Patent Description:
In the related art, image forming apparatuses such as ink-jet printers provided with a reading device or an image scanner that reads the image formed on a surface of a sheet such as a recording medium are known (see, for example, <CIT>). Such a reading device in the related art moves a reference plate such as a base member and a base white plate to a facing position at a prescribed timing, and performs calibration on the reader.

Further, technologies are known in the art in which the reference plate is configured to rotate along a side or the reading face of the reader (see, for example, <CIT>).

However, in the related art, when the reference plate comes into sliding contact with the reader, the reader or the to-be-scanned surface of the reference plate tends to be damaged, and there is a possibility that calibration of the reader cannot efficiently be performed (see, for example, <CIT>).

A more complete appreciation of embodiments and the many attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

It will be further understood that the terms "includes" and/or "including", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In describing example embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the present disclosure is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have the same structure, operate in a similar manner, and achieve a similar result.

Embodiments of the present disclosure are described below in detail with reference to the drawings. In the drawings, like reference signs denote like elements, and overlapping description may be simplified or omitted as appropriate.

<FIG> is a diagram illustrating an overall configuration of an imaging system <NUM> according to an embodiment of the present disclosure.

Firstly, an overall configuration and operation of the imaging system <NUM> is described below with reference to <FIG>.

As illustrated in <FIG>, the imaging system <NUM> according to the present embodiment is provided with a sheet feeder <NUM>, a pretreatment device <NUM>, an image forming apparatus <NUM>, a drying device <NUM>, a cooler <NUM>, a reversing device <NUM>, a sheet ejector <NUM>, a sheet conveyance device <NUM>, a controller <NUM>, and an operation panel <NUM>.

The sheet feeder <NUM> is provided with a sheet tray <NUM> on which a plurality of sheets P are stacked, a feeding device <NUM> that feeds the sheet P from the sheet tray <NUM>, and a plurality of conveyance roller pairs <NUM> that convey the fed sheet P. The multiple sheets P that are stacked in the sheet tray <NUM> are separated on a one-piece-by-one-piece basis by the feeding device <NUM>, and then sent to the pretreatment device <NUM> by the multiple conveyance roller pairs <NUM>.

The pretreatment device <NUM> is a device that performs predetermined pretreatment on the sheet P on which an image is not yet formed. More specifically, the pretreatment device <NUM> is provided with a treatment liquid applicator <NUM> that applies a treatment liquid such as a chemical agent that reacts with ink to prevent bleeding. Moreover, the pretreatment device <NUM> according to the present embodiment includes a first conveyance path <NUM> through which the sheet P conveyed from the sheet feeder <NUM> is conveyed to the treatment liquid applicator <NUM>, a second conveyance path <NUM> in which the front and back sides of the sheet P conveyed through the treatment liquid applicator <NUM> is turned and through which the sheet P is conveyed to the treatment liquid applicator <NUM> again, and a third conveyance path <NUM> through which the sheet P is conveyed to the image forming apparatus <NUM> without passing the sheet P through the treatment liquid applicator <NUM>. In these conveyance paths <NUM>, <NUM>, and <NUM>, a plurality of conveyance roller pairs <NUM> that convey the sheet P and a plurality of sheet sensors 125a to 125c that detect the sheet P that is being conveyed are arranged.

When the treatment liquid is applied to the sheet P, the sheet P is conveyed to the treatment liquid applicator <NUM> through the first conveyance path <NUM>. In such cases, the sheet P is stopped on a temporary basis when detected by a sheet sensor 125a arranged on the first conveyance path <NUM>, and then conveyed to the treatment liquid applicator <NUM> at a prescribed timing. After the treatment liquid is applied to one of the two sides of the sheet P by the treatment liquid applicator <NUM>, and the sheet P is conveyed to the image forming apparatus <NUM>.

When the treatment liquid is applied to both sides of the sheet P, the sheet P on one side of which the treatment liquid has been applied is conveyed to the second conveyance path <NUM>. As the sheet P is switched back in the second conveyance path <NUM>, the front and back sides of the sheet P is turned, and sent again to the treatment liquid applicator <NUM>. In such cases, the sheet P is stopped on a temporary basis when detected by a sheet sensor 125b arranged on the second conveyance path <NUM>, and then conveyed to the treatment liquid applicator <NUM> at a prescribed timing. The treatment liquid is applied to the rear side of the sheet P by the treatment liquid applicator <NUM>, and the sheet P is conveyed to the image forming apparatus <NUM>.

