JP2009155013A - Recording device and control method of recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve throughput by shortening time required to start to record on a recording medium. <P>SOLUTION: In a dot impact printer 10 having a paper insertion detection sensor 29 arranged at an upstream side of a carriage 19 on a transport route H and a paper width detection sensor 31 arranged for the carriage 19, the paper width detection sensor 31 is arranged at a position shifted from a recording head 11 in a carriage 19. The dot impact printer 10 sets a threshold value based on an output value of the paper insertion detection sensor 29 and detects a side end of the recording medium K by comparing the threshold value and the output value of the paper width detection sensor 31. On starting to record on the recording medium K, the carriage 19 is moved from a home position to another end and, after detecting the side end of the recording medium K during the movement, an image is recorded during the movement based on the detected side end. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording apparatus that records an image on a recording medium, and a control method for controlling the recording apparatus.

2. Description of the Related Art Conventionally, in a recording apparatus that records an image on a recording medium such as paper, a paper width sensor is provided in a carriage that is scanned in the width direction of the recording medium, and before the image is recorded on the recording medium by the recording head, the width of the recording medium is reduced. A device that performs a preliminary detection operation only for the purpose of detection is known (see, for example, Patent Document 1). In this preliminary detection operation, after the carriage is scanned in the width direction of the recording medium and scanning of the entire scanning range is completed, a threshold for determining the presence or absence of the recording medium is determined based on the output value of the paper width sensor being scanned. The side edge of the recording medium is detected based on this threshold value.
Japanese Unexamined Patent Publication No. 7-179248

However, the conventional recording apparatus has a problem in that it takes time to start recording because it is necessary to perform a preliminary detection operation before recording an image on a recording medium.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a recording apparatus capable of reducing the time required to start recording on a recording medium and improving throughput. And

In order to achieve the above object, the present invention provides a transport unit that transports a recording medium on a transport path, a carriage that is reciprocally scanned in the width direction of the recording medium, and an image provided on the recording medium. A recording head having a recording unit for recording the image, and a recording apparatus that records an image on the recording medium by the recording unit while scanning the carriage, and is provided on the upstream side of the carriage on the conveyance path. A medium detection sensor that outputs an output value according to the presence or absence of the recording medium, a width detection sensor that is provided in the carriage and outputs an output value according to the presence or absence of the recording medium, and an output of the medium detection sensor A threshold value setting means for setting a threshold value for determining the presence or absence of the recording medium based on the value; the threshold value set by the threshold value setting means; and the width detection sensor. A side edge detecting means for detecting a side edge of the recording medium by comparing the output value of the recording medium, and the carriage is positioned at one end of a scanning range of the carriage before the recording on the recording medium is started. A reference position is set, and the width detection sensor in the carriage is provided at a position shifted from the recording portion of the recording head to a side away from the reference position, and when recording on the recording medium is started, After the carriage is moved from the reference position toward the other end and the side end is detected by the side end detection means during the movement, recording by the recording unit is performed during the movement based on the detected side end. To provide a recording apparatus.
According to this configuration, based on the output value of the medium detection sensor provided on the upstream side of the carriage, the threshold value for determining the presence or absence of the recording medium is set without scanning the carriage to the end of the recording medium. Can do. Then, using this threshold value, the side edge of the recording medium is detected in one scanning of the carriage from the reference position toward the other end of the scanning range, and recording on the recording medium is performed based on the detected side edge. You can start. For this reason, scanning of the carriage for the purpose of detecting only the side edge of the recording medium can be omitted, and recording can be started when the carriage is first scanned, so that the time required to start recording can be shortened and throughput can be reduced. Can be improved.

In the recording apparatus according to the invention, the medium detection sensor and the width detection sensor irradiate light toward the conveyance path, detect the reflected light, and output values corresponding to the detected reflected light amount. May be constituted by a reflection type optical sensor that outputs.
According to this configuration, since both the medium detection sensor and the width detection sensor are configured by the reflection type optical sensor, the output value of the medium detection sensor and the output value of the width detection sensor for the same recording medium are very close to each other. The output values of these sensors can be regarded as substantially the same. Accordingly, since a threshold suitable for detection by the width detection sensor can be set based on the output value of the medium detection sensor, the side edge of the recording medium can be detected with high accuracy by the width detection sensor.

In the recording apparatus according to the invention, the threshold value setting means outputs an output value output when the width detection sensor does not exist in the recording medium and an output value output when the medium detection sensor exists in the recording medium. The threshold value may be set based on the value.
According to this configuration, the threshold value can be set based on the output value of the medium width detection sensor and the output value of the width detection sensor when there is no recording medium, so that an appropriate threshold value can be quickly obtained without scanning the carriage. Can be set.

In the recording apparatus of the above invention, the threshold setting means is based on an output value output by the medium detection sensor when the recording medium does not exist and an output value output when the recording medium exists. The threshold may be set.
According to this configuration, since the threshold value can be set according to the output value of the medium detection sensor, an appropriate threshold value can be quickly set without using the output value of the width detection sensor and without scanning the carriage. it can.

Further, in the recording apparatus of the above invention, the interval between the recording unit and the width detection sensor is based on an interval between an end of a range where the recording unit records an image on the recording medium and a side end of the recording medium. However, it may be secured widely.
According to this configuration, when the side edge of the recording medium on the side away from the reference position is detected by the width detection sensor, the recording unit exists within a range where an image is recorded on the recording medium. For this reason, after detecting the side edge of the recording medium on the side away from the reference position, the image recording by the recording unit can be completed with a margin. Thus, both the detection of the side edge of the recording medium and the recording of the image can be reliably performed during one scanning, and for example, a situation where the image protrudes can be reliably prevented.

