Sheet supplying apparatus and printing apparatus

A sheet supplying apparatus, in which a user can select either automatic sheet feeding or manual sheet feeding, includes a driving unit configured to cause a roll including a wound consecutive sheet to rotate in a first direction for feeding the sheet or a second direction opposite to the first direction, a first sensor that detects a leading end portion of the sheet separated from an outer circumferential surface of the roll, a second sensor that detects the leading end portion which is manually set in a conveyance path by the user, and a determination unit configured to determine whether or not automatic sheet feeding is performed on the basis of a detection result of the second sensor.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a sheet supplying apparatus and a printing apparatus which are capable of pulling a sheet out of a roll on which a continuous sheet is wound and supplying the sheet.

Description of the Related Art

A printing apparatus that detects a sheet leading end of an installed roll sheet (hereinafter also referred to simply as a “roll”) and automatically feeds the sheet is disclosed in Japanese Patent Laid-Open No. 2011-37557. In this apparatus, the roll is rotated in a winding direction opposite to a supply direction, and separation of the sheet leading end from the roll due to its own weight (hereinafter also referred to as “peeling”) is detected by an optical sensor placed near the roll.

SUMMARY OF THE INVENTION

The apparatus disclosed in Japanese Patent Laid-Open No. 2011-37557 performs automatic sheet feeding, but it may be better not to perform the automatic sheet feeding depending on a usage form of a user. For example, since it takes time to detect a sheet leading end in the automatic sheet feeding, the user who is skilled in the use of the apparatus may desire manual sheet feeding to shorten the time. Further, for example, in the automatic sheet feeding, there is a possibility that the sheet surface will be scratched, and the user who desires to perform high quality printing on a delicate sheet which is easily damaged may not desire the automatic sheet feeding. Any solution for solving such a problem is not disclosed in Japanese Patent Laid-Open No. 2011-37557.

It is an object of the present invention to provide a sheet supplying apparatus and a printing apparatus in which the user can easily select either the automatic sheet feeding or the manual sheet feeding.

A sheet supplying apparatus of the present invention includes a driving unit configured to cause a roll including a wound consecutive sheet to rotate in a first direction for feeding the sheet or a second direction opposite to the first direction, a first sensor that detects a leading end portion of the sheet separated from an outer circumferential surface of the roll, a second sensor that detects the leading end portion which is manually set in a conveyance path by a user, and a determination unit configured to determine whether or not automatic sheet feeding is performed on the basis of a detection result of the second sensor.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will be described with reference to the appended drawings. First, a basic composition of the present invention will be described.

FIGS. 1 to 5are explanatory diagrams of a basic configuration of a printing apparatus according to an embodiment of the present invention. A printing apparatus of the present example is an inkjet printing apparatus including a sheet supplying apparatus that supplies a sheet serving as a print medium and a printing unit that prints an image on the sheet. For the sake of description, coordinate axes are set as illustrated in the drawings. In other words, a sheet width direction of a roll R is set as an X-axis direction, a direction in which the sheet is conveyed in a printing unit400to be described later is set as a Y-axis direction, and a gravity direction is set as a Z-axis direction.

As illustrated inFIG. 1, in a printing apparatus100of the present example, the roll R (roll sheet) obtained by winding a sheet1which is a long continuous sheet (also referred to as a web) in a roll form can be set in each of two upper and lower roll holding units. An image is printed on the sheet1selectively pulled out of the rolls R. A user can input, for example, various commands to the printing apparatus100such as a command of designating a size of the sheet1or a command of performing switching between on-line and off-line using various switches installed in a manipulation panel28.

