Recording medium removing apparatus, erasing apparatus, automatic document feeding apparatus, and recording medium removing method

According to one embodiment, an erasing apparatus including a recording medium removing apparatus includes: a thickness determining unit configured to determine whether the thickness of a recording medium is equal to or larger than a first threshold, a conveyance guide forming a conveying path for the recording medium; a conveyance guide displacing device configured to lift the conveyance guide if the thickness determining device determines that the thickness of the recording medium is equal to or larger than the first threshold, and a removing mechanism configured to remove, from a recording medium conveying path, the recording medium determined as unconveyable.

FIELD

Embodiments described herein relate generally to a recording medium removing apparatus, an erasing apparatus, an automatic document feeding apparatus, and a recording medium removing method.

BACKGROUND

For saving of resources, in some case, image formation is performed using erasable developing materials. As the erasable developing materials, there are toner, ink, and the like erased by heat. Recording media on which images are formed with such erasable developing materials are reused after being heated by an erasing apparatus to have the images erased from the recording media.

However, recording media inserted into the erasing apparatus are not always separated one by one. For example, in some case, a stapled sheet bundle, a pasted and bound sheet bundle, or the like is inserted.

If such a sheet bundle is conveyed, not only a jam occurs but also the erasing apparatus is damaged.

Concerning this problem, there is proposed a technique for setting a double feed sensor and a thickness sensor in a recording medium conveying path and, if plural recording media are simultaneously conveyed, discarding the recording media in a disposal box.

However, if a sheet bundle having thickness equal to or larger than a measurement tolerance of the thickness sensor is conveyed, not only a jam occurs but also the thickness sensor is damaged.

Therefore, there is a demand for a recording medium removing apparatus that can remove a sheet bundle having thickness exceeding the tolerance of the thickness sensor without damaging the thickness sensor when the sheet bundle is conveyed thereto, an erasing apparatus and an automatic document feeding apparatus including the recording medium removing apparatus, and a recording medium removing method for use in the recording medium removing apparatus.

DETAILED DESCRIPTION

Throughout this description, the embodiments and examples shown should be considered exemplars, rather than limitations on the apparatus and methods of the present embodiments.

Exemplary embodiments of an erasing apparatus and an automatic document feeding apparatus including the recording medium removing apparatus, and a recording medium removing method for use in the recording medium removing apparatus of the present invention are explained in detail below with reference to the accompanying drawings.

In general, according to one embodiment, a recording medium removing apparatus includes: a first thickness sensor configured to change an output signal if the thickness of a recording medium is equal to or larger than a first threshold; a conveyance guide provided downstream in a recording medium conveying direction of the first thickness sensor and forming a conveying path for the recording medium; and a conveyance guide displacing device configured to displace the conveyance guide to expand the recording medium conveying path.

According to another embodiment, an erasing apparatus includes: a recording medium conveying mechanism configured to convey a recording medium; a first thickness sensor configured to change an output signal if the thickness of the recording medium is equal to or larger than a first threshold; a conveyance guide provided downstream in a recording medium conveying direction of the first thickness sensor and forming a conveying path for the recording medium; a conveyance guide displacing device configured to displace the conveyance guide to expand the recording medium conveying path; and a heating roller configured to heat the recording medium to temperature equal to or higher than erasing temperature.

According to still another embodiment, an automatic document feeding apparatus includes: a document tray on which an original document is placed; a pickup roller configured to pick up the original document from the document tray; a document feeding roller of a conveying mechanism configured to convey the original document; a first thickness sensor configured to change an output signal if the thickness of the original document is equal to or larger than a first threshold; a conveyance guide provided downstream in a document conveying direction of the first thickness sensor and forming a document conveying path; a conveyance guide displacing device configured to displace the conveyance guide to expand the document conveying path; a document reading section configured to cause the original document to pass to a scan position; a document reversing mechanism configured to reverse the front and the back of the original document; and a paper discharge tray onto which the original document is discharged and stacked.