In order to achieve the above object, the present invention provides a transport unit that transports a recording medium on a transport path, a carriage that is reciprocally scanned in the width direction of the recording medium, and the recording medium provided in the carriage. A recording head provided with a recording unit for recording an image on the recording medium, a medium detection sensor provided on the upstream side of the carriage on the conveyance path and outputting an output value according to the presence or absence of the recording medium, and the carriage A width detection sensor that outputs an output value corresponding to the presence or absence of the recording medium, and the position of the width detection sensor in the carriage shifted from the recording position of the recording head to the side away from the reference position. Is set to a reference position at which the carriage is positioned before recording on the recording medium at one end of the scanning range of the carriage. , Moving the carriage from the reference position toward the other end, setting a threshold for determining the presence or absence of the recording medium based on the output value of the medium detection sensor during the movement, and A recording apparatus characterized in that a side edge of the recording medium is detected by comparing with an output value of a width detection sensor, and recording is performed by the recording unit during the movement based on the detected side edge. Provide a control method.
According to this method, on the basis of the output value of the medium detection sensor provided on the upstream side of the carriage in the recording apparatus, the threshold for determining the presence or absence of the recording medium without scanning the carriage to the end of the recording medium. Can be set. Then, using this threshold value, the side edge of the recording medium is detected in one scanning of the carriage from the reference position toward the other end of the scanning range, and recording on the recording medium is performed based on the detected side edge. You can start. For this reason, scanning of the carriage for the purpose of detecting only the side edge of the recording medium can be omitted, and recording can be started when the carriage is first scanned, so that the time required to start recording can be shortened and throughput can be reduced. Can be improved.

  According to the present invention, it is possible to omit the scanning of the carriage only for detecting the side edge of the recording medium, shorten the time required to start recording, and improve the throughput.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing a printer main body 13 of the dot impact printer of this embodiment. FIG. 2 is a side sectional view of the printer main body 13 of FIG. FIG. 3 is a plan view of the main part of the printer main body 13 of FIG.
A dot impact printer 10 as a recording apparatus of the present invention strikes a large number of recording wires 11b of a recording wire protruding portion 11a (recording portion) of a recording head 11 against a recording medium K via an ink ribbon in an ink ribbon cassette 12. By recording dots, an image including characters is recorded.

The dot impact printer 10 includes a printer main body 13 as a recording apparatus main body, an upper case 14 (not shown) that covers the upper portion of the printer main body 13, and a lower case 15 (see FIG. 2) that covers the lower portion of the printer main body 13. And a sheet conveying unit 16 installed on the front side of the printer main body 13 for guiding the recording medium K.
Here, the recording medium K includes a cut sheet cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected. Examples of the cut sheet include cut sheet paper, copy paper, and cut film. Examples of the continuous sheet include continuous paper and continuous copy paper. The recording medium K may be a booklet such as a passbook.
A rolling roller 30 for moving the recording head 11 (or a flat platen 20 described later) up and down according to the thickness of the sheet or booklet while rolling on the recording surface of the recording medium K, A paper width detection sensor 31 (width detection sensor) is provided.

The printer main body 13 includes a pair of left and right side frames 17 and 18 constituting a main body frame.
Between the left side frame 17 and the right side frame 18, a lower carriage guide shaft 26a and an upper carriage guide shaft 27 are spanned in parallel in a vertical direction at a predetermined distance. The lower carriage guide shaft 26 a is pivotally supported by the left side frame 17 and the right side frame 18. Further, a flat platen 20 is disposed between the left side frame 17 and the right side frame 18 and a seat guide 25 is fixedly disposed.

Further, the printer main body 13 includes a carriage 19 on which the recording head 11 is mounted, a first conveyance roller 21, a second conveyance roller 22, a third conveyance roller 23, a fourth conveyance roller 24, a sheet guide 25, and an alignment shutter. 26, an alignment sensor 28, a paper width detection sensor 31, and the like.
The sheet conveyance unit 16 includes a second conveyance roller 22 that cooperates with the first conveyance roller 21 and a paper insertion detection sensor 29 (medium detection sensor). In this case, the second conveyance roller 22 and the paper insertion detection sensor 29 are configured to move up and down according to the thickness of the recording medium K.
Further, a first transport roller 21 and a second transport roller 22 are arranged on the front side of the printer main body 13 with respect to the flat platen 20. The first transport roller 21 is positioned below the transport path H (FIG. 2) together with the flat platen 20, and the second transport roller 22 is positioned above the transport path H. The recording medium K is sandwiched from above and below by the transport roller 22 and transported.
Further, the third conveyance roller 23 and the fourth conveyance roller 24 are arranged on the rear side of the printer main body 13. The third transport roller 23 is positioned below the transport path H, and the fourth transport roller 24 is positioned above the transport path H. With these third transport roller 23 and fourth transport roller 24, the recording medium K is , Transported sandwiched from above and below.