FIG. 2is a schematic cross-sectional view of a main part of the printing apparatus100. Two supplying apparatuses200corresponding to the two rolls R are installed one above the other. The sheet1pulled out of the roll R by the supplying apparatus200is conveyed, along a sheet conveyance path by a sheet conveying unit (conveying mechanism)300, to the printing unit400capable of printing an image. The printing unit400prints an image on the sheet1by ejecting ink from an inkjet type print head18. The print head18ejects ink from an ejection port using an ejection energy generating element such as an electrothermal transducer (heater) or a piezo element. The print head18is not limited only to the inkjet system, and a printing system of the printing unit400is not limited, and, for example, a serial scan system or a full line system may be used. In the case of the serial scan system, an image is printed in association with a conveyance operation of the sheet1and scanning of print head18in a direction intersecting with a conveyance direction of the sheet1. In the case of the full line system, an image is printed, while continuously conveying the sheet1, using the long print head18extending in a direction intersecting with the conveyance direction of the sheet1.

The roll R is set in the roll holding unit of the supplying apparatus200in a state in which a spool member2is inserted in a hollow hole portion of the roll R, and the spool member2is driven by a motor33for driving the roll R (seeFIG. 5) to rotate normally or reversely. The supplying apparatus200includes, as described later, a driving unit3, an arm member (mobile body)4, an arm rotational shaft5, a sensor unit6, a swing member7, driving rotating bodies (contact bodies)8and9, a separating flapper (upper side guide body)10, and a flapper rotational shaft11.

A conveyance guide12guides the sheet1to the printing unit400while guiding front and back surfaces of the sheet1pulled out from the supplying apparatus200. A conveying roller14is rotated normally or reversely in directions of arrows D1and D2by a conveying roller driving motor35(seeFIG. 5) to be described later. A nip roller15can be drivenly rotated in accordance with the rotation of the conveying roller14and can be brought into contact with or separated from the conveying roller14by a nip force adjusting motor37(seeFIG. 5), and nip force thereof can be adjusted. A conveyance speed of the sheet1by the conveying roller14is set to be higher than a pulled-out speed of the sheet1by the rotation of the roll R, so that it is possible to apply back tension to the sheet1and convey the sheet1in a state in which the sheet1is stretched.

A platen17of the printing unit400regulates the position of the sheet1, and a cutter20cuts the sheet1on which an image is printed. A cover42of the roll R prevents the sheet1on which an image is printed from entering the supplying apparatus200. The operation in the printing apparatus100is controlled by a CPU201(seeFIG. 5) to be described later. The platen17includes a sucking device using negative pressure or electrostatic force, and the sheet can be stably supported since the sheet is sucked onto the platen17.

FIGS. 3A and 3Bare explanatory diagrams of the supplying apparatus200, and the roll R inFIG. 3Ais in a state in which an outer diameter thereof is relatively large. The arm member (mobile body)4is attached to the conveyance guide12to be rotatable on the arm rotational shaft5in directions of arrows A1and A2. A guide portion4b(lower guide body) that guides a lower surface of the sheet1(a front surface or a print surface of the roll sheet) pulled out of the roll R is formed on an upper part of the arm member4. A helical torsion spring3cthat presses the arm member4in the direction of the arrow A1is interposed between the arm member4and a rotating cam3aof the driving unit3. The rotating cam3ais rotated by a pressing force adjusting motor34(seeFIG. 5) to be described later, and a force in which the helical torsion spring3cpresses the arm member4in the direction of the arrow A1changes in accordance with the rotational position thereof. When the leading end portion of the sheet1(a part of the sheet1including a leading end (edge)) is set in the sheet supply path between the arm member4and a separating flapper10, the pressing force of the arm member4by the helical torsion spring3cis switched to three stages depending on the rotational position of the rotating cam3a. In other words, the pressing force of the arm member4is switched to a pressing state by a comparatively small force (pressing force of a weak nip), a pressing state by a relatively large force (pressing force of a strong nip), and a pressing force releasing state.

