JP2003252482A - Printing method and device, program, and computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue the printing operation without stopping a printing device even in case a second sensor does not sense the leading edge of a material to be printed any more. <P>SOLUTION: The arrangement according to the invention comprises a first sensor to sense the leading edge of the material to be printed, a transporting mechanism to transport the material for the printing position, and the second sensor to sense the leading edge of the material on the way of the mechanism transporting the material from the first sensor having sensed the leading edge of the material till the printing position, wherein when the second sensor has sensed the leading edge of the material, the transporting mechanism transports the material till the printing position on the basis of the sensing result of the second sensor, and when the second sensor does not sense the leading edge of the material, the transporting mechanism transports the material till the printing position on the basis of the sensing result of the first sensor. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and a printing method for printing on an object to be printed such as paper. The present invention also relates to a program and a computer system for controlling such a printing device.

[0002]

2. Description of the Related Art As a printing apparatus for printing an image on various printing materials such as paper, cloth, and film, an ink jet printer is known which discharges ink intermittently for printing.
In such an ink jet printer, the step of ejecting ink while moving the nozzle in the scanning direction and the step of moving and positioning the printing medium in the paper feeding direction are alternately repeated to perform printing.

[0003]

In order to position an object to be printed, the printer is provided with a sensor for detecting paper, and this sensor detects the front end of the object to be printed, and based on the detection result, the object to be printed is detected. Transport.

However, the position where this sensor is provided is
If the printing object is far from the printing position, the positioning of the printing object at the printing position becomes inaccurate.

On the other hand, a second sensor may be provided closer to the printing position than the first sensor, and the printing medium may be conveyed based on the detection result of the second sensor. In this case, however, When the second sensor cannot detect the printing medium, the device may stop.

Therefore, the present invention provides a printing apparatus capable of continuing the printing operation without stopping the apparatus even when the second sensor does not detect the front end of the printing medium. The purpose is to

[0007]

A main invention for achieving the above object is to provide a first sensor for detecting a front end of an object to be printed, and a carrying mechanism for carrying the object to be printed toward a printing position. A second sensor that detects the leading edge of the printing medium while the transporting mechanism transports the printing medium from the first sensor detecting the leading edge of the printing medium to the printing position. A sensor, and when the second sensor detects the front end of the printing medium, the conveyance mechanism conveys the printing medium to the printing position based on the detection result of the second sensor. Then
When the second sensor does not detect the front end of the printing medium, the transport mechanism transports the printing medium to the printing position based on the detection result of the first sensor. Characterize.

Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION === Outline of Disclosure === At least the following matters will be made clear by the present specification and the description of the accompanying drawings.

A first sensor for detecting the leading edge of the printing medium, a transport mechanism for transporting the printing medium toward the printing position, and the first sensor for detecting the leading edge of the printing medium. From the printing position to the printing position, the second mechanism includes a second sensor that detects the leading end of the printing target while the feeding mechanism transports the printing target, and the second sensor is the leading end of the printing target. When detecting the, the transport mechanism transports the printing target to the printing position based on the detection result of the second sensor, and the second sensor detects the leading end of the printing target. If not, the transport mechanism transports the printing medium to the printing position based on the detection result of the first sensor. According to such a printing apparatus, the second
Even when the sensor of 1 does not detect the front end of the printing medium, the printing operation can be continued without stopping the apparatus.

In this printing apparatus, it is preferable that the second sensor is provided on a movable carriage. According to such a printing apparatus, the second sensor is arranged near the printing position.

In such a printing apparatus, it is desirable that the second sensor detect the width of the printing medium. According to such a printing apparatus, the second sensor can be used both as a sensor for detecting the tip of the printing target and as a sensor for detecting the width of the printing target.

In such a printing apparatus, it is desirable that the second sensor is an optical sensor. According to such a printing apparatus, even when the second sensor does not detect the leading edge of the paper due to dirt or the like, the printing operation can be continued without stopping the apparatus.

In such a printing apparatus, the second sensor has a light emitting portion and a light receiving portion, the light emitting portion irradiates the object to be printed with light, and the light receiving portion is the object to be printed. It is desirable to detect the light reflected by. According to such a printing apparatus, the second sensor can detect the front end of the printing object based on the presence / absence of reflected light.

In such a printing apparatus, the second sensor starts its operation when the carrying mechanism carries the object to be printed to a predetermined position. According to such a printing apparatus, it is not necessary to keep the second sensor continuously operating.

In such a printing apparatus, it is desirable that the first sensor is a mechanical sensor. According to such a printing apparatus, it is possible to detect the front end of the printing medium with a simple configuration.

In such a printing apparatus, it is desirable that the second sensor has higher accuracy than the first sensor in detecting the position of the tip of the printing medium. According to such a printing apparatus, when the second sensor detects the position of the tip of the printing medium, the printing medium can be positioned with high accuracy.

In such a printing apparatus, the transport mechanism keeps the operation until the second sensor detects the front end of the printing target after the first sensor detects the front end of the printing target. It is desirable to convey the printing medium based on the first sensor. According to such a printing apparatus, it is possible to position the printing target until the second sensor detects the front end of the printing target.

In such a printing apparatus, when the printing object has a property that can be detected by the second sensor, the second sensor does not detect the tip of the printing object. If so, it is desirable to give a warning. According to such a printing apparatus, the user can know that the second sensor has an abnormality.

