Driving apparatus and method for image scanning and/or forming machine

A driving apparatus for an office machine includes a driving motor rotating in first and second directions, a power transfer part transferring a power of the driving motor to a convey unit, a document discharge unit and a document supply unit, and a controller controlling the driving motor. A driving method for the office machine includes driving the driving motor in the first direction to operate the document supply unit and the convey unit in opposite directions with respect to a document-conveying direction till a front end of a document is arranged by the convey unit after the document is supplied by the document supply unit, determining whether the front end of the document is arranged, and driving the driving motor in the second direction to convey and discharge the document through the convey unit and the document discharge unit if the front end of the document is arranged.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Application No. 2002-35806, filed Jun. 25, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to driving apparatus and method for an image scanning and/or forming machine, such as an office machine including a facsimile machine, a laser printer, etc., and more particularly, to driving apparatus and method for an office machine capable of arranging front ends of sheets of paper or documents without using an extra reverse rotation prevention member or an extra power transfer member, such as a swing gear, thereby preventing a paper skew.

2. Description of the Related Art

In general, an office machine, such as a facsimile machine, a multi-function machine, etc., has a scanning device scanning data recorded on documents, a facsimile device transferring or receiving scanned data through communication lines, and a printing device printing the scanned data, the data received through the communication lines, or data inputted from a computer on sheets of paper as an output. The scanning device, which is one of constituents of the office machine, is essentially required to transfer the data recorded on the documents or print the data on the sheets of paper as the output.

FIG. 1shows a scanning device10applied to a general facsimile machine. The scanning device10includes a document supply unit13formed on an upper side of an apparatus to automatically supply sheets of documents D to be picked sheet by sheet, a scanner18reading data from the documents D delivered from the document supply unit13, and a document discharge unit21discharging the documents D passing through the scanner18outside the apparatus.

The document supply unit13supplying the documents D inside the scanning device10is provided with a document supply tray15loaded with the documents D, a document sensor1detecting whether the documents D is loaded, a pickup roller14picking up the documents D according to operations of the document sensor1, a friction pad16being in contact with the pickup roller14with a predetermined pressure to separate the documents D sheet by sheet, and a feed roller14′ conveying the documents D toward the scanner18.

The scanner18includes a contact image sensor19reading data from the documents D delivered by a rotation force of the feed roller14′, and a white roller20bringing the documents D to be in contact with the contact image sensor19.

The document discharge unit21has a document discharge roller22discharging the documents D, and a document discharge backup roller23coming in contact with the document discharge roller22with a predetermined pressure.

Further, the scanning device10includes a driving unit driving the pickup roller14, feed roller14′, white roller20, and document discharge roller22.

The driving unit has a driving motor5rotating in both directions, a swing gear train7switching power of the driving motor5, a first driving gear11meshing with a second swing gear9of the swing gear train7by the swing gear train7rotating in a direction of arrow A about a first swing gear8thereof when the driving motor5rotates in a clockwise direction as shown in a direction indicated in a solid line arrow ofFIG. 1, a feed roller gear (not shown) connected with the first driving gear11through a first idle gear12and coaxially formed with the feed roller14′, a pickup roller gear (not shown) connected to the feed roller gear through a second idle gear24and coaxially formed with the pickup roller14, a second driving gear26meshing with a third swing gear25of the swing gear train7by the swing gear train7rotating in the direction of an arrow A about the first swing gear8thereof when the driving motor5rotates in a counterclockwise direction as shown in a direction indicated in a dotted line arrow ofFIG. 1, a white roller gear (not shown) connected to the second driving gear26through a third idle gear27and coaxially formed with the white roller20, and a document discharge roller gear (not shown) connected to the second driving gear26and coaxially formed with the document discharge roller22.

Operations of the conventional scanning device10structured above are described with reference toFIG. 1.

First, when a document D is loaded in the document supply tray15to convey or photocopy the document D, the document D slides down due to its weight to operate the document sensor1. Accordingly, a controller applies electric power to the driving motor5to rotate the driving motor5in one direction, for example, in the clockwise direction as shown in the solid line arrow ofFIG. 1.

As the driving motor5rotates in the clockwise direction, the swing gear train7rotates in the direction of arrow A, that is, in the counterclockwise direction about the first swing gear8thereof to have the second swing gear9of the swing gear train7to mesh with the first driving gear11.

Accordingly, the feed roller14′, which is associated with the first driving gear11, the first idle gear12, and the feed roller gear (not shown), rotates in the counterclockwise direction, so does the pickup roller14associated with the feed roller14′ through the second idle gear24and the pickup roller gear.