The swing member7is swingably attached to the arm member4, and the first and second driving rotating bodies (rotating bodies)8and9which are positioned to deviate in a circumferential direction of the roll R are rotatably mounted to the swing member7. The driving rotating bodies8and9move in accordance with an outer shape of the roll R and come into pressure contact with the outer circumferential portion of the roll R from a lower side in the gravity direction in accordance with pressing force against the arm member4in the direction of arrow A1. In other words, the driving rotating bodies8and9come into pressure contact with the outer circumference portion of the roll R from a lower side in the gravity direction than a central shaft of the roll R in the horizontal direction. The pressure contact force is changed in accordance with pressing force of pressing the arm member4in the direction of arrow A1.

A plurality of arm members4each including the swing member7are provided at a plurality of different positions in the X-axis direction. As illustrated inFIG. 3B, the swing member7includes a bearing portion7aand a shaft fastening portion7b, and thus a rotational shaft4aof the arm member4is accepted with predetermined looseness.

The bearing portion7ais provided at a gravity center position of the swing member7and supported by the rotational shaft4aso that the swing member7has a stable attitude in each of the X-axis direction, the Y-axis direction, and the Z-axis direction. Further, since the rotational shaft4ais accepted with looseness, any of a plurality of swing members7are displaced along the outer circumference portion of the roll R depending on the pressing force against the arm member4in the direction of the arrow A1. With such a configuration (equalizing mechanism), a change in a pressure contact attitude of the first and second driving rotating bodies8and9with respect to the outer circumferential portion of the roll R is permitted. As a result, a contact region between the sheet1and the first and second driving rotating bodies8and9is kept at maximum, and the pressing force against the sheet1is equalized, and thus a variation the conveyance force of the sheet1can be suppressed. Since the driving rotating bodies8and9come into pressure contact with the outer circumference portion of the roll R, the occurrence of slack in the sheet1is suppressed, and conveyance force thereof is enhanced.

In a main body of the printing apparatus100(printer main body), the separating flapper10positioned above the arm member4is attached to be rotatable on the flapper rotational shaft11in the directions of the arrows B1and B2. The separating flapper10is configured to lightly press an outer circumferential surface of the roll R by its own weight. In a case in which it is necessary to more strongly press the roll R, biasing force by a biasing member such as a spring may be used. A driven roller (upper contact body)10ais rotatably provided at a contact portion of the separating flapper10with the roll R to suppress influence of the pressing force on the sheet1. A separating portion10bof the leading end of the separating flapper10is formed to extend up to a position as close to the outer circumferential surface of the roll R as possible in order to facilitate the separation of the leading end portion of the sheet from the roll R.

The sheet1is supplied through the supply path formed between the separating flapper10and the arm member4after the front surface (print surface) of the sheet is guided by the upper guide portion4bof the arm member4. Accordingly, it is possible to smoothly supply the sheet1using the weight of the sheet1. Further, since the driving rotating bodies8and9and the guide portion4are moved depending on the outer diameter of the roll R, it is possible to reliably pull out the sheet1from the roll R and convey the sheet even when the outer diameter of the roll R changes.

One of the features of the apparatus according to the present embodiment lies in an automatic sheet loading function (an automatic sheet feeding function). In the automatic loading, when the user sets the roll R in the apparatus, the apparatus detects the leading end of the sheet while rotating the roll R in a direction (which is referred to as an opposite direction or a second direction, a direction of arrow C2inFIG. 3A) opposite to a rotation direction (a first direction, that is, a direction of the arrow C1inFIG. 3A) when the sheet is supplied (fed). The sensor unit6is a unit including a leading end detecting sensor which detects the separation of the leading end portion of the sheet1from the outer circumferential surface of the roll R. In a case where the sensor unit6detects the separation of the leading end portion of the sheet1from the outer circumferential surface of the roll sheet wound inward, the apparatus rotates the roll R in the first direction and supplies the leading end portion including the leading end (edge) of the sheet1to the inside of the sheet supply path between the arm member4and the separating flapper10. A more detailed procedure of the automatic loading function will be described later.