When the sheet P is conveyed to the image forming apparatus <NUM> without being treated with the treatment liquid, the sheet P is conveyed through the third conveyance path <NUM>. In such cases, the sheet P is stopped on a temporary basis when detected by a sheet sensor 125c arranged on the third conveyance path <NUM>, and then conveyed to the image forming apparatus <NUM> at a prescribed timing.

The image forming apparatus <NUM> according to the present embodiment is provided with an image forming device <NUM> that serves as an ink discharging unit and discharges ink droplets onto the sheet P, and a first transfer barrel <NUM>, a conveying drum <NUM>, a second transfer barrel <NUM>, and a plurality of conveyance roller pairs <NUM> that together serve as a conveyor and conveys the sheet P.

The image forming device <NUM> according to the present embodiment is provided with a plurality of recording heads <NUM> that can handle a plurality of colors, and discharges ink of a plurality of colors to form an image on the sheet P. Each one of such multiple recording heads may be referred to as a liquid discharge head in the following description.

<FIG> are diagrams each illustrating the operation of the reading device <NUM> provided for the image forming apparatus <NUM>, according to the present embodiment.

Each one of the multiple recording heads <NUM> is a functional component that discharges and sprays liquid from discharge holes or nozzles. As illustrated in <FIG>, in the present embodiment, a recording head 135Y that discharges yellow (Y) ink, a recording head <NUM> that discharges magenta (M) ink, a recording head 135C that discharges cyan (C) ink, and a recording head <NUM> that discharges black (K) ink are arranged in parallel in the direction of rotation of the conveying drum <NUM> and in the direction of conveyance of the sheet P. More specifically, these recording heads are arranged in a counterclockwise direction as illustrated in <FIG>, <FIG> from an upstream portion to a downstream portion of the conveying drum <NUM> in the order listed.

The discharging operation of each one of the multiple recording heads 135Y, <NUM>, 135C, and <NUM> that handle liquid of four colors is controlled by the driving signals that are based on the image data. The recording heads 135Y, <NUM>, 135C, and <NUM> discharge the ink of multiple colors onto the front side of the sheet P being conveyed by the conveying drum <NUM> by superimposing multiple images on top of one another. As a result, a color image is formed on the front side of the sheet P as desired.

In the present embodiment, the multiple recording heads 135Y, <NUM>, 135C, and <NUM> of four colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged. However, no limitation is indicated thereby, and the number of the recording heads or the colors of the recording heads are not limited to the above configuration or structure. For example, recording heads of six colors may be arranged, or recording heads that discharge ink of special colors such as white, gold, and silver may be arranged.

The sheet P that is conveyed from the pretreatment device <NUM> is conveyed by the conveyance roller pair <NUM>, and is passed to the first transfer barrel <NUM>, the conveying drum <NUM>, and the second transfer barrel <NUM> in the order listed. All of the first transfer barrel <NUM>, the conveying drum <NUM>, and the second transfer barrel <NUM> has a cylindrical shape elongated in the axial direction.

Grippers <NUM>, <NUM>, and <NUM> that grip and receive the front end of the sheet P are disposed on the peripheral surfaces of the first and second transfer barrels <NUM> and <NUM> and the conveying drum <NUM>, respectively. Each one of the multiple grippers <NUM>, <NUM>, and <NUM> is a grip that grips the front end of the sheet P, and also serves as a receiver that receives the sheet P.

In the image forming apparatus <NUM> or the imaging system <NUM> according to the present embodiment, as illustrated in <FIG>, <FIG>, the reading device <NUM> is arranged downstream from the multiple recording heads 135Y, <NUM>, 135C, and <NUM> at a position facing the conveying drum <NUM> that serves as a conveyor. The reading device <NUM> according to the embodiments reads an image formed on the surface of the sheet P. The reading device <NUM> will be described later in more detail with reference to, for example, <FIG>, <FIG>, <FIG>.

Subsequently, the sheet P on which the image is formed by the image forming apparatus <NUM> is conveyed to the drying device <NUM> by the conveyance belt <NUM>.

The image on the surface of the sheet P that is conveyed to the drying device <NUM> is dried by a dryer <NUM>. The sheet P whose image thereon has been dried passes through the conveyance path <NUM>, and is conveyed to the cooler <NUM>.

