Printer and program

Abstract

To enable an optical sensor to detect an edge of a medium even when a mark or a graphic has been formed in the medium.SOLUTION: A printer comprises: first optical sensors 82 and 84 that detect first and second pinch rollers 17a and 17b; a carriage 26 provided with second optical sensors 92 and 94 that detect an end of a medium 200; and a control unit 74. The control unit 74 executes control including first operation for detecting positions of the first and second pinch rollers 17a and 17b and second operation performed after the first operation to detect the end of the medium 200. In the second operation, in a range outside the positions of the first and second pinch rollers 17a and 17b in a scanning direction which have been detected by the first operation, detection of an end position of the medium 200 based on detection signals of the second optical sensors 92 and 94 is executed.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a printing apparatus, a program, and the like.

Background Art

[0002] Patent Document 1 describes detecting the position of a pinch roller with a sensor provided on a carriage (for example,

[0064] of the specification). [[ID=I4]]

[0003] Patent Document 2 describes detecting the edge of a medium with an optical sensor provided on a carriage (for example, Claim 1,

[0074] to

[0077] of the specification).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, in relation to the control of the carriage scanning, there may be a case where position information of both ends of a medium (printing target, or in other words, recording target) in the scanning direction is required.

[0006] With the technology of Patent Document 1 above, the position of the pinch roller can be detected, but the positions of both ends of the medium in the scanning direction of the carriage cannot be measured.

[0007] When the technology of Patent Document 2 above detects the edge of a medium with an optical sensor, if marks, figures, etc. are already formed on the medium, there is a possibility of erroneously detecting the positions of those marks and figures as the edge of the medium.

[0008] Examples of marks or shapes already formed on the media include crop marks used for alignment during the cutting process of the media, or for alignment in multi-color printing.

[0009] One object of the present invention is to enable the detection of the edges of a medium by an optical sensor, even when marks or figures have already been formed on the medium. Other objects of the present invention will become apparent to those skilled in the art by referring to the embodiments and best embodiments described below, as well as the accompanying drawings. [Means for solving the problem]

[0010] The following are examples of embodiments of the present invention to facilitate understanding of its outline.

[0011] In an embodiment according to the present invention, the printing apparatus includes a carriage comprising: first and second pinch rollers rotatably in contact with a medium to be printed and arranged at a predetermined distance apart in a scanning direction perpendicular to the transport direction of the medium; a first optical sensor that is scannable and movable in the scanning direction and detects the first and second pinch rollers; and a second optical sensor located downstream of the first optical sensor in the transport direction of the medium and detecting the edge of the medium; and a control unit that controls the operation of the carriage and the first and second optical sensors. The control unit performs control including a first operation to detect the positions of the first and second pinch rollers by scanning the carriage, and a second operation performed after the first operation to detect the edge of the medium by scanning the carriage. In the second operation, the control unit detects the position of the edge of the medium based on a detection signal from the second optical sensor, within a range outside the positions of the first and second pinch rollers in the scanning direction detected in the first operation.

[0012] In this embodiment, prior to detecting the edge of the media, the positions of the first and second pinch rollers, which are arranged at predetermined intervals in the scanning direction, are detected.

[0013] The control unit recognizes the area between the first and second pinch rollers as the area where marks or shapes may be formed, and treats this area as a dead zone. When detecting the edge of the media, it ignores any marks or shapes that may be formed within this area.

[0014] In other words, the control unit detects the position of the media's edge based on the detection signal from the second optical sensor, within a range outside the positions of the first and second pinch rollers. Therefore, false detections do not occur.

[0015] Those skilled in the art will readily understand that the embodiments of the present invention illustrated can be further modified without departing from the spirit of the invention. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a perspective view showing the external appearance of an example of a printing device (inkjet printer). [Figure 2] Figure 2(A) is a front view showing the main carriage (printing carriage) and the sub-carriage (cutting carriage) connected via a connecting part, and Figure 2(B) is a front view showing the sub-carriage separated from the main carriage. [Figure 3] Figure 3 shows an example configuration of a pinch roller sensor, media edge sensor, and subcarriage board mounted on a subcarriage (cut carriage), as well as an example configuration of the printer's main board mounted on the printing device body. [Figure 4] Figure 4 is a side view showing an example of the structure of a subcarriage (cut carriage) having a pinch roller sensor and a media edge sensor. [Figure 5]FIG. 5(A) is a top view showing the detection of the position inside the pinch roller by the scanning (forward path) of the sub-carriage, FIG. 5(B) is a diagram showing the detection operation of the pinch roller sensor position based on the detection signal of the pinch roller sensor, and FIG. 5(C) is a waveform diagram showing an example of the detection signal output from the pinch roller sensor. [Figure 6] FIG. 6(A) is a top view showing the detection of the edge of the media by the scanning (return path) of the sub-carriage, FIG. 6(B) is a diagram showing the detection operation of the media edge based on the detection signal of the media edge sensor, and FIG. 6(C) is a waveform diagram showing an example of the detection signal output from the media edge sensor. [Figure 7] FIG. 7(A) is a top view showing the detection of the media clamp position by the scanning (forward and return paths) of the sub-carriage when there is a media clamp, FIG. 7(B) is a diagram showing the detection operation of the media clamp based on the detection signal of the media edge sensor, and FIG. 7(C) is a waveform diagram showing an example (including the reading signal of the recognition pattern on the media clamp) of the detection signal output from the media edge sensor. [Figure 8] FIGS. 8(A) and 8(B) are diagrams showing an example of the determination operation of whether the media clamp is in an appropriate position. [Figure 9] FIGS. 9(A) and 9(B) are diagrams showing another example of the determination operation of whether the media clamp is in an appropriate position. [Figure 10] FIG. 10 is a diagram showing an example of the control of the scanning speed of the sub-carriage based on the detected position of the edge of the media. [Figure 11] FIG. 11 is a flowchart showing the procedure of the setup process of the media by the control unit.

