JP3470408B2 - Paper release mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper releasing mechanism applied to a scanner section or a recording section of a facsimile apparatus or the like. 2. Description of the Related Art For example, as shown in FIG. 6, a scanner section of a facsimile apparatus using a contact image sensor as a document reading means includes a feed roller 1 and a feed roller A sensor unit 3 pressed by a spring 5 is provided on the peripheral surface, and an image of the document P fed by the feed roller 1 is continuously read by the sensor unit 3 nipped on the reading surface 3a. ing. In a scanner unit using this type of sensor, when a document jam occurs on the transport path, the document P
Remains in the nip between the feed roller 1 and the sensor unit 3, and in order to release the paper for extracting the document P, it is necessary to separate them from each other to the separation position. Therefore, the feed roller 1 and the sensor unit 3 are provided so as to be able to contact and separate from each other, and at the time of releasing the paper, one of them can be retracted to the separation position. Most commonly, as shown in FIG. 6, a support shaft 7 is provided near the feed roller 1, and the sensor unit 3 (or the feed roller 1) is moved up and down by a swinging operation (arrow a) around the support shaft 7. (Arrow b) A release lever 8 is attached. However, in the above-described conventional paper release mechanism, an extra part is required for mounting the release lever, the number of parts is large, the assembly is complicated, and the lever operation is difficult. There are drawbacks such as the required space becomes larger. The present invention newly provides a paper release mechanism having a simple structure capable of overcoming the above-mentioned drawbacks. In a paper releasing mechanism according to the present invention, a driving roller such as the above-mentioned feed roller is pressed against a peripheral surface of the driving roller, and a roller pressing member for nipping paper between the driving roller and the roller. A paper release mechanism with a cover that can be opened and closed around the support shaft of the drive roller so that a release lever that separates the drive roller and the roller pressure contact member is swingably attached, and the cover that covers the main body is provided. There is provided a contact portion which comes into contact with and pushes back the release lever which stands when the cover is closed. Here, in order to ensure smooth switching operation, it is effective to form the base end of the release lever, which is coaxial with the drive roller, on a cam having a roller pressing member as a cam follower. When the release lever is attached, it is reasonable that the cam formed at the base end portion is brought into contact with the bracket supporting the roller pressing member on the side of the roller pressing member. The release mechanism according to the present invention can be similarly applied to paper release of a recording section provided with a platen roller as a drive roller and a thermal head as a roller pressing member. In the paper releasing mechanism described above, since the release lever is mounted around the support shaft of the drive roller, a separate support shaft for mounting the lever is not required. FIG. 1 schematically shows an embodiment of a paper releasing mechanism according to the present invention. In FIG. 1, reference numeral 1 denotes a rubber feed roller (drive roller) for feeding an original (not shown), and reference numeral 2 denotes a roller shaft (support shaft) on which the roller 1 is externally fitted. (Not shown) and held in place. Reference numeral 3 denotes a sensor unit constituting a contact type image sensor. A reading surface 3a provided on the upper surface of the sensor unit 3 is pressed against the peripheral surface of the feed roller 1, and a document fed by the feed roller 1 is nipped at the reading surface 3a. And the original image is read. This sensor unit 3 is attached to a sensor bracket 4 disposed on the lower side,
Is urged upward by a spring 5 which is elastically contacted with the lower surface of the. [0013] At both ends of the sensor bracket 4 located on both sides of the feed roller 1, bracket side ends 4a which are once raised upward and then extend horizontally horizontally are integrally formed. Further, a guide piece 4b branched into two branches from the end of the bracket side end 4a is erected, and the guide piece 4b sandwiches the end of the roller shaft 2 to position the roller shaft 2 respectively. Thus, the sensor unit 3 can be retracted from the press-contact position to the separation position while maintaining the relative positional relationship with the feed roller 1 by bending the spring 5 downward while pressing down. At both ends of the roller shaft 2 of the feed roller 1, release levers 6 for separating the sensor unit 3 to the separating position are attached so as to be swingable about the same axis as the roller shaft 2. . The release lever 6 may be a lever type in which its working end is brought into contact with the upper surface of the sensor unit 3 or the like. However, in order to ensure a smooth contact / separation switching operation of the sensor unit 3, its base end 6A.
Is desirably formed on a cam having the sensor unit 3 as a cam follower. The upper surface of the bracket side end 4a extending laterally on both sides of the sensor unit 3 is selected as the cam contact position of the release lever 6 with respect to the sensor unit 3. FIGS. 2 and 3 show details of the shape of the release lever 6 and the mounting structure. The release lever 6 is integrally formed of a synthetic resin having flexibility, and a shaft through hole provided in the base end portion 6A is attached to the roller shaft 2 in a loosely fitted state without exerting frictional resistance on rotation of the shaft 2. And a base end 6 protruding so that the base end is pointed in a triangle.
In the lower half of A, a bracket-side end 4 forming a cam driven surface
a, continuous cam surfaces 6a, 6 which are close to or in contact with the upper surface of
b is formed. That is, as shown in FIG. 2, when the release lever 6 is depressed, the flat cam surface 6a formed at the position near the front end is opposed to the upper surface of the bracket side end 4a in a position close to and parallel to the upper surface. As shown in FIG. 3, when the release lever 6 is erected, the flat cam surface 6b formed near the base end rides on the upper surface of the bracket-side end portion 4a while pushing it downward to make surface contact. The stable state in which the sensor unit 3 is in contact with and retracted to the separated position is maintained. Therefore, in the paper release mechanism using the cam 6A, the switching operation of the sensor unit 3 to / from the feed roller 1 (arrow B in FIG. 1) can be stably switched by the raising / lowering operation of the release lever 6 (arrow A in FIG. 1). Become. FIG. 4 shows a specific example of attachment of the paper release mechanism shown in FIGS. 1 to 3 when applied to a scanner section of a facsimile apparatus equipped with a contact image sensor. Here, reference numeral 10 denotes a main body of the apparatus, and 11 denotes a feeder cover (panel cover) which is openably and closably attached to a front upper portion of the main body 10 so as to sandwich the conveyance path of the original P between the main body 10 and the cover. A hinge pin 13 provided on the frame 12 is fitted into a shaft support hole 15 of a sheet-metal side plate 14 protruding from both sides of the main body, and is attached to the hinge pin 13 as a fulcrum so as to be freely opened and closed. Others
Reference numeral 16 denotes a leaf spring stopper attached to the side surface of the cover frame 12, and when the cover is opened to a certain regulation angle as shown in FIG. A hemispherical projection 17 provided on the outer surface of the cover plate fits into a groove 18 provided in the side plate 14, and serves as an opening stopper for preventing further opening of the cover. In this facsimile apparatus, a step 19 is formed on the lower side of the cover frame 12 on the side surface of the frame 12 so that the lever accommodating portion 20 is formed.
Are provided, and the release levers 6 attached to both ends of the roller shaft 2 are compactly provided in the lever accommodating portion 20. In the paper release mechanism configured as described above, the release lever 6 can be mounted around the roller shaft 2 of the feed roller 1 coaxially, so that a separate support shaft for mounting the lever is not required. Therefore, compared to the conventional mechanism, it is sufficient to prepare a single lever, the number of parts is small, and the mounting operation is very simple. Also, the space required for the lever operation can be reduced. In particular, when the mounting structure illustrated in FIGS. 4 and 5 is adopted, as described above, the release lever 6 can be compactly accommodated in the side space of the cover frame 12, and FIG. As shown, the release lever 6 is
When the cover is closed from the open state of FIG. 5 when the cover is closed from the open state of the cover shown in FIG. 19 comes into contact with the distal end of the release lever 6 and pushes it back to the non-operation position. Therefore, even if the operator forgets the lever return operation, the lever return operation is automatically performed in conjunction with the cover closing operation. Is achieved. In the above embodiment, the case where the sensor unit 3 is retracted from the feed roller 1 by the operation of the release lever 6 has been described. However, the present invention can be applied to the case where the unit is fixed and the roller is movable. The paper releasing mechanism according to the present invention is a mechanism in which a driving roller and a roller pressing member are provided so as to be able to contact and separate from each other in a paper transport path, for example, a paper releasing mechanism between a platen roller and a thermal head in a thermal transfer recording section. May be applied as well. As described above, in the paper releasing mechanism according to the present invention, the release for separating the drive roller and the roller pressing member which is pressed against and separated from the roller around the support shaft of the drive roller. Since the lever is mounted, no extra parts are required for mounting the release lever, and a simple structure with a small number of parts is realized. In addition, an openable / closable cover for covering the main body is provided, and a contact portion is provided for contacting and pushing back the release lever that stands when the cover is closed, so that even if the operator forgets to return the lever, the cover can be closed. By the closing operation, the convenience that the drive roller and the roller pressing member can be returned from the separation position to the pressing position can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a main part of a scanner section showing an embodiment. FIG. 2 is a cross-sectional view of a main part of FIG. 1, illustrating an operation of a release lever. FIG. 3 is a cross-sectional view of a main part of FIG. 1, illustrating an operation of a release lever. FIG. 4 is a side sectional view of a main part of the facsimile apparatus showing a specific example of attachment of the release lever shown in FIG. 1; FIG. 5 is a view showing a cover opened state of FIG. 4; FIG. 6 is a schematic sectional view of a scanner section showing a conventional example. [Description of Signs] 1 Feed roller (drive roller) 2 Roller shaft 3 Sensor unit (contact type image sensor) 3a Reading surface 4 Sensor bracket 4a Bracket side end 4b Guide piece 5 Spring 6 Release lever 6A Base end (cam) 6a, 6b Cam surface 10 Main body 11 Feeder cover 12 Cover frame 19 Step 20 Lever housing P Document