In such a printing apparatus, it is determined whether or not the printing medium has a property that can be detected by the second sensor based on the input information of the printing medium. If the second sensor does not detect the tip of the printing object when it is determined that the printing object has a property that can be detected by the second sensor, a warning is issued. Is desirable.

A first sensor for detecting the front end of the printing medium, a transport mechanism for transporting the printing medium toward the printing position, and the first sensor for detecting the front end of the printing medium. From the printing position to the printing position, the second mechanism detects a front end of the printing medium while the transportation mechanism transports the printing medium, and the first sensor is a mechanical sensor. , The second sensor is provided on a movable carriage, the second sensor detects the width of the printing medium, and the second sensor irradiates the printing medium with light. An optical sensor having a light emitting portion and a light receiving portion for detecting light reflected by the printing medium, wherein the second sensor is located at a position closer to the tip of the printing medium than the first sensor. The detection is highly accurate, and the second sensor detects the tip of the printing target. At that time, the transport mechanism transports the printing target to the printing position based on the detection result of the second sensor, and the second sensor does not detect the leading end of the printing target. At this time, the transport mechanism transports the printing medium to the printing position based on the detection result of the first sensor. According to such a printing apparatus, even when the second sensor does not detect the front end of the printing medium, the printing operation can be continued without stopping the apparatus.

A printing method for a printing apparatus comprising a first sensor, a carrying mechanism and a second sensor, wherein the first sensor detects the front end of a printing medium, and the carrying mechanism ,
A step of transporting the printing object toward a printing position,
The second sensor detects the leading edge of the printing medium while the transport mechanism transports the printing medium from the position where the first sensor detects the leading edge of the printing medium to the printing position. And the second sensor detects the front end of the printing target, the transport mechanism detects the printing target up to the printing position based on the detection result of the second sensor. And the second sensor does not detect the front end of the object to be printed, the carrying mechanism, based on the detection result of the first sensor, transfers the object to the printing position. And a step of transporting a printed body. According to such a printing method, the printing operation can be continued without stopping the apparatus even when the second sensor does not detect the front end of the printing medium.

A first sensor for detecting the leading edge of the printing medium, a transport mechanism for transporting the printing medium toward the printing position, and the first sensor for detecting the leading edge of the printing medium. From the printing position to the printing position, the second sensor is attached to a printing apparatus including a second sensor that detects the front end of the printing medium while the transportation mechanism is transporting the printing medium. When the front end of the printed material is detected, based on the detection result of the second sensor, the function of conveying the material to be printed to the printing position by using the transportation mechanism, and the second sensor A program that realizes a function of transporting the printing medium to the printing position by using the transporting mechanism based on the detection result of the first sensor when the front end of the printing medium is not detected. According to such a program, it is possible to control the printing operation to continue without stopping the apparatus even when the second sensor does not detect the front end of the printing medium.

A computer system comprising a computer main body and a printing device connectable to the computer main body, wherein the printing device faces a printing position and a first sensor for detecting a front end of an object to be printed. And a transport mechanism for transporting the print medium, and the transport mechanism transports the print medium from the first sensor detecting the front end of the print medium to the printing position. A second sensor for detecting the front end of the printing target, and when the second sensor detects the front end of the printing target, the transport mechanism, based on the detection result of the second sensor, When the object to be printed is conveyed to the position for printing and the second sensor does not detect the leading end of the object to be printed, the conveyance mechanism detects the result of the detection by the first sensor. Use the transport mechanism to transport the printing target to the printing position Computer system according to claim Rukoto. According to such a computer system, the printing operation can be continued without stopping the apparatus even when the second sensor does not detect the front end of the printing medium.

=== Outline of Printing Apparatus (Inkjet Printer) === <Regarding Inkjet Printer Configuration> FIGS. 1 and 2
An outline of an inkjet printer will be described as an example of a printing apparatus with reference to FIGS.
Note that FIG. 1 is an explanatory diagram of the overall configuration of the inkjet printer of the present embodiment. Further, FIG. 2 is a schematic view of the vicinity of the carriage of the inkjet printer of this embodiment. Further, FIG. 3 is an explanatory diagram of the periphery of the transport unit of the inkjet printer of the present embodiment.

The ink jet printer of this embodiment is
It has a paper transport unit 10, an ink discharge unit 20, a cleaning unit 30, a carriage unit 40, a measuring instrument group 50, and a control unit 60.

The paper transport unit 10 feeds, for example, paper, which is a printing medium, to a printable position, and in a predetermined direction at the time of printing (a direction perpendicular to the paper surface in FIG. 1 (hereinafter, referred to as paper feeding direction)). This is for moving the paper by the moving amount. That is, the paper transport unit 10 functions as a transport mechanism that transports paper. The paper transport unit 10 includes a paper insertion opening 11A and a roll paper insertion opening 11B, a paper feed motor (not shown), a paper feed roller 13, a platen 14, a paper feed motor (hereinafter referred to as a PF motor) 15, Paper feed motor driver (hereinafter referred to as PF motor driver) 1
6, a paper feed roller 17A, a paper discharge roller 17B, a free roller 18A and a free roller 18B. However, these functions are not necessarily required for the paper transport unit 10 to function as a transport mechanism.

