JP2017215365A - Image formation device and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable accurate calibration of a position detection unit, and to enable highly accurate detection of a position of an image writing unit.SOLUTION: An image formation device comprises: a transfer member that is disposed so as to be contactable and separable with respect to an intermediate transfer medium; a position detection unit that is disposed on an upstream side higher in a position than the intermediate transfer medium, has a light emitting unit and light reception unit provided, and detects a position of an image writing unit; and a control unit 80 that causes the light emitting unit to emit light at a prescribed amount of light in a state causing the transfer member to abut on the intermediate transfer medium, irradiates the intermediate transfer medium with the light to cause a sensor output of the position detection unit to be generated in accordance with an amount of light of the light reception unit, and makes calibration of the position detection unit on the basis of the amount of light and the sensor output. The calibration of the position detection unit is made, and thus, a position of the intermediate transfer medium which the position detection unit is caused to oppose, angle thereof, and the like are not different upon printing, and the sensor output can be an identical value upon the printing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus and an image forming system.

  2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, facsimile machines, and multifunction machines, for example, electrophotographic printers, include a plurality of image forming units, and each color is provided on the surface of a photosensitive drum disposed in each image forming unit. The toner image is formed. That is, in each image forming unit, the surface of the photosensitive drum is uniformly charged by the charging roller, exposed by the LED head to form an electrostatic latent image, and the electrostatic latent image is developed by the developing roller. A toner image of each color is formed.

  In an intermediate transfer type printer having an intermediate transfer belt, the toner image on each photosensitive drum is transferred to the intermediate transfer belt by the primary transfer roller at the primary transfer portion, and the intermediate image is transferred by the secondary transfer roller at the secondary transfer portion. The toner image on the transfer belt is transferred to a sheet.

  By the way, in a plurality of image writing units arranged on a medium, for example, label paper, at a constant pitch, for example, a label printing apparatus as an image forming system for forming an image on a label, an unwinder as a paper feeding apparatus is provided. It is arranged adjacent to the printer.

  In the label printing apparatus, the position of each label is detected by a position detection sensor as a position detection unit including an LED and a phototransistor, and an image writing position in each label is determined based on the detected label position. Or a position for cutting the label paper, that is, a cutting position is determined (for example, see Patent Document 1).

  In the case of forming an image on a label sheet having a label affixed on the mount, a transmissive position detection sensor is used, and the light generated by the LED is transmitted through the label sheet, that is, the transmitted light, that is, When the phototransistor receives the transmitted light, the position of each label is detected. In addition, when label paper is affixed to the entire surface of the mount, a plurality of cuts for forming each label are formed on the label paper, and an image is formed on the label paper having a black mark disposed on the back surface of the mount A reflection type position detection sensor is used, and the light generated by the LED irradiates the back side of the label paper, and the light reflected from the back side, that is, the reflected light is received by the phototransistor, thereby the position of each label is determined. Detected.

JP 2003-170632 A

  However, the conventional label printing apparatus cannot accurately detect the label position.

  In other words, when using either a transmission type or reflection type position detection sensor, before starting printing, calibration is performed with the position detection sensor facing the label paper, and the amount of light emitted from the LED is adjusted. However, in this case, in order to suppress deterioration, wear, etc. of the photosensitive drum, the intermediate transfer belt, and the secondary transfer roller, the secondary transfer roller is set in the middle. Since the position detection sensor is calibrated while being separated from the transfer belt, the position, angle, and the like of the label paper that the position detection sensor faces may differ from those at the time of printing. The sensor output of the position detection sensor to be set cannot be the same as that at the time of printing.

  Therefore, calibration cannot be performed accurately, and it becomes impossible to accurately adjust the light emission amount of the LED and to accurately set the threshold value of the light reception amount of the phototransistor.

  In particular, when calibration is performed with the secondary transfer roller separated from the intermediate transfer belt using a reflective position detection sensor, the position and angle of the reflecting surface change when the label paper position and angle change. Therefore, the amount of light reflected by the label sheet is likely to change, and the sensor output when calibration is performed is likely to change. Therefore, the calibration cannot be performed accurately.

  As a result, the position of each label on the label sheet cannot be detected with high accuracy, and the image writing position on each label and the cut position on the label sheet cannot be determined with high accuracy.

  The present invention solves the problems of the conventional label printing apparatus, can accurately calibrate the position detection unit, and can accurately detect the position of the image writing unit, and An object is to provide an image forming system.

  Therefore, in the image forming apparatus of the present invention, the developer image formed on the image carrier is transferred to the medium via the intermediate transfer medium.

  A transfer member disposed so as to be able to contact with and separate from the intermediate transfer medium; and disposed upstream of the transfer member in the conveyance direction of the medium, and includes a light emitting unit and a light receiving unit. With the position detection unit for detecting the position and the transfer member in contact with the intermediate transfer medium, the light emission unit emits light with a predetermined light emission amount to irradiate the medium, and the position detection is performed according to the light reception amount of the light reception unit And a controller that calibrates the position detector based on the light emission amount and the sensor output.

  According to the present invention, in the image forming apparatus, the developer image formed on the image carrier is transferred to the medium via the intermediate transfer medium.

  A transfer member disposed so as to be able to contact with and separate from the intermediate transfer medium; and disposed upstream of the transfer member in the conveyance direction of the medium, and includes a light emitting unit and a light receiving unit. With the position detection unit for detecting the position and the transfer member in contact with the intermediate transfer medium, the light emission unit emits light with a predetermined light emission amount to irradiate the medium, and the position detection is performed according to the light reception amount of the light reception unit And a controller that calibrates the position detector based on the light emission amount and the sensor output.

  In this case, the light emitting unit emits light while the transfer member is in contact with the intermediate transfer medium, the medium is irradiated, the sensor output of the position detecting unit is generated according to the amount of light received by the light receiving unit, and the light emission Since the position detection unit is calibrated based on the amount and the sensor output, the position, angle, etc. of the medium that the position detection unit is opposed to are not different from those at the time of printing. Can be.

  Therefore, calibration can be performed accurately, the light emission amount in the light emitting unit can be adjusted with high accuracy, and the threshold value of the light reception amount in the light receiving unit can be set with high accuracy.

It is a control block of the label printing apparatus in embodiment of this invention. 1 is a conceptual diagram of a label printing apparatus in an embodiment of the present invention. FIG. 2 is a conceptual diagram of an image forming unit in the embodiment of the present invention. It is a side view of the label paper in embodiment of this invention. It is a rear view of the label paper in embodiment of this invention. It is the schematic which shows the contacting / separating mechanism in embodiment of this invention. It is a block diagram of the control part and writing sensor output circuit in embodiment of this invention. It is a flowchart which shows the 1st operation | movement of the control part in the case of performing calibration in embodiment of this invention. It is a flowchart which shows the 2nd operation | movement of the control part in the case of performing the calibration in embodiment of this invention. It is a flowchart which shows the 3rd operation | movement of the control part in the case of performing calibration in embodiment of this invention. It is a flowchart which shows the 4th operation | movement of the control part in the case of performing calibration in embodiment of this invention. It is a flowchart which shows the 5th operation | movement of the control part in the case of performing the calibration in embodiment of this invention. It is a time chart for demonstrating operation | movement of the control part in the case of performing the calibration in embodiment of this invention. It is a 1st figure for demonstrating the 2nd operation | movement of the control part in the case of performing the calibration in embodiment of this invention. It is a 2nd figure for demonstrating the 2nd operation | movement of the control part in the case of performing the calibration in embodiment of this invention. It is a 3rd figure for demonstrating the 2nd operation | movement of the control part in the case of performing the calibration in this Embodiment. It is a figure for demonstrating the 4th operation | movement of the control part in the case of performing the calibration in this Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a label printing apparatus as an image forming system and a printer as an image forming apparatus will be described.