  One of the first conveying roller 21 and the second conveying roller 22 is driven to rotate in the clockwise direction (CW) or counterclockwise direction (CCW) in FIG. 2 by a driving wheel train (not shown) as a driving roller, and the other is driven. As a roller, it rotates according to the driving roller. Similarly, one of the third conveyance roller 23 and the fourth conveyance roller 24 is rotationally driven in the clockwise direction (CW) or counterclockwise direction (CCW) in FIG. 2 by a driving wheel train (not shown) as a driving roller. The other rotates as a driven roller according to the driving roller. The recording medium K is manually supplied from the front side of the printer main body 13 as shown in FIG. 2 by the first transport roller 21, the second transport roller 22, the third transport roller 23, and the fourth transport roller 24. Then, the image is recorded in the direction of arrow A toward the rear of the printer main body 13, and after the image is recorded, it is conveyed in the direction of arrow B from the rear to the front of the printer main body.

As shown in FIG. 2, the carriage 19 is slidably inserted through the lower carriage guide shaft 26 a and the upper carriage guide shaft 27. Since the lower carriage guide shaft 26 a and the upper carriage guide shaft 27 are arranged in parallel with the flat platen 20, the carriage 19 coincides with the axial directions of the flat platen 20, the lower carriage guide shaft 26 a and the upper carriage guide shaft 27. It is provided so as to be able to reciprocate (scan) in the main scanning direction.
The carriage 19 is coupled to a timing belt (not shown) that is reciprocated by forward rotation or reverse rotation of a carriage drive motor 38 (FIG. 5). The carriage 19 is driven by the forward or reverse operation of the carriage drive motor 38, guided by the lower carriage guide shaft 26a and the upper carriage guide shaft 27, and scanned leftward or rightward in FIG. 1 in the main scanning direction.
The carriage drive motor 38 is configured by, for example, a stepping motor together with a transport motor (not shown) that drives the first transport roller 21, the second transport roller 22, the third transport roller 23, and the fourth transport roller 24.

  An ink ribbon is disposed between the recording head 11 and the recording medium K, and the recording head 11 projects a recording wire and strikes the ink ribbon while scanning with the carriage 19 in the main scanning direction. The ink on the ribbon is attached to the recording medium K conveyed between the flat platen 20 and the recording head 11 to record an image including characters.

  Before starting image recording on the recording medium K, the carriage 19 stands by at a home position HP (FIG. 3) as a reference position set at one end of the scanning range of the carriage 19. When the leading edge of the recording medium K is conveyed onto the platen 20, the carriage 19 scans the width direction of the recording medium K toward the other end of the scanning range (in the direction of arrow Y1 in FIG. 3). In the meantime, one line of recording is performed by the recording wire protrusion 11a (recording section) of the recording head 11. Each time one line of recording is performed, the sheet conveying mechanism (the platen 20, the first conveying roller 21, the second conveying roller 22, the third conveying roller 23, and the fourth conveying roller 24) sets the recording medium K to a predetermined value. The image is recorded by conveying in the long (ordinary line) conveyance direction and repeating these operations. The direction indicated by Y1 in FIG. 3 corresponds to the right direction in FIG. 1, and the direction indicated by Y2 corresponds to the left direction in FIG.

  The paper insertion detection sensor 29 and the paper width detection sensor 31 are disposed above the transport path H, emit detection light toward the transport path H, receive the reflected light, and output corresponding to the received reflected light amount. It is a reflective optical sensor that outputs a value. Since the paper insertion detection sensor 29 and the paper width detection sensor 31 can determine the presence or absence of the recording medium K below the information, the information on the recording medium K can be acquired using these. That is, the side edge position of the recording medium K can be detected based on the output value of the paper width detection sensor 31 during the scanning of the carriage 19 and the position of the carriage 19, and the recording medium can be detected from both the left and right side edge positions. The width of K can be obtained. Further, the reflectance of light on the surface (recording surface) of the recording medium K can also be obtained from the output value of the paper insertion detection sensor 29 or the paper width detection sensor 31.

  The paper insertion detection sensor 29 and the paper width detection sensor 31 are reflective optical sensors having the same specifications. Further, the paper insertion detection sensor 29 and the paper width detection sensor 31 are arranged so that their relative positions to the recording medium K are substantially the same. That is, as shown in FIG. 2, the vertical distance between the recording medium K transported along the transport path H and the paper insertion detection sensor 29 and the vertical distance between the recording medium K and the paper width detection sensor 31 are as follows. It is almost the same. Further, as described above, the paper insertion detection sensor 29 moves up and down in accordance with the thickness of the recording medium K, and the interval between the recording medium K and the paper insertion detection sensor 29 is kept constant regardless of the thickness of the recording medium K. Be drunk. Similarly, since the paper width detection sensor 31 moves up and down according to the thickness of the recording medium K, the interval between the recording medium K and the paper width detection sensor 31 is constant regardless of the thickness of the recording medium K. With these configurations, the output value of the paper insertion detection sensor 29 and the output value of the paper width detection sensor 31 for the same recording medium are substantially the same. In particular, in the present embodiment, since the paper insertion detection sensor 29 and the paper width detection sensor 31 are configured by reflection type optical sensors having the same specifications, these sensors have substantially the same output value for the same recording medium K. Can be regarded as output.

  Further, as shown in FIG. 2, the interval R1 between the paper insertion detection sensor 29 and the sheet guide 25a positioned immediately below is equal to the paper width detection sensor 31 when the carriage 19 is positioned at the home position HP. The distance R2 from the positioned sheet guide 25b is substantially the same. The surfaces of the sheet guide 25a and the sheet guide 25b are made of materials or specifications having the same reflectance. Accordingly, the output value of the paper insertion detection sensor 29 when the recording medium K is not present and the output value of the paper width detection sensor 31 when the carriage 19 is located at the home position HP are configured to be substantially the same. Yes.