Embodiments for Carrying Out the Invention

[0017] The best embodiments described below are used for easily understanding the present invention. Therefore, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below.

[0018] (First Embodiment) Refer to FIG. 1. FIG. 1 is a perspective view showing the appearance of an example of a printing device (an inkjet printer).

[0019] An inkjet printer 10 having printing and cutting functions is supported by a base member 12, and includes a base member (apron: a front-hanging support member that supports the media 200 in front of the printer body) 14 that extends and is disposed in the scanning direction, side members 16L and 16R that are disposed perpendicular to the base member 14 at both left and right ends of the base member 14, first and second pinch rollers 17a and 17b that are rotatably in contact with the media 200 and are disposed at a predetermined distance apart in the scanning direction perpendicular to the conveyance direction of the media 200, a central wall 18 that connects the two left and right side members 16L and 16R, a first guide rail 20 disposed in the scanning direction, a second guide rail 22 disposed parallel to the guide rail 20, a drive belt (refer to FIG. 2(A)) 24 that is movably disposed along the wall surface of the central wall 18 in the scanning direction, a servo motor 58 that runs the drive belt 24 in the scanning direction, and two carriages 26 and 28 that are fixed to the drive belt 24 run by the servo motor 58 and are movable in the scanning direction along the first guide rail 20. However, this is an example and is not limited thereto. The carriage may be relatively movable with respect to the media in the scanning direction. In other words, the carriage may be relatively movable with respect to the media. For example, when there is no conveyance of the media, the carriage may move relative to the media in a direction (preferably perpendicular) intersecting the scanning direction.

[0020] The carriage 26 is a printing carriage as a main carriage on which a print head 29 is mounted.

[0021] The carriage 28 is a cut carriage, which is a sub-carriage equipped with a cutter. There are two types of cutters: one is a cutting cutter for cutting the media into the shape of a figure (cutter 32 that holds the cutting blade 36 in Figure 1); and the other is a sheet cutter (not shown in Figure 1, reference numeral 91 in Figure 2(A)).

[0022] In this embodiment, the cut carriage, which serves as a sub-carriage, is equipped with a pinch roller sensor (see reference numeral 80 in Figures 2 and 3) for detecting pinch rollers 17a and 17b, and a media edge sensor (see reference numeral 90 in Figures 2 and 3) for detecting the edges of the media 200. Furthermore, this cut carriage 28 can be separated from the print carriage 26 and moved independently. These points will be described later.

[0023] Note that a sub-carriage is a separate carriage from the carriage on which the print head is mounted (main carriage), and is not limited to a cut carriage.

[0024] Furthermore, the media 200, which is the object to be printed (recorded), is placed on a flat platen made of metal (not shown in Figure 1, reference numeral 300 in Figure 4).

[0025] Furthermore, below the pinch rollers 17a and 17b, there are conveyor rollers (not shown). These conveyor rollers are driven by a servo motor, such as a stepping motor, to rotate and transport the media 200 from upstream to downstream in the transport direction.

[0026] The pinch rollers 17a and 17b rotate by power transmitted from the conveyor roller via a gear mechanism or the like. The pinch rollers 17a and 17b are mounted on a second guide rail 22 and are configured to move along the second guide rail 22 in the scanning direction. The second guide rail 22 is rotatable so that the mounted pinch rollers 17a and 17b come into contact with the media 200. Elastic materials such as rubber are provided on the surfaces of the conveyor roller and the pinch rollers 17a and 17b, and the media 200 is firmly held between the pinch rollers 17a and 17b and the conveyor roller.

[0027] Next, refer to Figure 2. Figure 2(A) is a front view showing the main carriage (printing carriage) and the sub-carriage (cutting carriage) connected via a connecting part, and Figure 2(B) is a front view showing the sub-carriage separated from the main carriage.

[0028] In Figure 2, the same reference numerals are used for the same parts as in the previously mentioned figure. This is also the case for the other drawings.

[0029] The main carriage, the printing carriage 26, is equipped with a print head 29. The sub-carriage, the cutting carriage 28, is equipped with a pinch roller sensor 80 for detecting pinch rollers 17a and 17b, a media edge sensor 90 for detecting the edges of the media 200, and a cutter 91 for sheet cutting.

[0030] The sheet cutting cutter 91 is configured to be raised and lowered by a solenoid (not shown). Furthermore, the cutting cutter 32, which cuts the media into the shape of a figure, is attached to the cutting carriage 28 and moves integrally with the cutting carriage 28. This cutting cutter 32 is also configured to be raised and lowered by a solenoid (not shown). Note that in Figure 2, the cutting blade 36 of the cutting cutter 32 (see Figure 1) is omitted from the illustration.

[0031] In Figure 2(A), the printing carriage 26 and the cutting carriage 28 are connected by a connecting member 40. For example, when printing on the media 200, the printing carriage (main carriage) 26 and the cutting carriage (sub-carriage) 28 are connected by the connecting part 40 and move as a single unit.