  FIG. 2 is a conceptual diagram of the label printing apparatus in the embodiment of the present invention, and FIG. 3 is a conceptual diagram of the image forming unit in the embodiment of the present invention.

  In the figure, reference numeral 10 denotes a label printing apparatus. The label printing apparatus 10 is disposed adjacent to the printer 11 for printing on a label sheet P as a medium and a transfer material, and the printer 11. The label paper P is sent to the printer 11 and has an unwinder 12 as a paper feeder for cutting the label paper P as necessary. Cs is a housing of the printer 11.

  In the present embodiment, label paper is affixed to the entire surface of the mount, and a plurality of cuts for forming a label as an image writing unit are formed on the label paper at a constant pitch, and the back surface of the mount The label paper P disposed by attaching or forming a black mark as a position detection mark is used.

  The unwinder 12 includes a roll paper storage unit 16 in which a label roll paper 14 formed by winding the label paper P in a roll shape is set, and the label paper P is transferred from the roll paper storage unit 16 to the medium transport path Rt1. It is drawn out.

  The medium transport path Rt1 includes a tension roller 18 that applies tension to the label paper P by pressing the label paper P fed from the roll paper storage unit 16 downward, and a tension roller 18 in the transport direction of the label paper P. From a paper end sensor 20 as a first medium detection unit that is arranged on the downstream side and detects the presence or absence of the label paper P by detecting the front end of the label paper P, and from the paper end sensor 20 in the conveyance direction of the label paper P A transport roller pair 22 as a first transport member that is disposed on the downstream side and transports the label paper P, and downstream of the transport roller pair 22 in the transport direction of the label paper P (upstream from a cutter unit 28 described later). The first position detecting unit 24 for determining the cutting position of the label paper P, for label From a pair of transport rollers 26 as a second transport member that is disposed downstream of the first position detection unit 24 in the transport direction of P and transports the label paper P, and from a pair of transport rollers 26 in the transport direction of the label paper P A cutter unit 28 as a cutting device disposed on the downstream side is provided. The label paper P that has passed through the cutter unit 28 is sent to the printer 11.

  The paper end sensor 20 is pivotably disposed so as to partially face the medium transport path Rt1 through which the label paper P is transported, and is rotated when the label paper P arrives. A photo interrupter (not shown) that changes the light shielding state and the light transmitting state as the lever rotates is provided.

  In addition, the first position detection unit 24 is a reflection type position detection unit disposed opposite to the back surface of the label paper P and is a cut-in sensor 30 as a position detection sensor, and the label paper P. The reflecting plate 31 is provided as a reflecting member disposed so as to face the surface.

  The cut-in sensor 30 is an optical sensor including an LED as a light emitting unit that generates infrared rays and a phototransistor as a light receiving unit having sensitivity to infrared rays, and the LED emits light having a predetermined emission intensity. And the back surface (reflection surface) of the label roll paper P is irradiated. The phototransistor receives light reflected from the back surface of the reflecting plate 31 or the label paper P, that is, reflected light, and generates a sensor output (output voltage) corresponding to the amount of received light.

  In this case, the reflectance of the back surface of the reflecting plate 31 or the label paper P is determined at the position where the cutter sensor 30 is disposed, that is, at the position where the first sensor is disposed. Whether the label paper P exists between the sensor 30 and the reflecting plate 31 (the presence or absence of the label paper P), and when the label paper P exists between the cutter sensor 30 and the reflecting plate 31 Depending on whether or not a black mark exists (whether or not a black mark exists), the cutter sensor 30 generates the sensor output corresponding to the reflectance.

  The cutter unit 28 includes a rotary cutter (not shown), and the label paper P is cut at a predetermined cutting position by rotating the rotary cutter.

  Further, the printer 11 performs intermediate transfer for transferring a toner image as a developer image formed on a photosensitive drum 35 as an image carrier onto a label paper P via an intermediate transfer belt 46 as an intermediate transfer medium. A printer of the type, and an image forming unit 33W, 33Y, 33M, 33C, 33Bk for each color of white, yellow, magenta, cyan, and black, and each image forming unit at the top of the main body of the printer 11, that is, the apparatus main body. An LED head 37 serving as an exposure device and an image writing device disposed to face the photosensitive drums 35 of 33W, 33Y, 33M, 33C, and 33Bk is disposed, and each image forming unit 33W, A transfer unit u1 is disposed below 33Y, 33M, 33C, and 33Bk. Medium transport path Rt2 for conveying the label paper P sent from Nwainda 12 is formed. Since the image forming units 33W, 33Y, 33M, 33C, and 33Bk all have the same structure, only the image forming unit 33Bk and the LED head 37 are shown in FIG.

  In each of the image forming units 33W, 33Y, 33M, 33C, and 33Bk, Hs is a unit case, and 38 is a toner as a developer storage chamber that is formed in the center of the unit case Hs and stores toner as a developer. The storage chamber 39 is a toner storage chamber that is formed above the toner storage chamber 38 in the unit case Hs, and serves as a developer storage section that stores toner to be supplied to the toner storage chamber 38.

  The photosensitive drum 35 is rotatably disposed in the direction of arrow A, and 41 is rotatably disposed in contact with the photosensitive drum 35 so that the surface of the photosensitive drum 35 is evenly distributed. A charging roller 42 serving as a charging device for charging is rotatably disposed in contact with the photosensitive drum 35, and attaches toner to an electrostatic latent image as a latent image formed on the surface of the photosensitive drum 35. A developing roller 43 as a developer carrying member for developing and forming a toner image is rotatably disposed in contact with the developing roller 42 in the toner storage chamber 38. A toner supply roller 44 as a developer supply member that supplies toner to the developing roller 42 is disposed with a predetermined portion in the vicinity of the tip in contact with the developing roller 42, and the toner on the developing roller 42 is a thin layer. Developer rules A developing blade 45 serving as a member is a cleaning blade serving as a cleaning member for removing toner remaining on the photosensitive drum 35 after the toner image is transferred to the intermediate transfer belt 46 that is moved in the direction of arrow B. It is. The toner supply roller 43 is rotated in the same direction as the developing roller 42, and rubs the toner against the developing roller 42 to frictionally charge to a negative polarity.

  The developing roller 42, the toner supply roller 43 and the developing blade 44 constitute a developing device. Then, the surface of the photosensitive drum 35 uniformly charged by the charging roller 41 is exposed by the LED head 37, whereby the electrostatic latent image is formed.