The image on the surface of the sheet P that is conveyed to the cooler <NUM> is dried by a cooling unit <NUM>. The sheet P whose image thereon has been cooled is conveyed to the sheet ejector <NUM> through the conveyance path <NUM> in the reversing device <NUM>. Finally, a plurality of sheets P are stacked on the output tray <NUM> or the large-capacity output tray <NUM> of the sheet ejector <NUM>.

Thus, a series of operations in the imaging system <NUM> is completed.

When a double-sided printing mode is selected, images need to be formed on both sides of the sheet P. In order to achieve such functions, the sheet P that is conveyed to the reversing device <NUM>, which is the sheet P whose image on the front side has been dried, is reversed by reversing the direction of conveyance by the reversing device <NUM>, and then is conveyed to a double-sided printing path <NUM>, and then is conveyed to the image forming apparatus <NUM> again. The sheet P on the other side or rear side of which the desired image has been formed in the image forming apparatus <NUM> passes through the drying device <NUM>, the cooler <NUM>, and the reversing device <NUM>, and is stacked on the output tray <NUM> or the large-capacity output tray <NUM> of the sheet ejector <NUM>.

The reading device <NUM> in the image forming apparatus <NUM> or the imaging system <NUM> according to the present embodiment will be described in detail with reference to, for example, <FIG>, <FIG>, and <FIG>.

As described above with reference to, for example, <FIG>, the image forming apparatus <NUM> according to the present embodiment includes, for example, the conveying drum <NUM> that serves as a conveyor and conveys the sheet P in a predetermined conveyance direction, and the multiple recording heads 135Y, <NUM>, 135C, and <NUM> that discharge ink droplets onto the surfaces of the sheet P conveyed in the direction of conveyance by the conveying drum <NUM>, which serves as a conveyor, to form an image.

The reading device <NUM> according to the present embodiment is arranged downstream from the multiple recording heads 135Y, <NUM>, 135C, and <NUM> in the direction of conveyance. The reading device <NUM> according to the embodiments reads an image formed on the surface of the sheet P. For example, the recording heads 135Y, <NUM>, 135C, and <NUM> are adjusted and controlled based on the image read by the reading device <NUM>. As a result, the color tone, the color shift, and the magnifying power of the image that is formed on the front side of the sheet P are corrected.

As illustrated in, for example, <FIG>, <FIG>, and <FIG>, the reading device <NUM> according to the present embodiment includes, for example, a reader <NUM>, a base unit <NUM>, a movement mechanism, a reference plate <NUM>, and a pulling spring <NUM> that serves as a pressurizing member.

<FIG> are diagrams each illustrating how the reader <NUM> and the reference plate <NUM> operate in the reading device <NUM>, according to the present embodiment.

The reader <NUM> according to the present embodiment is a scanner that reads the image formed on one surface of the sheet P when the sheet P is placed at a scanning position as illustrated in <FIG> and <FIG>.

More specifically, as illustrated in <FIG> and <FIG>, when the reader <NUM> that serves as a scanner is located at the scanning position, the reading face 210a gets close to the conveying drum <NUM> (see <FIG>). Due to such a configuration, the image that is formed on the front side of the sheet P can optically be scanned and obtained while the sheet P is passing through a gap between the conveying drum <NUM> and the reading face 210a of the reader <NUM>.

The reader <NUM> is held by the base unit <NUM> fixedly installed in the image forming apparatus <NUM>, in a movable manner in the right and left directions as illustrated in <FIG>, <FIG> so as to get close to or separated from the conveying drum <NUM>.

The movement mechanism moves the reader <NUM> between the scanning position as illustrated in <FIG> and <FIG> and the separated position separated from the scanning position as illustrated in <FIG> and <FIG>.

More specifically, the movement mechanism is composed of, for example, a motor <NUM>, a feed screw <NUM>, and a slide rail <NUM>. The motor <NUM> drives the feed screw <NUM> to rotate in both forward and reverse directions, and is fixed to the base unit <NUM> that is fixedly arranged in the image forming apparatus <NUM>. The feed screw <NUM> is threadably fitted to the female screw formed on a first projecting part 210c protruding from the top face of the reader <NUM>. The slide rail <NUM> is fixedly installed on the base unit <NUM>, and is slidably fitted into the hole formed in a second projecting part 210d protruding from the top face of the reader <NUM>. The feed screw <NUM> and the slide rail <NUM> are both formed so as to extend in the right and left directions as illustrated in <FIG>.

