JP2007144980A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which can reduce printing time. <P>SOLUTION: A printer 1 comprises a recording head 34 to discharge ink from a plurality of ink discharge nozzles 35 to a printing medium P, a carriage 32 to scan the printing medium P conveyed to a printing region opposite to the recording head 34, carrier rollers 16 (14, 18) to convey the printing medium P fed to the printing region by every predetermined amount, a printing medium detection sensor 51 to detect the presence or absence of the printing medium P disposed upstream the recording head 34 in the printing medium P-conveying direction and on the carriage 32, and a control means 93 to shift the conveyance of the printing medium P by the carrier rollers 16 (14, 18) to a speed-reduced paper feed control according to a detected condition of the printing medium P by the printing medium detections sensor 51. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printer.

Patent Document 1 discloses an ink jet printer. This inkjet printer
Printing is performed by conveying a sheet by a pair of PF rollers or the like disposed slightly upstream of the recording head, and discharging ink onto the sheet by a recording head provided on a carriage. PF
A paper detector having a sensor body and a detector is provided between the paper feed roller disposed upstream of the roller pair and the PF roller pair.

JP 2003-72963 A (Embodiment of the Invention, FIG. 3, etc.)

In a printer as disclosed in Patent Document 1, for example, the following control may be performed in order to ensure print quality.

That is, when the paper conveyed by the PF roller pair leaves the PF roller pair, the paper is pushed out by the PF roller pair, and the paper feed amount of the paper may slightly increase or decrease.
If this phenomenon occurs, the image at the trailing edge of the paper is printed out of alignment, resulting in a reduction in print quality. Therefore, in the printer, a sensor as a paper detector is provided between the LD roller and the PF roller pair that feeds paper from the paper feed tray, and once the trailing edge of the paper is detected by this sensor, the paper is detected once. The paper feed amount is reduced every time or the paper feed speed is lowered to suppress the paper extrusion by the PF roller pair.

In addition to this, for example, it is desired that the paper is accurately fed to a printing area facing the recording head. If the paper feed position is deviated, the image will be shifted and printed accordingly. For this reason, in a normal printer, an LD roller that feeds paper from a paper feed tray and a PF
A sensor as a paper detector is provided between the pair of rollers, and when the trailing edge of the paper is detected by this sensor, the paper feed speed is decelerated while being managed by PID control, etc. The deviation is suppressed.

In the printer, since these controls are performed, for example, simply increasing the maximum paper feed speed cannot shorten the printing time of one sheet as expected.

  An object of the present invention is to obtain a printer that can shorten the printing time.

The printer according to the present invention is provided with a recording head for ejecting ink from a plurality of ink ejection nozzles to a print medium, a carriage for scanning the print medium conveyed to a print area facing the print head, and a print area. A transport roller that transports the fed print medium by a predetermined transport amount; a print medium detection sensor that is disposed on the carriage upstream of the recording head in the transport direction of the print medium and detects the presence or absence of the print medium; When the print medium detection sensor detects the presence or absence of the print medium, the one-time conveyance amount of the print medium by the conveyance roller is
And a control means for driving the transport roller by reducing it below a predetermined transport amount.

If this configuration is adopted, the print medium is conveyed by reducing the conveyance amount once when the print medium is no longer detected by the print medium detection sensor. Therefore, since the print medium is conveyed little by little, it is difficult to be pushed out by the elastic force of the conveyance roller when separated from the conveyance roller. Printing at the rear end of the print medium is difficult to shift. In addition, since the print medium is detected and decelerated by the print medium detection sensor provided on the carriage, for example, a sensor that detects the paper between the LD roller and the PF roller pair that feeds the paper from the paper feed tray, for example. As compared with the case where the deceleration control is started based on the sheet detection by the printer, the conveyance amount of the print medium by the deceleration control can be reduced. That is, the slow paper feed can be reduced and the printing time for one sheet can be shortened.

In the printer according to the invention, in addition to the configuration of the invention described above, the interval between the print medium detection position detected by the print medium detection sensor and the plurality of ink discharge nozzles of the recording head is at least the plurality of ink discharge nozzles. This is not less than the arrangement width in the print medium conveyance direction.

