JP2020082482A - Inkjet printer - Google Patents

Abstract

To surely stop a carriage at a home position, and surely perform maintenance of the carriage by a maintenance device.SOLUTION: An inkjet printer includes: a movably arranged carriage; a plurality of recording heads Hdi; a carriage drive processing part Pr3 which drives a drive part for carriage movement and moves the carriage; a head drive processing part Pr1 forming an image on a recording medium; a position detection part which detects a detected member arranged at a home position of a device body; and a reference position calculation part Pr4 which calculates a reference position that is a base point when the carriage is moved on the basis of sensor output of the position detection part. The inkjet printer can surely stop the carriage at the home position, and surely perform maintenance of the carriage by a maintenance device.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inkjet printer.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer, a copier, a facsimile, and a multi-function machine, for example, an inkjet printer, a carriage is moved along a rail, and a plurality of recording heads mounted on the carriage eject ink of each color. Then, by being attached to the recording medium, a color image such as a character or an image is formed and printing is performed.

Therefore, a linear scale is arranged along the rail, the scale of the linear scale is optically read by an encoder arranged in the carriage, and the sensor output is sent to the control unit. And the moving speed of the carriage are calculated, and the carriage motor is driven based on the position and the moving speed of the carriage.

By the way, a home position is set in the inkjet printer as a movement starting point when the carriage is moved, and the carriage is stopped at the home position by abutting against a predetermined abutting portion provided in the inkjet printer ( For example, see Patent Document 1.).

JP, 2010-264766, A

However, in the conventional inkjet printer, when the carriage is repeatedly abutted against the abutting portion as printing is performed, the carriage and the abutting portion are deformed or worn, and the carriage and the abutting portion are abraded. Since dust and the like may be caught between the carriage and the carriage, the carriage cannot be reliably stopped at the home position.

In that case, not only the carriage cannot be moved with high accuracy, but also the maintenance of the carriage by the maintenance device arranged at the home position cannot be performed reliably.

The present invention solves the problems of the conventional inkjet printer described above, not only allows the carriage to be reliably stopped at the home position, but also allows the carriage to be moved with high precision, and ensures the maintenance of the carriage by the maintenance device. It is an object of the present invention to provide an inkjet printer capable of performing the above.

Therefore, in the ink jet printer of the present invention, a carriage that is movably arranged in the main scanning direction, a plurality of recording heads mounted on the carriage, and a drive unit for moving the carriage are driven to move the carriage. A carriage drive processing unit for driving, a head drive processing unit for driving each of the recording heads to form an image on a recording medium, and a detection target member mounted on the carriage and arranged at a home position of the apparatus main body. A position detection unit and a reference position calculation unit that calculates a reference position serving as a base point when the carriage is moved based on a sensor output of the position detection unit.

According to the present invention, in an ink jet printer, a carriage that is movably arranged in the main scanning direction, a plurality of recording heads mounted on the carriage, and a drive unit for moving the carriage are driven to move the carriage. A carriage drive processing unit for driving, a head drive processing unit for driving each of the recording heads to form an image on a recording medium, and a detection target member mounted on the carriage and arranged at a home position of the apparatus main body. A position detection unit and a reference position calculation unit that calculates a reference position serving as a base point when the carriage is moved based on a sensor output of the position detection unit.

In this case, the position detection unit mounted on the carriage serves as a base point for moving the carriage based on the sensor output of the position detection unit when detecting the detected member arranged at the home position of the apparatus body. Since the reference position is calculated, not only can the carriage be reliably stopped at the home position, but also the carriage can be moved accurately. Further, the maintenance of the carriage by the maintenance device arranged at the home position can be surely performed.

FIG. 3 is a control block diagram of the inkjet printer according to the embodiment of the present invention. FIG. 1 is a perspective view showing a main part of an inkjet printer according to an embodiment of the present invention. FIG. 3 is a perspective view of the carriage according to the embodiment of the present invention. FIG. 3 is a perspective view of a recording medium detection unit according to the embodiment of the present invention. It is a front view of the cap unit in an embodiment of the invention. It is a top view of a cap unit in an embodiment of the invention. It is a conceptual diagram for explaining the relationship between the carriage and the cap unit in the embodiment of the present invention. FIG. 6 is a first diagram for explaining an operation when the reference position calculation unit in the embodiment of the present invention calculates a reference position. FIG. 9 is a second diagram for explaining the operation when the reference position calculation unit in the embodiment of the present invention calculates the reference position. 6 is a first flowchart showing the operation of the control unit in the embodiment of the present invention. 6 is a second flowchart showing the operation of the control unit in the embodiment of the present invention. 7 is a third flowchart showing the operation of the control unit in the embodiment of the present invention. It is a 4th flow chart which shows operation of a control part in an embodiment of the invention.

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

FIG. 2 is a perspective view showing a main part of the inkjet printer according to the embodiment of the present invention.

In the figure, 10 is an inkjet printer, and Fr is a frame of the inkjet printer 10.

The frame Fr is a main body of the inkjet printer 10, that is, a receiving plate PB arranged so as to extend from the left end to the right end of the apparatus main body when viewed from the front side (front side in the drawing), and the left end of the receiving plate PB. A side plate PL1 as a first main frame formed by rising from above, a side plate PR1 as a second main frame formed by rising from the right end of the receiving plate PB, and a predetermined distance from the side plate PL1. A frame PL2 as a first sub-frame formed by standing up from the receiving plate PB on the right side, and a second sub-frame formed by standing up from the receiving plate PB on the left side by a predetermined distance from the side plate PR1. A frame body PR2 as a frame and an upper plate PT that connects the upper ends of the side plates PL1, PR1 and the frame bodies PL2, PR2 are provided.

In the inkjet printer 10, a rail 15 is arranged (built) between the side plates PL1 and PR1, and a carriage 17 is arranged along the rail 15 so as to be movable in the left-right direction, that is, the main scanning direction. For this reason, the driving side pulley 18 and the driven side pulley 19 are rotatably arranged on the side plate PR1, and the endless belt 21 travels by the driving side pulley 18 and the driven side pulley 19. The carriage 17 is freely stretched, and the carriage 17 is attached to a predetermined portion of the endless belt 21. In the carriage 17, one or a plurality of recording heads, in the present embodiment, seven recording heads, which will be described later, are formed so that a color image can be formed in the present embodiment. Hdi (i=1, 2,..., 7) (FIG. 7) is arranged with the nozzle surface facing downward. Further, a carriage motor 22 as a drive unit for moving the carriage is arranged in proximity to the drive side pulley 18. In the present embodiment, each recording head Hdi has four inks of black, cyan, magenta, and yellow, and light cyan, light magenta, and gray 3 produced by reducing the concentration of cyan, magenta, and black pigments. Composed of colored inks.

When the pulley 18 on the drive side is rotated by driving the carriage motor 22 and the endless belt 21 is run, the carriage 17 is moved in the main scanning direction, and each recording head Hdi is moved in the main scanning direction. it can.