With the movement mechanism configured as described above, when the motor <NUM> rotates in the forward direction under the control of the controller <NUM>, the reader <NUM> moves from the scanning position as illustrated in <FIG> to the separated position as illustrated in <FIG>. With the movement mechanism configured as described above, when the motor <NUM> rotates in the reverse direction under the control of the controller <NUM>, the reader <NUM> moves from the separated position as illustrated in <FIG> to the scanning position as illustrated in <FIG>.

The reference plate <NUM> according to the present embodiment is placed at the first position that is a closed position facing the reading face 210a of the reader <NUM> as illustrated in <FIG>, and is a used to obtain a reference value to be used when the reader <NUM> performs the scanning.

More specifically, as illustrated in <FIG>, the reference plate <NUM> according to the present embodiment is an approximately rectangular metallic plate, and has a to-be-scanned surface 230a formed on a portion of its surface. The to-be-scanned surface 230a is a portion that is directly scanned and read by the reader <NUM>, and is coated in white in the present embodiment. As illustrated in <FIG>, the reader <NUM> is calibrated at a prescribed timing when the reference plate <NUM> that serves as a base white plate faces the reading face 210a of the reader <NUM>. For example, the reader <NUM> is calibrated at a warm-up timing before the image-forming operation starts.

The reference plate <NUM> is held by the base unit <NUM> so as to be rotatable around a pair of axes <NUM>. This configuration or structure will be described below in detail.

The pulling spring <NUM> serves as a pressurizing member that pressurizes and brings the reference plate <NUM> close to the reader <NUM>.

More specifically, the pulling spring <NUM> according to the present embodiment has a hook on one end side coupled to one of a pair of latches 230c of the reference plate <NUM>, and the other end of the pulling spring <NUM> is coupled to a notch of a bent portion <NUM>. As illustrated in <FIG>, and <FIG>, the pair of latches 230c are arranged at positions apart from the pair of axes <NUM>. As illustrated in <FIG>, the bent portion <NUM> in a portion bent so as to protrude from the base unit <NUM>. The pulling spring <NUM> according to the present embodiment applies pressure to the reference plate <NUM> such that the reference plate <NUM> rotates around the pair of axes <NUM> in a clockwise direction as illustrated in <FIG>. The notch of the bent portion <NUM> is disposed at the lower left of the latch 230c as illustrated in <FIG> when the reference plate <NUM> is located at the second position as illustrated in <FIG>, and the pulling spring <NUM> applies pressing force to rotate the reference plate <NUM> around the pair of axes <NUM> in a clockwise direction as illustrated in <FIG>. Accordingly, as will be described later, the contact of the reference plate <NUM> with a pair of cam followers <NUM> is facilitated when the reference plate <NUM> rotates around the pair of axes <NUM>, and the contact of the multiple bosses 230b with the reader <NUM> when the reference plate <NUM> is positioned at the first position is facilitated.

In the present embodiment, the reading device <NUM> according to the present embodiment is configured such that the reference plate <NUM> rotates around the pair of axes <NUM> from the second position (or the first position) facing the side 210b of the reader <NUM> to the first position (or the second position) in conjunction with the movement of the reader <NUM> from the scanning position as illustrated in <FIG> (or the separated position) to the separated position as illustrated in <FIG> (or the scanning position) by the movement mechanism. The side 210b of the reader <NUM> may be referred to as a non-reading face in the following description.

In other words, as illustrated in <FIG>, when the reader <NUM> moves from the scanning position toward the separated position in the direction indicated by the hollow arrow, the reference plate <NUM> rotates in a clockwise direction around the pair of axes <NUM>, as indicated by an arrow in <FIG>, due to the pressure applied by the pulling spring <NUM>, from the second position as illustrated in <FIG> toward the first position as illustrated in <FIG>. The first position and the second position may be referred to as a closed position and an open position, respectively, in the following description.

By contrast, as illustrated in <FIG>, when the reader <NUM> moves from the separated position toward the scanning position, the reference plate <NUM> rotates in a counterclockwise direction around the pair of axes <NUM> from the first position as illustrated in <FIG> toward the second position illustrated in <FIG> so as to run against the pressure applied by the pulling spring <NUM>. In so doing, the reference plate <NUM> that is located at the first position is not pushed by the reading face 210a of the reader <NUM> so as to go against the pressure applied by the pulling spring <NUM>, but is pushed by the pair of cam followers <NUM> as will be described later in detail. Due to this configuration, the reference plate <NUM> and the reader <NUM> do not contact each other directly.