Further, the printing apparatus100of the present example includes the two upper and lower supplying apparatuses200, and it is possible to perform switching from a state in which the sheet1is supplied from one supplying apparatus200to a state in which the sheet1is supplied from the other supplying apparatus200. In this case, one supplying apparatus200rewinds the sheet1which has been supplied so far on the roll R. The leading end portion of the sheet1is evacuated up to the position at which the leading end thereof is detected by the sensor unit6.

FIG. 4is an explanatory diagram of the supplying apparatus200when the outer diameter of the roll R is relatively small. Since the arm member4is pressed in the direction of the arrow A1by the helical torsion spring3c, the arm member4moves in the direction of the arrow A1in accordance with a decrease in the outer diameter of the roll R. Further, by rotating the rotating cam3ain accordance with the change in the outer diameter of the roll R, the pressing force of the arm member4by the helical torsion spring3ccan be maintained within a predetermined range even though the outer diameter of the roll R changes. Since the separating flapper10is also pressed in the direction of arrow B1, the separating flapper10moves in the direction of arrow B1in accordance with the decrease in the outer diameter of the roll R. Accordingly, even when the outer diameter of the roll R is decreased, the separating flapper10forms the supply path with the conveyance guide12and guides the upper surface of the sheet1by a lower surface10c. As described above, the arm member4and the separating flapper10are rotated in accordance with the change in the outer diameter of the roll R, and thus even when the outer diameter of the roll R is changed, the supply path having a substantially constant size is formed between the arm member4and the separating flapper10.

FIG. 5is a block diagram for describing a configuration example of a control system in the printing apparatus100. The CPU201of the printing apparatus100controls the respective units of the printing apparatus100including the supplying apparatus200, the sheet conveying unit300, and the printing unit400in accordance with a control program stored in a ROM204. A type and a width of the sheet1, various setting information, and the like are input to the CPU201from the manipulation panel28via an input/output interface202. Further, the CPU201is connected to various external apparatuses29including a host apparatus such as a personal computer via an external interface205, and exchanges various information such as print data with the external apparatus29. Further, the CPU201performs writing and reading of information related to the sheet1and the like on a RAM203. The motor33is a roll driving motor for rotating the roll R normally or reversely through the spool member2, and constitutes a driving mechanism (rotation mechanism) capable of rotationally driving the roll R. The pressing force adjusting motor34is a motor for rotating the rotating cam3ain order to adjust the pressing force against the arm member4. The conveying roller driving motor35is a motor for rotating the conveying roller14normally or reversely. A roll sensor32is a sensor for detecting the spool member2of the roll R when the roll R is set in the supplying apparatus200. A roll rotation amount sensor36is a sensor (rotation angle detection sensor) for detecting a rotation amount of the spool member2, and is, for example, a rotary encoder that outputs pulses which correspond in number to the rotation amount of the roll R.

FIG. 6is a flowchart for describing a supply preparation process of the sheet1starting from the setting of the roll R.

The CPU201of the printing apparatus100stands by in a state in which the arm member4is pressed in the direction of the arrow A1by “weak pressing force” (a weak nip state), and first determines whether or not the roll R is set (step S1). In the present example, when the roll sensor32detects the spool member2of the roll R, the roll R is determined to be set. After the roll R is set, the CPU201switches a state in which the arm member4is pressed in the direction of the arrow A1by “strong pressing force” (a strong nip state) (step S2). Then, the CPU201executes a leading end portion setting process in which the leading end portion of the sheet1is set in the sheet supply path between the arm member4and the separating flapper10(step S3). With the leading end portion setting process (automatic loading), the leading end portion of the sheet1is set (inserted) in the sheet supply path. The leading end portion setting process will be described later in detail.