A linear scale 23 is arranged to extend along the rail 15 and in parallel with the rail 15, and an encoder 35 (FIG. 1), which will be described later, arranged on the carriage 17 adjusts the scale of the linear scale 23. The position of the carriage 17 is detected by reading. The sensor output of the encoder 35 is A/D-converted and sent to a control unit 80 (FIG. 1) described below, and the sensor output of the encoder 35 A/D-converted by a carriage drive processing unit Pr3 described below. Is read, the position and movement speed of the carriage 17 are calculated, and movement control of the carriage 17 is performed.

Then, as the carriage 17 moves, the ink of each color is ejected toward the recording medium P from each recording head Hdi in accordance with the position of the carriage 17, and is attached to the recording medium P. Images such as characters and images are formed on the.

In this way, recording by the recording head Hdi, that is, printing is performed.

As the recording medium P, in addition to paper, a resin film such as vinyl chloride or PET can be used.

A platen 25 having a plate-like shape is arranged along the rail 15 and in parallel with the rail 15, that is, extending in the main scanning direction. The platen 25 extends between the frames PL2 and PR2 on the receiving plate PB and supports the recording medium P conveyed on the platen 25.

Then, below the platen 25, an air suction device (not shown) for drawing the recording medium P to the platen 25 by a negative pressure is arranged. The air suction device is formed over the entire area below the platen 25 and includes a suction chamber, a suction fan, and the like. A plurality of holes are formed in the platen 25, and air on the platen 25 is sucked through the holes by a suction fan, whereby the recording medium P is supported flat by the platen 25.

Further, a rear paper guide (not shown) as a first medium guiding portion is disposed behind the platen 25, and the rear paper guide directs the recording medium P fed from a feeding roll (not shown) toward the platen 25. invite. Therefore, a pair of transport rollers 30 as a transport member is rotatably disposed between the rear paper guide and the platen 25.

The transport roller pair 30 is adjacent to the platen 25, extends in the scanning direction of the inkjet printer 10 and is rotatably provided as a transport roller 31 as a first roller, and above the transport roller 31. , A pinch roller 32 as a second roller that is rotatably arranged at a plurality of positions at a predetermined pitch and presses the recording medium P against the conveying roller 31. When the conveyance motor 34 (FIG. 1) as a conveyance driving unit described later is driven to rotate the conveyance roller 31, the pinch roller 32 is rotated together.

As a result, the recording medium P is delivered from the delivery roll while being sandwiched between the transport roller 31 and the pinch roller 32, and is fed toward the platen 25 on the rear paper guide. Then, while being conveyed on the platen 25, the recording medium P and the nozzle surface of the recording head Hdi are opposed to each other, and ink is ejected from the recording head Hdi and attached to the recording medium P.

In this case, the conveyance motor 34 is driven to convey the recording medium P by a predetermined distance, the conveyance motor 34 is stopped, and the carriage 17 is moved in this state to eject ink from the recording head Hdi. Scanning is performed and an image for one line is formed. When one scan is completed, the transport motor 34 is driven again to transport the recording medium P by a predetermined distance, and then the transport motor 34 is stopped, the carriage 17 is moved in this state, and ink is ejected from the recording head Hdi. As a result, one scan is performed and an image for one line is formed. By repeating this operation, an image is formed on the recording medium P and printing is performed.

In addition, in the present embodiment, printing is performed by the single pass method. However, when printing is performed by the multi-pass method, the distance by which the recording medium P is conveyed is greater than the nozzle row of the recording head Hdi. An image for one line is formed by shortening and performing a plurality of scans.

A front paper guide 33 as a second medium guiding portion for guiding and ejecting the recording medium P after printing is arranged in front of the platen 25. The front paper guide 33 has a curved shape in order to guide the recording medium P discharged horizontally from the platen 25 downward.

Therefore, the recording medium P is guided by the rear paper guide and sent to the platen 25, and the ink ejected from the recording head Hdi is attached to the platen 25 to perform printing, and after the printing is performed, The paper is guided by the front paper guide 33, sent to a winding device (not shown) arranged on the frame Fr, and wound up.

A heater (not shown) as a heating member is embedded in the rear paper guide, the platen 25, and the front paper guide 33, and the recording medium P is preheated in the rear paper guide and heated in the platen 25 and the front paper guide 33. This accelerates the drying of the ink attached to the recording medium P.

In the inkjet printer 10, the home position is set between the side plate PL1 and the frame body PL2, and the retracted position is set between the frame body PR2 and the side plate PR1, and the carriage 17 is folded back at the home position and the retracted position. , Can be moved back and forth.

Then, at the home position, a cap unit 42 as a first maintenance device including a cap that covers the nozzle surface of the recording head Hdi and prevents the ink from drying, an ink receiver that receives the ink whose viscosity has increased in the nozzle, and the like. Is provided. In addition, in order to hold the nozzles of the recording heads Hdi in a good state, the retracted position is provided with a wiper (not shown) for rubbing the nozzle surface of each recording head Hdi and removing dirt, ink, etc. adhering to the nozzle surface A wipe unit 41 as a second maintenance device is provided.

By the way, an abnormality such as wrinkling may occur in the recording medium P supported by the platen 25. In that case, when the recording medium P in which the abnormality occurs hits the recording head Hdi, the recording head Hdi is damaged or A jam may occur on the recording medium P.

Therefore, in the present embodiment, the carriage 17 is provided with a recording medium detection unit U1 (FIG. 3) which will be described later, and the recording medium detection unit U1 detects an abnormality that has occurred in the recording medium P. ..

Next, the recording medium detection unit U1 will be described.

3 is a perspective view of the carriage according to the embodiment of the present invention, and FIG. 4 is a perspective view of the recording medium detection unit according to the embodiment of the present invention.

In the figure, 17 is a carriage, 45 is a cover of the carriage 17, and the recording head Hdi is disposed in the cover 45. The cover 45 includes a top wall Ht, a front wall Hf, an inclined wall Hv formed between the top wall Ht and the front wall Hf, a back wall Hr, and a first side wall on the side plate PL1 (FIG. 2) side. The second side wall Hs2 on the Hs1 and side plate PR1 side is provided.

A recording medium detection unit U1 is arranged at a predetermined location of the carriage 17, in the present embodiment, at the lower ends of the first and second side walls Hs1 and Hs2. When it makes a reciprocating movement, when it comes into contact with the recording medium P, a detection signal SG1 is generated.

Therefore, the recording medium detection unit U1 includes a mounting block 46 as a mounting base, a sensor unit Q1 and a fixing plate 49 as a fixing member.

The mounting block 46 is fixed to the lower ends of the first and second side walls Hs1 and Hs2 by screws (not shown) as a fixing element, welding, or the like.

The sensor unit Q1 is attached to the carriage 17 by being sandwiched between the mounting block 46 and the fixed plate 49, and fixing the fixed plate 49 to the mounting block 46 with a plurality of screws bt1 as fixing elements.