  Further, the transfer unit u1 sequentially superimposes and transfers the color toner images formed in the image forming units 33W, 33Y, 33M, 33C, and 33Bk on the intermediate transfer belt 46, thereby forming a color toner image. The color toner image is transferred to the image writing position on each label of the label paper P.

  Therefore, the transfer unit u1 includes a driving roller R1 as a first roller, an idle roller R2 as a second roller, a backup roller R3 as a third roller, a tension roller R4 as a fourth roller, The intermediate transfer belt 46 that is caused to travel in accordance with the driving of the driving roller R1, and the primary transfer that is opposed to the photosensitive drum 35 of each of the image forming units 33W, 33Y, 33M, 33C, and 33Bk via the intermediate transfer belt 46. A primary transfer roller 47 serving as a transfer member, and a backup roller R3 facing the backup roller R3 via the intermediate transfer belt 46, and is rotatably driven and rotated as the intermediate transfer belt 46 travels. A secondary transfer roller 48 as a transfer member is provided. A primary transfer portion (primary transfer nip portion) as a first transfer portion is provided between each primary transfer roller 47 and each photosensitive drum 35, and a second transfer roller 48 and a backup roller R3 are provided with a first transfer portion. A secondary transfer portion (secondary transfer nip portion) as a second transfer portion is formed.

  The medium transport path Rt2 includes transport roller pairs 51 to 53 as third to fifth transport members that transport the label paper P sent from the unwinder 12, and transport roller pairs 53 in the transport direction of the label paper P. From a second position detection unit 55 that is disposed on the downstream side (upstream side of the secondary transfer roller 48) and detects the position of the label paper P, and from the second position detection unit 55 in the conveyance direction of the label paper P The secondary transfer roller 48 that is disposed on the downstream side and transfers the color toner image formed on the intermediate transfer belt 46 to the label paper P, and downstream of the secondary transfer roller 48 in the conveyance direction of the label paper P. A pair of conveyance rollers 57 as a sixth conveyance member that conveys the label paper P, and disposed downstream of the conveyance roller pair 57 in the conveyance direction of the label paper P. A fixing device 61 as a fixing device for fixing the color toner image transferred to the label paper P to the label paper P; and disposed downstream of the fixing device 61 in the transport direction of the label paper P. A discharge roller pair 63 serving as a first discharge member that discharges outside the main body, and is disposed downstream of the discharge roller pair 63 in the conveyance direction of the label paper P, and detects the front end and the rear end of the label paper P to detect the label. A discharge sensor 64 serving as a second medium detecting unit for detecting the presence or absence of the paper P, and a second downstream of the discharge sensor 64 in the conveyance direction of the label paper P, and discharges the label paper P out of the apparatus main body. A discharge roller pair 65 is provided as a discharge member.

  The second position detection unit 55 serves as a reflection type position detection unit disposed opposite to the back surface of the label paper P and as a position detection sensor, and the surface of the label paper P. And a reflecting plate 71 as a reflecting member disposed so as to face the surface.

  Similar to the cut-in sensor 30, the writing sensor 70 includes an LED 103 (FIG. 7), which will be described later, as a light-emitting unit that generates infrared light, and a phototransistor 104, which will be described later, as a light-receiving unit having sensitivity to the infrared light. The LED 103 generates light having a predetermined light emission intensity and irradiates the back surface of the label roll paper P. The phototransistor 104 receives light reflected by the reflection plate 71 or the back surface of the label paper P, and generates a sensor output corresponding to the amount of received light.

  The reflectance of the back surface of the reflecting plate 71 or the label paper P is the same as that of the writing sensor 70 at the position where the writing sensor 70 is disposed, that is, at the position where the writing sensor is disposed as the second detecting unit disposed position. Whether the label sheet P exists between the reflecting plate 71 (the presence or absence of the label sheet P) and the case where the label sheet P exists between the writing sensor 70 and the reflecting plate 71 will be described later. Depending on whether or not the black mark 74 (FIG. 4) exists (the presence or absence of the black mark 74), the writing sensor 70 generates the sensor output corresponding to the reflectance.

  The fixing device 61 includes a heating roller 67 as a first fixing member and a pressure roller 68 as a second fixing member, and heats and presses the color toner image on the label paper P for labeling. The image is fixed on the paper P and an image is formed at the label writing position.

  The discharge sensor 64 is swingably disposed so as to partially face the medium transport path Rt2 through which the label paper P is transported, and is rotated when the label paper P arrives and passes (not shown). A lever and a photointerrupter that changes the light shielding state and the light transmitting state with the rotation of the lever are provided, and the presence or absence of the label paper P is detected.

  Next, the label paper P will be described.

  FIG. 4 is a side view of the label sheet in the embodiment of the present invention, and FIG. 5 is a rear view of the label sheet in the embodiment of the present invention.

  In the figure, P is a label sheet. In the label sheet P, a label sheet is affixed to the entire surface of the mount Pb, and a plurality of cuts (not shown) for forming each label are formed on the label sheet at a predetermined pitch. Formed with. Further, 74 is a black mark disposed on the back surface of the mount Pb so as to extend in the width direction of the label paper P, eg1 is a downstream edge of the black mark 74 in the transport direction of the label paper P, and eg2 is This is the upstream edge of the black mark 74 in the conveyance direction of the label paper P.

  M is a mark-to-mark distance that is the distance between the edges eg1 of each black mark 74, and W is a mark width that is the distance between the edges eg1 and eg2 of the black mark 74. Each black mark 74 is arranged so that the position of the edge eg1 coincides with the position of the edge on the downstream side of the label, and the distance M between the marks is made equal to the pitch of the label. The inter-mark distance M and the mark width W are set differently depending on the type of the label paper P.

  By the way, in the label printing apparatus 10, before the printing is started, for example, the fixing device 61 is warmed up and various settings are performed. If the transfer roller 48 is in contact with the intermediate transfer belt 46, the intermediate transfer belt 46 and the secondary transfer roller 48 are deteriorated or worn out. Therefore, in the present embodiment, the secondary transfer roller 48 is disposed so as to be in contact with and away from the intermediate transfer belt 46, and the secondary transfer roller 48 is brought into contact with and separated from the intermediate transfer belt 46 as necessary. An approach / separation mechanism is arranged so that the

  Next, the contact / separation mechanism will be described.

  FIG. 6 is a schematic view showing the contact / separation mechanism in the embodiment of the present invention.

  In the drawing, reference numeral 48 denotes a secondary transfer roller, and Mr1 moves the secondary transfer roller 48 up and down to bring the secondary transfer roller 48 into and out of contact with the intermediate transfer belt 46 (FIG. 2). Release motors (secondary transfer motors) placed in contact with the transfer belt 46, that is, in contact, and separated from the intermediate transfer belt 46, that is, in a separated state, g1 to g4 constitute a reduction mechanism. A gear 77 is a lever as an interlocking member that is rotated in conjunction with the movement of the secondary transfer roller 48 in the vertical direction, and 78 is turned on / off in accordance with the rotation of the lever 77, and the secondary transfer roller 48 is a secondary transfer position sensor as a contact / separation state detection unit that detects 48 contact / separation states. The secondary transfer position sensor 78 is composed of a photo interrupter that changes a light shielding state and a light transmitting state as the lever 77 rotates, and is turned on when the secondary transfer roller 48 is placed in the contact state. When the sensor output becomes high and the secondary transfer roller 48 is placed in the separated state, the sensor output is turned off and the sensor output becomes low.