[0032] In Figure 2(B), the print carriage (main carriage) 26 is located near the rightmost end of its movable range. This is the position of the print carriage 26 when the printer is powered on. The position of the cut carriage (sub-carriage) 28 connected to the print carriage 26 at this position is the position of the cut carriage 28 when the printer is powered on (standby position, hereinafter also referred to as the home position). The locking member (locking claw) 45 provided on the print carriage 26 and the locking member (locking claw) 49 of the engaging part 47 provided on the outer wall of the printer body engage, preventing the print carriage 26 from moving.

[0033] Meanwhile, the cut carriage (sub-carriage) 28 is released from its connection by the connecting part 40, separated from the printing carriage 26, and becomes independently movable.

[0034] When cutting the media 200 to a predetermined size or forming perforations across the media 200, only the cut carriage 28 is scanned, as shown in Figure 2(B).

[0035] Furthermore, in this embodiment, even during media setup before printing, only the sub-carriage (cut carriage) 28 is scanned, as shown in Figure 2(B). During this scanning, the position of the pinch roller and the edge position of the media are detected using the pinch roller sensor 80 and the media edge sensor 90. By moving only the sub-carriage, it is possible to suppress the drying of the ink head during the detection operation. In addition, since the weight of the carriage to be moved is reduced, the carriage driving force can be reduced. Details will be described later.

[0036] Next, refer to Figure 3. Figure 3 shows an example configuration of a pinch roller sensor, media edge sensor, and subcarriage board mounted on a subcarriage (cut carriage), as well as an example configuration of the printer's main board mounted on the printing device body.

[0037] The subcarriage 28 is equipped with a subcarriage board 50, which has a subcarriage controller 52 mounted on it.

[0038] Furthermore, the subcarriage board 50 is provided with an I / O port (for example, a general-purpose I / O port) N1 as an output terminal. This subcarriage board 50 is also equipped with a serial communication module (not shown) of the same type as the serial communication module 76 mounted on the printer's main board 70. Using these serial communication modules enables UART (Universal Asynchronous Receiver / Transmitter) communication.

[0039] The pinch roller sensor 80 includes a light-emitting unit 82 having a light-emitting element (such as an LED) as a light source, and a light-receiving unit 84 having a light-receiving element (such as a photodiode) that receives reflected light from an object and converts it into an electrical signal. The detection signal (measurement signal) output from the light-receiving unit 84 is supplied to the subcarriage controller 52.

[0040] The media edge sensor 90 includes a light-emitting unit 92 having a light-emitting element (such as an LED) as a light source, and a light-receiving unit 94 having a light-receiving element (such as a photodiode) that receives reflected light from an object and converts it into an electrical signal. The detection signal (measurement signal) output from the light-receiving unit 94 is supplied to the subcarriage controller 52.

[0041] The printer's main board 70 includes a position detection unit 72, a control unit (CPU, MPU, etc.) 74 that comprehensively controls the operation of the printing device (printer), a serial communication module 76, and an I / O port (for example, a general-purpose I / O port) N2 as an input terminal.

[0042] The position detection unit 72 receives a rotational position signal from the servo motor 58 sent from the encoder 60 of the carriage drive unit 53, and has the function of detecting the position of the moving subcarriage 28 based on that rotational position signal.

[0043] The carriage drive unit 53 also includes a servo controller 54, a servo amplifier 56, a servo motor 58, an encoder 60, and a servo board 61. The servo board 61 transmits the output signal or its integrated value from the encoder 60 to the printer's main board 70.

[0044] Next, we will explain the method for transmitting detection signals (measurement signals) from the two sensors 80 and 90 from the subcarriage board 50 to the printer's main board 70. There are two transmission paths: one that goes through I / O port N1, I / O communication line (1-bit data communication line) 101, and I / O port N2, and another that uses UART communication (UART communication line 103).

[0045] However, while UART communication requires, for example, tens of milliseconds for data transmission, using I / O communication line 101 reduces the transmission time to, for example, several hundred microseconds. UART communication has too much transmission delay to be suitable for real-time control.

[0046] Therefore, in this embodiment, detection signals (measurement signals) from two sensors 80 and 90 are transmitted via a single I / O communication line 101.

[0047] Here, even if each data output from the pinch roller sensor 80 and the media edge sensor 90 is a single bit data, either "H" or "L", it totals two bits, and if we try to transmit each data simultaneously, two I / O communication lines are required.

[0048] As described above, the only usable communication line is the I / O communication line 101. Therefore, in this embodiment, the output data transmitted from the subcarriage board 50 to the main board 70 via the I / O communication line 101 is switched based on a command signal from the main board 70. The command signal from the main board 70 is transmitted to the subcarriage board 50 in advance, for example, via the UART communication line 103. This makes it possible to transmit two types of data using a single I / O communication line 101.

[0049] Preferably, the cut carriage (subcarriage) 28 is moved back and forth in the scanning direction across the media 200, and detection data for the pinch roller is transmitted from the subcarriage board 50 to the main board 70 during the forward scan, and detection data for the media edge is transmitted from the subcarriage board 50 to the main board 70 during the return scan. This enables efficient detection and reduces the time required for detection. Further details will be described later.

[0050] The control unit 74 mounted on the printer's main board 70 can detect the position of the pinch roller and the media edge by associating the detection data received from each of the sensors 80 and 90 with the position information of the moving subcarriage 28 in the scanning direction detected by the position detection unit 72.