First Embodiment

FIG. 1is a side view of an erasing apparatus10including a recording medium removing apparatus200. As shown inFIG. 1, the erasing apparatus10includes an inlet tray101on which recording media to be subjected to erasing are placed, a pickup roller102configured to pick up the recording media placed on the inlet tray101one by one, a passage sensor103configured to detect passage of the recording medium, a double feed sensor104configured to detect double feed of the recording media, conveying rollers106configured to convey the recording medium, the recording medium removing apparatus200configured to remove, from a recording medium conveying path, the recording medium determined as unconveyable, a heating roller107, as the heating device, configured to heat the recording medium to temperature equal to or higher than erasing temperature, an image detection sensor108configured to detect whether an image on the recording medium is erased, switching devices109configured to switch a conveying path for the recording medium, reuse boxes110in which reusable recording media are accumulated, a disposal box111in which unreusable recording media are accumulated, and a control unit.

The double feed sensor104causes, for example, ultrasound to pass from one surface to the other surface of the recording medium and outputs a level of the ultrasound passed through the recording medium. The control unit determines double feed on the basis of the level.

The heating roller107, as the heating device, is formed of metal and includes a heater on the inside thereof. The heating roller107heats an erasable developing material on the recording medium to temperature equal to or higher than the erasing temperature and subjects the recording medium to erasing.

Any heat source may be used for the heating device as long as the devices can heat the recording media to the color erasing temperature or higher. For the heating devices, for example, thermal heads, halogen heaters, graphite heaters, IH (Induction Heater), rollers formed by heat conducting materials with heat generating lamps inside, or the like may be employed.

Any heat source which heats the recording media without contacting also may be employed for the heating device.

Examples of the erasable developing material include a color-assuming compound, a developer, and a decolorizer. Examples of the color-assuming compound include a leuco dye. Examples of the developer include phenol. Examples of the decolorizer include a substance that, when heated, dissolves with the color-assuming compound and does not have affinity with the developer.

The erasable developing material develops a color according to a mutual action of the color-assuming compound and the developer. Since the mutual action of the color-assuming compound and the developer is interrupted by heating to temperature equal to or higher than the erasing temperature, the developing material is erased.

The recording medium is determined as unreusable if an un-erased image is present on the recording medium. The recording medium is conveyed through the recording medium conveying path switched by the switching devices109and accumulated in the disposal box111.

The recording medium removing apparatus200includes a thickness determining device201configured to determine whether the thickness of a recording medium is equal to or larger than a first threshold, a conveyance guide202forming a conveying path for the recording medium, conveyance guide displacing devices203configured to lift and lower the conveyance guide202, and a removing mechanism204configured to remove, from the recording medium conveying path, the recording medium determined as unconveyable.

The recording medium removing apparatus200is set upstream in the recording medium conveying direction of the heating roller107. The recording medium removing apparatus200is set further upstream in the recording medium conveying direction than a first curved portion of the recording medium conveying path.

The recording medium removing apparatus200includes the thickness determining device201further upstream in the recording medium conveying direction than the conveyance guide202.

The recording medium removing apparatus200includes the removing mechanism204below the conveyance guide202across the recording medium conveying path.

The recording medium removing apparatus200includes the disposal box111below the removing mechanism204.

FIG. 2is a perspective view of a recording medium conveying section of the recording medium removing apparatus200. InFIG. 2, a state in which the conveyance guide202is lowered is shown. As shown inFIG. 2, the conveyance guide202is formed in a plate shape. The conveyance guide displacing devices203support the conveyance guide202to be capable of being lifted and lowered. The recording medium removing apparatus200includes, in the recording medium conveying path, plural thickness detecting mechanisms201A configured to detect the thickness of the recording medium.

FIG. 3is a diagram of a state in which the recording medium removing apparatus200lifts the conveyance guide202. As shown inFIG. 3, if the erasing apparatus10determines, with the thickness determining device201, that the thickness of the recording medium is equal to or smaller than the first threshold, the erasing apparatus10displaces the conveyance guide202to be lifted and expands the recording medium conveying path.

FIG. 4is a side view of the recording medium removing apparatus200. InFIG. 4, a state in which the conveyance guide202is lowered is shown. As shown inFIG. 4, the thickness determining device201includes an inserting roller201B configured to insert the recording medium into the thickness determining device201, a detection roller201A1configured to move up and down according to the thickness of the recording medium, an actuator201A2configured to pivotably support the detection roller201A1, and a first thickness sensor201A3configured to change an output signal from OFF to ON if the thickness of the recording medium is equal to or larger than the first threshold according to the rotation of the actuator201A2.