Thereafter, the CPU201rotates the roll R in the direction of the arrow C1by the roll driving motor33and starts supplying the sheet1(step S4). When the leading end of the sheet1is detected by a sheet sensor6(step S5), the CPU201normally rotates the conveying roller14in a direction of arrow D1, picks up the leading end portion of the sheet1, and then stops the motor33and the motor35(step S6). Thereafter, the CPU201cancels the pressing force of pressing the arm member4in the direction of arrow A1, and causes the first and second driven rotating bodies8and9to be separated from the roll R (to enter a nip release state) (step S7).

Thereafter, the CPU201determines whether the sheet is conveyed (skewed) in a state in which the sheet is obliquely inclined in the sheet conveying unit300. Specifically, the sheet1is conveyed by a predetermined amount in the sheet conveying unit300, and an amount of skew occurring at that time is detected by a sensor installed in a carriage including the print head18or installed in the sheet conveying unit300. When the amount of skew is larger than a predetermined allowable amount, the sheet1is repeatedly fed or back-fed with the normal rotation and the reverse rotation of the conveying roller14and the roll R while applying back tension to the sheet1. With this operation, the skew of the sheet1is corrected (step S8). As described above, when the skew of the sheet1is corrected or when an operation of printing an image on the sheet1is performed, the supplying apparatus200is set to enter the nip release state. Thereafter, the CPU201causes the sheet conveying unit300to move the leading end of the sheet1to a standby position (a fixed position) before printing starts in the printing unit400(step S9). Accordingly, the preparation for supplying the sheet1is completed. Thereafter, the sheet1is pulled out from the roll R with the rotation of the roll R and conveyed to the printing unit400by the sheet conveying unit300.

The sensor unit6will be described below with reference toFIG. 7. As shown inFIG. 7, the sensor unit6is an optical sensor unit including a light emitting unit6csuch as an LED, an OLED, or an LD, and a light receiving unit6dsuch as a photodiode. Light of the light emitting unit6cirradiated toward the roll R is reflected by the front surface of the roll R and detected by the light receiving unit6d. The sensor unit6is connected to the CPU201, and the CPU201can acquire an output value of the sensor unit6at an arbitrary timing. The light which is irradiated from the light emitting unit6cand detected by the light receiving unit6dincludes light regularly reflected by the front surface of the roll R. The output value of the sensor unit6varies in accordance with a distance (interval) between the sensor unit6and the front surface of the sheet (the print surface on which printing is performed by the printing unit). In other words, the sensor unit6has a characteristic that the output value increases as the distance between the sensor unit6and the front surface of the roll R decreases, and the output value decreases as the distance increases. Here, as the sensor unit6, an arbitrary sensor may be used as long as the sensor has an output value changing according to the distance between the sensor unit6and the front surface of the roll R. Further, the light detected by the light receiving unit6dmay not include regularly reflected light.

<Leading End Portion Setting Process>

In the following, before description of a leading end portion setting process accompanied by a manual leading end portion setting detection operation in the present embodiment, a technique of detecting the leading end of the sheet which is executed at the time of the leading end portion setting process will be described with reference to FIG.8. As described above, the printing apparatus100has an automatic loading (automatic sheet feeding) function, and detects the leading end of the sheet using a technique to be described below and causes the leading end portion including the detected leading end to pass through between the separating flapper10and the arm member4and be guided to the inside of the sheet supply path.

First, the CPU201starts acquisition of the output value of the sensor unit6(step S31), and causes the roll R to rotate in an opposite direction (in the direction of arrow C2) (step S32). Then, the CPU201detects a change (inversion) from a high level (hereinafter an “H level”) to a low level (hereinafter an “L level”) in the output of the sensor unit6(step S33).

Here,FIG. 9Aillustrates a relation between a rotational angle of a shaft of the roll R and the output value of the sensor unit6. In this example, the acquisition of the output value of the sensor unit6is started in step S31, and the rotational angle at a time point at which the rotation of the roll R in the opposite direction is started in step S32is set to 0°. After the rotation of the roll R in the opposite direction starts, the leading end of the sheet1passes through the position at which the driven roller10ain the separating flapper10comes into contact with the roll R at a time point at which the rotational angle is 170°, and the leading end portion of the sheet1is separated from the outer circumferential surface of the roll sheet wound on the inside thereof due to its own weight and falls down onto the arm member4. In this case, the distance between the leading end portion of the sheet1and the sensor unit6decreases as in a state illustrated inFIG. 9B. Accordingly, the distance between the sensor unit6and the reflecting surface decreases, and thus the output value of the sensor unit6reaches the H level.