Therefore, the pickup roller14picks up the documents D sheet by sheet by a friction force with the friction pad16, and the feed roller14′ delivers a sheet of documents picked up by the pickup roller14toward a scan sensor17.

After the scan sensor17is opened by a front end of the document D when the front end of the document D reaches the white roller20with a lapse of a predetermined time, the front end of the document D is arranged in curl by the white roller20which is stationary due to a cutoff of a rotation power from the swing gear train7.

At this state, when a user presses a start button of the facsimile machine conveying or photocopying the document D, the driving motor5is driven in a reverse direction, that is, from the clockwise direction to the counterclockwise direction, by which the swing gear train7rotates in the direction of the arrow A, that is, in the clockwise direction about the first swing gear8, and the third swing gear25of the swing gear train7is meshed with the second driving gear26.

Accordingly, the white roller20, which is associated with the second driving gear26, the third idle gear27, and the white roller gear (not shown), rotates in the clockwise direction, so does the document discharge roller22associated with the second driving gear26through the document discharge roller gear (not shown).

Therefore, the document D passes through a nip between the contact image sensor19and the white roller20by the white roller20, and the contact image sensor19of the scanner18reads data from the document D.

As stated above, when the contact image sensor19of the scanner18completely reads out the data from the document D, the document D is discharged outside the apparatus by the document discharge roller22.

However, the conventional scanning device10as described above should use a power switching member or a reverse rotation prevention member, such as the swing gear train7including three swing gears8,9, and25to have the white roller20stationary without movements so that the front ends of the documents D are arranged while preventing the documents D from being skewed, when the power of the driving motor5is transferred to the pickup roller14and the feed roller14′. Accordingly, a problem occurs that a structure of the driving unit of the scanning device10becomes complicated and a manufacturing cost increases.

Further, the use of the swing gear train7causes a structure of the second and third swing gears9and25to move by a coupling force upon power switching operations of the driving motor5, which generates noise as well as vibrations or malfunctions due to irregular operations. Accordingly, jitter occurs on a final image obtained upon photocopying or conveying, or a document jam occurs, and the jitter or the document jam causes a problem that lowers the product reliability.

Furthermore, when the switching gear train7is switched by the driving motor5, it takes time to mesh the second and third swing gears9and25with the first and second driving gears11and26so that time for readout of the documents becomes prolonged, which causes a problem that delays photocopying or conveying times.

SUMMARY OF THE INVENTION

The present invention has been devised to solve the above and/or other problems, so it is an aspect of the present invention to provide driving apparatus and method for office machines capable of simplifying a structure thereof with a reduction of the number of constituent parts thereof.

It is another aspect of the present invention to provide driving apparatus and method for office machines capable of performing a function of arranging front ends of documents to prevent the documents from being skewed without any power switching member, such as swing gears, so that an occurrence of quality-lowering problems, such as noise, vibrations due to malfunctions, time delays, a paper jam, etc., caused by use of the power switching member is prevented, thereby enhancing product reliability.

To achieve the above and/or other aspects of the present invention, a driving apparatus for an image scanning and/or forming machine, such as an office machine, includes a document supply unit picking up and supplying sheets of paper documents one by one, a convey unit conveying each document supplied by the document supply unit, a document discharge unit externally discharging the document, and a driving unit driving the document supply unit, the convey unit, and the document discharge unit. The driving unit includes a driving motor rotating in both directions, a power transfer part transferring a power of the driving motor to the respective parts to convey the document in a different direction from the document supply unit so that the convey unit and the document discharge unit have functions arranging a front end of the document, conveying the document, and discharging the document, respectively, and a controller controlling the driving motor.

According to another aspect of the invention, the power transfer part includes a first driving portion transferring the power of the driving motor to the document supply unit in order for the document supply unit to operate in a document-supplying direction so that the document is supplied each time the driving motor rotates in a first direction, a second driving portion transferring the power of the driving motor to the convey unit in order for the convey unit to operate in a direction opposite to the document-supplying direction so that the front end of the document is arranged as the driving motor rotates in the first direction and a third driving portion transferring the power of the driving motor to the document discharge unit in order for the document discharge unit to operate in the document-supplying direction so that the document is discharged as the driving motor rotates in the second direction. The power transfer part may further include a sun gear coupling the driving motor with the first, second, and third driving portions.