Continuation of the front page (56) References JP-A-4-166373 (JP, A) JP-A-4-241566 (JP, A) JP-A-5-50680 (JP, A) JP-A-5-236194 (JP) JP-A-6-32483 (JP, A) JP-A-6-127068 (JP, A) JP-A-6-183597 (JP, A) JP-A-6-209389 (JP, A) 64-12663 (JP, A) Japanese Utility Model 1-169348 (JP, U) Japanese Utility Model 5-68171 (JP, U) Japanese Utility Model 6-34362 (JP, U) Japanese Utility Model 6-41276 (JP, U) U) (58) Investigated field (Int.Cl. ⁷ , DB name) H04N 1/00-1/00 108 H04N 1/04-1/207 B41J 13/00-13/32 B41J 25/304-25 / 316 B65H 5/02 B65H 5/06 B65H 5/22 B65H 29/12-29/24 B65H 29/32 G03G 15/00 510-534

Claims (1)

(57) Claims: 1. A driving roller and a roller pressing member which is pressed against a peripheral surface of the driving roller and nips a sheet between the driving roller and the driving roller are provided so as to be able to contact and separate from each other. A paper release mechanism that swingably mounts a release lever that separates the drive roller and the roller pressing member around the support shaft of the roller, and includes a cover that can be opened and closed to cover the main body. A paper release mechanism, wherein a contact portion that comes into contact with and pushes back the released lever is formed in a release lever accommodating portion of the cover.