The paper insertion port 11A is where the paper to be printed is inserted. The paper feed motor (not shown) is a motor that conveys the paper inserted into the paper insertion opening 11A into the printer, and is composed of a pulse motor. Paper feed roller 13
Is a roller that automatically conveys the paper inserted in the paper insertion port 11 into the printer, and is driven by the paper feed motor 12. The paper feed roller 13 has a substantially D-shaped cross section. The circumference of the circumference of the paper feed roller 13 is PF
Since it is set to be longer than the transport distance to the motor 15, the printed material can be transported to the PF motor 15 by using this circumferential portion. The rotational driving force of the paper feed roller 13 and the frictional resistance of the separation pad (not shown) prevent a plurality of printing materials from being fed at one time. The sequence of transporting the printing medium will be described in detail later.

The platen 14 supports the paper S being printed. The PF motor 15 is a motor that feeds, for example, paper, which is an object to be printed, in the paper feeding direction, and is composed of a DC motor. The PF motor driver 16 is for driving the PF motor 15. The paper feed roller 17A is a roller that feeds the paper S conveyed into the printer by the paper feed roller 13 to a printable area, and the PF motor 15
Driven by. The free roller 18A is provided at a position facing the paper feed roller 17A, and presses the paper S toward the paper feed roller 17A by sandwiching the paper S with the paper feed roller 17A.

The paper discharge roller 17B is for the paper S on which printing has been completed.
Is a roller that discharges the toner to the outside of the printer. The paper discharge roller 17B is driven by the PF motor 15 by a gear (not shown). The free roller 18B is the discharge roller 17
B is provided at a position facing B, and the paper S is ejected by a paper ejection roller 17B
The paper S is pressed toward the paper discharge roller 17B by being sandwiched between the paper and the paper.

The ink ejection unit 20 is for ejecting ink onto a printing medium such as paper. The ink ejection unit 20 has a head 21 and a head driver 22. The head 21 has a plurality of nozzles, which are ink ejection portions, and ejects ink intermittently from each nozzle. The head driver 22 drives the head 21 to intermittently eject ink from the head. The timing of ejecting ink will be described later.

The cleaning unit 30 includes a head 21.
This is to prevent clogging of the nozzle. The cleaning unit 30 includes a pump device 31 and a capping device 35. The pump device sucks ink from the nozzles in order to prevent clogging of the nozzles of the head 21, and includes a pump motor 32 and a pump motor driver 33. The pump motor 32 sucks ink from the nozzles of the head 21. The pump motor driver 33 drives the pump motor 32. The capping device 35 prevents the nozzles of the head 21 from being clogged so that the head 21 does not print (standby).
The nozzle of is sealed.

The carriage unit 40 is for moving the head 21 in a predetermined direction (left and right direction of the paper surface in FIG. 1 (hereinafter, referred to as scanning direction)). The carriage unit 40 includes a carriage 41, a carriage motor (hereinafter referred to as CR motor) 42, and a carriage motor driver (hereinafter referred to as CR motor driver).
43, a pulley 44, a timing belt 45, and a guide rail 46. The carriage 41 is movable in the scanning direction and fixes the head 21 (thus, the nozzles of the head 21 intermittently eject ink while moving along the scanning direction). The carriage 41 also includes an ink cartridge 48 that contains ink.
Is detachably held. The CR motor 42 is a motor that moves the carriage in the scanning direction, and is composed of a DC motor. The CR motor driver 43 is for driving the CR motor 42. Pulley 44 is CR
It is attached to the rotary shaft of the motor 42. The timing belt 45 is driven by the pulley 44. The guide rail 46 guides the carriage 41 in the scanning direction.

The measuring group 50 includes a linear encoder 5
1, a rotary encoder 52, and a paper detection sensor 5
3 and the gap sensor 54. The linear encoder 51 is for detecting the position of the carriage 41. The rotary encoder 52 is for detecting the rotation amount of the paper feed roller 17A. The configuration of the encoder will be described later. The paper detection sensor 53 is for detecting the position of the front end of the paper to be printed. The paper detection sensor 53 is provided at a position where the position of the leading end of the paper can be detected while the paper feed roller 13 conveys the paper toward the paper feed roller 17A. The paper detection sensor 53 is a mechanical sensor that detects the leading edge of the paper by a mechanical mechanism. In detail,
The paper detection sensor 53 has a lever rotatable in the paper feeding direction, and this lever is arranged so as to project into the paper conveyance path. Therefore, the leading edge of the paper comes into contact with the lever and the lever is rotated, and the paper detection sensor 53 detects the position of the leading edge of the paper by detecting the movement of the lever. The paper width sensor 54 is attached to the carriage 41. The paper width sensor 54 is an optical sensor having a light emitting unit 541 and a light receiving unit 543, and detects the presence of paper at the position of the paper width sensor 54 by detecting the light reflected by the paper. Then, the paper width sensor 54
Detects the position of the edge of the paper while moving by the carriage 41 to detect the width of the paper. In addition, the paper width sensor 54
Can detect the leading edge of the paper depending on the position of the carriage 41. Since the paper width sensor 54 is an optical sensor, its position detection accuracy is higher than that of the paper detection sensor 53.

