Automatic Feeding Device for Copying Machines

The present invention relates to a device for operating a registration member in an automatic feeding device for original documents utilized in a copying machine.

In an automatic feeding device for original documents in a copying machine, it has been general practice to carry out the registration of original documents by abutting the tip end of the original document against a registration member. When the original document is no longer needed for copying, it is necessary that the registration member be moved such as by retracting it to a standby position which is at a position lower than the surface of the original document and at which the tip end of the original document will not strike thereagainst. To implement this, the prior art technique was to transfer a member directly coupled to the registration member to a standby position with a reciprocating device such as a solenoid. For this reason, space was required for the reciprocating device thereby greatly restricting the overall available space while the mechanism needed was complex and costly.

Also, a large length was required for the registration member so that all the edge surface of the original document in the widthwise direction would properly abut the registration member. This is a great disadvantage both in spacial and constructional requirements.

Consequently, it is an object of the invention to provide an operating device for a registration member in an automatic feeding device for original documents which requires only a narrow space and which can transfer documents uniformly and smoothly over all the lengthwise direction thereof.

This, as well as other objects of the invention, are met by a registration device for an automatic feeding device for original documents in a copying machine in which a magnetic registration member is disposed adjacent an edge of a platen member. In a copying position upon the upper surface of the platen, the leading edge of an original document to be copied is in abutment with an upper stepped portion of the registration member. The registration member is formed with a permanent magnet extending longitudinally thereof. The registration member is movable between upper and lower positions defined by an adjacent guide means. In the upper position, the upper stepped portion of the registration member extends above the upper surface of the platen while in the lower position, the registration member is entirely below the upper surface of the platen. Spring means urges the registration member upwardly to the copying position. An electromagnet means is located in an adjacent cover. The electromagnet means extends longitudinally preferably by the same length as the registration member. When exited, the electromagnet means produces a magnetic field which urges the registration member to the lower position below the surface of the platen so that original documents can be extracted therefrom. Preferably, the edge of the platen and hence the registration member and guide means are sloped so that light from the copying system can reach the entire surface of the original document.

FIG. 1 is a general schematic view showing a copying machine constructed in accordance with the present invention;

FIG. 2 is an enlarged cross-sectional view of portions of FIG. 1;

FIG. 3 is a cross-sectional view similar to FIG. 2 showing a lowered portion of a registration member;

FIG. 4 is a cross-sectional view of another embodiment of an automatic feeding device of the invention; and

FIG. 5 is a cross-sectional view used for explaining why an end surface of the platen is cut obliquely.

Preferred embodiments of the present invention will be described referring to the drawings.

FIG. 1 is a general diagrammatic cross-sectional view of a copying machine of the invention in which a platen 2 is provided on the upper portion 1a of the copying machine body 1 and an automatic feeding device 3 for original documents is mounted above the platen 2.

The automatic feeding device 3 includes a feeding belt 5 for the original documents provided at a position in contact with the upper surface (also, the running surface of the original document) 2a of the platen 2. The feeding belt 5 is disposed within a platen cover 4 opening downwardly. The feeding belt 5 operates to transfer an original document A inserted through a take-in guide 6 along the upper surface 2a of the platen. The copying position of the original document A is determined by a registration member 7 against which the feeding edge of the document abuts. After the completion of the copying operation, the registration member 7 is moved to a standby position and the original document A is delivered to a holding tray 8.

The registration member 7 is made of a permanent magnet having an elongated shape with an upper stepped portion 7a and is freely movable in the vertical direction between one end surface 2b of the platen 2 and the upper end of a guide 9 attached to the upper portion of the copying machine body 1a. The registration member 7 is urged toward the copying position with the upper stepped portion 7a in contact with a lower stepped portion 9a of the guide 9 by a spring 10. In this position, the upper surface 7b of the registration member 7 projects slightly upward beyond the upper surface 2a of the platen 2.

An electromagnet 11 is mounted on the platen cover 4 facing the upper surface 7b of the registration member 7. The electromagnet 11 is energized by a signal indicative of the delivery of an original document. The magnetic field produced by the electromagnet 11 has the same polarity as that of the registration member 7. In FIG. 1, reference numeral 12 designates a lamp, 13 a reflecting optical system, and 14 a photosensitive drum.

When the electromagnet is deenergized, the registration member 7 is moved to the copying position by the spring 10 as shown in FIG. 2 in which the leading edge of the original document A transferred by the original document feeding belt 5 abuts the upper surface of the registration member 7 with positioning thereby effected. When the electromagnet 11 is energized by a signal indicative of the delivery of the original document, a repulsive force is produced between the electromagnet 11 and the registration member 7 whereby the registration member 7 is retracted downwardly against the force of the spring 10 to a standby position in abutment with a stop 15. In the standby position, the upper surface 7b of the registration member 7 is situated below the upper surface 2a of the platen so that it will not obstruct the transfer of the original document A.

As described above, since the registration member 7 is moved to the standby position by utilizing the repulsive force of the magnet, there is no need of providing a reciprocating device such as solenoid and only an electromagnet 11 need be provided on the platen cover 4 whereby the construction of the feeding device is made simpler and the number of parts required is also decreased. Thus, the registration member 4 is constructed utilizing only a narrow space effectively.

Also, since the repulsive force of the magnet is uniform in the longitudinal direction, a uniform pushing force is effected so that the registration member 7 is positioned uniformly without being tilting with respect to the longitudinal direction with only a small amount of transfer movement. With this construction, the original document will not be damaged because of the fact that the leading edge of the original is engaged with the registration member 7 when it is delivered.

Mispositioning between the leading edge of the original document and the position at which the exposure is commenced or terminated can be prevented by providing a sloped end surface 2b of the platen 2 as shown in FIG. 4. That is to say, if the end surface 2b of the platen is vertical, the light B may not reach the leading edge A' of the original document as illustrated in FIG. 5. To prevent this, the end surface 2b of the platen may be cut obliquely. In the case of a sloped end surface 2a, the guide 9 is disposed parallel to the end surface 2b of the platen and both of the end surfaces 7c and 7d of the registration member 7 are made to be parallel to the guide 9 and the end surface 2b of the platen.

With the feeding device of the present invention constructed as described above, only a registration member 7 and an electromagnet 11 are required to be provided so that the construction is simpler, the number of parts is much reduced, and the device can be installed utilizing a narrower space effectively compared with the prior art construction.

Furthermore, since the registration member 7 is moved utilizing the repulsive force of a magnet, the registration member 7 can be moved uniformly over the longitudinal extend thereof and the registration member 7 can be moved downward uniformly from the running surface 2a of the original document with only a relatively small force so that the original document A will not be damaged when it is delivered.