The conveyance guide202includes, on the recording medium conveying path side, a second thickness sensor202A1configured to detect the thickness of the recording medium.

The second thickness sensor202A1brings an actuator into contact with the recording medium, transmits the movement of the actuator to a permanent magnet, detects the movement of the permanent magnet with a magnetic sensor, and outputs a signal corresponding to the thickness of the recording medium. The control unit determines the thickness of the recording medium on the basis of the output signal.

The second thickness sensor202A1is lifted and lowered according to lifting and lowering of the conveyance guide202. The erasing apparatus10determines, with the second thickness sensor202A1, whether the recording medium has thickness equal to or larger than a second threshold smaller than the first threshold.

The removing mechanism204includes conveyance driving rollers204A configured to convey the recording medium in the recording medium conveying direction, conveying rollers204A2configured to rotate following the conveyance driving rollers204A, a conveying roller solenoid204A3configured to lift and lower the conveying rollers204A2, and a conveying motor204A1configured to drive the conveyance driving rollers204A.

The removing mechanism204further includes, on a side at a right end or a left end with respect to the recording medium conveying direction, a pair of discharge rollers204B having rotation axes in parallel to the recording medium conveying direction and a discharge motor204B1configured to drive the discharge rollers204B.

FIG. 5is a side view of the recording medium removing apparatus200that lifts the conveyance guide202. As shown inFIG. 5, if the erasing apparatus10determines, with the thickness determining device201, that the thickness of the recording medium is equal to or larger than the first threshold, the erasing apparatus10lifts the conveyance guide202together with the second thickness sensor202A1and expands the recording medium conveying path.

FIG. 6is a front view of the recording medium removing apparatus200viewed from upstream in the recording medium conveying direction.FIG. 7is a front view of a state in which the recording medium removing apparatus200lifts the conveyance guide202.

As shown inFIG. 6andFIG. 7, the removing mechanism204includes a clutch204A5configured to move, when connected, the conveyance driving rollers204A and the conveying rollers204A2to the discharge rollers204B side in a direction perpendicular to the recording medium conveying direction and a vertical moving mechanism204A4.

If the erasing apparatus10determines, with the thickness determining device201, that the thickness of the recording medium is equal to or larger than the first threshold, first, the erasing apparatus10lifts the conveyance guide202together with the second thickness sensor202A1. At this point, the conveyance driving rollers204A and the conveying rollers204A2keep nipping the recording medium.

Subsequently, the erasing apparatus10turns on, i.e., connects the clutch204A5to drive the discharge motor204B1. The vertical moving mechanism204A4moves the conveyance driving rollers204A and the conveying rollers204A2to the discharge rollers204B side in the direction perpendicular to the recording medium conveying direction. Therefore, the side ends of the recording medium reach the discharge rollers204B.

If the erasing apparatus10detects, with a paper discharge sensor807set beside the discharge rollers204B, that the side ends of the recording medium reach the discharge rollers204B, the erasing apparatus10turns off, i.e., releases the clutch204A5, lifts the conveying rollers204A2with the conveying roller solenoid204A3, and releases the recording medium.

The discharge rollers204B discharge the released recording medium to the disposal box111.

FIG. 8is a block diagram of the configuration of the erasing apparatus10. As shown inFIG. 8, the erasing apparatus10includes a main CPU801serving as a control unit, a control panel802serving as a display device, and a ROM and RAM803serving as a storage device.

The main CPU801is connected to the double feed sensor104, the first thickness sensor201A3, the second thickness sensor202A1, a passage sensor806provided at a lower end of the recording medium conveying path of the removing mechanism204and configured to detect that the recording medium reaches a dischargeable position, and the paper discharge sensor807, all of which are included in the erasing apparatus10. The main CPU801receives outputs of these sensors.

The main CPU801is connected to an erasing device804configured to drive the heating roller107, a recording medium conveying device805, the conveying motor204A1, the discharge motor204B1, the clutch204A5, the conveying roller solenoid204A3, and a conveyance guide solenoids202A2configured to drive the conveyance guide displacing devices203and lift and lower the conveyance guide202. The main CPU801controls the operations of these devices.