The control unit 60 is for controlling the printer. The control unit 60 includes a CPU 61
, Timer 62, interface unit 63, ASI
It has a C 64, a memory 65, and a DC controller 66. The CPU 61 is for controlling the entire printer, and gives a control command to the DC controller 66, the PF motor driver 16, the CR motor driver 43, the pump motor driver 32, and the head driver 22.
The timer 62 periodically generates an interrupt signal to the CPU 61. The interface unit 63 transmits / receives data to / from a host computer 67 provided outside the printer. The ASIC 64 controls the print resolution, the head drive waveform, and the like based on print information sent from the host computer 67 via the interface unit 63. Memory 65 is ASIC 64 and CP
It is for securing an area for storing the U61 program, a work area, and the like, and includes PROM, RAM, and EEPRO.
It has a storage means such as M. The DC controller 66 is C
The PF motor driver 16 and the CR motor driver 43 are controlled based on the control command sent from the PU 61 and the output from the measuring instrument group 50.

<Regarding Encoder Configuration> FIG. 4 is an explanatory diagram of the linear encoder 51.

The linear encoder 51 includes the carriage 4
It is for detecting the position of No. 1 and has a linear scale 511 and a detector 512.

The linear scale 511 has a predetermined interval (for example, 1/180 inch (1 inch = 2.54 cm)).
A slit is provided for each and is fixed to the printer body side.

The detector 512 is provided so as to face the linear scale 511, and is provided on the carriage 41 side. The detection unit 512 includes a light emitting diode 512A,
It includes a collimator lens 512B and a detection processing unit 512C, and the detection processing unit 512C has a plurality of (for example, 4
Number of photodiodes 512D and the signal processing circuit 51
2E and two comparators 512Fa and 512Fb.

The light emitting diode 512A emits light when the voltage Vcc is applied through the resistors at both ends, and this light is incident on the collimator lens. Collimator lens 512
B makes the light emitted from the light emitting diode 512A parallel light and irradiates the linear scale 511 with parallel light. The parallel light that has passed through the slit provided on the linear scale passes through a fixed slit (not shown) and is incident on each photodiode 512D. Photodiode 512D
Converts the incident light into an electric signal. The electric signal output from each photodiode is the comparator 512F.
a, 512Fb, and the comparison result is output as a pulse. Then, the comparators 512Fa, 5
Pulse ENC-A and pulse E output from 12Fb
NC-B is the output of the linear encoder 51.

FIG. 5 is a timing chart showing waveforms of two types of output signals of the linear encoder 51. FIG. 5A is a timing chart of the waveform of the output signal when the CR motor 42 is rotating normally. FIG. 5B shows
It is a timing chart of the waveform of the output signal when the CR motor 42 is reversed.

As shown in FIGS. 5A and 5B, whether the CR motor 42 is rotating normally or reversing,
The pulse ENC-A and the pulse ENC-B have a phase of 90.
Deviated. When the CR motor 42 is rotating normally, that is, when the carriage 41 is moving in the main scanning direction, the phase of the pulse ENC-A is 90 degrees greater than that of the pulse ENC-B, as shown in FIG. 5A. It is progressing. on the other hand,
When the CR motor 42 is reversing, the pulse ENC-A is 90 times faster than the pulse ENC-B as shown in FIG. 5B.
The phase is delayed by degrees. In one cycle T of each pulse, the carriage 41 has a slit interval of the linear scale 511 (for example, 1/180 inch (1 inch = 2.54c).
m)) is equal to the time it takes to travel.

The position of the carriage 41 is detected as follows. First, regarding the pulse ENC-A or ENC-B, a rising edge or a falling edge is detected,
Count the number of detected edges. The position of the carriage 41 is calculated based on this count number. The count number is incremented by "+1" when one edge is detected while the CR motor 42 is rotating normally, and the CR motor 4
If one edge is detected when 2 is inverted, "-1" is added. Since the cycle of the pulse ENC is equal to the slit interval of the linear scale 511, the amount of movement from the position of the carriage 41 when the count number is "0" can be obtained by multiplying the count number by the slit interval. That is, the linear encoder 5 in this case
The resolution of 1 is the slit interval of the linear scale 511. Further, the position of the carriage 41 may be detected using both the pulse ENC-A and the pulse ENC-B.
Since each cycle of the pulse ENC-A and the pulse ENC-B is equal to the slit interval of the linear scale 511, and the phases of the pulse ENC-A and the pulse ENC-B are deviated by 90 degrees, the rising edge of each pulse is increased. If a falling edge and a falling edge are detected and the number of the detected edges is counted, the count number “1” is calculated by
Corresponds to 1/4 of the slit interval of. Therefore, by multiplying the count number by 1/4 of the slit interval, the movement amount can be obtained from the position of the carriage 41 when the count number is "0". That is, the resolution of the linear encoder 51 in this case is 1/4 of the slit interval of the linear scale 511.

The velocity Vc of the carriage 41 is detected as follows. First, the pulse ENC-A or ENC-B
For, the rising edge or the falling edge is detected. On the other hand, the time interval between the edges of the pulses is counted by the timer counter. From this count value, the cycle T
(T = T1, T2, ...) Is required. When the slit spacing of the linear scale 511 is λ, the speed of the carriage can be sequentially obtained as λ / T. Further, the speed of the carriage 41 may be detected using both the pulse ENC-A and the pulse ENC-B. By detecting the rising edge and the falling edge of each pulse, the time interval between the edges corresponding to 1/4 of the slit interval of the linear scale 511 is counted by the timer counter. From this count value, the cycle T (T
= T1, T2, ...) is required. When the slit spacing of the linear scale 511 is λ, the carriage velocity Vc can be sequentially obtained as Vc = λ / (4T).

