 and a wire spring 17 according to the first embodiment of the present invention.

FIG. 5 is a view showing a fitted state of the shaft and the bearing of the conveying roller of the present invention.

6 (a) and 6 (b) are spring members according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of a structure portion that suppresses axial play of a conventional transport roller.

[Explanation of symbols]

 3 Chassis 4 Platen 5 Guide Rail 6 Carriage 7 Pulley 8 Timing Belt 10 Conveyor Roller 12, 13, 41, 51, 61, 71 Bearing 17, 63, Wire Spring (Spring Member) 30 Groove 30a Axial Pressing Face 30b Radial Pressing Surface 34,35 End (locking part) 36,37 End (biasing part) 38,39 Fixed part 73 Leaf spring (spring member)

Front page continuation (72) Inventor Hiroyuki Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Soichi Hiramatsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Hideki Yamaguchi, 3-30-2 Shimomaruko, Ota-ku, Tokyo, Canon Inc. (72) Inventor Takashi Nojima, 3-30-2, Shimomaruko, Ota-ku, Tokyo (72) Invention Takeshi Iwasaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A sheet material conveying apparatus including a conveying roller for conveying a sheet material, wherein at least one bearing of the conveying roller or an end portion of the conveying roller is provided with an engaging portion having an axial pressing surface and a radial pressing surface. A sheet material conveying device, wherein a spring member for urging the two pressing surfaces of the engaging portion at the same time is locked to a fixing portion of the apparatus main body. 2. The spring member uses a non-coil type wire spring or a leaf spring, and a locking portion that is locked to a fixed portion of the apparatus body and a biasing force that biases the engaging portion. And an axial portion and a radial portion between the engaging portion and the urging portion.
The sheet material conveying device according to claim 1, further comprising a bending margin in a direction. 3. The one bearing is movably held in the apparatus main body in the axial direction of the carrying roller, and is provided with an abutting portion for urging the carrying roller in the other bearing direction. Item 3. The sheet material conveying device according to item 1 or 2. 4. The sheet material conveying device according to claim 1, wherein the spring member is a conductive member. 5. A conveying roller for a sheet material used in an image forming apparatus for forming an image on a sheet material, wherein at least one bearing of the conveying roller or an end portion of the conveying roller has a radial pressing surface and an axial pressing surface. An image forming apparatus, comprising: an engaging portion having a spring member, and a spring member for simultaneously urging the two pressing surfaces of the engaging portion is locked to a fixing portion of the apparatus main body.