FIG. 4 is a plan view showing the configuration of the recording head 11. In FIG. 4, the paper width detection sensor 31 provided on the carriage 19 is shown together with the carriage 19 and the recording head 11.
As shown in FIG. 4, a recording wire protrusion 11 a is provided at the approximate center of the lower surface of the recording head 11. The recording wire protruding portion 11a functions as a recording portion for recording an image on the recording medium K, and nine recording wires 11b arranged in a line in the front-rear direction of the printer main body 13 are exposed at the center thereof. . When the recording operation is executed, the recording wire 11b protrudes from the recording wire protruding portion 11a to the ink ribbon.
As shown in FIG. 4, the paper width detection sensor 31 is disposed on the lower surface of the carriage 19 so as to be aligned with the recording wire protruding portion 11a. The paper width detection sensor 31 includes an optical sensor unit 31a having a light emitting unit made of an LED or the like and a light receiving unit made of a phototransistor or the like. The optical sensor portion 31a is provided at a position shifted from the recording wire protruding portion 11a in the main scanning direction (Y1 side in the drawing) of the carriage 19.

FIG. 5 is a block diagram showing a schematic configuration of a control system of the dot impact printer.
The control system of the dot impact printer 10 is roughly divided into a paper insertion detection sensor 29 and a paper width detection sensor 31, and a sensor that outputs the output value of the paper width detection sensor 31 and the output value of the paper insertion detection sensor 29 to the controller 52. A circuit 51; a controller 52 that controls the entire dot impact printer 10; a motor drive driver 53 that drives the carriage drive motor 38 under the control of the controller 52 and outputs carriage position data CRPOS; And a memory 54 for storing data.

Here, CRPOS is data indicating the current position of the carriage 19 and is expressed as the number of pulses moved from the home position HP. The number of pulses is the total number of pulses output from the motor drive driver 53 to the carriage drive motor 38 in order to move the carriage 19 from the home position HP in the direction of the arrow Y1. For example, when the carriage 19 is at the home position HP, the value of CRPOS is “0”, and when the number of pulses output from the motor drive driver 53 to the carriage drive motor 38 is 50, CRPOS is “50”. .
The controller 52 includes a microprocessor (not shown), a control ROM for storing a control program, a control RAM for temporarily storing various data at the time of control, and the dot impact printer by executing the control program by the microprocessor. 10 is controlled.

  Some conventional dot impact printers scan the carriage 19 from the home position HP to the other end for the purpose of detecting the side edge of the recording medium K before recording an image on the recording medium K. When the dot impact printer 10 according to the present embodiment starts recording an image on the recording medium K, the dot impact printer 10 starts scanning the carriage 19 to detect the side edge of the recording medium K. After detecting, recording starts during the scanning. Hereinafter, the operation of the dot impact printer 10 will be described in detail.

FIG. 6 is a flowchart showing the recording operation of the dot impact printer 10.
The operation shown in FIG. 6 is realized by the controller 52 reading and executing the control program stored in the control ROM. In addition, when the operation of FIG. 6 is executed, the controller 52 functions as a threshold setting unit and a side end detection unit.

Prior to the operation shown in FIG. 6, the dot impact printer 10 is turned on, and the dot impact printer 10 includes the image data to be recorded on the recording medium K, the size of the recording medium K, the margin size, and the margin position. A position at which image recording is started on the recording medium K, a position at which image recording is ended, and the like are input from a host computer not shown.
The controller 52 waits until the paper insertion detection sensor 29 detects that the recording medium K has been inserted (step SA1).
When it is detected that the recording medium K has been inserted (step SA1: YES), the controller 52 acquires the output value EH of the paper insertion detection sensor 29 via the sensor circuit 51 and stores it in the control RAM. The output value EH stored here is an output value based on the detection operation for the surface of the recording medium K.

Further, in step SA2, the controller 52 acquires the output value EL of the paper width detection sensor 31 and stores it in the control RAM. At the time when the recording medium K is inserted, the paper width detection sensor 31 mounted on the carriage 19 is positioned at the home position HP. Therefore, the output value EL stored here is the paper width in the state where the recording medium K does not exist. This is the output value of the detection sensor 31.
After storing the output values EH and EL in the control RAM, the controller 52 performs a threshold setting process which is a process for setting the threshold EA (step SA3). Here, the threshold value EA will be described prior to the description of the threshold setting process. The threshold value EA is a threshold value that is compared with the output value of each sensor when the paper width detection sensor 31 detects the side edge of the recording medium K. is there. In the operation described later, the controller 52 determines that the recording medium K is present at the detection position of the paper width detection sensor 31 when the output value of the paper width detection sensor 31 is higher than the threshold value EA, and detects when the output value is lower than the threshold value EA. It is determined that the recording medium K does not exist at the location. When the controller 52 detects the paper width as the carriage 19 scans, the controller 52 changes the output value from a level lower than the threshold EA to a higher level, and the output value changes from a level higher than the threshold EA to a lower level. The side edge of the recording medium K is detected.

In the threshold value setting process in step SA3, the controller 52 sets the average value of the output value EH and the output value EL obtained in step SA2 as the threshold value EA. As described above, conventionally, when the threshold value EA is set, the carriage 19 is scanned in the width direction, and is set based on the output value of the paper width detection sensor 31 accompanying this scanning. By using the output value of the detection sensor 29, an appropriate threshold EA can be set without causing the carriage 19 to scan in the width direction. In particular, in this embodiment, as described above, the output values of the paper insertion detection sensor 29 and the paper width detection sensor 31 for the same recording medium K are substantially the same, so the carriage 19 is scanned. The threshold value EA can be set without any change, and this threshold value EA is a threshold value suitable for the paper width detection sensor 31 as in the case where the threshold value EA is set based on the output value of the paper width detection sensor 31 by scanning of the carriage 19. is there.
After setting the threshold value EA, the controller 52 transports the recording medium K by the first transport roller 21 and the second transport roller 22, aligns the recording medium K by the alignment shutter 26 (step SA4), and further Then, the recording medium K is conveyed to a predetermined position on the platen 20 (step SA5).