<FIG> is a perspective view of the reference plate <NUM> held by a pair of hinges <NUM>, according to the present embodiment.

More specifically, as illustrated in <FIG>, the reference plate <NUM> is fixed to a pair of first members 232a of the pair of hinges <NUM>. The pair of second members 232b of the pair of hinges <NUM> are fixed to the base unit <NUM>. The pair of axes <NUM> are inserted into the multiple holes 232c of the first member 232a and the second member 232b. Each one of the pair of axes <NUM> according to the present embodiment is provided with a pair of retaining rings whose outside diameter is wider than the diameter of the multiple holes 232c at both ends in the axial direction so as not to fall off from the corresponding one of the pair of hinges <NUM>. In other words, such a pair of retaining rings are arranged at both outer ends of the corresponding one of the pair of hinges <NUM>.

Due to such a configuration as above, the reference plate <NUM> rotates around the pair of axes <NUM>.

For the sake of explanatory convenience, the relative positions of the pair of axes <NUM> and the reference plate <NUM> as illustrated in <FIG>, <FIG> are different from the relative positions of the pair of axes <NUM> and the reference plate <NUM> as illustrated in <FIG>. However, no limitation is indicated thereby, and it is satisfactory as long as the reference plate <NUM> rotates around the pair of axes <NUM> in any one of the above drawings.

As illustrated in <FIG> and <FIG>, when the reader <NUM> is positioned at the scanning position and the reference plate <NUM> releases the reading face 210a, the image of the sheet P that passes through the position facing the reading face 210a is scanned and read by the reader <NUM>. Based on the results of scanning, each element related to the image formation is adjusted and controlled.

By contrast, as illustrated in <FIG> and <FIG>, when the reader <NUM> is positioned at the separated position and the reference plate <NUM> releases the reading face 210a, the reference plate <NUM> that serves as a to-be-scanned surface and faces the reading face 210a is scanned and read by the reader <NUM>. The reader <NUM> is calibrated based on the results of the above scanning or reading.

The reader <NUM> can be calibrated using a method similar to the methods known in the art. For example, the radiation intensity of the light to be output from the reader <NUM> is adjusted such that the output level of the reader <NUM> has a predetermined value when the to-be-scanned surface 230a that is in white is read.

As described above, in the reading device <NUM> according to the present embodiment, the reference plate <NUM> is configured to be rotatable around the pair of axes <NUM> along the side 210b or the reading face 210a of the reader <NUM>. Due to such a configuration, compared with cases in which the reference plate is configured to be slidable in the conveyance direction of the sheet, the space in which the reference plate <NUM> is movable can be saved. In particular, the space in the conveyance direction of the sheet P can be saved. In particular, as a plurality of members such as the plurality of recording heads <NUM> are disposed around the conveying drum <NUM> and space in the sheet P conveyance direction is limited, the configuration according to the present embodiment is useful.

As illustrated in <FIG>, the reader <NUM> according to the present embodiment is provided with the pair of cam followers <NUM> that together serve as an abutment part or a rotor. The pair of cam followers <NUM> according to the present embodiment contact the reference plate <NUM> when the reference plate <NUM> rotates around the pair of axes <NUM>, and maintains the clearance or space between the reader <NUM> and the reference plate <NUM>.

Due to this configuration, even if the reference plate <NUM> is configured to rotate around the pair of axes <NUM> along the side 210b or the reading face 210a of the reader <NUM>, the reference plate <NUM> is less likely to come into sliding contact with the reader <NUM> and the reader <NUM> or the reference plate <NUM> is less likely unintentionally damaged. Accordingly, the reader <NUM> can be stably and favorably calibrated over time.

More specifically, the pair of cam followers <NUM> are rotatably installed at a corner where the reading face 210a and the side 210b intersect with each other in the reader <NUM>. More specifically, the pair of cam followers <NUM> are arranged so as to protrude from both the reading face 210a and the side 210b at the above-described corner.

As illustrated in <FIG>, when the reader <NUM> is located at the scanning position, the pair of cam followers <NUM> according to the present embodiment contact around the front end of the reference plate <NUM>. Such a front end of the reference plate <NUM> is at a position farthest from the pair of axes <NUM>.