In the rotary encoder 52,
The linear encoder 51 is different in that the linear scale 511 of the linear encoder 51 is a rotating disk that rotates in accordance with the rotation of the paper feed roller 17A.
Is almost the same as.

=== Paper Feeding Sequence === FIG. 6 is a flowchart showing the paper feeding sequence. The control unit 60 executes this sequence. FIG. 7 is a diagram showing a positional relationship between each component and the paper when the paper is conveyed from the paper insertion port to the print start position. Note that FIG. 7 is a diagram of each component viewed from above, and the downward direction of the drawing is the paper feeding direction. Since the same reference numerals as those used in the above description are attached to the respective constituent elements, the description of the respective constituent elements will be omitted.

First, when a print instruction is given to the printer, rotation of the paper feed roller 13 is started (S101). The position of the first paper S is as shown in FIG. 7A. The rotational driving force of the paper feed roller 13 and the frictional resistance of the separation pad (not shown) prevent a plurality of paper sheets S from being fed at one time.

Next, the paper S is conveyed by the paper feed roller 13 in the paper feed direction (S102). The position of the paper S at this time is as shown in FIG. 7B. Since the circumferential length of the circumferential portion of the paper feed roller 13 is set longer than the transport distance to the PF motor 15, the printing medium can be transported to the PF motor 15 using this circumferential portion.

Next, the position of the front end of the paper S is detected by the paper detection sensor 53 (S103). That is, the paper S
The front end of the sheet S contacts the lever of the paper detection sensor 53 and the rotation of the lever is detected, whereby it is possible to detect that the front end of the paper S reaches the position of the paper detection sensor 53. The position of the paper S at this time is as shown in FIG. 7C.

Next, the inclination of the paper is corrected (S104).
The paper skew correction process will be described with reference to FIGS. 8 and 9. Note that FIG. 8 is a flow chart of paper skew correction.
Further, FIG. 9 is a diagram of the state of paper skew correction as viewed from the top. First, while the rotation of the paper feed roller 17A is stopped, the paper feed roller 13 is rotated in the forward direction (the rotation direction in which the paper is conveyed in the paper feed direction) to convey the paper S in the paper feed direction (S201). , FIG. 9A). Next, the paper S contacts the paper feed roller 17A (S202, FIG. 9B). Next, the paper feed roller 13 is further moved in the forward direction by a predetermined amount (S20).
3). At this time, since the paper feed roller 17A is in a stopped state, the paper S is not conveyed, so that slippage occurs between the paper feed roller 13 and the paper, and the leading end of the paper S becomes parallel to the paper feed roller 17A (see FIG. 9C). Next, the paper feed roller 13 is rotated in the reverse direction to separate the paper S from the paper feed roller 17A (S20).
4, FIG. 9D). Then, in order to convey the paper S, the rotation of the paper feed roller 17A is started. At this time, the paper feed roller 1
The paper feed roller 13 and the paper feed roller 17A are rotated in synchronization so that the paper feed amount by 3 and the paper feed amount by the paper feed roller 17A are the same (S205). By performing the above processing, the inclination of the paper can be corrected and the paper can be conveyed. The amount of rotation of the paper feed roller 13 in the above-described paper skew correction process is controlled based on the position of the leading edge of the paper detected by the paper detection sensor 53.

Next, from the state of FIG. 7D (FIG. 9D), it is set to convey the paper S up to the predetermined paper feed amount X.
The value of the counter (not shown) is set to X (S105), and PF is set.
The motor 15 is rotated to decrease the counter value based on the pulse signal from the rotary encoder 52 (S1
06), the PF motor 15 is driven until the predetermined paper feed amount X is fed (S108).

If the paper width sensor 54 detects the leading edge of the paper S (S107) while the paper S is being conveyed to the paper feed amount X (FIG. 7E), the remaining paper feed amount is changed to a predetermined value. The value of the counter is set so that the paper S is conveyed up to the paper feed amount Y of (S111). That is, the paper detection sensor 53
The carry amount set based on the detection result of (1) is changed based on the detection result of the paper width sensor 54. Then, the PF motor 15 is rotated, the value of the counter is reduced based on the pulse signal from the rotary encoder 52 (S112), and the PF motor 15 is driven until the paper feed amount Y is sent (S113, FIG. 7F). Note that FIG.
In F, since the paper width sensor 54 detects the edge of the paper,
The location of the carriage 41 has moved.

If the paper width sensor 54 cannot detect the leading edge of the paper S (S107), the paper feed amount X is directly maintained.
Continue to subtract the value of the counter. That is, when the paper width sensor 54 cannot detect the leading end of the paper S, the paper feed amount X set based on the detection result of the paper detection sensor 53 is conveyed (S108, FIG. 7F).

The position of the paper S when the paper S has been conveyed by the paper feed amount Y or the paper feed amount X as described above is called the "head position". By transporting the paper S from this indexing position by a predetermined transport amount, the paper S is transported to the position where printing is performed, and printing is started (S109).
That is, when the paper width sensor 54 detects the leading edge of the paper S, the paper S is conveyed to the printing position based on the detection result of the paper width sensor. On the other hand, when the paper width sensor 54 does not detect the leading edge of the paper S, the paper S is conveyed to the printing position based on the detection result of the paper detection sensor 53.