  Then, the controller 52 compares the output value of the paper width detection sensor 31 with the threshold value EA, and monitors whether the output value is higher than the threshold value EA (step SA7), while moving the carriage 19 from the home position HP to the arrow Y1 ( 3) Scan in the direction. If the output value of the paper width detection sensor 31 exceeds the threshold EA during scanning of the carriage 19 (step SA7; YES), the controller 52 determines the position of the optical sensor unit 31a of the paper width detection sensor 31 at that time as the recording medium K. The CRPOS value input from the motor drive driver 53 is stored in the control RAM in order to store the position of the side end in the arrow Y2 direction (step SA8).

Next, the controller 52 calculates the interval between the position of the recording wire protrusion 11a and the recording start position of the recording medium K based on the CRPOS stored in step SA8, and the recording wire protrusion 11a starts recording on the recording medium K. The carriage 19 is moved in the direction of arrow Y1 so as to reach the position (step SA9). When the recording wire protrusion 11a reaches the recording start position of the recording medium K, the recording head 11 is driven to start image recording (step SA10). Here, the recording start position is a position in the main scanning direction at which image recording is started on the recording medium K, and the recording wire 11b is projected from the recording start position by the recording head 11 while moving the carriage 19. Records are recorded.
As described above, in this embodiment, in the first scanning of the carriage 19, the side edge in the arrow Y2 direction of the recording medium K can be detected by using the threshold EA set based on the output value of the paper insertion detection sensor 29. Furthermore, since the optical sensor portion 31a of the paper width detection sensor 31 is provided on the arrow Y1 direction side with respect to the recording wire protruding portion 11a, image recording can be started after detection of the side edge.

After the start of image recording, the controller 52 performs scanning of the carriage 19 and recording of a predetermined image (step SA11), and the image to be recorded by the current scanning of the carriage 19 while executing the recording of this image. Is monitored (step SA12), and whether the output value of the paper width detection sensor 31 is below the threshold EA.
If the recording of the image to be recorded is completed before the output value of the paper width detection sensor 31 falls below the threshold value EA (step SA12: YES), the controller 52 determines whether the output value of the paper width detection sensor 31 falls below the threshold value EA. Whether or not (step SA15) is monitored, the carriage 19 is further moved in the direction of the arrow Y1. If the output value of the paper width detection sensor 31 falls below the threshold value EA during the movement of the carriage 19 (step SA15: YES), the controller 52 determines the position of the optical sensor unit 31a at this time on the arrow Y1 direction side of the recording medium K. The CRPOS value input from the motor drive driver 53 is stored in the control RAM (step SA16). Thereafter, the controller 52 completes the first scan of the carriage 19 by scanning the carriage 19 to the end of the scan range on the arrow Y1 direction side (step SA17).

On the other hand, if the output value of the paper width detection sensor 31 falls below the threshold value EA before the recording of the image to be recorded ends in steps SA11 to SA13 (step SA13: YES), the controller 52 performs the optical sensor unit at this time. The position of 31a is specified as the side edge of the recording medium K on the arrow Y1 direction side, and the CRPOS value input from the motor drive driver 53 is stored in the control RAM (step SA18). Next, the controller 52 scans the carriage 19 and records an image until the recording wire protrusion 11a reaches the recording end position of the recording medium K (step SA19). Here, the recording end position is a position in the main scanning direction at which image recording ends on the recording medium K, and the recording wire 11b does not protrude beyond the recording end position.
During the execution of the recording operation in step SA19, the controller 52 determines whether or not the recording of the image to be recorded has ended (step SA20), and whether or not the recording wire protrusion 11a has reached the recording end position T3 (step S20). SA21) is monitored. If the recording of the image is completed before the recording wire protrusion 11a reaches the recording end position T3 (step SA20: YES), the controller 52 proceeds to step SA17.
On the other hand, in steps SA19 to SA21, when the recording wire protrusion 11a reaches the recording end position T3 in a state where the recording of the image to be recorded has not been completed (step SA21: YES), the controller 52 records the image. The process is forcibly terminated (step SA22), and the process proceeds to step SA17.
In step SA17, the controller 52 moves the carriage 19 to the end of the scanning range, and ends the first scan of the carriage 19. Thereafter, the controller 52 executes image recording while moving the carriage 19 in the reverse direction (the direction of the arrow Y2).

FIG. 7 is a chart showing the relationship between the position of the carriage 19 and the output value of the paper width detection sensor 31, where the horizontal axis is the CRPOS value indicating the position of the carriage 19 and the vertical axis is the output value of the paper width detection sensor 31. .
As shown in FIG. 7, when the output value of the paper width detection sensor 31 is monitored while the carriage 19 is moved by the controller 52 (steps SA6 to SA7 in FIG. 6), until the paper width detection sensor 31 reaches the vicinity of the recording medium K. The output value of the paper width detection sensor 31 is at an EL level that is significantly lower than the threshold value EA. When the paper width detection sensor 31 detects the reflected light from the end of the recording medium K as the carriage 19 moves, the output value of the paper width detection sensor 31 increases and exceeds the threshold value EA at P1 in the figure. The controller 52 specifies the position of the carriage 19 at P1 (the position of the optical sensor unit 31a) as the position of the side edge of the recording medium K. After exceeding this position, the output value of the paper width detection sensor 31 increases and reaches the maximum output value EH when the optical sensor unit 31a completely overlaps the recording medium K.