In a case in which the rotation is continued thereafter, the leading end of the sheet1passes over the sensor unit6at a time point at which the rotational angle exceeds 200° and enters a state as illustrated inFIG. 9C. In this state, the sensor unit6detects the light reflected by the front surface of the roll R again other than the leading end portion of the sheet1, and the distance between the sensor unit6and the reflecting surface increases, and thus the output of the sensor unit6changes from the H level to the L level. Thereafter, the rotation is continued, and the leading end of the sheet1passes through the position at which the driven rotating body9comes into contact with the roll R. At this point, the output of the sensor unit6maintains the state of the L level.

The H level and L level indicate the levels to which the output values of the sensor unit6belong. The output of the sensor unit6having the H level indicates that the distance between the sensor unit6and the reflecting surface is short, and the output of the sensor unit6having the L level means that the distance between the sensor unit6and the reflecting surface is long. A leading end detection threshold value TH used for determining whether the output of the sensor unit6is the H level or the L level is stored in a non-volatile memory in the printer main body or the sensor unit. In this example, the threshold value TH is set to TH=(H0+L0)/2. Here, L0is an output value of the sensor unit6when the leading end portion of the sheet1is positioned between the driven rotating body8and the sensor unit6(FIG. 9C). Further, H0is an output value of the sensor unit6when the sheet1abuts on the arm member4, and the leading end portion of the sheet1is positioned between the sensor unit6and the driven roller10a(FIG. 9B). Since the threshold value TH varies due to a variation occurring when a sensor is manufactured, L0and H0may be measured for each individual sensor, and the threshold value TH may be calculated on the basis of the measured value.

The description returns to the flow ofFIG. 8. In a case in which the output of the sensor unit6is detected to change from the H level to the L level (YES in step S33), it can be regarded that the leading end of the sheet1is in a state immediately after it has just passed over the sensor unit6, and the leading end is positioned close to the sensor unit6. In this case, the CPU201determines whether or not the output of the sensor unit6maintains the state of the L level when the roll R is caused to rotate by a predetermined rotational angle or more (this rotational angle is assumed to be “A”) from the state immediately after the leading end of the sheet1has passed over the sensor unit6(step S34). Here, the predetermined rotational angle A is determined to satisfy θ′>A on the basis of an angle (θ′) formed by a straight line connecting a rotation center C with the sensor unit6and a straight line connecting the rotation center C and the driven rotating body8. In this example, A=θ′/2. In a case in which YES is determined in step S34, the CPU201causes the rotation of the roll R to be stopped (step S35). At this time, the leading end of the sheet1is positioned between the driven roller10aand the arm member4. Therefore, the CPU201then causes the spool member2to rotate in the forward direction (the direction of the arrow C1) (step S36), so that the leading end portion of the sheet1can be guided to the inside of the sheet supply path between the arm member4and the separating flapper10.

In a case in which NO is determined in step S33or step S34, the CPU201determines whether or not the roll R has performed one or more rotations from a rotation start time point (step S37). In a case in which NO is determined in step S37, the process returns to step S33, and on the other hand, in a case in which YES is determined, the CPU201stops the rotation of the roll R and the inversion detection of the output of the sensor unit6and urges the user to perform a manual manipulation (manual sheet feeding). Specifically, since automatic leading end portion setting has failed, a message for urging manual leading end portion setting is displayed on the manipulation panel28(step S38). The user who has seen the message displayed in step S38inserts the leading end portion of the sheet1into the sheet supply path manually and sets the sheet1.