  The gear g1 includes a large-diameter gear ga and a small-diameter gear gb, and the gear g2 includes a large-diameter gear gc and a small-diameter gear gd. Are engaged, the gear g3 and the gear g4 are engaged, the rotation of the release motor Mr1 is decelerated and transmitted to the gear g4, and the lever 77 is rotated. When the release motor Mr1 is driven in the forward direction, the secondary transfer roller 48 is moved downward and placed in a separated state, the secondary transfer position sensor 78 is turned off, and the release motor Mr1 is driven in the reverse direction. Then, the secondary transfer roller 48 is moved upward and put in contact, and the secondary transfer position sensor 78 is turned on.

  By the way, in the cutter sensor 30 and the writing sensor 70, it is necessary to perform calibration by adjusting the light emission amount in the LED and setting the threshold value of the light reception amount in the phototransistor. However, the secondary transfer roller 48 is placed in a separated state. If the calibration is performed in a state where the cutter sensor 30 and the writing sensor 70 are in contact with each other, the position and angle of the label paper P to which the cutter sensor 30 and the writing sensor 70 are opposed are different from those at the time of printing. Cannot be set to the same value as when printing.

  Therefore, in the present embodiment, calibration is performed with the secondary transfer roller 48 placed in a contact state.

  Next, the control device of the label printing apparatus 10 will be described.

  FIG. 1 is a control block diagram of a label printing apparatus according to an embodiment of the present invention.

  In the figure, reference numeral 80 denotes a control unit that performs overall control of the label printing apparatus 10, and 81 denotes an operation panel as an operation unit disposed at a predetermined position of the casing Cs (FIG. 2) of the printer 11. The operation panel 81 includes keys, switches, buttons and the like as operation elements, and a liquid crystal screen as a display element.

  20 is a paper end sensor, 37 is an LED head, 64 is a discharge sensor, 78 is a secondary transfer position sensor, and 84 is a cut-in sensor as a first sensor output control circuit that controls the sensor output of the cut-in sensor 30. An output circuit, 85 is a writing sensor output circuit as a second sensor output control circuit for controlling the sensor output of the writing sensor 70, 87 is a photosensitive drum 35, a charging roller 41, a developing roller 42, a toner supply roller 43, This is a high voltage circuit for applying a high voltage to the primary transfer roller 47 and the like.

  In addition, Mr1 is a release motor. The release motor Mr1 is a brushless DC motor, and is connected to the lever 77 through a gear train including the gears g1 to g4.

  Mr2 is a feeder-side conveyance motor as a first conveyance drive unit for rotating the conveyance roller pair 22, 26 of the unwinder 12 (FIG. 2). The feeder-side conveyance motor Mr2 and the conveyance roller pair 22 , 26 are connected via a gear train (not shown), and the conveyance roller pair 22, 26 is rotated by driving the feeder-side conveyance motor Mr2. The feeder-side transport motor Mr2 is composed of a stepping motor, and the rotation speed is controlled based on the frequency of pulses supplied from the control unit 80.

  Further, Mr3 is a printer-side conveyance motor as a second conveyance drive unit for rotating the conveyance roller pairs 51-53, 57 of the printer 11, and the printer-side conveyance motor Mr3 and the conveyance roller pairs 51-53. , 57 are connected via a gear train (not shown), and the conveyance roller pair 51 to 53, 57 is rotated by driving the printer-side conveyance motor Mr3. The printer-side transport motor Mr3 is composed of a stepping motor, and the rotation speed is controlled based on the frequency of pulses supplied from the control unit 80.

  Mr4 is a cutter motor as a cutting drive unit for rotating the cutter unit 28, and the cutter motor Mr4 and the rotary cutter of the cutter unit 28 are connected via a gear train (not shown). The rotary cutter is rotated by driving Mr4. The cutter motor Mr4 is formed of a stepping motor, and the rotation speed is controlled based on the frequency of the pulses supplied from the control unit 80.

  Further, Mr5 is a belt motor as a drive unit for running the intermediate transfer medium for rotating the drive roller R1, and the belt motor Mr5 and the drive roller R1 are connected via a gear train (not shown), and the belt motor Mr5. Is driven to rotate the driving roller R1. The belt motor Mr5 is a brushless DC motor.

  Mr6 is a drum motor as an image forming drive for rotating the photosensitive drum 35. The drum motor Mr6 and the photosensitive drum 35 are connected via a gear train (not shown), and the drum motor Mr6 is connected. Is driven to rotate the photosensitive drum 35. The drum motor Mr6 is a brushless DC motor.

  Further, Mr7 is a fixing motor as a fixing driving unit for rotating the heating roller 67. The fixing motor Mr7 and the heating roller 67 are connected via a gear train (not shown) to drive the fixing motor Mr7. As a result, the heating roller 67 is rotated. The fixing motor Mr7 is a brushless DC motor.

  Mr8 is a discharge motor as a discharge drive for rotating the discharge roller pair 63, 65. The discharge motor Mr8 and the discharge roller pair 63, 65 are connected via a gear train (not shown), By driving the discharge motor Mr8, the discharge roller pair 63, 65 is rotated. The discharge motor Mr8 includes a stepping motor, and the rotation speed is controlled based on the frequency of the pulses supplied from the control unit 80.

  Next, the writing sensor output circuit 85 will be described. The cutter sensor output circuit 84 has the same configuration as the writing sensor output circuit 85, and thus the description thereof is omitted.

  FIG. 7 is a block diagram of the control unit and the writing sensor output circuit in the embodiment of the present invention.

  In the figure, 80 is a control unit, 85 is a writing sensor output circuit connected to the control unit 80, and the control unit 80 is a signal generation circuit comprising a digital / analog conversion circuit for converting a digital signal into an analog signal. A DA converter 101 and an AD converter 106 as a signal acquisition circuit including an analog / digital conversion circuit for converting an analog signal into a digital signal are provided. The writing sensor output circuit 85 includes a writing sensor 70, an operational amplifier (comparator) OP. , A transistor Tr as a switching element, and resistors r1, r2 having one end grounded. The writing sensor 70 includes an LED 103 and a phototransistor 104.

  Both the DA converter 101 and the AD converter 106 have 3.3 [V] full scale and 8 [bit] resolution capability. When the analog voltage VDA is generated as an analog light emission amount setting signal for setting the light emission amount generated by the LED 103 in the DA converter 101 and sent to the write sensor output circuit 85, the write sensor The output circuit 85 causes the LED 103 to emit light having a light emission amount corresponding to the analog voltage VDA, generates a sensor output VSNS of the writing sensor 70 as an analog detection signal corresponding to the light reception amount in the phototransistor 104, and the AD converter 106. The control unit 80 acquires the sensor output VSNS from the AD converter 106.

  For this purpose, the anode of the LED 103 and the power supply of 3.3 [V] are connected, the cathode of the LED 103 and the collector of the transistor Tr are connected, and the emitter of the transistor Tr and one end of the resistor r1 are connected via the contact q1. The other end of the resistor r1 is grounded.