Thereafter, the carriage 19 is continuously moved while recording an image, and when the optical sensor unit 31a is very close to the side edge of the recording medium K, the output value of the paper width detection sensor 31 decreases, and eventually the threshold value EA is set at P2 in the figure. Below. The controller 52 specifies the position of the carriage 19 at P2 (the position of the optical sensor unit 31a) as the position of the side edge of the recording medium K. After exceeding this position, the output value of the paper width detection sensor 31 further decreases, and becomes the minimum output value EL when the optical sensor unit 31a is completely removed from the recording medium K.
As described above, since the threshold value EA is set in advance in the threshold value setting process (step SA3 in FIG. 6), the controller 52 quickly specifies the position of the side edge of the recording medium K based on the output value of the paper width detection sensor 31. it can.

FIG. 8 is a plan view showing the positional relationship between the recording head 11 and the recording medium K during the operation shown in FIG. 6, and particularly shows a state when the side edge of the recording medium K on the home position HP side is detected. .
In FIG. 8, T1 indicates the position of the recording wire 11b, and T2 indicates the recording start position of the recording medium K. The positions T1 and T2 are both positions in the main scanning direction, that is, the digit direction.
As shown in FIG. 8, when the carriage 19 is moved from the home position HP and the side edge of the recording medium K is detected by the paper width detection sensor 31, the recording wire 11b is just a distance D1 from the recording start position. It is in. Therefore, after the side end position of the recording medium K is detected in step SA7 in FIG. 6, the carriage 19 is moved in step SA9, and the recording wire 11b reaches the recording start position T2, and then the image recording is performed in step SA10. A series of operations up to the start of can be executed with a sufficient margin.

FIG. 9 is a plan view showing the positional relationship between the recording head 11 and the recording medium K during the operation shown in FIG. 6, and particularly when detecting the side edge of the recording medium K far from the home position HP. Indicates the state. In the figure, T3 indicates the recording end position of the recording medium K in the main scanning direction.
As described above, in the present embodiment, the optical sensor portion 31a of the paper width detection sensor 31 is shifted in the main scanning direction (arrow Y1 side) from the center of the recording wire protruding portion 11a (position of the recording wire 11b). It is in. An interval D2 between the optical sensor unit 31a and the recording wire 11b in the main scanning direction is larger than an interval D3 between the recording end position T3 of the recording medium K and the side end of the recording medium K on the arrow Y1 direction side. For this reason, the optical sensor unit 31a reaches the side end of the recording medium K on the arrow Y1 direction side, and when this side end is detected, the recording wire 11b is positioned closer to the home position HP than the recording end position T3. ing. Accordingly, a series of operations from the detection of the side edge of the recording medium K to the end of image recording can be performed with sufficient margin. For example, the image is recorded beyond the recording end position T3. There is no such thing.

Accordingly, in the first scanning of the carriage 19, the controller 52 can calculate the recording end position T3 based on the side edge after detecting the side edge of the recording medium K by the paper width detection sensor 31. Based on the calculated recording end position T3 and CRPOS, an interval D4 between the current position T1 of the recording wire protrusion 11a and the recording end position T3 can be calculated. Further, based on the calculated interval D4, Image recording can be executed until the recording wire protrusion 11a reaches the recording end position T3.
In addition, when an image is recorded on the recording medium K of various sizes by the dot impact printer 10, it is preferable that the recording medium K of all sizes and types can be supported. For this purpose, the distance between the optical sensor portion 31a of the paper width detection sensor 31 and the recording wire 11b in the recording head 11 should be made wider than the margin width of the recording medium K having the largest margin size. Good.

  As described above, the dot impact printer 10 according to the present embodiment performs the first carriage 19 without scanning the carriage 19 for detecting the side edge of the recording medium K before starting image recording. In this scanning, the side edge detection and recording operation of the carriage 19 can be executed. For this reason, the number of scans of the carriage 19 until the start of image recording can be reduced, the time until the start of recording can be shortened, and the throughput can be improved.

  As described above, in the present embodiment, the threshold value EA for determining the presence or absence of the recording medium K is set based on the output value of the paper insertion detection sensor 29 provided on the upstream side of the carriage 19. Yes. Further, a paper width detection sensor 31 for detecting the side edge of the recording medium K is disposed at a position shifted to the arrow Y1 direction side from the recording wire protrusion 11a of the recording head 11. Due to this configuration, the side edge of the recording medium K and the recording start position T2 can be detected by using the threshold value EA in the first (first) scanning of the carriage 19 when recording an image. The image recording can be started from the recording start position T2. For this reason, the scanning of the carriage 19 only for detecting the side edge of the recording medium K can be omitted, the time required to start recording can be shortened, and the throughput can be improved.

  In the present embodiment, both the paper insertion detection sensor 29 and the paper width detection sensor 31 are configured by reflection type optical sensors, so that the output value of the paper insertion detection sensor 29 and the output value of the paper width detection sensor 31 for the same recording medium. Are very close to each other, and the output values of these sensors can be regarded as substantially the same. Accordingly, since the threshold value EA suitable for detection by the paper width detection sensor 31 can be set based on the output value of the paper insertion detection sensor 29, the side edge of the recording medium K can be detected with high accuracy by the paper width detection sensor 31.