Further, the sensor units Q1 are provided as a plurality of recording medium detection units in the present embodiment, which are arranged adjacent to each other in the conveyance direction of the recording medium P, and are positions for secondary detection. A sensor Sj (j=1, 2, 3) as a detection unit and a detection plate 48 as a detection unit holding member that is integrally formed with each sensor Sj and holds each sensor Sj are provided.

Each of the sensors Sj is composed of a piezoelectric element (not shown) as a detection element having a rectangular shape, is deformed as the detection plate 48 is deformed by an external force, generates power, and detects the sensor output. Generate signal SG1.

Terminals t1 and t2 for outputting a detection signal SG1 are formed near the upper edge of each sensor Sj, and lead wires 51 and 52 are connected to the terminals t1 and t2, respectively.

The detection plate 48 is a plate-shaped body having a rectangular shape, has an upper edge eg1, a lower edge eg2, and left and right side edges eg3, eg4, and is a pocket as a hole having a rectangular shape at three locations in the left-right direction. pk is formed, and the sensor Sj is fitted in the pocket pk.

The width of the detection plate 48 is longer than the width of the recording head Hdi (the length in the transport direction of the recording medium P), and preferably the width of the carriage 17 so that an abnormality of the recording medium P can be reliably detected. (Distance between the front wall Hf and the back wall Hr of the cover 45) is made substantially equal.

Further, the fixing plate 49 is formed of a plate-shaped body having a rectangular shape, includes an upper edge ek1, a lower edge ek2, and left and right side edges ek3, ek4, and is fixed to the mounting block 46 by a screw bt1, A predetermined portion of the detection plate 48 is covered to protect the detection plate 48, and the detection plate 48 and the sensor Sj are positioned with respect to the mounting block 46, that is, with respect to the carriage 17.

As a result, the detection plate 48 is fixed to the mounting block 46 so that the lower edge eg2 is located at the same height as or slightly lower than the nozzle surface of the recording head Hdi, so that the recording medium P is fixed to the recording head Hdi. It is possible to prevent the contact.

Further, the detection plate 48 is fixed to the mounting block 46 so that the lower edge eg2 is parallel to the platen 25. As a result, the distance between the detection plate 48 and the platen 25 becomes constant, and the recording medium P can be accurately detected at any part on the platen 25.

In the present embodiment, the lower edge eg2 of the detection plate 48 is continuously extended below each sensor Sj without being divided for each sensor Sj. Therefore, the recording medium P is detected by the detection plate 48. The same deformation occurs even if any part of the recording medium P is brought into contact with any of the sensors, and any one of the sensors Sj can detect the abnormality of the recording medium P. It should be noted that a slit can be formed in the detection plate 48 corresponding to each sensor Sj, and in that case, each sensor Sj independently detects the recording medium P.

Of the sensors Sj, the most upstream sensor S1 in the transport direction of the recording medium P is disposed so as to face the upstream edge of the platen 25 in the transport path of the recording medium P and a portion in the vicinity thereof. The most downstream sensor S3 in the transport direction of the recording medium P is arranged to face the downstream edge of the platen 25 in the transport path of the recording medium P and its vicinity. Therefore, the recording medium detection unit U1 can detect not only the abnormality of the recording medium P immediately before reaching the platen 25, but also the abnormality of the recording medium P immediately after passing through the platen 25.

As described above, the air suction device is arranged below the platen 25, and the recording medium P on the platen 25 is attracted to the platen 25 by the negative pressure. On the side, the recording medium P is not drawn to the transport path. Therefore, when an abnormality occurs in the recording medium P on the upstream side and the downstream side of the platen 25, the abnormality of the recording medium P can be reliably detected by the recording medium detection unit U1.

The fixed plate 49 is fixed to the mounting block 46 such that the lower edge ek2 is located above the lower edge eg2 of the detection plate 48 and the lower edge eh2 of each sensor Sj by a predetermined distance.

At this time, since the fixed plate 49 is arranged so as to cover a predetermined portion of each sensor Sj, by fixing the fixed plate 49 to the mounting block 46, each sensor Sj is pressed against the mounting block 46 with equal pressure. Be done. Therefore, it is possible to suppress variations in the detection signals SG1 of the sensors Sj, and thus the control unit 80 can accurately determine whether the recording medium P contacts the detection plate 48.

The portion of each sensor Sj covered by the fixed plate 49 is pushed by the fixed plate 49 and is not deformed.

Further, a cut-and-raised part 55 as a protective member is formed from an edge on one side of the terminals t1 and t2 of the fixed plate 49, and one of the lead wires 51 and 52 is formed by the cut-and-raised part 55. Covered and protected. Since the sensor 55 is pressed against the fixed plate 49 around the lead wires 51, 52 by the cut-and-raised parts 55, the vicinity of the upper end of each sensor Sj is not deformed.

That is, the portion of the detection plate 48 covered by the fixed plate 49 does not deform unnecessarily, and only the portion of the detection plate 48 and each sensor Sj below the lower edge ek2 of the fixed plate 49 deforms. Therefore, each sensor Sj can stably generate the detection signal SG1.

Next, the cap unit 42 will be described.

5 is a front view of the cap unit according to the embodiment of the present invention, FIG. 6 is a plan view of the cap unit according to the embodiment of the present invention, and FIG. 7 shows a relationship between the carriage and the cap unit according to the embodiment of the present invention. It is a conceptual diagram for explaining.

In the figure, 17 is a carriage movably arranged in the directions A and B (main scanning direction), 42 is a home position, and is below the carriage 17 when the carriage 17 is placed at the home position. The reference numeral 48 is a detection unit of the recording medium detection unit U1 attached to the first and second side walls Hs1 and Hs2 of the carriage 17.

Ws is a housing of the cap unit 42, and the housing Ws is a front panel Pf, a side panel Ps1 as a first support member vertically protruding from the receiving plate PB on the side plate PL1 side, and a frame body. On the side of PL2, the side panel Ps2 as a second support member is provided so as to project in parallel with the side panel Ps1 and vertically from the receiving plate PB, and the rear panel Pr. The side panels Ps1 and Ps2 are horizontally arranged from the lower ends thereof. It is attached to the receiving plate PB by a screw bt2 as a fixing element via a mounting piece fp protruding in the direction.

In the housing Ws, an elevating unit u1 is provided so as to be movable in the directions of arrows C and D (vertical direction). The elevating unit u1 has a box-shaped cap frame 56 having an open upper end, and the cap frame 56. The cap frame 56 is provided with seven caps Cp and ink receivers Ir, which are accommodated in the cap frame 56 so as to be alternately adjacent to each other and face the recording heads Hdi.

In the home position, two positions in the main scanning direction of the carriage 17 are detected. In the present embodiment, the position of the carriage 17 is detected on each of the side walls PL1 side and frame PL2 side sidewalls at the upper end of the cap frame 56. First and second detection protrusions Sr1 and Sr2 as first and second detected members and as detected members for secondary detection penetrate the side panels Ps1 and Ps2 and Is formed so as to project toward. The first and second detection protrusions Sr1 and Sr2 are moved up and down in conjunction with the cap Cp and the ink receiver Ir.