  Also, the DA converter 101 and the non-inverting input terminal of the operational amplifier OP are connected, the contact q1 and the inverting input terminal of the operational amplifier OP are connected, and the output terminal of the operational amplifier OP and the base of the transistor Tr are connected.

  Further, the collector of the phototransistor 104 and the power source of 3.3 [V] are connected, the emitter of the phototransistor 104 and one end of the resistor r2 are connected via the contact q2, and the other end of the resistor r2 is grounded. The contact q2 and the AD converter 106 are connected.

  The operational amplifier OP, the transistor Tr, and the resistor r1 constitute a constant current circuit, and the analog voltage VDA generated by the DA converter 101 is input to the non-inverting input terminal of the operational amplifier OP, and the voltage at the contact q1 is inverted from the operational amplifier OP. When a predetermined current input to the input terminal and generated at the output terminal of the operational amplifier OP flows to the base of the transistor Tr, the transistor Tr is turned on, the forward current IF flows through the LED 103, and the LED 103 is set to the analog voltage VDA. On the other hand, light of a light emission amount proportional to linear is generated.

  The phototransistor 104 receives the light generated by the LED 103 and reflected by the reflecting plate 71 (FIG. 2) or the back surface of the label paper P, generates an output current proportional to the amount of received light, and generates a resistor r2. When an output current flows through the contact q2, a voltage proportional to the output current is generated at the contact q2, and the voltage is sent to the AD converter 106 as the sensor output VSNS of the writing sensor 70.

  Next, the operation of the control unit 80 when the writing sensor 70 is calibrated will be described. In this case, as described above, with the secondary transfer roller 48 in a contact state, the LED 103 emits light with a predetermined light emission amount to irradiate the label paper P, and according to the light reception amount of the phototransistor 104. The sensor output of the writing sensor 70 is generated, and the writing sensor 70 is calibrated based on the light emission amount and the sensor output.

  Note that the operation of the control unit 80 when calibrating the cutter sensor 30 is the same as that when the writing sensor 70 is calibrated, and thus the description thereof is omitted.

  Further, since the inter-mark distance M and the mark width W are different for each paper P used in the label printing apparatus 10, when performing calibration, the operator operates the operation panel 81 in advance to operate the inter-mark distance M and the mark width W. The mark width W is input to the printer 11. The control unit 80 reads the input mark distance M and mark width W and records them in a memory built in the control unit 80.

  FIG. 8 is a flowchart showing a first operation of the control unit when performing calibration according to the embodiment of the present invention, and FIG. 9 is a second operation of the control unit when performing calibration according to the embodiment of the present invention. FIG. 10 is a flowchart showing a third operation of the control unit when performing calibration in the embodiment of the present invention, and FIG. 11 is a flowchart of the control unit when performing calibration in the embodiment of the present invention. FIG. 12 is a flowchart showing the fourth operation, FIG. 12 is a flowchart showing the fifth operation of the control unit in the case of performing calibration in the embodiment of the present invention, and FIG. 13 is the case of performing calibration in the embodiment of the present invention. FIG. 14 is a time chart for explaining the operation of the control unit of FIG. FIG. 15 is a first diagram for explaining the second operation of the control unit when performing calibration in the present embodiment, and FIG. 15 is a second diagram for explaining the second operation of the control unit when performing calibration in the present embodiment. FIG. 16 is a third diagram for explaining the second operation of the control unit when performing calibration in the present embodiment, and FIG. 17 is a control unit when performing calibration in the present embodiment. It is a figure for demonstrating the 4th operation | movement.

  First, the first operation of the control unit shown in FIG. 8 when performing calibration will be described.

  At timing T0, the label printing apparatus 10 (FIG. 2) is placed in the initial state, the label paper P has not reached the second position detection unit 55, and the label is placed between the writing sensor 70 and the reflection plate 71. The paper P does not exist. Further, the secondary transfer roller 48 is placed in a separated state, the secondary transfer position sensor 78 is turned off, and the sensor output is low.

  The control unit 80 generates a predetermined analog voltage VDA of the DA converter 101 as the first reference value when the label sheet P is not present between the writing sensor 70 and the reflection plate 71.

  For this purpose, the control unit 80 first sets the analog voltage VDA of the DA converter 101 to 00h expressed in hexadecimal. Thereby, the transistor Tr is turned off, so that the LED 103 does not generate light, the phototransistor 104 is turned off, and the sensor output VSNS of the writing sensor 70 becomes 0 [V]. Since the DA converter 101 is composed of a digital / analog conversion circuit, the digital signal 00h is actually converted into an analog signal voltage.

  Subsequently, the control unit 80 increases the light emission amount of the LED 103 by increasing the analog voltage VDA of the DA converter 101 by 10 h, and the sensor output VSNS of the writing sensor 70 indicating the light reception amount of the phototransistor 104 is the threshold value VL1 (= 1.8 [V]), the analog voltage VDA of the DA converter 101 is increased by 10 h until the sensor output VSNS of the writing sensor 70 becomes higher than the threshold value VL1.

  When the sensor output VSNS of the writing sensor 70 becomes higher than the threshold value VL1, the control unit 80 reduces the light emission amount of the LED 103 by lowering the analog voltage VDA of the DA converter 101 by 01h, and the sensor output of the writing sensor 70. It is determined whether or not VSNS is equal to or lower than the threshold value VL1, and the analog voltage VDA of the DA converter 101 is lowered by 01 h until the sensor output VSNS of the writing sensor 70 becomes equal to or lower than the threshold value VL1.

  When the sensor output VSNS of the writing sensor 70 becomes equal to or lower than the threshold value VL1, the control unit 80 records the analog voltage VDA of the DA converter 101 at the timing T1 as the first reference value VDA1 at the timing T1 and stores it in the memory. . In this way, the predetermined analog voltage VDA is generated as the first reference value VDA1 when the label sheet P does not exist between the writing sensor 70 and the reflecting plate 71. The threshold value VL1 is a first threshold value for adjusting the light emission amount of the LED 103 when the label sheet P does not exist between the writing sensor 70 and the reflection plate 71.

Next, a flowchart will be described.
Step S1: The control unit 80 sets the analog voltage VDA of the DA converter 101 to 00h.
Step S2 The controller 80 increases the analog voltage VDA of the DA converter 101 by 10 hours.
Step S3 The controller 80 determines whether or not the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL1. If the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL1, the process proceeds to step S4. If the sensor output VSNS of the writing sensor 70 is equal to or less than the threshold value VL1, the process returns to step S2.
Step S4 The controller 80 lowers the analog voltage VDA of the DA converter 101 by 01h.
Step S5: The controller 80 determines whether or not the sensor output VSNS of the writing sensor 70 is equal to or less than the threshold value VL1. When the sensor output VSNS of the writing sensor 70 is not more than the threshold value VL1, the process proceeds to step S6, and when the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL1, the process returns to step S4.
Step S6 The control unit 80 sets the analog voltage VDA of the DA converter 101 at the timing T1 to the first reference value VDA1, and ends the process.

  Next, the second operation of the control unit shown in FIG. 9 when performing calibration will be described. 14-16, 53 is a conveyance roller pair, 48 is a secondary transfer roller, R3 is a backup roller, 70 is a writing sensor, 71 is a reflector, 74 is a black mark, and P is a label sheet.