In the present embodiment, when the paper width sensor 54 detects the leading edge of the paper S, the setting of the paper feed amount set based on the detection result of the paper detection sensor 53 is changed, and the detection result of the paper width sensor 54 is changed. The paper feed amount is set based on.
As a result, in the present embodiment, the paper S is transported to the printing position with high positional accuracy.

Further, in this embodiment, when the paper width sensor 54 does not detect the leading edge of the paper S, the paper detection sensor 53
The paper conveyance is continued based on the detection result of. Therefore, even when the paper width sensor 54 does not detect the leading edge of the paper S, the printing operation can be continued without stopping the apparatus.

In particular, when the material to be printed is a transparent material such as OHP paper, when the material to be printed is colored like colored paper, or when dirt is attached to the material to be printed, In some cases, the paper width sensor 54 cannot detect the leading edge of the paper S, but in the present embodiment, the printing operation can be continued even in such a case. In addition, the paper width sensor 54 may not be able to detect the leading edge of the paper S when the paper width sensor 54 is out of order or when the light receiving portion of the paper width sensor is dirty. Even in this case, the printing operation can be continued.

=== Paper Width Sensor Abnormality Warning === If the cause of the paper width sensor 54 not being able to detect the leading edge of the printing medium is due to the paper width sensor 54 (sensor failure, dirt on the light receiving portion, etc.), Since there is something wrong with the device, it is necessary to warn the user of the abnormality. However, if the cause of the paper width sensor 54 not being able to detect the front end of the printing target is the printing target (for example, the printing target is OHP paper), it means that there is no abnormality in the apparatus. It is not necessary to warn the device of abnormalities. Therefore, in order to warn the user of the abnormality of the apparatus, it is necessary to determine whether the cause of the paper width sensor 54 not being able to detect the front end of the printing material is the printing material or the paper width sensor 54. .

FIG. 10 is a flow chart showing the abnormality detection processing of the paper width sensor 54. This abnormality detection processing is started when the user gives a command to the printer to perform the abnormality detection processing.

First, a paper (for example, white paper) that can be detected by the paper width sensor 54 is inserted into the paper insertion opening 11A (S30).
1). After that, to the position where the paper width sensor 54 can detect,
The paper is conveyed (S302). Then, it is determined whether the paper width sensor 54 can detect the presence of paper (S303).

If the paper width sensor 54 can detect the presence of paper, it is determined that the paper width sensor 54 has no abnormality (S304), and the user is informed that the paper width sensor 54 has no abnormality (S305). ).

If the paper width sensor 54 cannot detect the presence of the paper even though the paper width sensor can detect the paper, it is determined that the paper width sensor 54 has an abnormality (S).
311) and warns the user that the paper width sensor 54 is abnormal (S312). The user is warned by sound or screen display. The warning screen display may be performed on a display device provided in the printer, or may be performed on a display device (described later) connected to the computer main body.

According to the present embodiment, it is possible to determine whether the cause of the paper width sensor 54 not being able to detect the front end of the printing material is the printing material or the paper width sensor 54. When it is determined that the cause is the paper width sensor 54, a warning is given to the user, so that the user can know that the printer has a failure. However, as described above, the printing process can be continued even if the leading edge of the paper cannot be detected due to the abnormality in the paper width sensor 54.

=== Configuration of Computer System ==
= Next, regarding the embodiment of the computer system, the computer program, and the recording medium recording the computer program, which is an example of the embodiment according to the present invention,
A description will be given with reference to the drawings.

FIG. 11 is an explanatory diagram showing the external structure of the computer system. Computer system 100
0 is a computer main body 1102 and a display device 1104.
A printer 1106, an input device 1108, and a reading device 1110. Computer 1102
In the present embodiment, is housed in a mini-tower type housing, but is not limited to this. Display device 1104
In general, a CRT (CathodeRay Tube), a plasma display, a liquid crystal display device, or the like is used, but the invention is not limited to this. Printer 11
For 06, the printer described above is used.
The input device 1108 is the keyboard 110 in this embodiment.
8A and mouse 1108B are used, but are not limited thereto. In the present embodiment, the reading device 1110 includes flexible disk drive devices 1110A and C.
Although the D-ROM drive device 1110B is used, the D-ROM drive device 1110B is not limited to this.
Optical) Disk drive device and DVD (Digital Ve
Other types such as rsatile disk) may be used.

FIG. 12 is a block diagram showing the configuration of the computer system shown in FIG. An internal memory 1202 such as a RAM and a hard disk drive unit 1204 are housed in a housing accommodating the computer main body 1102.
An external memory such as is further provided. The computer program for controlling the operation of the printer described above is recorded on a flexible disk FD, a CD-ROM, or the like, which is a recording medium, and read by the reading device 1110. Also, the computer program may be downloaded to the computer system 1000 via a communication line such as the Internet.

In the above description, the printer 1
Reference numeral 106 denotes a computer main body 1102 and a display device 110.
4, an example in which the computer system is configured by being connected to the input device 1108 and the reading device 1110 has been described, but the present invention is not limited to this. For example, the computer system may include the computer main body 1102 and the printer 1106, and the computer system may not include any of the display device 1104, the input device 1108, and the reading device 1110. Further, for example, the printer 1106 may be the computer main body 110.
2, the display device 1104, the input device 1108, and the reading device 1110 may have a part of their respective functions or mechanisms. As an example, the printer 1106 includes an image processing unit that performs image processing, a display unit that performs various displays, and
It may be configured to have a recording medium attaching / detaching portion for attaching / detaching a recording medium on which image data taken by a digital camera or the like is recorded.