The elevating unit u1 is arranged movably in the vertical direction by the elevating drive mechanism 58, and has an upper position, a middle position and a lower position. The up-and-down drive mechanism 58 is rotatably disposed in contact with the lower surface of the cap frame 56, and includes a cam 59 as a motion direction conversion member that converts rotational motion into linear motion, and the cam 59 and the shaft sh1. It is provided with a lifting motor 60 (FIG. 1) and the like, which are connected to each other and rotate the cam 59, which will be described later as a lifting driving unit.

The carriage motor 22 (FIG. 2) is driven, the carriage 17 is placed at the cap position as the first maintenance position, the nozzle surface Sa of each recording head Hdi is opposed to each cap Cp, and the lifting motor 60 is driven. Then, when the elevating unit u1 is placed at the upper position, each nozzle surface Sa is covered with the cap Cp. This can prevent the nozzles of the recording head Hdi from drying.

Further, the carriage motor 22 is driven, the carriage 17 is placed at the ink ejection position as the second maintenance position, the nozzle surface Sa of each recording head Hdi is made to face each ink receiver Ir, and the lifting motor 60 is driven. Then, when the elevating unit u1 is placed at the upper position, the ink receiver Ir is located below each nozzle surface Sa. Then, by driving the piezoelectric element 26 (FIG. 1) as a driving element provided in the recording head Hdi, ink is ejected from the nozzle, and the ink is received by the ink receiver Ir.

Further, when the elevating motor 60 is driven and the elevating unit u1 is placed at the middle position, a predetermined distance is provided between the nozzle surface Sa of the recording head Hdi and the cap Cp and the ink receiver Ir. The upper ends eg11, eg12 of the first and second detection protrusions Sr1, Sr2 are placed at a position higher than the lower edge eg2 of the detection plate 48.

When the elevating unit u1 is placed in the middle position and the carriage 17 is moved, the detection plate 48 comes into contact with the first and second detection protrusions Sr1 and Sr2 at a predetermined position to be deformed, and the sensor Sj is deformed. Then, the detection signal SG1 is generated. In the present embodiment, the length of the first and second detection protrusions Sr1 and Sr2 in the transport direction of the recording medium P is longer than that of the detection plate 48. The distance between the first and second detection protrusions Sr1 and Sr2 is longer than the length of the carriage 17 in the main scanning direction.

In the home position, the lifting unit u1 is placed in the lower position while the carriage 17 is moved.

In the present embodiment, the lifting drive mechanism 58 is provided with a cam 59. However, instead of the cam 59, a ball screw and a ball nut are used as a motion direction changing member, and the ball screw is lifted by a motor. It can be rotated by 60.

Further, in the present embodiment, the length of the first and second detection protrusions Sr1 and Sr2 in the recording medium P transport direction is longer than the detection plate 48, but can be shorter than the detection plate 48. .. In that case, when the detection plate 48 comes into contact with the first and second detection protrusions Sr1 and Sr2, the sensor Sj can reliably generate the detection signal SG1 so that the detection signal SG1 is generated. It is preferable to arrange Sr1 and Sr2 directly below the sensor Sj.

Further, the first and second detection protrusions Sr1 and Sr2 are arranged adjacent to each other at a plurality of positions in the main scanning direction (for example, three sheets at an equal pitch), and the detection plate 48 is provided to the first and second detection plates 48. The detection projections Sr1 and Sr2 may be brought into contact with each other a plurality of times to generate detection signals at predetermined intervals.

In that case, the interval at which the detection signal is generated is determined by the interval at which the plurality of first and second detection protrusions Sr1 and Sr2 are arranged. Therefore, the control unit 80 performs detection based on the detection signal from the sensor Sj. It is possible to reliably determine whether the plate 48 has come into contact with the first and second detection protrusions Sr1 and Sr2.

Next, the control device of the inkjet printer 10 will be described.

FIG. 1 is a control block diagram of an inkjet printer according to an embodiment of the present invention.

In the figure, reference numeral 80 is a control unit that controls the entire sequence of the inkjet printer 10 and performs print control, 81 is a ROM as a first storage device including a non-volatile memory, and 82 is a second storage device including a volatile memory. RAM as a storage device, 83 is an interface (I/F) control unit that receives print data and control commands from a host computer (not shown) as a higher-level device, 50 is an operation panel, 53 is a sensor group, U1 is a recording medium detection unit, Sj is a sensor, and 61 is a home position sensor as a position detection unit for primary detection.

The control unit 80 includes a CPU (not shown) as an arithmetic unit, an input/output port, a timer, and the like, and performs various processes based on a program recorded in the ROM 81. In the ROM 81, various initial setting values and the like are recorded in addition to the programs, and in the RAM 82, various data are temporarily recorded. The RAM 82 also functions as a work area when the CPU performs calculation.

Further, the control unit 80 includes a head drive processing unit Pr1, a transport processing unit Pr2, a carriage drive processing unit Pr3, a reference position calculation unit Pr4, a medium abnormality determination unit Pr5, a lift processing unit Pr6 and the like.

The head drive processing unit Pr1 generates image data based on the print data and the control command sent from the host computer, and sends the image data to the recording head Hdi. The recording head Hdi prints according to image data.

The recording head Hdi is provided with the piezoelectric element 26 for each nozzle. When a voltage is applied between electrodes (not shown) arranged at both ends of the piezoelectric element 26, the piezoelectric element 26 is driven and expanded/contracted according to the voltage, whereby side walls of the flow path for sending ink to the nozzles. Is transformed. Then, the cross-sectional area of the ink flow path changes in accordance with the expansion and contraction of the piezoelectric element 26, so that an amount of ink corresponding to the change in the cross-sectional area of the ink flow path is ejected from the nozzle as an ink droplet.

The transport processing unit Pr2 drives the transport motor 34, rotates the transport roller pair 30 (FIG. 2), and moves the recording medium P from the rear paper guide side toward the front paper guide 33 side (in the sub-scanning direction). Transport.

Further, the carriage drive processing unit Pr3 drives the carriage motor 22 by PWM control to drive the endless belt 21 and reciprocate the carriage 17 in the directions of arrows A and B (FIG. 7). Therefore, the carriage drive processing unit Pr3 reads the target position and target speed of the carriage 17 from the ROM 81, receives the sensor output of the encoder 35, performs A/D conversion to calculate the position of the carriage 17, and sets the position as a control value. A PWM control signal is generated and sent to the carriage motor 22. The carriage motor 22 receives the PWM control signal, changes the rotation speed in proportion to the duty of the PWM control signal, and accelerates or decelerates the carriage 17 to move the carriage 17 to the target position at the target speed. Further, the carriage drive processing unit Pr3 sends the position of the carriage 17 to the head drive processing unit Pr1, and the head drive processing unit Pr1 matches the position of the carriage 17 and at the timing calculated based on the image data, the recording head Hdi. Ink is ejected from.