Once the reader <NUM> starts moving from the scanning position as illustrated in <FIG> toward the separated position as illustrated in <FIG>, the reference plate <NUM> rotates around the pair of axes <NUM> while contacting the peripheral surfaces of the pair of cam followers <NUM> that are approximately cylindrical. In the above configuration, the pair of cam followers <NUM> intervene between the reference plate <NUM> and the reader <NUM> without exception. Accordingly, the clearance between the reference plate <NUM> and the reader <NUM> is kept constant, and the reference plate <NUM> and the reader <NUM> do not contact each other. As the pair of cam followers <NUM> are rotated by frictional resistance with the reference plate <NUM>, the wear and tear of the reference plate <NUM> and the pair of cam followers <NUM> are reduced.

At a timing immediately before the reader <NUM> reaches the separated position as illustrated in <FIG>, the contact between the pair of cam followers <NUM> and the reference plate <NUM> is released. After that, the reader <NUM> reaches the separated position as illustrated in <FIG>, and the reference plate <NUM> reaches the first position. In other words, the pair of cam followers <NUM> do not contact the reference plate <NUM> during the entire process from the second position of the reference plate <NUM> where the rotation starts to the first position of the reference plate <NUM> where the rotation terminates, but the pair of cam followers <NUM> contact the reference plate <NUM> during a certain process.

When the reader <NUM> moves from the separated position as illustrated in <FIG> toward the scanning position as illustrated in <FIG>, an operation in reverse order to the above operation is performed.

According to the present embodiment as described above, for example, the separated position of the reader <NUM>, the shape or arrangement of the pair of cam followers <NUM>, and the trajectory of the rotation of the reference plate <NUM> are set or adjusted such that the pair of cam followers <NUM> that together serve as an abutment part does not contact the reference plate <NUM> when the reference plate <NUM> is located at the first position as illustrated in <FIG>.

As illustrated in <FIG>, in the reference plate <NUM> that is located at the first position, the multiple bosses 230b that are arranged on the reference plate <NUM> contacts the reading face 210a of the reader <NUM>. Due to this configuration, the distance between the reference plate <NUM> that serves as a to-be-scanned surface and the reading face 210a of the reader <NUM> is determined.

In other words, in the present embodiment, the reference plate <NUM> is provided with a plurality of bosses 230b that contact the reader <NUM> when the reference plate <NUM> is at the first position. Due to such bosses, the distance between the reference plate <NUM> and the reading face 210a can be kept constant.

Due to such a configuration, the reader <NUM> can stably be calibrated with a high degree of accuracy using the reference plate <NUM>.

<FIG> is a top view of the reference plate <NUM>, according to the present embodiment.

More specifically, as illustrated in <FIG>, the multiple bosses 230b are three bosses 230b that are arranged as if they draw a triangle on the surface of the reference plate <NUM>, and are arranged on the reference plate <NUM> outside the region of the to-be-scanned surface 230a to be scanned or read by the reader <NUM>.

As described above, the three bosses 230b that are arranged as if they draw a triangle are used in the present embodiment. Due to such a configuration, the reference plate <NUM> can be supported at three points with respect to the reading face 210a of the reader <NUM>. Accordingly, compared with a case in which a plurality of bosses 230b are arranged in a straight line, the position of the reference plate <NUM> relative to the reader <NUM> can be determined with desired balance.

As the multiple bosses 230b are arranged outside the region of the to-be-scanned surface 230a, the multiple bosses 230b do not interfere with the reading operation performed by the reader <NUM> on the to-be-scanned surface 230a.

As illustrated in <FIG>, in the present embodiment, backlash or space is formed between the pair of axes <NUM> and the multiple holes 232c that are formed on the pair of hinges <NUM> and rotatably hold the pair of axes <NUM>.

In other words, the pair of axes <NUM> are not tightly inserted into the multiple holes 232c without backlash or play, but are rather loosely inserted with some space or play.

Due to such a configuration, as described above, when the reference plate <NUM> reaches the first position as illustrated in <FIG>, the pair of cam followers <NUM> that were contacting the reference plate <NUM> is separated from the reference plate <NUM>, and the position of the reference plate <NUM> relative to the reading face 210a is smoothly determined by the three bosses 230b.

As illustrated in <FIG>, the positions or the like of the pair of cam followers <NUM> that together serve as an abutment part are determined so as to contact portions of the reference plate <NUM> outside the region of the to-be-scanned surface 230a to be scanned or read by the reader <NUM> on the reference plate <NUM>. Such portions of the reference plate <NUM> outside the region of the to-be-scanned surface 230a may be referred to as regions M as illustrated in <FIG>.