The amount of conveyance of the print medium by the conveyance roller during printing is usually equal to or less than the arrangement width of the plurality of ink ejection nozzles in the print medium conveyance direction, as long as there is no blank to be printed. Therefore, if this configuration is adopted, when the detection state of the print medium detection sensor during carriage scanning changes from the state with paper to the state without paper for the first time, it faces the plurality of ink ejection nozzles of the recording head. A print medium is disposed in the print area. The ink ejected from the plurality of ink ejection nozzles adheres to the print medium. Moreover, by adopting this configuration,
Since the detection of the printing medium controlled to be decelerated can be performed at the time of scanning for ink ejection control of the carriage, it is not necessary to separately perform this detection scanning, and the printing time is reduced by shortening the paper feeding period which has been decelerated. There is no loss of the shortening effect.

In the printer according to the invention, in addition to the configuration of the invention described above, the distance between the print medium detection position detected by the print medium detection sensor and the plurality of ink ejection nozzles of the recording head is at least a predetermined conveyance of the conveyance roller. If the light receiving element of the print medium detection sensor does not receive the reflected light from the print medium during scanning of the carriage when the control means discharges ink from the plurality of ink discharge nozzles to the print medium. The transport amount of the printing medium by the transport roller is reduced from a predetermined transport amount.

When this configuration is adopted, when the detection state of the print medium detection sensor during carriage scanning changes from the state with paper to the state without paper for the first time, the print area facing the plurality of ink ejection nozzles of the recording head A print medium is arranged on the screen. The ink ejected from the plurality of ink ejection nozzles adheres to the print medium. In addition, since the detection of the print medium subjected to the deceleration control is performed at the time of scanning for the ink ejection control of the carriage, it is not necessary to perform this detection scanning separately, and the printing is performed by shortening the paper feed period that is decelerated. There is no loss of time saving effect.

Another printer according to the present invention is provided with a recording head that discharges ink from a plurality of ink discharge nozzles to a printing medium, a carriage that scans the printing medium conveyed to a printing area facing the recording head, and printing A conveyance roller that conveys the medium to the print region, a print medium detection sensor that is disposed on the carriage upstream of the recording head in the conveyance direction of the print medium and detects the presence or absence of the print medium, and the print medium is detected by the print medium detection sensor And a control unit that, when detected, decelerates and stops the conveyance roller while managing the conveyance speed of the print medium by the conveyance roller.

If this configuration is adopted, the transport roller that transports the print medium to the print area is decelerated while the print medium transport speed is controlled when the print medium is detected by the print medium detection sensor provided on the carriage. Stop. The print medium is accurately fed without causing a large positional shift to the print area. Moreover, since the print medium is detected by a print medium detection sensor provided on the carriage and decelerated and stopped, the decelerated paper feed can be reduced.
The printing time for one sheet can be shortened.

Another printer according to the present invention includes a print medium detection sensor in addition to the above-described configuration of the invention.
An optical sensor having a light emitting element and a light receiving element that receives light reflected from the printing medium by the light emitting element, and the carriage is moved to a position where the light receiving element can receive the reflected light from the printing medium fed to the printing area. In the moving state, the control means starts conveying the printing medium to the printing area, and continuously drives the conveying roller until the light receiving element receives reflected light from the printing medium.

If this configuration is adopted, the print medium is quickly fed by continuous driving of the transport roller. On the other hand, for example, when the conveyance of the printing medium is started without setting the carriage to a position where the light receiving element can receive the reflected light, the light receiving element provided on the carriage is fed to the light receiving element in the middle of paper feeding. In order to receive the reflected light, the transport roller must be driven intermittently. In this manner, the print medium being fed can be detected by the print medium detection sensor provided on the carriage without reducing the paper feed speed of the print medium by the transport roller. The printing time for one sheet is shortened.

Still another printer according to the present invention is provided with a recording head that discharges ink from a plurality of ink discharge nozzles to a printing medium, and a carriage that scans the printing medium conveyed to a printing area facing the recording head; A conveyance roller that conveys the print medium, a print medium detection sensor that is disposed on the carriage upstream of the recording head in the conveyance direction of the print medium and detects the presence or absence of the print medium, and a detection state of the print medium detection sensor And a control means for shifting to a paper feed control in which the conveyance of the printing medium by the conveyance roller is decelerated.