  In the present embodiment, the threshold value EA is set using the output value of the paper insertion detection sensor 29. For this reason, the threshold value EA can be reliably set without scanning the carriage 19. For example, the controller 52 sets the threshold value based on the output value output when the paper width detection sensor 31 does not exist in the recording medium K and the output value output when the paper insertion detection sensor 29 exists in the presence of the recording medium K. By doing so, it is possible to quickly set an appropriate threshold without scanning the carriage. For example, if the paper insertion detection sensor 29 sets a threshold based on the output value output when the recording medium K does not exist and the output value output when the recording medium K exists, the paper insertion detection is performed. The threshold value can be set only by the output value of the sensor 29, and the appropriate threshold value can be quickly set without using the output value of the paper width detection sensor 31 and without scanning the carriage.

In the dot impact printer 10, the distance between the recording wire protruding portion 11 a (recording wire 11 b) and the optical sensor portion 31 a of the paper width detection sensor 31 is such that the recording end position of the recording medium K and the side edge of the recording medium K are It is secured wider than the interval. For this reason, after detecting the side edge of the recording medium K far from the home position HP, the recording of the image by the recording wire protrusion 11a can be completed with a margin.
In the first scanning of the carriage 19, the controller 52 can calculate the recording end position T 3 based on the side edge after detecting the side edge of the recording medium K by the paper width detection sensor 31. Based on the calculated recording end position T3 and CRPOS, an interval D4 between the current position T1 of the recording wire protrusion 11a and the recording end position T3 can be calculated. Further, based on the calculated interval D4, Image recording can be executed until the recording wire protrusion 11a reaches the recording end position T3.

Some conventional dot impact printers 10 detect a skew, which is an inclination from the conveyance direction of the recording medium K, using a paper width detection sensor 31 provided on the carriage 19. Some dot impact printers 10 of this type scan the carriage 19 only to detect skew.
On the other hand, in the dot impact printer 10 according to the present embodiment, it is possible to improve the throughput by omitting the scanning of the carriage 19 performed only for skew detection by the following operation.
Hereinafter, the operation of the dot impact printer 10 at the time of skew detection will be described.

FIG. 10 is a flowchart showing the operation of the dot impact printer 10.
First, the controller 52 performs the first scan of the carriage 19 by executing a series of operations described in the flowchart of FIG. At this time, as described above, the threshold value EA can be set before the carriage 19 is scanned, and the side edge of the recording medium K can be detected and the image of the first line can be recorded.
Here, CRPOS at the side edge in the arrow Y2 direction of the recording medium K detected in the first scanning of the carriage 19 is set to “CR-L1”, and the controller 52 performs the CR− L1 is stored in the control RAM (step SB1).
Next, the controller 52 executes the second scanning of the carriage 19 to record the image of the second row. Also in this second carriage scan, the controller 52 detects the width edge of the recording medium K by comparing the threshold value EA and the output value of the paper width detection sensor 31. Here, CRPOS at the side edge on the arrow Y2 direction side of the recording medium K detected in the second scanning of the carriage 19 is set to “CR-L2”, and the controller 52 stores this “CR-L2” in the control RAM. Store (step SB2).

Thereafter, the controller 52 compares CR-L1 and CR-L2 to detect a deviation amount indicating the degree of inclination with respect to the conveyance direction of the recording medium K (step SB3), and recording is performed based on the detected deviation amount. It is determined whether or not the inclination of the medium K with respect to the transport direction is within an allowable range (step SB4). When the inclination is within the allowable range (step SB4: YES), the controller 52 determines that no skew has occurred (step SB5), and executes the following process. When the inclination is outside the allowable range (step SB4: NO), the controller 52 determines that skew has occurred (step SB6), and performs processing corresponding to the occurrence of skew, such as discharging the recording medium K, for example. Is executed (step SB7).
As described above, according to the dot impact printer 10 according to the present embodiment, since the skew can be detected together with the image recording without performing the scanning of the carriage 19 for the purpose of skew detection only, the throughput is reduced. It is possible to reliably detect the skew without doing so.

As described above, the present invention has been described based on the embodiment, but the present invention is not limited to this, and the following modifications are possible.
For example, when setting the threshold value EA, the controller 52 according to the present embodiment averages the output value of the paper insertion detection sensor 29 for the recording medium K and the output value of the paper width detection sensor 31 located at the home position HP. Or the average value of the output value of the paper insertion detection sensor 29 when there is no recording medium K and the output value of the paper insertion detection sensor 29 for the recording medium K. Further, for example, the threshold EA may be set by an average value of a predetermined set value and an output value of the paper insertion detection sensor 29 for the recording medium K.
In this embodiment, the average value of the output value of the paper insertion detection sensor 29 for the recording medium K and the output value of the paper width detection sensor 31 located at the home position HP is used as the threshold value EA. The threshold EA can be obtained by using other average values such as a geometric average (so-called geometric average) or a harmonic average, or appropriately giving a weight, for example.