  In this case, the control unit 80 causes the LED 103 to emit light with the light emission amount of the LED 103 set to the first reference value VDA1, conveys the label paper P, and the label paper P between the writing sensor 70 and the reflecting plate 71. To exist.

  For this purpose, the controller 80 sets the analog voltage VDA of the DA converter 101 to the first reference value VDA1.

  Next, at timing T2, the control unit 80 drives the release motor Mr1 in the forward direction to start contact (operation) of the secondary transfer roller 48 with the intermediate transfer belt 46, and the secondary transfer position sensor 78 Determine if the sensor output is high. When the sensor output of the secondary transfer position sensor 78 becomes high, the control unit 80 stops the drive of the release motor Mr1 in the positive direction at the timing T3, and the secondary transfer roller 48 contacts the intermediate transfer belt 46 ( Operation). As a result, the secondary transfer roller 48 is placed in contact.

  Subsequently, the control unit 80 drives the feeder-side transport motor Mr2 and the printer-side transport motor Mr3 at timing T4, and starts transporting the label paper P as shown in FIG.

  Then, the control unit 80 determines whether or not the sensor output VSNS is lower than the threshold value VL2 (= 1.7 [V]), and continues the conveyance of the label paper P until the sensor output VSNS becomes lower than the threshold value VL2. When the output VSNS becomes lower than the threshold value VL2, it is determined that the label sheet P exists between the writing sensor 70 and the reflecting plate 71 at timing T5. Note that the threshold value VL2 is set lower than the threshold value VL1.

  Subsequently, the control unit 80 determines that the label sheet P is present between the writing sensor 70 and the reflection plate 71, and then drives the feeder-side transport motor Mr2 and the printer-side transport motor Mr3 to thereby label the sheet. Further transport P.

Then, as shown in FIGS. 14 and 15, the control unit 80 moves the label sheet P from the first predetermined distance, in the present embodiment, from the position of the writing sensor 70 to the position of the secondary transfer roller 48. Distance L1 half the distance X
L1 = X / 2
The belt motor Mr5 and the drum motor Mr6 are driven at the timing T6 when the image is conveyed only, and the image forming unit including the photosensitive drum 35, the intermediate transfer belt 46, and the like is driven. As a result, the photosensitive drum 35, the charging roller 41, the developing roller 42, the toner supply roller 43, the primary transfer roller 47, and the like are rotated, and the intermediate transfer belt 46 is caused to travel. The secondary transfer roller 48 is rotated.

  The threshold value VL2 is a second threshold value for determining whether or not the label paper P exists between the writing sensor 70 and the reflection plate 71, and is lower than the threshold value VL that is the first threshold value. Is set.

Further, the distance L1 is determined so that the label sheet P is present between the writing sensor 70 and the reflection plate 71 and the image is formed until the front end of the label sheet P reaches the secondary transfer portion. This is set to prevent the secondary transfer roller 48 from being rotated and the secondary transfer roller 48 from rotating. In the present embodiment, the distance L1 is L1 = X / 2
The distance L1 is set to X / 2 <L1 <X
Can be set to be

  Therefore, even if the secondary transfer roller 48 is in contact, the image forming unit is not driven until the front end of the label paper P reaches the secondary transfer unit, and the secondary transfer roller 48 is rotated. Therefore, deterioration, wear and the like of the image forming unit and the secondary transfer roller 48 can be suppressed.

Subsequently, the control unit 80 drives the feeder-side transport motor Mr2 and the printer-side transport motor Mr3, and as shown in FIG. 16, the label paper P is moved to the second predetermined distance, in the present embodiment, the mark Distance L2 obtained by subtracting distance X / 2 from half distance M / 2 of distance M
L2 = (M / 2)-(X / 2)
Then, at timing T7, the driving of all the motors (feeder side conveyance motor Mr2, printer side conveyance motor Mr3, belt motor Mr5 and drum motor Mr6) is stopped. In this way, the writing sensor 70 is opposed to the center (near) between two adjacent black marks 74 on the label paper P.

Next, a flowchart will be described.
Step S11 The controller 80 sets the analog voltage VDA of the DA converter 101 to the first reference value VDA1.
Step S12 The controller 80 starts the contact of the secondary transfer roller 48 to the intermediate transfer belt 46.
Step S13: The controller 80 determines whether the sensor output of the secondary transfer position sensor 78 is high. If the sensor output of the secondary transfer position sensor 78 is high, the process proceeds to step S14.
Step S14 The controller 80 ends the contact of the secondary transfer roller 48 with the intermediate transfer belt 46.
Step S15 The control unit 80 starts conveying the label paper P.
Step S16 The controller 80 determines whether or not the sensor output VSNS is lower than the threshold value VL2. If the sensor output VSNS is lower than the threshold value VL2, the process proceeds to step S17. If the sensor output VSNS is greater than or equal to the threshold value VL2, the process returns to step S15.
Step S17 The control unit 80 conveys the label paper P by the distance L1, and drives the image forming unit.
Step S18 The control unit 80 conveys the label paper P by the distance L2, stops driving of all the motors, and ends the process.

  Next, the third operation of the control unit shown in FIG. 10 when performing calibration will be described.

  In this case, the writing sensor 70 is opposed to the center between two adjacent black marks 74 of the label paper P, the secondary transfer roller 48 is placed in contact, and the secondary transfer position sensor 78 is turned on. Sensor output is high.

  Then, the control unit 80 sets the predetermined analog voltage VDA when the label sheet P is present between the writing sensor 70 and the reflection plate 71 as the second reference value VDA2 higher than the first reference value VDA1. generate.

  For this purpose, the controller 80 first sets the analog voltage VDA of the DA converter 101 to 00h. As a result, the transistor Tr is turned off, so that the LED 103 does not generate light, the phototransistor 104 is turned off, and the sensor output VSNS of the writing sensor 70 becomes 0 [V] again.

  Subsequently, the control unit 80 increases the light emission amount of the LED 103 by increasing the analog voltage VDA of the DA converter 101 by 10 h, and the sensor output VSNS of the write sensor 70 indicating the light reception amount of the phototransistor 104 is the threshold value VL3 (= 2.7 [V]), the analog voltage VDA of the DA converter 101 is increased by 10 h until the sensor output VSNS of the writing sensor 70 becomes higher than the threshold value VL3.

  When the sensor output VSNS of the writing sensor 70 becomes higher than the threshold VL3, the control unit 80 reduces the light emission amount of the LED 103 by lowering the analog voltage VDA of the DA converter 101 by 01h, and the sensor output of the writing sensor 70. It is determined whether or not VSNS is equal to or lower than the threshold value VL3, and the analog voltage VDA of the DA converter 101 is lowered by 01 h until the sensor output VSNS of the writing sensor 70 becomes equal to or lower than the threshold value VL3.