FIG. 9is a schematic diagram of the recording medium removing apparatus200.FIG. 10is a schematic diagram of a state in which the recording medium removing apparatus200lifts the conveyance guide202.

As shown inFIG. 9andFIG. 10, the inserting roller201B and an insertion guide201B2forming the recording medium conveying path of the thickness determining device201are locked by elastic members201B1to be displaceable up and down. The conveyance guide202is locked by elastic members202B to be displaceable up and down.

FIG. 11andFIG. 12are diagrams of a speed changing mechanism for the conveyance driving roller204A. If the erasing apparatus10determines that the thickness of the recording medium is equal to or larger than the first threshold or the second threshold, the erasing apparatus10changes conveying speed for the recording medium.

Specifically, the erasing apparatus10changes the conveying speed such that conveying speed of a recording medium determined as conveyable exceeds conveying speed of the recording medium determined as unconveyable. If the erasing apparatus10determines that the recording medium is unconveyable, the erasing apparatus10reduces the conveying speed for the recording medium. Alternatively, if the erasing apparatus10determines that the recording medium is conveyable, the erasing apparatus10increases the conveying speed for the recording medium. If the conveying speed falls, conveying torque increases and even a thick recording medium can be conveyed.

When a stepping motor is used for the conveying motor204A1as a speed changing mechanism, the erasing apparatus10reduces pulse width of a stepping pulse to increase the conveying speed and increases the pulse width to reduce the conveying speed.

The erasing apparatus10can also use the speed changing mechanism. As shown inFIGS. 11 and 12, the speed changing mechanism includes a first gear train1102including a planetary gear1101driven by the conveying motor204A1and plural gears driven by the planetary gear1101, a second gear train1103including gears smaller in number than the number of gears of the first gear train1102by two or more and including the number of teeth of the gears smaller than the number of teeth of the gears of the first gear train1102, a last gear1102A of the first gear train1102, a last gear1103A of the second gear train1103, and a last driven gear1104connected to the conveyance driving roller204A.

As shown inFIG. 11, if the conveying motor204A1regularly rotates in a direction of an arrow X1, the planetary gear1101falls down to the first gear train1102side to drive the first gear train1102.

As shown inFIG. 12, if the conveying motor204A1reversely rotates in a direction of an arrow X2, the planetary gear1101falls down to the second gear train1103side to drive the second gear train1103.

The number of teeth of the gears of the second gear train1103is smaller than the number of teeth of the gears of the first gear train1102. The number of gears of the first gear train1102is larger than the number of gears of the second gear train1103by two or more. Therefore, if the conveying motor204A1regularly rotates in the direction of the arrow X1, the conveyance driving roller204A rotates in a direction of an arrow X3at low speed and high torque. If the conveying motor204A1reversely rotates in the direction of the arrow X2, the conveyance driving roller204A rotates in the direction of the arrow X3at high speed and low torque.

FIG. 13is a flowchart for explaining the operation of the erasing apparatus10. As shown inFIG. 13, in Act1301, the erasing apparatus10conveys a recording medium and inserts the recording medium into the recording medium removing apparatus200.

In Act1302, the erasing apparatus10determines whether the first thickness sensor201A3is turned on. If the erasing apparatus10determines that the first thickness sensor201A3is turned on, the erasing apparatus10proceeds to Act1303. If the erasing apparatus10determines that the first thickness sensor201A3is not turned on, the erasing apparatus10proceeds to Act1304.

In Act1303, the erasing apparatus10lifts the conveyance guide202.

In Act1305, the erasing apparatus10determines whether the passage sensor806detects the recording medium. If the erasing apparatus10determines that the passage sensor806detects the recording medium, the erasing apparatus10proceeds to Act1307. If the erasing apparatus10determines that the passage sensor806does not detect the recording medium, the erasing apparatus10returns to Act1305.

In Act1307, the erasing apparatus10turns on the clutch204A5and moves, with the vertical moving mechanism204A4, the recording medium nipped by the conveyance driving rollers204A and the conveying rollers204A2to the discharge rollers204B side in the direction perpendicular to the recording medium conveying direction.

In Act1308, the erasing apparatus10rotates the discharge rollers204B.