[0051] For example, by detecting the position of the subcarriage at the moment the detected data changes from "H" to "L," the position of the pinch roller and the media edge can be identified.

[0052] Next, refer to Figure 4. Figure 4 is a side view showing an example of the structure of a subcarriage (cut carriage) having a pinch roller sensor and a media edge sensor.

[0053] The media 200 is placed on the platen 300. The light-emitting unit 92 and light-receiving unit 94, which constitute the media edge sensor 90, are attached to the lower end of the main body 27 of the subcarriage (cut carriage) 28.

[0054] The light-emitting unit 92 emits light R1 diagonally downward, and the light-receiving unit 94 receives reflected light R2 from the media 200 (or platen 300).

[0055] Furthermore, a mounting portion 97 for the pinch roller sensor 80 is provided between the main body portion 27 and the first guide rail 20, and the light-emitting portion 82 and the light-receiving portion 84 that constitute the pinch roller sensor 80 are attached to the lower end of this mounting portion 97.

[0056] The light-emitting unit 82 emits light R3 diagonally downward. A colored reflector (hereinafter referred to as the pinch roller detection plate) 220 for detecting the pinch rollers is provided above the pinch rollers 17 (first and second pinch rollers 17a and 17b). The light-receiving unit 84 receives the reflected light R4 from the pinch roller detection plate 220. When the pinch roller detection plate 220 is present, the detection output is H ("1"), and when it is not present, it is L ("0").

[0057] Furthermore, the media edge sensor 90 is located downstream (towards the end) of the media transport direction by a predetermined distance Δy from the pinch roller sensor 80. Therefore, for example, when the media edge sensor 90 detects the edge of the media 200, problems such as mistakenly detecting the pinch roller detection plate 220 do not occur.

[0058] Next, refer to Figure 5. Figure 5(A) is a top view showing the detection of the inner position of the pinch roller by scanning (forward path) of the subcarriage, Figure 5(B) is a diagram showing the pinch roller sensor position detection operation based on the detection signal of the pinch roller sensor, and Figure 5(C) is a waveform diagram showing an example of the detection signal output from the pinch roller sensor.

[0059] In Figure 5(A), the first and second pinch rollers 17a and 17b are rotatably in contact with the media 200, which is the printing target (recording target), and are positioned at a predetermined distance apart in the scanning direction perpendicular to the transport direction of the media 200. The media 200 is also provided with crop marks CR1 and CR2 indicating the positions for cutting the media 200 to the finished size.

[0060] When the media 200 is placed on the platen 300, the control unit 74 performs a predetermined media setup process. In this media setup process, the pinch rollers 17a and 17b are first detected (first operation).

[0061] As explained earlier, the cut carriage (subcarriage) 28 is equipped with a pinch roller sensor 80 (first optical sensor) that detects the first and second pinch rollers 17a and 17b.

[0062] In Figure 5(A), the cut carriage (subcarriage) 28, located to the right of the set media 200, is scanned in the scanning direction and moves across the media 200. During this forward movement, as shown in Figure 5(B), the detection data from the pinch roller sensor 80 is transmitted to the control unit 74 of the printer's main board 70 via the subcarriage controller 52, I / O pin N1, I / O communication line 101, and I / O pin N2.

[0063] As shown in Figure 5(C), scanning of the subcarriage 28 begins at time t1 and ends at time t6. Between times t1 and t2, a first pulse waveform corresponding to the first pinch roller 17a is obtained, and between times t4 and t5, a second pulse waveform corresponding to the second pinch roller 17b is obtained.

[0064] In the detection signal shown in Figure 5(C), there are only as many pulse waveforms as there are pinch rollers 17, making it easy to identify each pulse waveform corresponding to each pinch roller 17a and 17b. However, due to disturbances, pulse waveforms that do not correspond to the pinch rollers 17 may be mixed into the detection signal. In such cases, for example, pulse waveforms present in the detection signal whose difference between the pulse width and the actual width of each pinch roller 17a and 17b pre-stored in the memory unit 75 is within a predetermined range can be detected as the pulse waveform corresponding to each pinch roller 17a and 17b.

[0065] Here, for the first pulse waveform, the position of the subcarriage 28 corresponding to the timing of the falling edge at time t3 is detected (identified). In other words, the inner position P1 of the first pinch roller 17a, as shown in Figure 5(A), is detected. Note that the "inner position" refers to "the position of the end of the first pinch roller 17a that is closer to the center line, assuming a virtual center line that divides the media 200 into two equal parts in the scanning direction."

[0066] For the second pulse waveform, the position of the subcarriage 28 corresponding to the timing of the rising edge at time t4 is detected (identified). In other words, the inner position P2 of the second pinch roller 17b, as shown in Figure 5(A), is detected. Note that the "inner position" refers to "the position of the end of the second pinch roller 17b that is closer to the center line, assuming a virtual center line that divides the media 200 into two equal parts in the scanning direction."

[0067] The reason for detecting the inner position of each pinch roller 17a, 17b here is that, for example, even if each pinch roller 17a, 17b is positioned to straddle the media 200 and the platen 300, the inner position is reliably within the range where the media 200 exists. However, the position detected for each pinch roller 17a, 17b is not limited to the inner position. For example, the center position of each pinch roller 17a, 17b may be detected.