The document supply unit has a supply roller picking up the documents one by one, and the first driving portion has a one-way power transfer gear transferring the power in only one way coupled with the sun gear, and a supply roller gear coupled with the one-way power transfer gear and coaxially formed with the supply roller. At this time, the document supply unit further includes a pickup roller picking up the document, and the first driving portion further includes at least one first mid-coupling gear coupled with the supply roller gear in order for the pickup roller to rotate in the same direction as the supply roller and a pickup roller gear coupled with the first mid-coupling gear and coaxially formed with the pickup roller.

The convey unit includes a feed roller conveying the document conveyed by the supply roller, and an idle roller disposed to be in contact with the feed roller in a predetermined pressure, and the second driving portion includes at least one first satellite gear coupled with the sun gear and a feed roller gear coupled with the first satellite gear and coaxially formed with the feed roller.

Further, the document discharge unit includes a document discharge roller discharging the document and a backup roller being in contact with the document discharge roller with a predetermined pressure, and the third driving portion includes at least one second satellite gear coupled with the sun gear, at least one second mid-coupling gear coupled with the second satellite gear, and a document discharge roller gear coupled with the second mid-coupling gear and coaxially formed with the document discharge roller.

The controller controls the driving motor to be driven in one direction till the front end of the document is arranged by the feed roller and the idle roller of the convey unit after the documents are supplied one by one by the document supply unit, and controls the driving motor to be driven in the second direction to convey and discharge the document through the convey unit and the document discharge unit after the front end of the document is arranged. At this time, the convey unit further includes a register sensor disposed between the document supply unit and the convey unit to detect the front end of the document. It is possible that the controller determines the time to drive the driving motor in the second direction after the front end of the document is arranged, that is, a period of time lapsed after the register sensor of the convey unit is operated by the front end of the document.

According to another aspect of the present invention, the driving method for an office machine includes a document supply unit picking up and supplying sheets of paper or document one by one, a convey unit conveying the document supplied by the document supply unit, a document discharge unit externally discharging the document, a driving unit driving the document supply unit, the convey unit, and the document discharge unit and having a driving motor rotating in first and second directions, a power transfer part transferring a power of the driving motor to the respective units to convey the document in a different direction from the document supply unit so that the convey unit and the document discharge unit have functions arranging the front end of document, conveying the document, and discharging the document, respectively, and a controller controlling the driving motor. The method includes driving the driving motor in the first direction in order for the document supply unit and the convey unit to operate in directions opposite to each other with respect to a document-conveying direction till the front end of the document is arranged by the convey unit after each document is supplied by the document supply unit, determining whether the front end of the document is arranged, and driving the driving motor in the second direction to convey and discharge the document through the convey unit and the document discharge unit if the front end of the document is arranged.

According to another aspect of the invention, the deciding of whether the front end of the document is arranged includes counting time after a register sensor located between the document supply unit and the convey unit operates, and determining whether the counted time is a predetermined time.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a driving apparatus for office machines according to an embodiment of the present invention is described in detail with reference to the accompanying drawings.

FIG. 2schematically shows a scanning device100of a facsimile machine to which a driving apparatus or unit130is applied.

The scanning device100has a document supply unit113supplying documents D picked up sheet by sheet, a convey unit115conveying a document D supplied by the document supply unit113, a scanner118reading data from the document D conveyed by the convey unit115, a document discharge unit121externally discharging the document, and the driving unit130driving the document supplying unit113, the convey unit115, and the document discharge unit121.

The document supply unit113includes a document sensor102detecting whether documents D are loaded in a document supply tray (not shown), a pickup roller114picking up a document D according to an operation of the document sensor102, a supply roller114′ conveying the document D picked up by the pickup roller114toward the convey unit115, and a friction pad111being in contact with the supply roller114′ with a predetermined pressure to separate the documents D sheet by sheet by a friction force.

The convey unit115is constructed with a register sensor103detecting a convey amount of the document D to arrange a front end of the document D conveyed by the supply roller114′ with respect to the scanner118or in a scanning direction of the scanner118, a feed roller116conveying the document D, and an idle roller117formed of a plastic material and disposed to be in contact with the feed roller116with a certain pressure for arrangement and conveying of the front end of the document D.

Accordingly, when the document D passes through the register sensor103and arrives near the feed roller116and idle roller117rotating in a direction opposite to a document supply direction in which the document D is supplied by the driving unit130to be described later as shown inFIG. 4A, the front end of the document D comes in contact with a circumferential surface of the idle roller117to be led to a nip between the feed roller116and the idle roller117as shown inFIG. 4B, is curled and arranged by a force by which the document D is conveyed as shown inFIG. 4C, and passes through the nip when the feed roller116reverse-rotates in the document supply direction that the document D is supplied, by the driving unit130as shown inFIG. 4D.