More specifically, the pair of cam followers <NUM> are disposed so as to be able to contact both ends in the width direction of the reference plate <NUM>. The pair of cam followers <NUM> contact the reference plate <NUM> while moving to the reference plate <NUM> within a range from the lower end to the upper end of the regions M as illustrated in <FIG> by the rotation of the reference plate.

Due to such a configuration as described above, undesired rubbing on the to-be-scanned surface 230a as the pair of cam followers <NUM> contact the reference plate <NUM> can be prevented.

As described above, the reading device <NUM> according to the present embodiment in the image forming apparatus <NUM> includes the reader <NUM> that reads the image formed on one surface of the sheet P when the sheet P is placed at the scanning position, the movement mechanism that moves the reader <NUM> between the scanning position and a separated position away from the scanning position, and the reference plate <NUM> that is placed at the first position facing the reading face 210a of the reader <NUM> and is used to obtain a reference value to be used when the reader <NUM> performs the scanning. The reading device <NUM> according to the present embodiment is configured such that the reference plate <NUM> rotates around the pair of axes <NUM> from the second position (or the first position) facing the side 210b of the reader <NUM> to the first position (or the second position) in conjunction with the movement of the reader <NUM> from the scanning position (or the separated position) to the separated position (or the scanning position) by the movement mechanism. The reader <NUM> according to the present embodiment is provided with a pair of cam followers <NUM> that together serves as an abutment part. The pair of cam followers <NUM> according to the present embodiment contact the reference plate <NUM> when the reference plate <NUM> rotates around the pair of axes <NUM>, and maintain the clearance between the reader <NUM> and the reference plate <NUM>.

Due to such a configuration, the reader <NUM> and the reference plate <NUM> can be prevented from being damaged easily.

In the above description, the embodiments of the present disclosure are applied to the reading device <NUM> provided for the image forming apparatus <NUM> that serves as an ink-jet printer in the imaging system <NUM>. However, no limitation is intended thereby, and the embodiments of the present disclosure may be applied to, for example, a reading device provided for an image forming apparatus that is not provided for an imaging system, a reading device provided for a mimeographic or silk-screen printer or an electrophotographic image forming apparatus other than an ink-jet printer, a reading device provided for a device or apparatus other than an image forming apparatus, and a reading device that is a stand-alone device and is not provided for any device or apparatus.

Also in such a configuration as above, advantageous effects similar to those of the embodiments as described above can be achieved.

Further, for example, the number, position, and the shape of the above components are not limited to those of the present embodiment, and may be changed to any desired number, position, and shape suitable for implementing the embodiments of the present disclosure.

In the description of the present application or other technical documents, the term sheet is not limited to a sheet of paper, but may be all sorts of the sheet-shaped recording medium such as coated paper, label paper, an overhead projector (OHP) sheet, and a metal sheet.

Note that numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the embodiments of the present disclosure may be practiced otherwise than as specifically described herein. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.

Claim 1:
A reading device (<NUM>) comprising:
a reader (<NUM>) disposed at a scanning position, the reader being configured to read an image formed on a surface of a sheet (P);
a movement mechanism (<NUM>, <NUM>, <NUM>) configured to move the reader (<NUM>) between the scanning position and a separated position away from the scanning position; and
a reference plate (<NUM>) disposed at a first position facing a reading face (210a) of the reader (<NUM>), the reference plate being configured to obtain a reference value to be used when the reader (<NUM>) reads the image,
wherein the reference plate (<NUM>) is configured to rotate around an axis (<NUM>) from a second position facing a side (210b) of the reader (<NUM>) to the first position or from the first position to the second position in conjunction with movement of the reader (<NUM>) from the scanning position to the separated position by the movement mechanism (<NUM>, <NUM>, <NUM>) or movement of the reader (<NUM>) from the separated position to the scanning position, and
wherein the reader (<NUM>) includes an abutment part (<NUM>) contacting the reference plate (<NUM>) when the reference plate (<NUM>) rotates around the axis (<NUM>), and the abutment part (<NUM>) maintains clearance between the reader (<NUM>) and the reference plate (<NUM>)
and wherein the abutment part (<NUM>) is a cam follower (<NUM>) disposed at a corner where the reading face (210a) and the side (210b) intersect with each other in the reader (<NUM>).