[0068] As explained earlier, in media edge detection, the range between each pinch roller 17a and 17b is set as a dead zone where marks and shapes are not detected. If the "outer position" of each pinch roller 17a and 17b is detected, and that outer position is outside the media 200, the dead zone will be set to cover the entire scanning direction of the media 200, making edge detection of the media 200 impossible. By detecting a position inside the "outer position" of each pinch roller 17a and 17b, the above problem does not occur.

[0069] In Figure 5, the inner positions of each pinch roller 17a and 17b were directly detected from the first and second pulse waveforms. However, the center positions of each pinch roller 17a and 17b may be calculated from the first and second pulse waveforms, and the inner positions of each pinch roller 17a and 17b may be identified as positions located a predetermined distance inward from the center positions. Depending on the accuracy of the pinch roller sensor 80 (first optical sensor), the width between the position of the subcarriage 28 at the rising edge and the falling edge of the pulse waveform may be larger or smaller than the actual width of the pinch roller 17. Alternatively, the center position between the position of the subcarriage 28 at the rising edge and the falling edge of the pulse waveform may be calculated, and the inner positions of each pinch roller 17a and 17b may be identified as positions located half the actual width of the pinch roller 17 from the center positions.

[0070] Next, refer to Figure 6. Figure 6(A) is a top view showing the detection of the media edge by scanning (return path) of the subcarriage, Figure 6(B) is a diagram showing the media edge detection operation based on the detection signal of the media edge sensor, and Figure 6(C) is a waveform diagram showing an example of the detection signal output from the media edge sensor.

[0071] In Figure 6(A), the cut carriage (subcarriage) 28, located to the left of the set media 200, is scanned in the scanning direction and moves across the media 200. During this return movement, an operation (second operation) is performed to detect the edge position of the media 200.

[0072] As shown in Figure 6(B), the detection signal (detection data) from the media edge sensor (second optical sensor) 90 is transmitted to the control unit 74 of the printer's main board 70 via the subcarriage controller 52, I / O pin N1, I / O communication line 101, and I / O pin N2.

[0073] In Figure 6(A), the control unit 74 defines the range za between the first and second pinch rollers 17a and 17b detected during the forward scan as a dead zone where no marks or figures are detected.

[0074] In other words, the control unit 74 detects the edge position of the media 200 based on the detection data of the media edge sensor (second optical sensor) 90 in the range zb and zc outside the positions of the first and second pinch rollers 17a and 17b in the scanning direction.

[0075] In Figure 6(A), crop marks CR1 and CR2 are present at positions P4 and P5 in the scanning direction, but these crop marks are not detected. Therefore, false detections are reliably prevented.

[0076] In Figure 6(C), periods Tza, Tzb, and Tzc correspond to ranges za, zb, and zc in Figure 6(A). The period from time t11 to t16 is the dead zone period Tza. The period from time t10 to t11 is period Tzb, and the period from time t16 to t17 is period Tzc.

[0077] The control unit 74 detects the falling edge of the detection signal at time t10 during period Tzb, and sets position P3 at this detection timing as the left edge position of the media 200. Furthermore, at time t17 during period Tzc, it detects the rising edge of the detection signal, and sets position P6 at this detection timing as the right edge position of the media 200. Note that the detection signal changes in accordance with crop marks CR1 and CR2 at times t11-t13 and t14-t15, but this is ignored because it falls within the dead zone period Tza.

[0078] In this way, prior to detecting the edge of the media 200, the positions of the first and second pinch rollers 17a and 17b, which are arranged at a predetermined interval in the scanning direction, are detected. The control unit 74 then recognizes the range between the first and second pinch rollers 17a and 17b as a range where marks or figures may be formed, and treats this range as a dead zone. When detecting the edge of the media 200, even if marks or figures are formed in this range, they are ignored.

[0079] In other words, the control unit 74 detects the position of the edge of the media 200 based on the detection signal from the media edge sensor (second optical sensor) 90, within a range outside the positions of the first and second pinch rollers. Therefore, false detections do not occur.

[0080] Furthermore, "outward direction" when referring to a position outside the positions of the first and second pinch rollers can be defined, for example, as a direction away from the central position obtained by dividing the media in two equal parts along the scanning direction of the carriage (scanning direction or left-right direction).

[0081] Furthermore, in this embodiment, as previously explained with reference to Figure 3, the detection signals from the two sensors (first and second optical sensors) are transmitted from the subcarriage board 50 to the main board (and control unit) via I / O communication lines (I / O data communication lines) electrically connected to I / O ports provided on the main board.

[0082] Even if only one I / O communication line is available, by switching the output data transmitted from the subcarriage board 50 to the main board 70 and communicating the output data from each sensor, it becomes possible to transmit two types of data using a single I / O communication line.

[0083] Furthermore, as shown in Figures 5 and 6, preferably, the carriage is moved back and forth across the media, with pinch roller detection (first operation) performed on the forward path and media edge detection (second operation) performed on the return path. This allows for detection of both the pinch roller and media edge in a single back-and-forth scan, thereby reducing the operating time.

[0084] Furthermore, as explained earlier using Figure 5, when detecting the pinch roller, the position inside the pinch roller is detected. This makes it possible to appropriately set the range in which the edge detection operation is performed, even if the pinch roller is positioned to straddle the edge of the media.