If this configuration is adopted, the print medium is detected by a print medium detection sensor provided on the carriage, and the paper feed control is performed at a reduced speed. Therefore, for example, printing after deceleration is performed as compared with a case where this deceleration control is started based on detection of a sheet by a sensor that detects a sheet between an LD roller and a PF roller pair that supplies the sheet from a sheet feeding tray. The conveyance amount of the medium can be reduced. That is, it is possible to reduce the paper feeding that has been decelerated. For example, it is possible to maximize the effect of shortening the printing time of one sheet by increasing the maximum paper feeding speed.

In the printer according to the present invention, in addition to the components of the above-described invention, the print medium detection sensor has a resin main body in which the light emitting element and the light receiving element are arranged side by side. And the upstream surface of the resin body in the print medium transport direction is aligned with the upstream surface of the carriage in the print medium transport direction.

If this configuration is adopted, the light emitting element and the light receiving element are accurately arranged at predetermined positions of the carriage. In addition, for example, compared to a case where the light emitting element and the light receiving element are arranged in the conveyance direction of the print medium, the print medium detection position of the print medium by the print medium detection sensor and the plurality of ink ejections of the recording head are utilized. It is possible to secure the maximum distance from the printing area for ejecting ink from the nozzles. Further, since the print medium detection sensor does not jump out of the carriage, the print medium detection sensor does not hit various peripheral members arranged densely around the carriage when the carriage is scanned. Therefore, it is not necessary to change the design around the carriage in order to provide the print medium ejection sensor on the carriage.

Hereinafter, a printer according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, a sheet such as plain paper will be described as an example of the print medium.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a main mechanism configuration of a printer 1 according to Embodiment 1 of the present invention.
When the external I / F (interface) 41 receives print data, the printer 1 executes paper feed control and ink ejection control from the recording head 34 according to the print data, and the plain paper transported by the paper feed control. An image based on the print data is printed on the print medium.

In order to perform such printing, the printer 1 includes a print medium transport mechanism that transports the paper P placed on the paper feed tray 10 to the paper discharge tray 11, and a print position set on the transport path of the print medium. And an ink discharge mechanism for discharging ink. Hereinafter, the transport path of the paper P from the paper feed tray 10 to the paper discharge tray 11 is referred to as a print medium transport path, the paper feed tray 10 side is referred to as an upstream side in the print medium transport direction, and the paper discharge tray 11 side is transported as a print medium. It is called the direction downstream side.

The print medium transport mechanism that transports the paper P from the paper feed tray 10 to the paper discharge tray 11 is mainly used.
An LD (load) roller 14 as a kind of conveyance roller, a substantially flat sheet guide 15, a PF (paper feed) roller 16 as a kind of conveyance roller, a platen 17, a discharge roller 18 as a kind of conveyance roller, and the like. Have. The LD roller 14 is unitized as an automatic paper feed unit (ASF) 6 together with the paper feed tray 10.

The LD roller 14 is rotatably disposed with a rotation shaft 19 extending in a direction substantially perpendicular to the paper surface of FIG. As shown in FIG. 1, the LD roller 14 has a substantially D-shaped cross section in which one side portion of a disk is cut out. The LD roller 14 is disposed on the end of the paper feed tray 10 on the paper discharge side. Further, the paper feed tray 10 is disposed in an inclined posture in which the side on which the LD roller 14 is disposed is lowered from the opposite side. Note that a hopper 12, a separation member 13, and the like may be disposed at a position facing the LD roller 14.

The PF roller 16 is a substantially cylindrical roller. A driven roller 23 having a substantially cylindrical shape is disposed on the upper side of the PF roller 16. The PF roller 16 and the driven roller 23 are shown in FIG.
These are arranged so as to be rotatable about a direction substantially perpendicular to the paper surface as a rotation axis.

The platen 17 has a plurality of guide ribs 17a on its upper surface. The platen 17 is disposed such that the extending direction of the guide rib 17a is in the direction along the print medium conveying direction. Platen 1
7 is formed of a resin material different from the paper P, such as black. The platen 17 may be provided with an ink receiving member such as a sponge. The ink receiving member is disposed so as to be lower than the guide rib 17a.