The reference position calculation unit Pr4 calculates a reference position that serves as a base point when the carriage 17 is moved.

Then, the medium abnormality determination unit Pr5 reads the detection signal SG1 generated by the sensor Sj, and when determining that an abnormality has occurred in the recording medium P, stops the carriage motor 22 and stops the carriage 17, and conveys the medium. The motor 34 is stopped and the conveyance of the recording medium P is stopped.

Further, the elevation processing unit Pr6 reads the sensor output of the sensor Sj, drives the elevation motor 60, rotates the cam 59, and moves the elevation unit u1 in the directions of arrows C and D.

The operation panel 50 includes an LED screen (not shown) as a display unit for displaying the state of the inkjet printer 10, a switch, a key, etc. as an operation unit for an operator to input an instruction to the inkjet printer 10. .. When the operation panel 50 is formed by a touch panel, the display section also functions as an operation section.

The sensor group 53 includes various sensors for monitoring the operating state of the inkjet printer 10, such as a temperature sensor and a humidity sensor for detecting the environment in which the inkjet printer 10 is placed.

Further, the home position sensor 61 is an optical sensor including a light emitting portion 62 and a light receiving portion 63, is attached to the second side wall Hs2 of the carriage 17, and when the carriage 17 is placed at the home position, the home position sensor is installed. At, the detected part 65 (FIG. 8) as a detected member for primary detection, which will be described later, attached to the apparatus main body is detected. When a sensor driver (not shown) of the home position sensor 61 receives a sensor control signal from the reference position calculation unit Pr4, the light emitting unit 62 causes light to be emitted to irradiate the detected portion 65 and reflected light from the detected portion 65. Is received by the light receiving unit 63, the sensor output of the light receiving unit 63 is A/D converted, and is sent to the reference position calculation unit Pr4 as a detection signal SG2.

By the way, when the inkjet printer 10 is powered on, the carriage 17 is placed at the home position. At this time, if the position of the carriage 17 is unknown, the carriage 17 may be moved to perform printing. Can not.

Therefore, in the present embodiment, the reference position calculation unit Pr4 calculates the reference position of the carriage 17 based on the detection signal SG2 of the home position sensor 61.

Next, the operation when the reference position calculation unit Pr4 calculates the reference position will be described.

FIG. 8 is a first diagram for explaining the operation when the reference position calculation unit according to the embodiment of the present invention calculates a reference position, and FIG. 9 is a reference position calculation unit according to the embodiment of the present invention. It is a 2nd figure for demonstrating the operation|movement at the time of calculating.

In the figure, P is a recording medium, Hdi is a recording head, HP is a home position, TP is a retracted position, 17 is a carriage, 18 and 19 are pulleys, 21 is an endless belt, 22 is a carriage motor, 23 is a linear scale, and 30 is A conveying roller pair, 35 is an encoder, 42 is a cap unit, 48 is a detection plate, 61 is a home position sensor, and 65 is a detected portion. Further, mk is a marker attached to a predetermined position on the linear scale 23 at the home position HP.

Further, in FIG. 8, L1 is a home position detection section in which the home position sensor 61 detects the detection target portion 65, and in the home position detection section L1, reflection of light emitted from the light emitting unit 62 by the detection target portion 65. Light is received by the light receiving unit 63, and the detection signal SG2 becomes high level. Further, L2 is a constant speed section in which the carriage 17 is moved on the platen 25 and the moving speed is constant.

In FIG. 9, L1 is a home position detection section, Arc is a region corresponding to the carriage 17 in the cap unit 42 when the carriage 17 is at the reference position, and δL is a home position from the second side wall Hs2 of the carriage 17. It is the amount of protrusion of the sensor 61, that is, the correction value of the reference position represented by the dimension of the home position sensor 61 in the main scanning direction. Since the correction value δL changes due to the component accuracy of the home position sensor 61, the assembly error of the carriage 17, and the like, it is measured in advance and recorded in the ROM 81.

By the way, the home position sensor 61 sends the sensor output of the light receiving portion 63 when the detected portion 65 is detected to the reference position calculating portion Pr4 (FIG. 1) as a detection signal SG2. Since the detected portion 65 is arranged to extend over a predetermined distance in the main scanning direction, the detection signal SG2 is at a high level while the home position sensor 61 detects the detected portion 65.

Therefore, in the present embodiment, the reference position is calculated based on the detection signal SG2 of the home position sensor 61 and the correction value δL.

Therefore, the reference position calculation unit Pr4 reads the detection signal SG2 while the carriage 17 is moved toward the home position HP in the direction of arrow B (home position detection direction) in FIG. When the home position sensor 61 detects the edge eg21 of the detected portion 65 on the side plate PL1 side, that is, the position of the carriage 17 when the detection signal SG2 rises is read as the detection position α, and the correction value δL is read from the ROM 81. , The position where the correction value δL is added to the detected position α is calculated as the reference position.

Then, the carriage drive processing unit Pr3 reciprocates the carriage 17 between the home position HP and the retracted position TP based on the calculated reference position, and controls the moving speed of the carriage 17.

The carriage drive processing unit Pr3 sets the moving speed on the outward path to 0 while the carriage 17 is placed at the home position HP, increases it until it reaches the position of the edge eg31 of the platen 25, and moves between the edges eg31 and eg32. It is kept constant for a certain period, lowered until reaching the retracted position TP, and set to 0 at the retracted position TP.

Further, the carriage drive processing unit Pr3 sets the moving speed in the return path to 0 while the carriage 17 is in the retracted position TP, and increases it until the position of the edge eg32 of the platen 25 is reached, and the distance between the edges eg32 and eg31 is set. It is kept constant during the movement, lowered until reaching the home position HP, and set to 0 at the home position HP.

Since the reference position corresponds to the first maintenance position at the home position HP, when the carriage 17 is placed at the reference position, the carriage 17 is placed in the area Arc shown in FIG. The cap Cp (FIG. 5) faces the nozzle surface Sa of each recording head Hdi. Therefore, each nozzle surface Sa can be covered with the cap Cp. Further, when the carriage 17 is moved and placed at the ink ejection position, each ink receiver Ir of the cap unit 42 is made to face the nozzle surface Sa of each recording head Hdi. Therefore, the ink ejected from each nozzle can be received by the ink receiver Ir.

In the present embodiment, the reference position calculation unit Pr4 reads the detection signal SG2 of the home position sensor 61, but the reference position calculation unit Pr4 detects the detection signal SG2 due to a transfer error or the like. It may not be possible to read SG2. In that case, the control unit 80 gradually decreases the communication speed of the detection signal SG2 until the reference position calculation unit Pr4 can read the detection signal SG2.