[0085] Furthermore, as explained earlier using Figure 2(B), the pinch roller sensor and optical sensor are mounted on a sub-carriage separate from the carriage on which the ink head is mounted. By moving only the sub-carriage, it is possible to suppress the drying of the ink head during the detection operation. In addition, since the weight of the carriage to be moved is reduced, the carriage driving force can be reduced.

[0086] (Second embodiment) Next, refer to Figure 7. Figure 7(A) is a top view showing the detection of the media clamp position by scanning the subcarriage (forward and return paths) when a media clamp is present. Figure 7(B) is a diagram showing the media clamp detection operation based on the detection signal from the media edge sensor. Figure 7(C) is a waveform diagram showing an example of the detection signal output from the media edge sensor (including the reading signal of the recognition pattern on the media clamp). The media clamp 303 is configured to be attachable to the second guide rail 22 and is movable along the second guide rail 22 in the scanning direction. Alternatively, it may be fixed by fitting it into a groove provided in the platen 300. Alternatively, the media clamp 303 may simply be placed on top of the media 200 as a weight.

[0087] In Figure 7(A), the right end of the media 200 is held in place by a metal media clamp 303a, and the left end is held in place by a metal media clamp 303b.

[0088] Since the media 200 is hidden beneath the media clamps 303a and 303b, it is not possible to detect the edges of the media 200 by utilizing the difference in light reflectivity between the media and the platen, as in the first embodiment.

[0089] Therefore, in this embodiment, recognition patterns (patterns 305a, 305b, 305c, and 305d that cause the control unit 74 to recognize each media clamp) are formed on each media clamp 303a and 303b, and the position of each media clamp 303a and 303b is detected by detecting these patterns.

[0090] For example, the inner positions (positions P8 and P9 in Figure 7(A)) are defined as the edge positions of the media 200. Therefore, even if media clamps 303a and 303b are present, the position of the media edge can be detected. However, the position of the media edge is not limited to the inner positions of the media clamp. For example, the center position of the media clamp may be defined as the edge position of the media 200.

[0091] Furthermore, as shown in Figure 7(A), the recognition patterns 305a and 305b, 305c and 305d are composed of two vertically elongated rectangles of a predetermined width placed adjacent to each other. Each rectangle is preferably a white (or black) pattern. However, this is just an example, and the color and shape of the patterns are not limited to the above example.

[0092] By reading a distinctive recognition pattern and detecting (identifying) the position of each media clamp, the optical sensor can reliably detect the position of each media clamp and improve its detection accuracy.

[0093] As clearly shown in the upper right of Figure 7(A), the upstream position Pb of the recognition patterns 305a and 305b (and similarly 305c and 305d) in the media transport direction is different from the downstream position Pa of the pinch roller 17a (17b), and the two positions do not overlap in the transport direction. Therefore, the presence of the recognition patterns does not adversely affect the detection of the pinch roller.

[0094] In this embodiment as well, the I / O communication line 101, which is directly connected to the printer's main board 70, is used for data transmission. This is the same as in the previously described embodiment.

[0095] As shown in Figure 7(C), by reading the characteristic recognition patterns 305c and 305d, two pulse waveforms are obtained at times t20-t21 and t22-t23. Then, the position P8 corresponding to the timing of the falling edge that appears immediately after at time t24 is set as the inside position of the media clamp 303b, and for example, this position can be set as the edge position of the media 200.

[0096] However, since the width (width in the scanning direction) of the area where the media is held down by the media clamp is known, it is also possible to add this known width to the above position P8 and use the resulting position as the position of media 200. Such modifications can be made as appropriate. Furthermore, in Figure 7(C), when D1 is the width of the period from time t23 to t24, this width D1 is less than or equal to a predetermined threshold Dth. This is a normal state. When the media clamp is in an inappropriate position, a change occurs in the relationship between the width D1 and the threshold Dth. Therefore, by focusing on this point, it is also possible to detect that the media clamp is in an inappropriate position. This point will be explained later using Figure 9(A).

[0097] Next, refer to Figure 8. Figures 8(A) and 8(B) show an example of the operation for determining whether the media clamp is in the correct position.

[0098] In the example shown in Figure 8, the control unit 74 performs an operation to determine whether the media clamp is in the correct position based on the detected position of the media clamp and the known width of the media.

[0099] As shown in Figure 8(A), the distance between positions P8 and P9 inside the detected media clamps 303a and 303b is Wa. The width of the media 200 (width in the scanning direction) is Wb, and this value is assumed to be known. For example, if the user inputs the width of the media 200 into the printer, or if the width of the media 200 is detected by, for example, an optical sensor before attaching the media clamps 303a and 303b, then the width of the media 200 is known.

[0100] Therefore, the control unit 74 determines whether or not the following equation (1) is satisfied, as shown in Figure 8(B). Wth1 ≤ Wb - Wa ≤ Wth2 ···(1) In equation (1), Wth1 and Wth2 are threshold values ​​for determination.

[0101] If equation (1) above is satisfied, the media clamp is determined to be in the correct position; otherwise, it is determined to be in an inappropriate position.

[0102] In this way, it is also possible to detect whether the media clamp is in the correct position. If the media clamp is not in the correct position, the edges of the media may lift up. If printing is performed in this state, the lifted edges of the media may come into contact with the print carriage 26, which may obstruct the movement of the print carriage 26.

[0103] As shown in the example in Figure 8, it is possible to determine in advance whether the media clamp is in the correct position, thus avoiding the problems described above.