The scanner118is constructed with a scan sensor104detecting the document D conveyed by a rotation force of the feed roller116, a charge-coupled device (CCD)119, such as a solid state imaging device, reading data from the document D, and a white bar120guiding the document D to come into contact with the scanner118. Selectively, the scanner118may be constructed with the contact image sensor19and the white roller20like as in a conventional scanning device10illustrated inFIG. 1.

The document discharge unit121includes a document discharge roller126and a document discharge backup roller127discharging the document D passing through the scanner118outside the device.

As shown inFIG. 3, the driving unit130driving the pickup roller114and the supply roller114′ of the document supply unit113, the feed roller116of the convey unit115, and the document discharge roller126of the document discharge unit121are provided (coupled) with a driving motor131rotating in first and second directions, power transfer units132,122,123, and124transferring a power of the driving motor131to the respective units113,115, and121so that the convey unit115and the document discharge unit121convey the document D in the direction different from that of the document supply unit113, and a controller (not shown) controlling the driving motor131.

The power transfer units132,122,123, and124are constructed with a sun gear132connected with a power transfer gear131aof the driving motor131, a first driving portion122transferring the power of the driving motor131to the pickup roller114and the supply roller114′ in order for the pickup roller114and the supply roller114′ to rotate in the document supply direction in which the document D is supplied, that is, in a clockwise direction, as the driving motor131rotates in the first direction, for example, in a counterclockwise direction as shown inFIG. 2, a second driving portion123transferring the power of the driving motor131to the feed roller116in order for the feed roller116to rotate in the direction opposite to the document feeding direction in which the document D is supplied, that is, in the clockwise direction, as the driving motor131rotates in the counterclockwise direction so that the convey unit115arranges the front end of the document D, and a third driving unit124transferring the power of the driving motor131to the document discharge roller126in order for the document discharge roller126to rotate in the document supply direction, that is, in the counterclockwise direction, as the driving motor131rotates in the second direction, that is, in the clockwise direction, to discharge the document D.

The first driving portion122has a one-way power transfer gear134, such as a latch gear, coupled with the sun gear132to transfer the power of the driving motor131only in one direction, that is, in the counterclockwise direction, and first and second supply roller gears114a′ and114a″ (refer toFIG. 3) coupled with the one-way power transfer gear134and coaxially formed on both sides of the supply roller114′. The pickup roller114is coupled with the second supply roller gear114a″ through a first mid-coupling gear112and the pickup roller gear114acoaxially formed with the pickup roller114in order for the pickup roller114to rotate together with the supply roller114′ in the same direction.

Alternatively, the one-way power transfer gear134is described as the latch gear in the present embodiment, but the gear134may be replaced with another one-way power transfer part so that the power of the driving motor131is not transferred to the supply roller114′ and the pickup roller114when the driving motor131rotates in the second direction, that is, in the clockwise direction, to transfer the document D.

The second driving portion123has a first satellite gear133coupled with the sun gear132and a feed roller gear116acoupled with the first satellite gear133and coaxially formed with the feed roller116.

Further, the third driving portion124includes a second satellite gear136coupled with the sun gear132, second and third mid-coupling gears137and138coupled with the second satellite gear136, and a document discharge roller gear126acoupled with the third mid-coupled gear138and coaxially formed with the document discharge roller126.

The controller controls the driving motor131to be driven in the first direction, that is, in the counterclockwise direction, until the front end of the document D is arranged by the feed roller116and the idle roller117of the convey unit115rotating in the direction opposite to the document supply direction as shown inFIG. 4Cafter the document D is picked up by the pickup roller114of the document supply unit113and supplied by the supply roller114′. The controller controls the driving motor131to be driven in the second direction, that is, in the clockwise direction, so that the feed roller116and the document discharge roller126rotate in the document supply direction, that is, in the counterclockwise direction, to convey and discharge the document D after the front end of the document D is arranged, and the document D is scanned by the scanner118. At this time, a time to drive the driving motor131in the clockwise direction after the front end of the document D is arranged is set to the time when a certain amount of curl at the front end of the document D is formed, that is, a lapse of a predetermined period of time after the register sensor103of the convey unit115is operated by the front end of the document D.