The paper discharge roller 18 is a substantially cylindrical roller. A driven roller 24 having a substantially cylindrical shape is disposed above the paper discharge roller 18. The discharge roller 18 and the driven roller 24 are shown in FIG.
These are arranged so as to be rotatable about a direction substantially perpendicular to the paper surface as a rotation axis.

A sheet guide 15, a PF roller 16, a platen 17, and a paper discharge roller 1 in the print medium conveyance mechanism
8 are arranged in a line between the automatic paper feeding unit 6 and the paper discharge tray 11. An ink discharge mechanism is disposed above the print medium transport mechanism. The ink ejection mechanism is mainly
A carriage shaft 31, a carriage 32, an ink tank 33, a recording head 34, and the like are included.

The carriage shaft 31 is a cylindrical shaft member. The carriage shaft 31 is a PF roller 16
1 is disposed in a direction extending in a direction substantially perpendicular to the paper surface of FIG.

The carriage 32 is held by the carriage shaft 31 and is located above the platen 17. The carriage 32 is movable along the axial direction of the carriage shaft 31.

The ink tank 33 is a container that stores liquid ink, and is detachably disposed in a tank storage hole 32 a formed in the upper part of the carriage 32. The printer 1 generally uses 4 to 8 colors of ink. One ink tank 33 may store ink for one color or may store ink of a plurality of colors.

The recording head 34 has a plurality of ink discharge nozzles 35. Piezo elements (not shown) are disposed inside each ink discharge nozzle 35. The piezoelectric element is deformed when a predetermined voltage pulse is applied. Due to the deformation of the piezo element, the ink filled in the ink ejection nozzle 35 is ejected so as to be pushed out from the ink ejection nozzle 35.

The recording head 34 is disposed at a substantially central portion on the lower surface of the carriage 32 so as to face the platen 17. The plurality of ink ejection nozzles 35 of the recording head 34 are arranged in a direction for ejecting ink to the platen 17. The plurality of ink ejection nozzles 35 are arranged side by side, for example, in the print medium conveyance direction and the carriage 32 movement direction. A region between the plurality of ink discharge nozzles 35 and the platen 17 is a print region in which ink is attached to the paper P.

FIG. 2 is a diagram showing a main hardware configuration of a control system for controlling the printer mechanism of FIG. FIG. 3 is a block diagram showing a control configuration realized in the printer 1 of FIG. Printer 1
The control system includes an external I / F 41 to which the host computer 2 is connected, and a power button 42.

The external I / F 41 includes, for example, a USB (Universal Serial Bus) cable, a printer 1 cable, and a SCSI (Small Computer System).
(Interface) cable or the like, which has a connector (not shown) that can be connected. External I /
F41 receives print data from the host computer 2 via this connector. The external I / F 41 is a Bluetooth, wireless LAN (Local Area Network).
or the like) may be connected to the host computer 2 by wireless communication.

The power button 42 is, for example, a push button that contacts and separates two terminals according to button operations.

The external I / F 41 and the power button 42 are ASIC (Application Speed).
connected to a specific integrated circuit) 43. The ASIC 43 is a CPU (Central Processing Un) (not shown).
It: a computer having a central processing unit), a RAM (Random Access Memory), a programmable ROM (Read Only Memory), a timer, and the like, and a predetermined operation based on a program stored in the programmable ROM.

Further, the ASIC 43 includes an I / O (Input / Output: input / output) port, an ADC (Analog to Digital Converter), and a DAC (Di (Di) not shown).
(digital to Analog Converter). The I / O port is used for input / output of digital signals. The ADC samples the waveform of the input signal at a predetermined cycle. The DAC outputs a signal that changes to a level corresponding to a set value at a predetermined sampling period.

Connected to such an ASIC 43 is a PW (paper wide) sensor 51, a linear encoder 52, and a rotary encoder 53 as a print medium detection sensor for detecting the edge of a print medium such as paper for detecting the state of the printer 1. Is done. In addition to this, the ASIC 43 includes, for example, a PF sensor as a sensor for detecting the edge of a print medium such as a sheet between the LD roller 14 and the PF roller 16, a sheet P and a recording head 34 or a carriage 32. A PG (paper gap) sensor that detects a distance, a CDR (CD Recordable) tray sensor that detects a CDR tray on which a CDR is mounted, a CDR guide sensor, and the like may be connected.