In Act1309, the erasing apparatus10determines whether the paper discharge sensor807detects the recording medium. If the erasing apparatus10determines that the paper discharge sensor807detects the recording medium, the erasing apparatus10proceeds to Act1310. If the erasing apparatus10determines that the paper discharge sensor807does not detect the recording medium, the erasing apparatus10returns to Act1309.

In Act1310, the erasing apparatus10turns off the clutch204A5.

In Act1311, the erasing apparatus10lifts the conveying rollers204A2. Therefore, the recording medium is discharged to the disposal box111by the discharge rollers204B.

In Act1312, the erasing apparatus10determines whether the paper discharge sensor807detects the recording medium. If the erasing apparatus10determines that the paper discharge sensor807detects the recording medium, the erasing apparatus10returns Act1301. If the erasing apparatus10determines that the paper discharge sensor807does not detect the recording medium, the erasing apparatus10returns to Act1312.

In Act1304, the erasing apparatus10lowers the conveyance guide202. In Act1306, the erasing apparatus10conveys the recording medium.

In Act1313, the erasing apparatus10determines, on the basis of an output of the second thickness sensor202A1, whether the thickness of the recording medium is equal to or larger than the second threshold. If the erasing apparatus10determines that the thickness of the recording medium is equal to or larger than the second threshold, the erasing apparatus10proceeds to Act1303. If the erasing apparatus10determines that the thickness of the recording medium is not equal to or larger than the second threshold, the erasing apparatus10proceeds to Act1314.

In Act1314, the erasing apparatus10executes an erasing operation on the recording medium.

As explained above, the erasing apparatus10including the recording medium removing apparatus200according to this embodiment includes the thickness determining device201configured to determine whether the thickness of the recording medium is equal to or larger than the first threshold, the conveyance guide202forming the conveying path for the recording medium, the conveyance guide displacing devices203configured to lift the conveyance guide202if the thickness determining device201determines that the thickness of the recording medium is equal to or larger than the first threshold, and the removing mechanism204configured to remove, from the recording medium conveying path, the recording medium determined as unconveyable.

Therefore, there is an effect that, even if a sheet bundle having thickness exceeding a tolerance of the thickness sensor is conveyed to the erasing apparatus10, it is possible to remove the sheet bundle without damaging the thickness sensor.

Second Embodiment

FIG. 14is a side view of an automatic document feeding apparatus20including the recording medium removing apparatus200. As shown inFIG. 14, the automatic document feeding apparatus20includes a document tray301on which original documents are placed, a pickup roller302configured to pick up the original documents from the document tray301one by one, a double feed sensor104, a document feeding roller303of a conveying mechanism configured to convey the original document, the first thickness sensor201A3, the conveyance guide202provided downstream in the recording medium conveying direction of the first thickness sensor201A3, the conveyance guide solenoid202A2configured to displace the conveyance guide202in an inner direction to expand the recording medium conveying path, the second thickness sensor202A1configured to be displaced together with the conveyance guide202, a conveying roller204A9configured to convey the recording medium, a document reading section304formed of a cutout section or a transparent material and configured to cause the original document to pass to a scan position, a document reversing mechanism306configured to reverse the front and the back of the original document, and a paper discharge tray305onto which the original document is discharged and stacked.

The recording medium removing apparatus200includes the first thickness sensor201A3, the conveyance guide202, and the conveyance guide solenoid202A2. The recording medium removing apparatus200is provided upstream in a document feeding direction of the document reading section304.

FIG. 15is a diagram of a state in which the automatic document feeding apparatus20displaces the conveyance guide202.

As shown inFIG. 15, the automatic document feeding apparatus20picks up an original document with the pickup roller302and conveys the original document in the direction of the document reading section304with the document feeding roller303. The automatic document feeding apparatus20reverses the front and the back of the original document, which passes the document reading section304, with the document reversing mechanism306and causes the original document to pass the document reading section304again. The automatic document feeding apparatus20discharges the original document to the paper discharge tray305.

If the automatic document feeding apparatus20determines, with the first thickness sensor201A3, that the thickness of the original document is equal to or larger than the first threshold, the automatic document feeding apparatus20displaces the conveyance guide202to expand the recording medium conveying path.

The automatic document feeding apparatus20reversely rotates a conveying motor204A8, which drives a conveying roller204A9, and the document feeding roller303to discharge the original document to the document tray301.