Further, in the above-mentioned embodiment, the computer program for controlling the printer may be loaded in the memory 65 of the control unit 60. And
The operation of the printer in the above-described embodiment may be achieved by the control unit 60 executing this computer program.

The computer system thus realized is superior to the conventional system as a whole system.

=== Other Embodiments === The printer and the like according to the present invention have been described above based on the one embodiment. However, the above embodiment is for facilitating the understanding of the present invention. However, the present invention is not intended to be limitedly interpreted. It goes without saying that the present invention can be modified and improved without departing from the spirit thereof and that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the printing apparatus according to the present invention.

<Regarding Paper Tilt Correction Processing> In the above-described embodiment, the paper tilt correction processing was performed. However, the paper skew correction process may not be performed. However, it goes without saying that the paper can be positioned with high accuracy by correcting the inclination of the paper.

<Paper Width Sensor> In the above-described embodiment, the paper width sensor 54 provided on the carriage is used to detect the leading edge of the paper on the downstream side of the paper detection sensor 53. However, it is not limited to this. For example, to detect the leading edge of the paper, the paper width sensor 54
A second paper detection sensor may be provided instead of the combined use of the above.

Further, in the above-described embodiment, the paper width sensor 5
No. 4 was in a state in which it continued to operate at all times. However, it is not limited to this. For example, when the paper is conveyed by a predetermined amount, and when the paper is conveyed to a predetermined position (for example, the paper reaches the paper feed roller 17A, the paper feed roller 1
Paper width sensor 54
May be set to start operating.

<Regarding Abnormality Detection Processing> In the above embodiment, the abnormality detection processing of the paper width sensor 54 was started by the user giving a command to the printer to perform the abnormality detection processing. However, it is not limited to this.

FIG. 13 is a flow chart showing another abnormality detecting process of the paper width sensor 54. Compared with the embodiment of FIG. 6, the step of first inputting information on the printing medium (S401)
And a step (S402, S) of determining whether or not to give a warning after the printing process is completed in a predetermined case.
403) is different. The description of the same steps as those in FIG. 6 will be omitted.

In this embodiment, there is a step of first inputting information on the printing medium (S401). The input information about the printing medium is used for setting the printing conditions in the printing process (S109) and the abnormality detection process (described later) of the paper width sensor 54. The input information about the printing medium is, for example, information about the type of paper, information indicating that the paper is OHP paper, and the like.

In the present embodiment, the paper width sensor 54
Does not detect the leading edge of the paper, the printing process (S1
After step 09) is completed, it is determined whether or not the paper has a property that can be detected by the paper width sensor 54 based on the information about the printing medium input in S401 (S402). If the printing target is of a type that is not detected by the paper width sensor 54, it is determined that the paper width sensor 54 has no abnormality. However, if the printing target is a type of paper that can be detected by the paper width sensor 54, it is determined that the paper width sensor 54 has an abnormality, and the user is warned that the paper width sensor 54 has an abnormality (S403). . The user is warned by sound or screen display. The warning screen display is
It may be performed on a display device provided in the printer or may be performed on a display device connected to the computer main body.

According to this embodiment, the abnormality of the paper width sensor can be automatically detected without the user giving a command to the printer to perform the abnormality detection processing.

[0079]

According to the printing apparatus of the present invention, even when the second sensor (for example, the paper width sensor 54) does not detect the front end of the object to be printed (for example, the paper S). The printing operation can be continued without stopping the apparatus.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an overall configuration of an inkjet printer of this embodiment.

FIG. 2 is a schematic diagram of the vicinity of the carriage of the inkjet printer of the present embodiment.

FIG. 3 is an explanatory diagram around a carrying unit of the inkjet printer according to the present embodiment.

FIG. 4 is an explanatory diagram of a configuration of a linear encoder.

FIG. 5 is a timing chart showing a waveform of an output signal of a linear encoder.

FIG. 6 is a flowchart showing a paper feeding sequence.

FIG. 7 is a diagram showing a positional relationship between each component and the paper when the paper is conveyed from the paper insertion opening to the print start position.

FIG. 8 is a flowchart of paper skew correction.

FIG. 9 is a diagram showing a state where the inclination of the paper is corrected as viewed from above.

FIG. 10 is a flowchart showing an abnormality detection process of the paper width sensor.

FIG. 11 is an explanatory diagram showing an external configuration of a computer system.

12 is a block diagram showing the configuration of the computer system shown in FIG.

FIG. 13 is a flowchart showing another abnormality detection process of the paper width sensor.

[Explanation of symbols]

10 Paper Conveying Unit 11A Paper Inserting Port 11B Roll Paper Inserting Port 13 Paper Feeding Roller 14 Platen 15 Paper Feed Motor (PF Motor) 16 Paper Feed Motor Driver (PF Motor Driver) 17A Paper Feed Roller 17B Paper Ejection Rollers 18A, 18B Free Roller 20 Ink Ejection Unit 21 Head 22 Head Driver 30 Cleaning Unit 31 Pump Device 32 Pump Motor 33 Pump Motor Driver 35 Capping Device 40 Carriage Unit 41 Carriage 42 Carriage Motor (CR Motor) 43 Carriage Motor Driver (CR Motor Driver) 44 Pulley 45 Timing Belt 46 Guide rail 50 Measuring instrument group 51 Linear encoder 511 Linear scale 512 Detector 512A Light emitting diode 512B Collimator lens 5 2C detection processing unit 512D photodiode 512E signal processing circuit 512F comparator 52 rotary encoder 53 paper detection sensor 54 the paper width sensor 60 control unit 61 CPU 62 Timer 63 interface unit 64 ASIC 65 memory 66 DC controller 67 host computer