By the way, in the present embodiment, as described above, when the carriage 17 is placed at the home position HP, the detected portion 65 is detected by the home position sensor 61. When an abnormality occurs, the home position sensor 61 cannot detect the detected portion 65.

Therefore, in the present embodiment, when the home position sensor 61 cannot detect the detected portion 65, the reference position calculation unit Pr4 sets the reference based on the sensor output of the sensor Sj arranged on the detection plate 48. It is designed to calculate the position.

Therefore, the reference position calculation unit Pr4 reads the position of the carriage 17 when the sensor output of the sensor Sj becomes high level as the detection position β, and reads the component accuracy of the sensor unit Q1 (FIG. 3) and the carriage 17 from the ROM 81. The correction value δL that has been measured and recorded in advance according to the assembly error and the like is read, and the position where the correction value δL is added to the detection position β is calculated as the reference position.

As described above, the sensor Sj is formed of a piezoelectric element and generates a sensor output according to the deformation of the detection plate 48. Therefore, the detection accuracy is low, but the cap unit 42 causes the carriage to move. The sensor output can be used to obtain the timing for performing the 17 maintenance.

Further, the reference position calculation unit Pr4 can calculate the reference position by reading the marker mk attached to the linear scale 23 at the home position HP with the encoder 35.

In that case, when the carriage 17 is moved at the home position HP and the position where the marker mk is read by the encoder 35 is the end position of the carriage 17 on the home position HP, the end position is the position of the marker mk on the linear scale 23. It is represented by. Therefore, the reference position calculation unit Pr4 can calculate the reference position based on the distance between the end position and the reference position which is measured in advance.

Further, a position sensor 71 including an optical sensor is arranged at a predetermined position of the apparatus main body at the home position HP, and the position sensor 71 detects a detected portion 72 arranged at a predetermined position of the cover 45 of the carriage 17. You can do it.

In that case, the reference position calculation unit Pr4 reads the detection signal SG2 of the position sensor 71, and calculates the reference position based on the detection signal SG2 and the correction value measured in advance and recorded in the ROM 81.

Next, the operation of the control unit 80 when calculating the reference position by the reference position calculation unit Pr4 will be described.

10 is a first flowchart showing the operation of the control unit in the embodiment of the present invention, FIG. 11 is a second flow chart showing the operation of the control unit in the embodiment of the present invention, and FIG. 12 is the operation of the present invention. FIG. 13 is a third flowchart showing the operation of the control unit in the embodiment, and FIG. 13 is a fourth flowchart showing the operation of the control unit in the embodiment of the present invention.

When the ink jet printer 10 is powered on, the reference position calculation unit Pr4 determines whether the home position sensor 61 has detected the detected portion 65, depending on whether the detection signal SG2 of the home position sensor 61 can be read. to decide. When the detection signal SG2 of the home position sensor 61 can be read and the home position sensor 61 detects the detected portion 65, the reference position calculation unit Pr4 causes the reference position calculation unit Pr4 to detect the carriage 17 when the detection signal SG2 of the home position sensor 61 rises. The reference position is calculated by adding the correction value δL to the detection position α.

When the detection signal SG2 of the home position sensor 61 cannot be read and the home position sensor 61 does not detect the detected portion 65, the lifting/lowering processing unit Pr6 drives the lifting/lowering motor 60 to move down the lifting/lowering unit u1. The upper ends eg11, eg12 of the first and second detection protrusions Sr1, Sr2 are placed at a position lower than the lower edge eg2 of the detection plate 48.

Subsequently, the carriage drive processing unit Pr3 drives the carriage motor 22 to move the carriage 17 toward the platen 25 side (direction of arrow A) by a predetermined amount La, and places the carriage 17 on the platen 25. The detection unit 65 is not detected. The predetermined amount La is set to a value such that the entire carriage 17 is placed on the platen 25, for example.

Then, the lifting/lowering processing unit Pr6 drives the lifting/lowering motor 60 to move the lifting/lowering unit u1 upward and place it in the middle position. At the middle position, the upper ends eg11, eg12 of the first and second detection protrusions Sr1, Sr2 are located at a predetermined distance between the nozzle surface Sa of the recording head Hdi and the cap Cp and the ink receiver Ir. , The carriage 17 on the platen 25 is placed at a position higher than the lower edge eg2 of the detection plate 48.

Subsequently, the carriage drive processing unit Pr3 moves the carriage 17 to the home position HP side (arrow B direction) with the elevating unit u1 placed in the middle position. Along with this, the home position sensor 61 is opposed to the detected portion 65, and the sensor Sj on the first side wall Hs1 side of the carriage 17 is moved over the first and second detection protrusions Sr1 and Sr2. Then, the operation test of the sensor Sj is performed.

Then, the reference position calculation unit Pr4 determines whether or not the home position sensor 61 has detected the detected portion 65 depending on whether or not the detection signal SG2 of the home position sensor 61 can be read.

When the detection signal SG2 of the home position sensor 61 can be read and the home position sensor 61 detects the detected portion 65, the reference position calculation unit Pr4 determines that the home position sensor 61 is operating normally, The reference position is calculated based on the detection signal SG2 of the home position sensor 61.

By the way, when the home position sensor 61 does not detect the detected portion 65 when the power of the inkjet printer 10 is turned on, there is a possibility that an abnormality has occurred in the home position sensor 61. Therefore, in the present embodiment, the carriage drive processing unit Pr3 reduces the moving speed when moving the carriage 17 to the home position HP side, thereby suppressing damage to the home position sensor 61, the carriage 17, and the like. I am trying. The detection sensitivity of the home position sensor 61 can be increased by reducing the moving speed of the carriage 17.

Further, as described above, the control unit 80 lowers the communication speed of the detection signal SG2, so that the detection signal SG2 of the home position sensor 61 is easily read.

Furthermore, the reference position calculation unit Pr4 increases the frequency of data parity check when reading the detection signal SG2 to increase the accuracy of error detection by the reference position calculation unit Pr4, and multiplex transmission of data. It is possible to prevent the occurrence of a transfer error of the detection signal SG2.

When the reference position calculation unit Pr4 cannot read the detection signal SG2 of the home position sensor 61 and the home position sensor 61 does not detect the detected part 65, the reference position calculation unit Pr4 outputs the sensor output of the sensor Sj. The reference position is calculated based on this.

Therefore, the reference position calculation unit Pr4 determines whether or not the sensor Sj on the first side wall Hs1 side has detected the first and second detection protrusions Sr1 and Sr2.

If the sensor Sj on the first side wall Hs1 side does not detect the first and second detection protrusions Sr1 and Sr2, the carriage 17 has not moved sufficiently to the home position HP side, so the carriage drive processing unit Pr3 Further, the carriage 17 is moved to the home position HP side.

When the sensor Sj on the first side wall Hs1 side detects the first and second detection protrusions Sr1 and Sr2, the carriage drive processing unit Pr3 determines that the sensor Sj on the first side wall Hs1 side detects the first detection protrusion. After overcoming Sr1, the deformation is restored, and the movement of the carriage 17 to the home position HP side is continued until there is no sensor output.