FIG. 4 is a partially enlarged exploded perspective view of the PW sensor 51 and the carriage 32 in FIG.
FIG. 4 is a perspective view looking up at the lower surface of the carriage 32 from the platen 17 side. In FIG. 4, the paper P is transported from the upper left side of the paper toward the lower right direction. The carriage 32 is movable in a substantially lower left direction and upper right direction on the paper surface.

The PW sensor 51 includes a light emitting element 101, a light receiving element 102, a resin mold part, and a plurality of connection terminals 103. A plurality of connection terminals 103 are connected to a body-side connector 121 connected to an ASIC 43 described later, and a light reception signal that changes according to the amount of light received by the light receiving element 102 is transmitted via the connection terminals 103 to the ASIC 43. Is output.

The resin mold part is made of a resin material, and includes a resin main body 104, a pair of engaging parts 105, and a pair of leg parts 106. Resin body 104, a pair of engaging portions 105, and a pair of legs 1
06 is formed simultaneously by one molding. The resin main body 104 has a square substantially flat plate shape. The light emitting element 101 and the light receiving element 10 are formed in two concave portions in front of the resin main body 104.
2 are arranged side by side. The pair of engaging portions 105 are disposed so as to protrude in opposite directions from both side portions of the resin main body 104.

As described above, the light emitting element 101, the light receiving element 102, and the plurality of connection terminals 103 of the PW sensor 51 are integrated by utilizing molding using a resin material.
Accordingly, for example, the light emitting element 101, the light receiving element 102, and the plurality of connection terminals 10 are provided.
Compared with the case where the PW sensor 51 is formed by soldering 3 on the substrate, it is possible to expect an effect of extending the life of the sensor or improving the reliability of the sensor.

In addition, the connector portion constituted by the plurality of connection terminals 103 and the pair of leg portions 106 is disposed in a portion of the side portion of the resin main body 104 where the pair of engaging portions 105 are not formed. . Therefore, like the resin main body 104, the connector portion can be disposed along the carriage 32, and when the PW sensor 51 is attached to the carriage 32, the protrusion of the PW sensor 51 from the carriage 32 can be minimized. . The PW sensor 51 is connected to the carriage 32.
And the sheet P can be accommodated without any gap (gap). As a result, in order to provide the PW sensor 51 in the carriage 32, it is not necessary to change the design to widen the gap (gap) between the carriage 32 and the paper P or widen the gap between the carriage 32 and its peripheral members.

A recording head 34 is disposed at the center of the back surface of the carriage 32. In the posture illustrated in FIG. 5, a holder 110 having a fixed portion 111 and four protruding plates 112 is disposed at a corner portion in the upper right direction of the drawing. The PW sensor 51 has a pair of engaging portions 105 each having two pairs.
It is held by the holder 110 so as to enter between the protruding plates 112.

In the state held by the holder 110, the upstream surface of the PW sensor 51 in the printing medium conveyance direction is flush with the lower surface of the carriage 32 in the printing medium conveyance direction, as shown in FIG. Further, the light emitting element 101 and the light receiving element 102 of the PW sensor 51 are arranged in the scanning direction of the carriage 32 as shown in FIG.

By disposing the PW sensor 51 on the carriage 32 in this way, detection of the paper P on the print medium conveyance path where the light emitting element 101 of the PW sensor 51 emits light and the light receiving element 102 receives reflected light. The position (see FIG. 1) can be set to a position farthest from the printing area by making use of the size of the carriage 32 even though the PW sensor 51 is provided on the carriage 32. The interval (“A” in FIG. 1) between the detection position and the print area is equal to or larger than the width of the print area in the print medium conveyance direction. That is, the interval between the detection position and the print area is ensured to be equal to or larger than the width of the plurality of ink discharge nozzles 35 of the recording head 34 in the print medium conveyance direction.

Returning to the description of the configuration based on FIGS. As shown in FIG.
It has an elongated reflecting plate 52a and a reflective optical sensor 52b in which a light emitting element and a light receiving element are arranged side by side.