  When the sensor output VSNS of the writing sensor 70 becomes equal to or less than the threshold VL3, the control unit 80 records the analog voltage VDA of the DA converter 101 at the timing T8 as the second reference value VDA2 at the timing T8 in the memory. . In this manner, the predetermined analog voltage VDA when the label sheet P is present between the writing sensor 70 and the reflecting plate 71 is generated as the second reference value VDA2. The threshold value VL3 is a third threshold value for adjusting the light emission amount of the LED 103 when the label sheet P exists between the writing sensor 70 and the reflection plate 71, and is the first threshold value. It is set higher than a certain threshold value VL1.

Next, a flowchart will be described.
Step S21 The controller 80 sets the analog voltage VDA of the DA converter 101 to 00h.
Step S22 The controller 80 increases the analog voltage VDA of the DA converter 101 by 10h.
Step S23 The controller 80 determines whether or not the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL3. When the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL3, the process proceeds to step S24, and when the sensor output VSNS of the writing sensor 70 is equal to or less than the threshold value VL3, the process returns to step S22.
Step S24 The controller 80 lowers the analog voltage VDA of the DA converter 101 by 01h.
Step S25 The control unit 80 determines whether or not the sensor output VSNS of the writing sensor 70 is equal to or less than the threshold value VL3. When the sensor output VSNS of the writing sensor 70 is not more than the threshold value VL3, the process proceeds to step S26, and when the sensor output VSNS of the writing sensor 70 is higher than the threshold value VL3, the process returns to step S24.
Step S26 The controller 80 sets the analog voltage VDA of the DA converter 101 at the timing T8 to the second reference value VDA2, and ends the process.

  Next, the fourth operation of the control unit shown in FIG. 11 when performing calibration will be described. In FIG. 17, 53 is a pair of conveying rollers, 48 is a secondary transfer roller, R3 is a backup roller, 70 is a writing sensor, 71 is a reflecting plate, 74 is a black mark, and P is a label sheet.

  In this case, the control unit 80 causes the LED 103 to emit light while the analog voltage VDA is set to the second reference value VDA2, conveys the label paper P, and a black mark 74 is provided between the writing sensor 70 and the reflection plate 71. Make it exist.

  Therefore, the control unit 80 sets the analog voltage VDA of the DA converter 101 to the second reference value VDA2.

  Then, at timing T9, the control unit 80 drives the feeder-side transport motor Mr2 and the printer-side transport motor Mr3, starts transporting the label paper P, drives the belt motor Mr5 and the drum motor Mr6, and drives the image forming unit. To drive. At this time, since the secondary transfer roller 48 is placed in contact, it is rotated as the intermediate transfer belt 46 travels and the label paper P is conveyed.

  The control unit 80 sets a predetermined sensor output VSNS when the label paper P is conveyed and the image forming unit is driven as a threshold value of the sensor output VSNS for detecting the label position.

  Therefore, the control unit 80 determines whether the sensor output VSNS is lower than the threshold value VL4 (= 1.7 [V]), and continues the conveyance of the label paper P until the sensor output VSNS becomes lower than the threshold value VL4. When the sensor output VSNS becomes lower than the threshold value VL4, it is determined that the black mark 74 exists between the writing sensor 70 and the reflection plate 71 at timing T10. The threshold value VL4 is a fourth threshold value for determining whether or not the black mark 74 of the label paper P has reached the writing sensor 70, and is set lower than the threshold value VL3 that is the third threshold value.

  Subsequently, the control unit 80 drives the feeder-side transport motor Mr2, the printer-side transport motor Mr3, the belt motor Mr5, and the drum motor Mr6 to further transport the label paper P.

Then, the control unit 80 moves the label paper P to a third predetermined distance, which is a distance L3 that is half the mark width W in this embodiment.
L3 = W / 2
Only carry.

  In this way, as shown in FIG. 17, when the writing sensor 70 is opposed to the center (near) of the black mark 74, the control unit 80 causes all the motors (feeder-side transport motor Mr2) at timing T11. , The driving of the printer-side transport motor Mr3, the belt motor Mr5, and the drum motor Mr6) is stopped. Thereby, the conveyance of the label paper P and the driving of the image forming unit are stopped.

Subsequently, the control unit 80 acquires the sensor output VSNS when the label paper P is transported by the distance L3 as the mark level Vm representing the value when the black mark 74 is detected, and the black mark on the label paper P is obtained. 74 is a threshold value of the sensor output VSNS for determining whether or not 74 exists, that is, a threshold value Vmark of the amount of light received by the phototransistor 104.
Vmark = Vm + C
C: Calculate a constant and record the threshold value Vmark in the memory.

The threshold value Vmark is a fifth threshold value for determining whether or not the black mark 74 exists, and is set lower than the threshold value VL4 that is the fourth threshold value. The constant C is set to a predetermined value. By setting the constant C to 0 [V],
Vmark = Vm
Can be.

  Therefore, when the sensor output voltage VSNS of the writing sensor 70 is higher than the threshold value Vmark, it is determined that the black mark 74 does not exist between the writing sensor 70 and the reflection plate 71, and the sensor output voltage VSNS is equal to or lower than the threshold value Vmark. In this case, by determining that the black mark 74 exists between the writing sensor 70 and the reflecting plate 71, the writing position of the image on the label can be determined.

Next, a flowchart will be described.
Step S31 The controller 80 sets the analog voltage VDA of the DA converter 101 to the second reference value VDA2.
Step S32 The control unit 80 starts conveying the label paper P and drives the image forming unit.
Step S33 The controller 80 determines whether or not the sensor output VSNS is lower than the threshold value VL4. If the sensor output VSNS is lower than the threshold value VL4, the process proceeds to step S34, and if the sensor output VSNS is greater than or equal to the threshold value VL4, the process returns to step S32.
Step S34 The controller 80 conveys the label paper P by the distance L3.
Step S35: The controller 80 stops driving all the motors.
Step S36 The controller 80 acquires the sensor output VSNS as the mark level Vm.
Step S37: The control unit 80 sets the threshold value Vmark.
Vmark = Vm + C
C: A constant is calculated.
Step S38: The control unit 80 records the threshold value Vmark in the memory, and ends the process.

  Next, a fifth operation of the control unit shown in FIG. 12 when performing calibration will be described.

  At timing T12, the control unit 80 drives the release motor Mr1 in the reverse direction to start separation (operation) of the secondary transfer roller 48 from the intermediate transfer belt 46, and the sensor output of the secondary transfer position sensor 78 is low. It is determined whether or not. When the sensor output of the secondary transfer position sensor 78 becomes low, the control unit 80 stops the reverse driving of the release motor Mr1 at timing T13, and the secondary transfer roller 48 is separated from the intermediate transfer belt 46 (operation). ) Ends. As a result, the secondary transfer roller 48 is placed in a separated state.

  When the calibration of the writing sensor 70 is completed in this way, the controller 80 places the secondary transfer roller 48 in the separated state, and at timing T14, the feeder-side transport motor Mr2 and the printer-side transport motor Mr3. Is driven, the label paper P is conveyed, and at timing T15, the cutter motor Mr4 is driven to rotate the cutter unit 28, and the label paper P is cut at a predetermined cutting position.

  Then, at timing T16, the control unit 80 drives the discharge motor Mr8 to rotate the discharge roller pair 63 and 65, and discharges the label paper P outside the apparatus main body.