Then, the carriage drive processing unit Pr3 moves the carriage 17 to the platen 25 side at a moving speed lower than that when recording is performed by the recording head Hdi.

Subsequently, the reference position calculation unit Pr4 waits for the sensor Sj on the first side wall Hs1 side to detect the first detection protrusion Sr1, and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. Is detected, the position of the carriage 17 when the first detection protrusion Sr1 is detected is acquired as the first detection position and recorded in the RAM 82.

Next, the reference position calculation unit Pr4 waits for the sensor Sj on the second side wall Hs2 side to detect the second detection protrusion Sr2, and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2. Is detected, the position of the carriage 17 when the second detection protrusion Sr2 is detected is acquired as the second detection position and recorded in the RAM 82.

Then, the carriage drive processing unit Pr3 moves the carriage 17 to the platen 25 side until the deformation is restored and the sensor output is lost after the sensor Sj on the second side wall Hs2 side has passed over the second detection protrusion Sr2. continue.

Subsequently, the carriage drive processing unit Pr3 moves the carriage 17 to the home position HP side at a moving speed lower than that at the time of recording by the recording head Hdi.

Then, the reference position calculation unit Pr4 waits for the sensor Sj on the second side wall Hs2 side to detect the second detection protrusion Sr2, and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2. When detected, the position of the carriage 17 when the second detection protrusion Sr2 is detected is acquired as the third detection position and recorded in the RAM 82.

Subsequently, the reference position calculation unit Pr4 waits for the sensor Sj on the first side wall Hs1 side to detect the first detection protrusion Sr1, and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. Is detected, the position of the carriage 17 when the first detection protrusion Sr1 is detected is acquired as the fourth detection position and recorded in the RAM 82.

In this way, when the first to fourth detection positions are recorded in the RAM 82, the reference position calculation unit Pr4 reads the first to fourth detection positions from the RAM 82 and sets them to the first to fourth detection positions. The reference position is calculated based on this.

By the way, the first detection position is the position of the carriage 17 when the carriage 17 is moved to the platen 25 side and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. The detection position is the position of the carriage 17 when the carriage 17 is moved to the home position HP side and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. Depending on the detection position, the carriage 17 is moved to the platen 25 side and the home position HP side, and the position shift of the carriage 17 when the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1 can be known.

The second detection position is the position of the carriage 17 when the carriage 17 is moved to the platen 25 side and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2, and the third detection position is the third position. The detection position is the position of the carriage 17 when the carriage 17 is moved to the home position HP side and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2. Depending on the detection position, the carriage 17 is moved to the platen 25 side and the home position HP side, and the position shift of the carriage 17 when the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2 can be known.

In this case, an intermediate position between the first and fourth detection positions can be estimated as a position where the detection plate 48 on the first side wall Hs1 side and the first detection protrusion Sr1 overlap, and the second and third detection positions can be estimated. It is possible to estimate the position intermediate between the detection positions of 1 and 2 as the position where the detection plate 48 on the second side wall Hs2 side and the second detection protrusion Sr2 overlap.

Therefore, the reference position calculation unit Pr4 sets the intermediate position between the first and fourth detection positions as the first intermediate position X1, and the intermediate position between the second and third detection positions as the second intermediate position X2. The distance Wa between the detection plates 48 on the first and second intermediate positions X1, X2, the first and second side walls Hs1, Hs2, and the distance between the first and second detection protrusions Sr1, Sr2 are calculated. The reference position is calculated based on Wb.

Then, the carriage drive processing unit Pr3 drives the carriage motor 22 to move the carriage 17 to the reference position and place it at the cap position.

Subsequently, the lifting/lowering processing unit Pr6 drives the lifting/lowering motor 60, places the lifting/lowering unit u1 in the upper position, and covers each nozzle surface Sa with the cap Cp.

Then, the reference position calculation unit Pr4 notifies the operator by displaying on the display unit that an abnormality has occurred in the home position sensor 61.

Next, the flowchart will be described.
Step S1 The reference position calculation unit Pr4 determines whether or not the home position sensor 61 has detected the detected portion 65. If the home position sensor 61 detects the detected portion 65, the process proceeds to step S2. If the home position sensor 61 does not detect the detected portion 65, the process proceeds to step S3.
Step S2 The reference position calculation unit Pr4 calculates the reference position and ends the process.
Step S3 The lifting processing unit Pr6 places the lifting unit u1 in the lower position.
Step S4 The carriage drive processing unit Pr3 moves the carriage 17 to the platen 25 side.
Step S5 The lifting processing unit Pr6 places the lifting unit u1 in the middle position.
Step S6 The carriage drive processing unit Pr3 moves the carriage 17 to the home position HP side.
Step S7 The reference position calculation unit Pr4 determines whether or not the home position sensor 61 has detected the detected portion 65. If the home position sensor 61 detects the detected portion 65, the process proceeds to step S8, and if the home position sensor 61 does not detect the detected portion 65, the process proceeds to step S9.
Step S8 The reference position calculation unit Pr4 calculates the reference position and ends the process.
Step S9 The reference position calculation unit Pr4 determines whether or not the sensor Sj on the first side wall Hs1 side has detected the first and second detection protrusions Sr1 and Sr2. When the sensor Sj on the first side wall Hs1 side detects the first and second detection protrusions Sr1 and Sr2, the process proceeds to step S10, and the sensor Sj on the first side wall Hs1 side detects the first and second detection protrusions Sr1. , Sr2 is not detected, the process returns to step S6.
Step S10 The carriage drive processing unit Pr3 continues the movement of the carriage 17 until there is no sensor output.
Step S11 The carriage drive processing unit Pr3 moves the carriage 17 to the platen 25 side.
Step S12 The carriage drive processing unit Pr3 waits for the sensor Sj on the first side wall Hs1 side to detect the first detection protrusion Sr1, and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. If so, the process proceeds to step S13.
Step S13 The reference position calculation unit Pr4 acquires the first detection position.
Step S14 The reference position calculation unit Pr4 waits for the sensor Sj on the second side wall Hs2 side to detect the second detection protrusion Sr2, and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2. If so, the process proceeds to step S15.
Step S15 The reference position calculation unit Pr4 acquires the second detection position.
Step S16 The carriage drive processing unit Pr3 continues the movement of the carriage 17 until there is no sensor output.
Step S17 The carriage drive processing unit Pr3 moves the carriage 17 to the home position HP side.
Step S18 The reference position calculation unit Pr4 waits for the sensor Sj on the second side wall Hs2 side to detect the second detection protrusion Sr2, and the sensor Sj on the second side wall Hs2 side detects the second detection protrusion Sr2. If so, the process proceeds to step S19.
Step S19 The reference position calculation unit Pr4 acquires the third detected position.
Step S20 The reference position calculation unit Pr4 waits for the sensor Sj on the first side wall Hs1 side to detect the first detection protrusion Sr1, and the sensor Sj on the first side wall Hs1 side detects the first detection protrusion Sr1. If so, the process proceeds to step S21.
Step S21 The reference position calculation unit Pr4 acquires the fourth detection position.
Step S22 The reference position calculation unit Pr4 calculates the reference position based on the first to fourth detection positions.
Step S23 The carriage drive processing unit Pr3 moves the carriage 17 to the reference position.
Step S24 The elevation processing unit Pr6 covers the nozzle surface Sa with the cap Cp.
Step S25 The reference position calculation unit Pr4 notifies the operator that an abnormality has occurred in the home position sensor 61, and ends the process.