The elongated reflecting plate 52a is a reflecting plate 52a in which, for example, a white pattern and a black pattern are repeatedly printed along the longitudinal direction thereof. As shown in FIG. 1, the reflection plate 52 a is disposed on the side of the automatic paper feeding unit 6 of the carriage 32 so that the longitudinal direction thereof is in the direction along the carriage shaft 31.

As shown in FIG. 1, the reflective optical sensor 52b of the linear encoder 52 includes a carriage 3
2 is disposed on the side surface upstream of the print medium conveyance direction. The light emitting element irradiates light to the reflection plate 52a. The light receiving element receives the light reflected by the reflection plate 52a. The amount of light received by the light receiving element differs depending on whether the light is reflected by the white pattern on the reflection plate 52a or the black pattern. The light receiving element outputs to the ASIC 43 a light receiving signal that changes digitally according to the amount of received light.

The rotary encoder 53 includes a disk 53a and a transmissive optical sensor 53b in which a light emitting element and a light receiving element are arranged to face each other.

As shown in FIG. 1, the disk 53a has a plurality of slits 54c along its outer periphery. The disc 53 a is integrated with the PF roller 16. Thereby, the disk 53a is PF
It rotates with the roller 16.

As shown in FIG. 1, the transmissive optical sensor 53b of the rotary encoder 53 is disposed so that the outer periphery of the disc 53a is sandwiched between the light emitting element and the light receiving element. When the slit 54c is positioned between the light emitting element and the light receiving element, the light from the light emitting element is received by the light receiving element. When the disc 53a itself is located between the light emitting element and the light receiving element, the light of the light emitting element is blocked. The light receiving element outputs to the ASIC 43 a light receiving signal that changes digitally according to the amount of received light.

In addition, a recording head control circuit 61, a CR (carriage) motor driver 62, and a PF motor driver 64 are connected to the ASIC 43.

The recording head control circuit 61 is connected to a plurality of piezo elements disposed in the plurality of ink ejection nozzles 35 of the recording head 34. The recording head control circuit 61 applies a voltage to the plurality of piezo elements based on the ink ejection pattern data supplied from the ASIC 43.

The CR motor driver 62 rotates the CR motor 63 based on a control signal from the ASIC 43. The CR motor 63 is a DC motor, for example. The rotational speed of the DC motor is accelerated and decelerated by controlling the magnitude of the current flowing through it, for example. The CR motor 63 rotationally drives a rotating belt (not shown) to which the carriage 32 is fixed.

The PF motor driver 64 is driven to rotate based on a control signal from the ASIC 43. P
The F motor 65 is a DC motor, for example, and accelerates / decelerates, for example, by controlling the magnitude of the current flowing therethrough. The rotational driving force of the PF motor 65 is transmitted to the LD roller 14, the PF roller 16 and the paper discharge roller 18. The CR motor 63 and the PF motor 65 may be a pulse motor such as a stepping motor.

The drive transmission mechanism that transmits the rotational driving force of the PF motor 65 to the LD roller 14, the PF roller 16, and the paper discharge roller 18 is, for example, the peripheral speed of the rotating LD roller 14, the peripheral speed of the PF roller 16, and the paper discharge. The driving force is transmitted so that the circumferential speed of the roller 18 becomes substantially uniform. Further, the drive transmission mechanism transmits a driving force for the LD roller 14 so as to pause the rotation of the LD roller 14 every rotation. For example, the drive transmission mechanism may start a single rotation of the LD roller 14 by operating a lock lever (not shown) that locks the rotation of the gear that transmits the drive to the LD roller 14 with the carriage 32. Good.

In addition, a system bus 71 is connected to the ASIC 43. A CPU 72, ROM 73, RAM 74, timer 75, and the like that are separate from the ASIC 43 are connected to the system bus 71. The CPU 72, ROM 73, RAM 74, and timer 75 may be formed as separate chips or may be integrated into a single chip.

The timer 75 measures time. The timer 75 can set an elapsed time, a time, and the like. When the set time is reached, the timer 72 generates a timer interrupt.

The ROM 73 stores a firmware program 81 and various control data. The control data includes, for example, a paper feed table 82, a paper feed deceleration table 83, a normal one-time paper feed table 84, a decelerated one-time paper feed table 85, a paper discharge table 86, a carriage speed table 87, and the like. .