[0104] Next, refer to Figure 9. Figures 9(A) and 9(B) show other examples of the operation for determining whether the media clamp is in the correct position. In Figure 9(A), the entire media clamp 303b is located on the platen 300. In other words, the media clamp 303b is not located on the media 200 and does not serve to hold the media in place. In this case, the time interval D1 from time t23 to t24 becomes greater than the predetermined threshold Dth. In other words, the relationship D1 ≤ Dth shown in Figure 7(C) does not hold. In this way, by detecting whether the time interval D1 from the time when the detection of the media clamp recognition pattern is completed (time t23) to the time when the media edge is detected (time t24) is within a predetermined threshold Dth, it is possible to detect whether the media clamp position is appropriate or inappropriate.

[0105] Furthermore, in the case of Figure 9(B), the entire media clamp 303b is on the media 200, and the media clamp 303b is located inside the position P2 of the pinch roller 17b. In this case, the media clamp is entering the printing area. In this case, between times t27 and t28, a change occurs in the detection signal corresponding to the left and right edges of the media clamp 303b, or to the media clamp recognition patterns 305c and 305d. The location of this change is indicated by the symbol RL in the figure. However, the change in the detection signal occurs during the dead zone period Tza and is therefore ignored. Consequently, the position of the media clamp 303b is not detected. In this case, it is determined that the media clamp is located inside the pinch roller position, or that the media clamp is not installed at all.

[0106] Next, refer to Figure 10. Figure 10 shows an example of controlling the scanning speed of the subcarriage based on the position of the detected media edge.

[0107] As explained earlier using Figure 2, by moving the cut carriage 28, which acts as a sub-carriage, across the media, the media 200 can be cut or perforated.

[0108] The cut carriage 28 scans at a constant speed in the area where the media 200 is present, but in the area where the media is not present (outside the media), it is accelerated to shorten the scanning time and decelerated to stably complete the scan.

[0109] If the edge position of media 200 is detected in advance, the acceleration and deceleration of the subcarriage can be appropriately controlled.

[0110] In Figure 10, the control unit 74 moves the cut carriage (subcarriage) 28 to a first position located a predetermined distance further from the home position than the first end of the media 200 (the end furthest from the home position of the cut carriage, for example, the left end) by time t30.

[0111] At time t31, the cut carriage 28 begins to move from its first position. At this point, the control unit 74 increases the movement speed (scanning speed) of the cut carriage 28. In other words, the cut carriage 28 is accelerated.

[0112] During the period from time t32 to t33, the cut carriage 28 is on the media 200, so here the cut carriage moves at a constant speed.

[0113] At time t33, the cut carriage 28 reaches the second end (right end) of the media 200, opposite to the first end (left end). At this point, the control unit 74 reduces the movement speed (scanning speed) of the cut carriage 28. In other words, the cut carriage 28 is decelerated.

[0114] After time t34, high-speed movement such as when cutting media is no longer necessary, so the cut carriage 28 moves at a low speed and stops at the home position. In this way, by utilizing the information of the media edge position detected in advance, appropriate acceleration and deceleration control of the cut carriage 28 is achieved.

[0115] In the control shown in Figure 10, for example, the acceleration period of the cut carriage 28 (times t31 to t32) can be made sufficiently short (preferably minimized).

[0116] If the edge position of the media is unknown, the cut carriage needs to be accelerated from a position considerably far from the edge. This results in inefficient acceleration and increases the power consumption required for scanning the cut carriage. As shown in the example in Figure 10, such inefficiency is avoided, and the increase in power consumption can be suppressed. Furthermore, performing a sheet cut from a position excessively far from the edge results in extra cutting time. However, by performing the sheet cut starting from a position only the minimum distance required from the edge to accelerate to the speed required for sheet cutting, the cutting time can be reduced.

[0117] Furthermore, when the edge position of the media is unknown, the cut carriage 28 must begin to decelerate only after it has reliably passed the media 200. In this case as well, deceleration is delayed, resulting in wasted travel and increased power consumption.

[0118] In the example shown in Figure 10, since the edge position of the media 200 is precisely known, the cut carriage 28 can begin decelerating as soon as it reaches that edge position. Therefore, efficient deceleration is possible. This contributes to reducing power consumption. It also contributes to miniaturization of the printing device (printer).

[0119] However, deceleration during the period from time t33 to t34 is not necessarily required. After cutting, move the cut carriage to the home position. It is also possible to not decelerate during the period from time t33 to t34, but to decelerate and stop the cut carriage from just before the home position.

[0120] Next, refer to Figure 11. Figure 11 is a flowchart showing the procedure for media setup processing by the control unit.

[0121] First, it is determined whether the media is already set (step S1). If the result is N, the system waits for the media to be set; if the result is Y, the system proceeds to step S2. Whether the media is already set can be determined, for example, by observing the movement of the pinch roller support member, which brings the pinch roller into contact with or away from the media.

[0122] In step S2, the carriage (e.g., cut carriage) is scanned to detect the position of the pinch roller (first operation).

[0123] In step S3, the carriage scan begins in order to perform media edge detection (second operation).

[0124] In step S4, the presence or absence of a media clamp is determined. For example, this determination can be made by checking whether or not a detection waveform corresponding to the recognition pattern attached to the media clamp appears. If the result is N, proceed to step S5; if the result is Y, proceed to step S6.

[0125] In step S5, the media edge is detected in the area excluding the area between the two pinch rollers.

[0126] In step S6, the position of the media clamp is detected.