As stated above, the driving unit130of the scanning device100operates the pickup roller114and the supply roller114′ of the document supply unit113in the clockwise direction when the driving motor131rotates in the counterclockwise direction, and thereby the documents D are supplied sheet by sheet and the front end of the document D is arranged by the feed roller116and the idle roller117of the convey unit115rotating in the direction opposite to the document supply direction, that is, in the clockwise direction.

Further, as the driving motor131rotates in the clockwise direction with the lapse of the predetermined period of time after the register sensor103is operated, a power transfer from the driving motor131to the pickup roller114and the supply roller114′ of the document supply unit113is cut off by the one-way power transfer gear134, and the feed roller116of the convey unit115and the document discharge roller126of the document discharge unit121are driven in the counterclockwise direction. As a consequence, the document D is conveyed toward the scanner118and discharged.

As illustrated and described above, the driving unit130of the present invention is applied only to the scanning device100of the facsimile machine, but the present invention may be applied to a driving unit of a printing device for the facsimile machine or a paper supply device for a printer with the same structure as the driving unit130to arrange a sheet of paper to be printed. The driving unit of the printing device for the facsimile machine or the paper supply device for the printer may have a developing unit or a printing head instead of the scanner118to print an image on the sheet.

Operations of the scanning device100to which the driving unit130structured above according to the present invention is applied will be described with reference toFIGS. 2 to 4D.

First, if documents D are loaded in the document supply tray to transfer or photocopy the documents D, the documents D slide down due to their own weight and operate the document sensor102. As a result, the controller supplies an electric power to the driving motor131so that the driving motor131rotates in one way (first direction), for example, in the counterclockwise direction indicated in a solid line arrow ofFIG. 1.

As the driving motor131rotates in the counterclockwise direction, the supply roller114′ rotates in the clockwise direction by the sun gear131, one-way power transfer gear134, and first supply roller gear114a′, and, accordingly, the pickup roller114coupled with the second supply roller gear114a′ through the pickup roller gear114aand the first idle gear112also rotates in the clockwise direction.

Therefore, the pickup roller114picks up and conveys the documents D toward the supply roller114′, and the supply roller114′ separates and conveys the documents D sheet by sheet by the friction force with a friction pad111toward the register sensor103.

When one of the documents D passes through the register sensor103and arrives near the feed roller116and the idle roller117as shown inFIG. 4A, the front end of the document D is led into the nip between the feed roller116and the idle roller117to be in contact with the circumferential surface of the idle roller117as shown inFIG. 4B.

At this time, since the feed roller116of the convey unit115rotates in the direction opposite to the document supply direction, that is, in the clockwise direction, by the feed roller gear116aand the first satellite gear133coupled with the sun gear132, the front end of the document D does not pass through the nip between the feed roller116and the idle roller117, but is curled and at the same time arranged by the force by which the document D is conveyed as shown inFIG. 4C.

Thereafter, when the predetermined period of time lapses from the time the register sensor103operates, the controller drives the driving motor131in a reverse direction (second direction), that is, in the clockwise direction. Accordingly, the feed roller116rotates in the counterclockwise direction through the sun gear132, the first satellite gear133, and the feed roller gear116awhile the power transfer to the pickup roller114and the supply roller114′ is cut off by the one-way power transfer gear134.

As a consequence, the document D is conveyed toward the scan sensor104through the nip between the feed roller116and the idle roller117as shown inFIG. 4D.

When the predetermined period of time lapses after the scan sensor104is operated, the document D passes through the nip between the CCD119and the white bar120of the scanner118, and the CCD119of the scanner118reads data from the document D.

As above, when the CCD119of the scanner118completely reads data from the document D, the document D is discharged outside the scanning device100by the sun gear132, the second satellite gear136, the second and third mid-coupling gears137and138, and the document discharge roller126rotating in the counterclockwise direction by the document discharge roller gear126a.

As described above, the driving apparatus and the method for office machine according to the present invention perform an operation of arranging the front ends of documents without using complicated power switching members, such as swing gears, thereby reducing the number of constituent parts and simplifying the structure so that a manufacture cost is reduced, as well as preventing problems, such as noise due to the use of the complicated power switching members, vibrations due to malfunctions, time delays, jams, etc., from occurring so that product reliability is enhanced, and a quality is not lowered.

As above, a specific preferred embodiment of the present invention has been illustrated and described. However, it will be understood by those skilled in the art that the present invention should not be limited to the described preferred embodiment, but various changes and modifications can be made within the spirit and scope of the present invention as defined by the appended claims and their equivalents.