As described above, in the present embodiment, when the home position sensor 61 mounted on the carriage 17 can detect the detected portion 65 disposed at the home position HP of the apparatus body, the home position sensor 61 is used. Based on the detection signal SG2, the reference position that is the base point when the carriage 17 is moved is calculated.

Further, when the home position sensor 61 cannot detect the detected portion 65, the sensor Sj mounted on the carriage 17 has the first and second detection protrusions Sr1 arranged at the home position HP of the apparatus body. , Sr2 can be detected, the reference position is calculated based on the detection signal SG1 of the sensor Sj.

Therefore, the carriage 17 can be reliably stopped at the home position HP. Further, the carriage 17 can be moved accurately, and the maintenance of the carriage 17 by the cap unit 42 can be reliably performed at the home position HP.

If the home position sensor 61 cannot detect the detected portion 65, it is determined that an abnormality has occurred in the home position sensor 61, and the notification is made. Therefore, the operator is informed of the home position sensor 61, the carriage 17, etc. Can be repaired.

Further, in the present embodiment, when the home position sensor 61 cannot detect the detected portion 65, the reference position is calculated based on the first to fourth detection positions, so that the detection accuracy is high. Even if the sensor Sj which is not expensive is used, the reference position can be accurately calculated.

In the present embodiment, the reference position is calculated based on the first to fourth detection positions, but in the cap unit 42, the displacement of the position of each cap Cp and the ink receiver Ir is allowed. , The first and fourth detection positions are substantially the same, and the second and third detection positions are substantially the same, based on any one of the first to fourth detection positions, The reference position can be calculated.

Whether the carriage drive processing unit Pr3 moves the carriage 17 and places it between the first and second detection protrusions Sr1 and Sr2, and whether the home position sensor 61 can detect the detected portion 65 in this state. By determining, the home position sensor 61 can be tested.

Although the inkjet printer 10 is described in the present embodiment, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, a multifunction machine, and a plotter.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

10 Inkjet Printer 17 Carriage 22 Carriage Motor 61 Home Position Sensor 65 Detected Section Hdi Recording Head HP Home Position P Recording Medium Pr1 Head Drive Processing Section Pr3 Carriage Drive Processing Section Pr4 Reference Position Calculation Section Sj Sensors Sr1, Sr2 First and Second Detection protrusion

Claims (13)

(A) a carriage movably arranged in the main scanning direction,
(B) a plurality of recording heads mounted on the carriage,
(C) a carriage drive processing unit that drives a carriage moving drive unit to move the carriage;
(D) a head drive processing unit that drives each of the recording heads to form an image on a recording medium,
(E) A position detection unit that is mounted on the carriage and that detects a detection target member that is disposed at the home position of the apparatus main body,
(F) An inkjet printer, comprising: a reference position calculation unit that calculates a reference position serving as a base point when the carriage is moved, based on a sensor output of the position detection unit. (A) The detected member is arranged to extend in the main scanning direction at the home position,
(B) The reference position calculation unit moves the carriage to the home position side, and calculates the reference position based on the position of the carriage when the position detection unit detects the edge of the detected member. Inkjet printer. The inkjet printer according to claim 2, wherein the reference position calculation unit calculates the reference position based on a position of the carriage and a correction value when the position detection unit detects an edge. (A) The position detection unit is held by detection plates attached to the first and second side walls of the carriage cover,
(B) The detected member includes first and second detected members arranged at two positions in the main scanning direction at the home position,
(C) The reference position calculation unit moves the carriage to the platen side and the home position side, and the carriage when the position detection units on the first and second side wall sides detect the first and second detected members. The inkjet printer according to claim 3, wherein the reference position is calculated based on the position of. The carriage is moved to the platen side, the position of the carriage when the position detecting unit on the first side wall side detects the first detected member is set as the first detection position, and the carriage is moved to the platen side. The position of the carriage when the position detection unit on the side wall side detects the second detected member is set as the second detection position, the carriage is moved to the home position side, and the position detection unit on the second side wall moves to the first position. When the position of the carriage when the second detected member is detected is the third detection position, the carriage is moved to the home position side, and the position detection unit on the first side wall side detects the first detected member. The inkjet printer according to claim 4, wherein when the position of the carriage is set to a fourth detection position, the reference position calculation unit calculates the reference position based on the first to fourth detection positions. The reference position calculation unit calculates the reference position based on an intermediate position between the first detection position and the fourth detection position and an intermediate position between the second detection position and the third detection position. Item 5. The inkjet printer according to item 5. The inkjet printer according to any one of claims 4 to 6, wherein the position detection unit is deformed according to the deformation of the detection plate to generate a sensor output. The inkjet printer according to claim 7, wherein the position detection unit is brought into contact with and deformed by the first and second detection target members. The inkjet printer according to claim 8, wherein the position detection unit is deformed by contacting a recording medium. (A) A cap unit is provided at the home position,
(B) The inkjet printer according to claim 7 or 8, wherein the first and second detected members are moved up and down in conjunction with the cap of the cap unit. 11. The ink jet printer according to claim 10, wherein the first and second detected members are brought into contact with the position detecting unit with a predetermined distance between the nozzle surface of the recording head and the cap. The inkjet printer according to any one of claims 4 to 11, wherein a distance between the first and second detected members is longer than a length of the carriage in the main scanning direction. (A) a carriage movably arranged in the main scanning direction,
(B) a plurality of recording heads mounted on the carriage,
(C) a carriage drive processing unit that drives a carriage moving drive unit to move the carriage;
(D) a head drive processing unit that drives each of the recording heads to form an image on a recording medium,
(E) A primary detection position detection unit that is mounted on the carriage and that is provided at a home position of the apparatus body and that detects a primary detection target member;
(F) A secondary detection position detection unit that is mounted on the carriage and that is disposed at the home position of the apparatus main body and that detects a secondary detection target member;
(G) A reference position calculation unit that calculates a reference position serving as a base point when the carriage is moved based on the sensor output of the position detection unit for primary detection and the sensor output of the position detection unit for secondary detection With
(H) The reference position calculation unit determines whether or not the primary detection position detection unit can detect the primary detection target member, and the primary detection position detection unit detects the primary detection target member. An inkjet printer, wherein when the detected member cannot be detected, the position detection unit for secondary detection determines whether or not the detected member for secondary detection can be detected.

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