When the automatic document feeding apparatus20reversely rotates the conveying motor204A8and the document feeding roller303, the automatic document feeding apparatus20changes conveying speed.

Specifically, the automatic document feeding apparatus20changes the conveying speed such that conveying speed of a recording medium determined as conveyable exceeds conveying speed of the recording medium determined as unconveyable. If the automatic document feeding apparatus20determines that the recording medium is unconveyable, the automatic document feeding apparatus20reduces the conveying speed for the recording medium. Alternatively, if the automatic document feeding apparatus20determines that the recording medium is conveyable, the automatic document feeding apparatus20increases the conveying speed for the recording medium. If the conveying speed falls, conveying torque increases and even a thick recording medium can be conveyed.

When a stepping motor is used for the conveying motor204A8as a speed changing mechanism, the automatic document feeding apparatus20reduces pulse width of a stepping pulse to increase the conveying speed and increases the pulse width to reduce the conveying speed.

The automatic document feeding apparatus20can also use the speed changing mechanism described in the first embodiment.

FIG. 16is a block diagram of the configuration of the automatic document feeding apparatus20. As shown inFIG. 16, the automatic document feeding apparatus20includes the main CPU801serving as a control unit and the ROM and RAM803serving as a storage device.

The main CPU801is connected to the double feed sensor104, the first thickness sensor201A3, the second thickness sensor202A1, and the passage sensor806provided in an inlet of a document conveying path, all of which are included in the automatic document feeding apparatus20. The main CPU801receives outputs of these sensors.

The main CPU801is connected to the conveying motor204A1and the conveyance guide solenoids202A2configured to drive the conveyance guide displacing devices203and lift and lower the conveyance guide202. The main CPU801controls the operations of these devices.

FIG. 17is a diagram of the operation of the automatic document feeding apparatus20. As shown inFIG. 17, in Act1701, the automatic document feeding apparatus20conveys an original document.

In Act1702, the automatic document feeding apparatus20determines whether the first thickness sensor201A3is turned on. If the automatic document feeding apparatus20determines that the first thickness sensor201A3is turned on, the automatic document feeding apparatus20proceeds to Act1703. If the automatic document feeding apparatus20determines that the first thickness sensor201A3is not turned on, the automatic document feeding apparatus20proceeds to Act1706.

In Act1703, the automatic document feeding apparatus20lifts the conveyance guide202.

In Act1704, the automatic document feeding apparatus20reversely rotates the conveying roller204A9and the document feeding roller303.

In Act1705, the automatic document feeding apparatus20determines whether the passage sensor806detects the recording medium. If the automatic document feeding apparatus20determines that the passage sensor806does not detect the recording medium, the automatic document feeding apparatus20ends the processing. If the automatic document feeding apparatus20determines that the passage sensor806detects the recording medium, the automatic document feeding apparatus20returns to Act1705.

In Act1706, the automatic document feeding apparatus20displaces the conveyance guide202to a home position.

In Act1707, the automatic document feeding apparatus20conveys the original document.

In Act1708, the automatic document feeding apparatus20determines, on the basis of an output of the second thickness sensor202A1, whether the thickness of the recording medium is equal to or larger than the second threshold. If the automatic document feeding apparatus20determines that the thickness of the recording medium is equal to or larger than the second threshold, the automatic document feeding apparatus20proceeds to Act1703. If the automatic document feeding apparatus20determines that the thickness of the recording medium is not equal to or larger than the second threshold, the automatic document feeding apparatus20proceeds to Act1709.

In Act1709, the automatic document feeding apparatus20conveys the original document to the document reading section304and returns to Act1701.

As explained above, the automatic document feeding apparatus20including the recording medium removing apparatus200according to this embodiment includes the first thickness sensor201A3configured to detect the thickness of the original document, the conveyance guide202forming the conveying path for the original document, and the conveyance guide solenoid202A2configured to lift the conveyance guide202if the automatic document feeding apparatus20determines that the thickness of the original document is equal to or larger than the first threshold.

Therefore, there is an effect that, even if a sheet bundle having thickness exceeding a tolerance of the thickness sensor is conveyed to the automatic document feeding apparatus20, it is possible to feed the sheet bundle backward and remove the sheet bundle without damaging the thickness sensor.