Claims (15)

[Claims] 1. A first sensor for detecting the front end of the printing target, a transport mechanism for transporting the printing target toward a printing position, and the first sensor for detecting the front end of the printing target. And a second sensor for detecting the front end of the printing medium while the transportation mechanism is transporting the printing medium to the printing position. When the leading end of the printing target is detected, the transport mechanism transports the printing target to the printing position based on the detection result of the second sensor, and the second sensor moves the leading end of the printing target. When not detecting, the conveyance mechanism conveys the printing medium to the printing position based on the detection result of the first sensor. 2. The printing apparatus according to claim 1, wherein the second sensor is provided on a movable carriage. 3. The printing apparatus according to claim 1, wherein the second sensor detects a width of the printing medium. 4. The printing apparatus according to claim 1, wherein the second sensor is an optical sensor. 5. The printing apparatus according to claim 4, wherein the second sensor has a light emitting portion and a light receiving portion, and the light emitting portion irradiates the printing medium with light. The light receiving unit detects the light reflected by the printing medium. 6. The printing apparatus according to claim 1, wherein the second sensor starts operating when the transport mechanism transports the print medium to a predetermined position. . 7. The printing apparatus according to claim 1, wherein the first sensor is a mechanical sensor. 8. The printing apparatus according to claim 1, wherein the second sensor is more accurate than the first sensor in detecting the position of the tip of the printing medium. Is high. 9. The printing apparatus according to claim 1, wherein the first sensor detects a front end of the printing medium and then the second sensor detects the printing medium. The transport mechanism transports the printing medium based on the first sensor until the leading edge is detected. 10. The printing device according to claim 1, wherein the second sensor is provided when the printing medium has a property that can be detected by the second sensor. If does not detect the front end of the printing medium, a warning is issued. 11. The printing apparatus according to claim 10, wherein the printing object has a property that can be detected by the second sensor based on the input information of the printing object. The second sensor does not detect the front end of the printing object when determining whether the printing object has the property that the printing object has a property that can be detected by the second sensor. If it does, give a warning. 12. A first sensor for detecting the front end of the printing target, a transport mechanism for transporting the printing target toward a printing position, and the first sensor detecting the front end of the printing target. And a second sensor that detects the front end of the printing medium while the transportation mechanism is transporting the printing medium to the printing position, and the first sensor is a mechanical sensor. And the second sensor is provided on a movable carriage, the second sensor detects a width of the print target, and the second sensor detects light on the print target. An optical sensor having a light emitting portion that irradiates the printed material and a light receiving portion that detects the light reflected by the printing material, wherein the second sensor is more sensitive to the printing material than the first sensor. The detection of the position of the tip is highly accurate, and the first sensor is Until the second sensor detects the front end of the printing target after the front end of the printing target is detected, the transport mechanism transports the printing target based on the first sensor, When the second sensor detects the front end of the printing target, the transport mechanism transports the printing target to the printing position based on the detection result of the second sensor, When the sensor does not detect the front end of the printing medium, the conveyance mechanism conveys the printing medium to the printing position based on the detection result of the first sensor. Printing device. 13. A printing method for a printing apparatus comprising a first sensor, a transport mechanism and a second sensor, the first sensor detecting a front end of a printing medium, and the transport method. A mechanism for transporting the printing medium toward a printing position; and the second sensor, from the detection of the leading edge of the printing medium by the first sensor to the printing position, A step of detecting the tip of the printing medium while the transport mechanism is transporting the printing medium, and a step of detecting the tip of the printing medium by the second sensor,
The transport mechanism, based on the detection result of the second sensor,
A step of transporting the printing medium to the printing position; and when the second sensor does not detect the front end of the printing medium, the transport mechanism is based on the detection result of the first sensor. And a step of transporting the object to be printed to the printing position. 14. A first sensor for detecting the front end of the printing target, a transport mechanism for transporting the printing target toward a printing position, and the first sensor detecting the front end of the printing target. Then, the second sensor is attached to a printing device including a second sensor that detects the front end of the printing medium while the transportation mechanism is transporting the printing medium to the printing position. A function of transporting the print medium to the printing position by using the transport mechanism based on the detection result of the second sensor when the front end of the print medium is detected; Does not detect the front end of the printing medium, it realizes the function of conveying the printing medium to the printing position by using the conveyance mechanism based on the detection result of the first sensor. program. 15. A computer system comprising a computer main body and a printing device connectable to the computer main body, wherein the printing device comprises a first sensor for detecting a front end of an object to be printed and a printing position. A transport mechanism for transporting the print medium toward the direction toward the print position after the first sensor detects the front end of the print medium while the transport mechanism transports the print medium. A second sensor that detects the tip of the printing medium, and when the second sensor detects the tip of the printing medium, the transport mechanism is based on the detection result of the second sensor. When the second sensor does not detect the front end of the printing medium, the transportation mechanism conveys the printing medium to the printing position, and based on the detection result of the first sensor, , The material to be printed up to the printing position by using the transport mechanism Computer system, characterized in that the transport.