  Subsequently, the control unit 80 determines whether or not the sensor output of the discharge sensor 64 is low, and ends the process when the sensor output of the discharge sensor 64 is low.

  In the present embodiment, the calibration of the writing sensor 70 has been described. However, the cutter sensor 30 can also be calibrated by a similar method.

Next, a flowchart will be described.
Step S41 The controller 80 starts the separation of the secondary transfer roller 48 from the intermediate transfer belt 46.
Step S42: The controller 80 determines whether the sensor output of the secondary transfer position sensor 78 is low. If the sensor output of the secondary transfer position sensor 78 is low, the process proceeds to step S43.
Step S43 The controller 80 ends the separation of the secondary transfer roller 48 from the intermediate transfer belt 46.
Step S44 The controller 80 conveys the label paper P.
Step S45 The control unit 80 cuts the label paper P.
Step S46: The controller 80 determines whether the sensor output of the discharge sensor 64 is low. If the sensor output of the discharge sensor 64 is low, the process is terminated.

  As described above, in the present embodiment, the LED 103 is caused to emit light while the secondary transfer roller 48 is in contact with the label paper P, and writing is performed according to the amount of light received by the phototransistor 104. The sensor output VSNS of the output sensor 70 is generated, and the write sensor 70 is calibrated based on the light emission amount of the LED 103 and the sensor output of the write sensor 70. Therefore, the cutter sensor 30 and the write sensor 70 face each other. The position, angle, etc. of the label paper P to be made are not different from those at the time of printing, and the sensor outputs VSNS of the cutter sensor 30 and the writing sensor 70 can be set to the same values as at the time of printing.

  Therefore, calibration can be performed accurately, the light emission amount in the LED 103 can be adjusted with high accuracy, and the threshold value of the light reception amount in the phototransistor 104 can be set with high accuracy.

  In this embodiment, the operator operates the operation panel 81 in advance to input the mark distance M and the mark width W of the label paper P to be used to the printer 11. The mark distance M (= 25.4 [mm]) and the mark width M (= 3.0 [mm]) determined by the above specifications can be set.

  Further, in the present embodiment, label paper is affixed to the entire surface of the mount Pb, and a plurality of cuts for forming each label on the label paper are formed at a predetermined pitch. The black mark 74 is disposed on the back surface of the label paper P, the reflective cutter sensor 30 and the writing sensor 70 are used, and the light generated by the LED 103 irradiates the back surface of the label paper P, The position of each label is detected by the reflected light being received by the phototransistor 104. Instead of the label paper P, a label paper having a label affixed on the mount is used. can do. In that case, a transmission type cut-in sensor and a writing sensor as a position detection unit and a position detection sensor are used, and the light generated by the LED is transmitted through the label sheet, that is, the transmitted light, that is, When the phototransistor receives the transmitted light, the position of each label is detected.

  Furthermore, in the present embodiment, the label paper P is used as a medium, but a preprinted continuous paper can be used as the medium.

  In that case, a plurality of pre-printed images as image writing units are formed on the pre-printed continuous paper at a constant pitch, and the images are formed in an overlapped manner at the set image writing position of each pre-printed image. Then, the position of the pre-printed image as the reference position is detected by the transmission type writing position detection sensor and the reflection type writing position detection sensor.

  Further, as a medium, in addition to continuous paper such as label paper P, pre-printed continuous paper, paper on which a plurality of labels are affixed at a constant pitch, a plurality of pre-printed images are formed at a constant pitch, Paper or the like on which black marks are arranged can be used.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

11 Printer 35 Photosensitive drum 46 Intermediate transfer belt 48 Secondary transfer roller 70 Writing sensor 80 Control unit 103 LED
104 Phototransistor P Label paper

Claims (15)

In an intermediate transfer type image forming apparatus that transfers a developer image formed on an image carrier to a medium via an intermediate transfer medium.
(A) a transfer member disposed so as to be able to contact with and separate from the intermediate transfer medium;
(B) a position detection unit that is disposed upstream of the transfer member in the medium conveyance direction, includes a light emitting unit and a light receiving unit, and detects the position of the image writing unit on the medium;
(C) With the transfer member in contact with the intermediate transfer medium, the light emitting part emits light with a predetermined light emission amount to irradiate the medium, and the sensor output of the position detection part is generated according to the light reception amount of the light receiving part And a control unit that calibrates the position detection unit based on the light emission amount and the sensor output.   Connected to the control unit, includes the light emitting unit and the light receiving unit, receives a light emission amount setting signal for setting the light emission amount of the light emitting unit from the control unit, and outputs a sensor output corresponding to the light reception amount of the light receiving unit to the control unit The image forming apparatus according to claim 1, further comprising a sensor output control circuit for sending.   The image forming apparatus according to claim 2, wherein the control unit includes a signal generation circuit that generates a light emission amount setting signal including an analog signal, and a signal acquisition circuit that acquires a sensor output including the analog signal.   The signal generation circuit generates a predetermined light emission amount setting signal when the medium is not present at the position where the position detection unit is provided as a first reference value, and the position detection unit is provided. The image forming apparatus according to claim 3, wherein a predetermined light emission amount setting signal when a medium is present at a position is generated as a second reference value.   The image forming apparatus according to claim 4, wherein the control unit places the transfer member in contact with an intermediate transfer medium when the first reference value is generated.   The image forming apparatus according to claim 5, wherein the control unit conveys the medium in a state where the transfer member is in contact with an intermediate transfer medium when the first reference value is generated.   The control unit determines whether a medium is present at a position where the position detection unit is disposed based on a sensor output while the medium is being conveyed, and the position detection unit is disposed. The image forming apparatus according to claim 6, wherein the image forming unit is driven when it is determined that the medium is present at the position.   The control unit according to claim 7, wherein the control unit drives the image forming unit when the medium is conveyed by a predetermined distance after determining that the medium exists at a position where the position detection unit is disposed. Image forming apparatus.   The image forming apparatus according to claim 7, wherein the control unit drives the image forming unit by rotating an image carrier and running an intermediate transfer medium.   When the control unit determines that a medium is present at the position where the position detection unit is disposed, the control unit stops the conveyance of the medium and the drive of the image forming unit, and the second reference value The image forming apparatus according to claim 4, wherein:   The control unit detects a position of the image writing unit on the medium by detecting a predetermined sensor output when the medium is transported and the image forming unit is driven when the second reference value is generated. The image forming apparatus according to claim 10, wherein the image forming apparatus is set as a threshold value of a sensor output for performing the operation. (A) a mark for detecting the position of the image writing unit is disposed on the medium;
(B) The image forming apparatus according to any one of claims 1 to 11, wherein the light receiving unit receives reflected light from the medium when the light emitting unit emits light.   The image forming apparatus according to claim 1, wherein the light receiving unit receives transmitted light that passes through a medium when the light emitting unit emits light. (A) a mark for detecting the position of the image writing unit is disposed on the medium;
(B) When the control unit determines that a mark is present at the position where the position detection unit is disposed, the control unit outputs a sensor output when the medium is conveyed by a predetermined distance. The image forming apparatus according to claim 10, wherein the image forming apparatus is set as a threshold value of a sensor output for detecting the position of the sensor.   An image forming system comprising the image forming apparatus according to claim 1.

Images