In this example, it is determined in step S37whether or not the roll R has performed one or more rotations, but a threshold value used for determining whether or not the roll R has performed a predetermined number of rotations or more is not limited to 1 and may be arbitrarily set. The content of the leading end portion setting process in the present embodiment has been described above.

According to the present embodiment, when the roll R is set, the leading end portion of the sheet1is automatically guided to the inside of the sheet supply path between the arm member4and the separating flapper10. Therefore, the user need not manually set the leading end portion of the sheet in the sheet supply path after the roll R is set. Thus, the convenience in the case of setting the roll is improved.

As described above, the printing apparatus according to the present embodiment has the automatic loading function, and when the roll is set, the automatic sheet feeding in which the leading end portion of the sheet is automatically guided to the inside of the sheet supply path is executed. However, it is not always desirable for the user to perform the automatic sheet feeding in the case of setting the roll. This is because, for example, it takes time to perform the automatic sheet feeding, and thus the skillful user may desire the sheet feeding (the manual sheet feeding) from the manual leading end portion setting which takes less time. Further, for example, in the automatic sheet feeding, since the driven rotating bodies8and9come into pressure contact with the outer circumferential portion of the roll R, there is a possibility that the sheet of the printing target may be damaged, and thus the user may not desire the automatic sheet feeding, for example, in the case of a sheet which is easily damaged.

In this regard, in light of the above problem, in the present embodiment, in a case in which the user who desires the manual sheet feeding manually sets the leading end portion of the sheet in the sheet supply path, the printing apparatus100is controlled such that the automatic sheet feeding accompanied with the leading end detection operation described above is not executed.

<Mechanism of Detecting Manual Leading End Portion Setting in Manual Sheet Feeding>

A mechanism of detecting the manual leading end portion setting according to the present embodiment, specifically, a mechanism of detecting that the user manually sets the leading end portion of the sheet in the sheet supply path will be described below with reference toFIG. 10.

FIG. 10is an explanatory diagram of the supplying apparatus200according to the present embodiment. As illustrated inFIG. 10, the supplying apparatus200according to the present embodiment further includes a sensor unit13(hereinafter referred to as a “page end (PE) sensor unit”) that detects the leading end portion when the manual leading end portion setting is performed. The PE sensor unit13is a non-contact type optical sensor unit having a similar structure to the sensor unit6described above with reference toFIG. 7, and detects the leading end portion of the sheet1placed thereabove. Here, an output of the PE sensor unit13having an H level indicates that the sheet1is placed above the PE sensor unit13because a distance between the PE sensor unit13and the reflecting surface is small. On the other hand, an output of the PE sensor13having an L level indicates that no sheet1is placed above the PE sensor unit13because the distance between the PE sensor unit13and the reflecting surface is large. The PE sensor unit13is installed on the downstream side further than the sensor unit6in the conveyance direction such that the sheet1does not come into contact with the PE sensor unit13when the roll R rotates in the opposite direction (that is, at a position at which the leading end of the sheet1does not pass over the PE sensor unit13when the roll R rotates in the opposite direction). In this example, the optical sensor unit is used as the PE sensor unit13, but the PE sensor unit13is not limited to the optical sensor unit. For example, the contact of the sheet may be detected using a mechanical sensor including a detection lever or a vibration sensor.

<Leading End Portion Setting Process Accompanied by Manual Leading End Portion Setting Detection Operation>

The leading end portion setting process accompanied by the manual leading end portion setting detection operation according to the present embodiment will be described below with reference toFIG. 11.FIG. 11is a flowchart of the leading end portion setting process according to the present embodiment. In this process, it is detected whether or not the user has manually set the leading end portion of the sheet in the sheet supply path, and it is determined whether or not the automatic sheet feeding is executed in accordance with a detection result.