In the present embodiment, the paper insertion detection sensor 29 and the paper width detection sensor 31 are configured as reflective optical sensors having the same specifications, and the distance between these sensors and the recording medium K is substantially the same. Although the output values of these sensors for the same recording medium K are substantially the same, for example, by performing calibration in advance and adjusting the output values of these sensors, the output values of these sensors become the same. You may do it. In this case, even if there is a difference in output characteristics, detection characteristics, or installation state between the paper insertion detection sensor 29 and the paper width detection sensor 31, the threshold value EA can be easily set as in the present embodiment. .
Furthermore, in the present embodiment, the configuration in which one paper width detection sensor 31 is provided on the arrow Y1 side with respect to the recording wire protruding portion 11a has been described as an example. You may provide in the both sides of the protrusion part 11a. In this case, if the interval between the recording wire protruding portion 11a and each paper width detection sensor 31 is ensured to be larger than the predetermined distance as described above, not only the scanning of the carriage 19 in the arrow Y1 direction but also the carriage 19 is performed. When scanning in the arrow Y2 direction, the side edge of the recording medium K can be detected, and there is an advantage that image recording can be started after the side edge is detected. That is, the time until the start of recording can always be shortened without being restricted by the scanning direction of the carriage 19 at the start of recording and the position of the home position HP.

  In the present embodiment, the case where the present invention is applied to a dot impact printer has been described. However, the present invention is not limited to this, and the carriage is scanned in the main scanning direction, and an image is printed on the recording medium conveyed in the sub scanning direction. As long as it can record, it can also be used for various printers such as inkjet printers, thermal printers using thermal sheets, thermal transfer printers, etc., and printers that are built into the housing of ATMs and other devices. Applicable.

1 is a perspective view showing a main body of a dot impact printer according to an embodiment. It is sectional drawing of a dot impact printer. It is a principal part top view of a dot impact printer. FIG. 3 is a plan view illustrating a configuration of a recording head. It is a block diagram of a control system of a dot impact printer. 3 is a flowchart illustrating an operation of a dot impact printer. It is a chart which shows the relationship between the position of a carriage and the output value of a paper width detection sensor. FIG. 3 is a plan view illustrating a configuration of a recording head. FIG. 3 is a plan view illustrating a configuration of a recording head. 3 is a flowchart illustrating an operation of a dot impact printer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Dot impact printer, 11 ... Recording head, 11a ... Recording wire protrusion part (recording part), 11b ... Recording wire, 19 ... Carriage, 20 ... Platen, 21 ... 1st conveyance roller, 22 ... 2nd conveyance roller, 23 3rd transport roller, 24 ... 4th transport roller, 29 ... Paper insertion detection sensor (medium detection sensor), 31 ... Paper width detection sensor (width detection sensor), 31a ... Optical sensor unit, 38 ... Carriage drive motor, 52 ... Controller (threshold setting means, side edge detection means), H ... conveying path, K ... recording medium, HP ... home position (reference position)

Claims (6)

A transport unit that transports a recording medium on a transport path; a carriage that is reciprocally scanned in the width direction of the recording medium; a recording head that is provided on the carriage and includes a recording unit that records an image on the recording medium; A recording apparatus for recording an image on the recording medium by the recording unit while scanning the carriage,
A medium detection sensor provided on the upstream side of the carriage on the transport path and outputs an output value corresponding to the presence or absence of the recording medium, and an output value provided on the carriage and corresponding to the presence or absence of the recording medium. An output width detection sensor;
Threshold setting means for setting a threshold for determining the presence or absence of the recording medium based on the output value of the medium detection sensor;
Side edge detecting means for detecting a side edge of the recording medium by comparing a threshold set by the threshold setting means with an output value of the width detection sensor;
A reference position at which the carriage is positioned before starting recording on the recording medium is set at one end of the scanning range of the carriage,
In the carriage, the width detection sensor is provided at a position shifted from the recording portion of the recording head to the side away from the reference position.
When starting recording on the recording medium, the carriage is moved from the reference position toward the other end, the side end is detected by the side end detecting means during the movement, and then based on the detected side end. Recording by the recording unit during the movement,
A recording apparatus. The medium detection sensor and the width detection sensor are configured by a reflective optical sensor that irradiates light toward the transport path, detects the reflected light, and outputs an output value corresponding to the amount of the detected reflected light. Has been done,
The recording apparatus according to claim 1. The threshold setting means sets the threshold based on an output value output by the width detection sensor when the recording medium does not exist and an output value output by the medium detection sensor when the recording medium exists. To do,
The recording apparatus according to claim 1, wherein: The threshold setting means sets the threshold based on an output value output by the medium detection sensor when the recording medium does not exist and an output value output when the recording medium exists;
The recording apparatus according to claim 1, wherein: An interval between the recording unit and the width detection sensor is secured wider than an interval between an end of a range where the recording unit records an image on the recording medium and a side end of the recording medium;
The recording apparatus according to claim 1, wherein: A transport unit that transports a recording medium on a transport path; a carriage that is reciprocally scanned in the width direction of the recording medium; a recording head that is provided on the carriage and includes a recording unit that records an image on the recording medium; A medium detection sensor provided on the upstream side of the carriage on the transport path and outputs an output value corresponding to the presence or absence of the recording medium, and an output value provided on the carriage and corresponding to the presence or absence of the recording medium. A width detection sensor for output,
Controlling the recording device provided in the carriage at a position where the width detection sensor is shifted from the recording portion of the recording head to the side away from the reference position;
A reference position at which the carriage is positioned before starting recording on the recording medium is set at one end of the scanning range of the carriage,
Moving the carriage from the reference position toward the other end;
Based on the output value of the medium detection sensor during this movement, set a threshold for determining the presence or absence of the recording medium,
By detecting the side edge of the recording medium by comparing the threshold value and the output value of the width detection sensor,
Recording by the recording unit during the movement based on the detected side edge;
A control method for a recording apparatus.

Images