[0127] Step S7 is performed if necessary. In step S7, it is determined whether the media clamp is in the correct position.

[0128] In step S8, the edges of the media are detected. For example, inside the media clamp. Perform processing such as setting the position to an edge position.

[0129] By using a computer program, it is possible to make the computer mounted on the printer's main board function as a control unit that performs the control operations described above. In this case, it is easy to implement as it only requires installing the computer program into the control unit's memory.

[0130] As described above, according to the present invention, even if marks, figures, etc., are already formed on the media, the edges of the media can be detected by the optical sensor.

[0131] The present invention is not limited to the exemplary embodiments described above, and those skilled in the art will be able to easily modify the exemplary embodiments described above to the extent included in the claims. [Explanation of Symbols]

[0132] 10...Printing device (inkjet printer with cutting function), 12...Base member, 14...Base member (apron), 16L, 16R...Side members, 17 (17a, 17b)...Pinch rollers (first and second pinch rollers), 18...Central wall, 20...First guide rail, 22...Second guide rail, 24...Drive belt, 26...Main carriage (printing carriage), 28...Sub-carriage (cutting carriage), 29...Printing head, 32...Cutter, 36...Cutting blade, 40...Connecting section, 50...Sub-carriage board, 52...Sub-carriage controller, 54...Servo controller, 56...Servo amplifier, 58...Servo Motor, 60... Encoder, 70... Printer main board, 72... Position detection unit, 74... Control unit, 76... Serial communication module, 80... Pinch roller sensor, 82, 92... Light-emitting unit, 84, 94... Light-receiving unit, 90... Media edge sensor, 101... I / O communication line, 103... UART communication line, 200... Media (medium, recording medium, print target), 300... Platen, N1... I / O port as output port (general-purpose I / O terminal, etc.), N2... I / O port as input port (general-purpose I / O terminal, etc.), 303 (303a, 303b)... Media clamp, 305a and 305b, 305c and 305d... Pattern for media clamp recognition.

Claims

1. First and second pinch rollers that are rotatably in contact with a medium to be printed and are arranged at a predetermined distance apart in a scanning direction orthogonal to the conveyance direction of the medium; A carriage including a first optical sensor that is movable by being scanned in the scanning direction and detects the first and second pinch rollers, and a second optical sensor that is provided at a position downstream of the first optical sensor in the conveyance direction of the medium and detects an end of the medium; A control unit that controls the operation of the carriage and the first and second optical sensors; characterized by comprising: The control unit: Performs a first operation of detecting the positions of the first and second pinch rollers by scanning the carriage; Performs a second operation of detecting the end of the medium by scanning the carriage, which is performed after the first operation; Performs control including these; In the second operation, within a range outside the positions of the first and second pinch rollers in the scanning direction detected in the first operation, the position of the end of the medium is detected based on a detection signal from the second optical sensor. A printing apparatus.

2. The carriage reciprocates across the medium, The first operation is executed on the forward path, The second operation is executed on the return path. The printing apparatus according to Claim 1.

3. The carriage is a sub-carriage that is separate from a printing carriage on which a print head is mounted and is movable independently of the printing carriage. The printing apparatus according to Claim 1.

4. The control unit is mounted on the main board of the printing apparatus, Detection signals of the first and second optical sensors are transmitted to the main board via I / O communication lines electrically connected to an I / O port provided on the main board. The printing apparatus according to Claim 1.

5. In the first operation, the positions of the first and second pinch rollers that are inside from the outer ends are detected. The printing apparatus according to Claim 1.

6. The control unit: When there is a media clamp that presses the media at the end of the media, based on the detection signal from the second optical sensor, detects the position of the media clamp, and sets the detected position as the end of the media. The printing apparatus according to Claim 1.

7. The media clamp is provided with a recognition pattern. The control unit detects the position of the media clamp based on a detection signal of the recognition pattern by the second optical sensor. The printing apparatus according to claim 6.

8. The control unit when there is a media clamp for pressing the media on a platen on which the media is placed, detects the position of the media clamp based on the detection signal by the second optical sensor, and determines whether or not the position of the media clamp is at an appropriate position on the platen. When it is determined that the position of the media clamp is at the appropriate position on the platen, the detected position of the media clamp is set as the end of the media. The printing apparatus according to claim 1.

9. The carriage is a cut carriage that holds a cutting blade capable of cutting the media. The control unit when moving the cut carriage to cut the media, between a standby position of the cut carriage when the power of the printing apparatus is turned on and a first position located in a direction away from the standby position by a predetermined moving distance from a first end that is far from the standby position among the ends of the media detected in the second operation, moves the cut carriage. The printing apparatus according to claim 1.

10. A program for operating a computer as the control unit according to any one of claims 1 to 9.

11. First and second pinch rollers that are rotatably in contact with a media to be printed and are arranged at a predetermined distance in a scanning direction, a carriage that is relatively movable with respect to the media in the scanning direction and includes an optical sensor that detects the first and second pinch rollers and an end of the media, a control unit that controls operations of the carriage and the optical sensor, and The control unit performs a first operation of detecting positions of the first and second pinch rollers by scanning of the carriage, and a second operation of detecting the end of the media by scanning of the carriage, which is performed after the first operation, and performs control including these. In the second operation, detection of the position of the end of the medium based on the detection signal from the optical sensor is performed in a range outside the positions of the first and second pinch rollers in the scanning direction, which were detected in the first operation. Printing apparatus.

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