The process illustrated inFIG. 11starts when the roll R is detected to be set in step S1illustrated inFIG. 6, and the supplying apparatus200enters the strong nip state in step S2. In step S30, the CPU201determines whether or not the output of the PE sensor unit13changes from the L level to the H level within a predetermined period (for example, 5 seconds). In a case in which it is determined in step S30that the output of the PE sensor unit13changes from the L level to the H level within a predetermined period (YES in step S30), it is regarded that the user manually set the leading end portion of the sheet in the sheet supply path. In this case, the roll R is caused not to rotate in the opposite direction (a process of step S31to step S35is not executed), but the process proceeds to step S36, the roll R is caused to rotate in the forward direction, and the sheet feeding starts automatically. The present invention is not limited to the example in which the sheet feeding starts on the basis of the detection of the PE sensor unit13, and an operation of waiting for a sheet feeding instruction given by the user who has performed the manual sheet feeding through an input unit of the apparatus may be performed, and a control unit may cause the roll R to rotate in the forward direction on the basis of the instruction. In both cases, the apparatus does not perform the automatic loading, and the sheet feeding (manual sheet feeding) of the sheet manually fed by the user is performed.

On the other hand, in a case in which it is determined in step S30that the output of the PE sensor unit13does not change from the L level to the H level within a predetermined period (NO in step S30), the user is determined to desire the automatic sheet feeding, and the process proceeds to step S31. Then, the automatic loading process is performed. A subsequent process is similar to the process described above with reference toFIG. 8, and description thereof is omitted.

As described above, in the present embodiment, it is determined whether the automatic sheet feeding or the manual sheet feeding is performed, depending on whether or not the leading end portion of the sheet1passes through the PE sensor unit13, that is, whether or not the user inserts the leading end portion manually. In other words, it is possible to select either the automatic sheet feeding or the manual sheet feeding depending on the intention of the user. As a result, in a case in which the user does not desire the automatic sheet feeding which takes time or in a case in which the user desires printing using a sheet which is easily damaged, the user can perform the manual sheet feeding by manual feeding, and thus the convenience of the user is improved. Further, even in a case in which the automatic sheet feeding is selected, in a case where the leading end is not detected well due to a characteristic of a sheet, since switching to the manual sheet feeding can be performed, the sheet feeding can be carried out more reliably.

Modified Example

As the sensor unit6, a distance sensor other than an optical sensor can be used as long as the sensor has an output value changing according to a distance to the sheet. For example, a distance sensor such as an ultrasonic sensor or an electrostatic sensor that detects the distance to the object in a non-contact manner can be used.

The printing apparatus is not limited to the configuration including the two sheet supplying apparatuses corresponding to the two roll sheets and may be a configuration including one sheet supplying apparatus or three or more sheet supplying apparatuses. Further, the printing apparatus is not limited to only the inkjet printing apparatus as long as an image can be printed on a sheet supplied from the sheet supplying apparatus. Further, the printing system and configuration of the printing apparatus are arbitrary as well. For example, a serial scan system of repeating scanning of the print head and the sheet conveyance operation and printing an image or a full-line system of continuously conveying a sheet to a position opposite to a long print head and printing an image may be employed.

Further, the present invention can be applied to various sheet supplying apparatuses in addition to the sheet supplying apparatus which supplies sheets serving as the print medium to the printing apparatus. For example, the present invention can be applied to an apparatus that supplies a reading target sheet to a reading apparatus such as a scanner or a copying machine, or an apparatus that supplies a sheet-like processing material to a processing apparatus such as a cutting apparatus. Such a sheet supplying apparatus may be configured separately from an apparatus such as the printing apparatus, the reading apparatus, or the processing apparatus and may include a control unit (CPU) for the sheet supplying apparatus.

Other Embodiments

According to the present invention, since the user can easily select either the automatic sheet feeding or the manual sheet feeding, the convenience of the user is improved.

This application claims the benefit of Japanese Patent Application No. 2017-046440, filed Mar. 10, 2017, which is hereby incorporated by reference herein in its entirety.