The paper feed table 82 and the paper feed deceleration table 83 are used for the paper P placed on the paper feed tray 10.
Is a table used for transport control of the paper P that transports to the printing area. The normal one-time paper feed table 84 and the decelerated one-time paper feed table 85 are tables used for control for transporting the paper P fed to the printing area by a predetermined amount each time ink ejection control is performed. is there. The paper discharge table 86 is a table used for transport control of the paper P that transports the paper P in the print area to the paper discharge tray 11. In these tables, a predetermined target speed curve of the PF motor 65 is stored as a plurality of discrete data.

The carriage speed table 87 is a table used for one scan of the carriage 32.
In the carriage speed table 87, a predetermined target speed curve of the CR motor 63 is stored as a plurality of discrete data.

The firmware program 81 and control data stored in the ROM 73 are stored in the printer 1.
May be stored in the ROM 73 before the shipment of the printer 1, or may be stored in the ROM 73 after the shipment of the printer 1. The firmware program 81 and control data stored in the ROM 73 after the shipment of the printer 1 are read from a computer-readable recording medium such as a CD-ROM or downloaded via a transmission medium such as an electric communication line. Anything is acceptable. Further, only part of the firmware program 81 and control data stored in the ROM 73 may be updated and stored after shipment of the printer 1.

The CPU 72 reads the firmware program 81 stored in the ROM 73 into the RAM 74 and executes it. Thus, as shown in FIG. 3, the printer 1 includes a stop determination unit 91, a next control determination unit 92, a transport control execution unit 93 as a control unit, an ink discharge control execution unit 94, an error control execution unit 95, and the like. Realized.

The stop determination unit 91 determines whether or not the printer 1 is in a stopped state. Specifically, for example, the stop determination unit 91 determines whether or not the light receiving element output from the rotary encoder 53 to the ASIC 43 and the light receiving signal output from the light receiving element of the linear encoder 52 to the ASIC 43 for a predetermined time. When there is no change (for example, several microseconds to several hundred milliseconds), it is determined that the printer 1 is in a stopped state.

The conveyance control execution unit 93 executes control for conveying the paper P. For example, the conveyance control execution unit 93 conveys the paper P placed on the paper feed tray 10 to the printing area, conveys the paper P in the printing area by a predetermined amount, or discharges the paper P in the printing area. Or conveyed to the tray 11.
Specifically, the conveyance control execution unit 93 includes, for example, a paper feed table 82 and a paper feed deceleration table 83.
Using the normal one-time paper feed table 84, the decelerated one-time paper feed table 85, the paper discharge table 86, etc., the PF is supplied via the DC unit 97 and the PF motor driver 64 implemented in the ASIC 43. The motor 65 is driven and controlled.

The DC unit 97 generates various signals to be output to the recording head control circuit 61, the CR motor driver 62, and the PF motor driver 64 using, for example, the DAC, I / O port, or the like of the ASIC 43. The DC unit 97 updates a signal to be output to the CR motor driver 62 and the PF motor driver 64 every predetermined short cycle (for example, several tens of microseconds).

The ink discharge control execution unit 94 executes ink discharge control for the paper P supplied to the printing area. Specifically, the ink discharge control execution unit 94 drives and controls the CR motor 63 via the DC unit 97 and the CR motor driver 62 using, for example, a carriage speed table 87. The ink discharge control execution unit 94 also outputs an ink discharge control signal for one scan of the carriage 32 from the recording head control circuit 61 via the DC unit 97.

The error control execution unit 95 executes control for eliminating the abnormal state of the printer 1. For example, when the paper feeding is not normally performed, the error control execution unit 95 continuously drives and controls the PF motor 65 for a predetermined time or more so as to discharge all the paper P on the paper transport path.

The next control determination unit 92 instructs the conveyance control execution unit 93, the ink discharge control execution unit 94, the error control execution unit 95, and the like to execute. When the process instructed to execute is completed, the next control determination unit 92 determines a process to be executed next, and instructs the control execution unit to execute the determined process. The next control determination unit 92 basically instructs one control execution unit to execute at a time. The next control determination unit 92 does not instruct execution to a plurality of control execution units at the same time.

  Next, the operation of the printer 1 according to the first embodiment having the above configuration will be described.

When the power button 42 of the printer 1 is operated, the ASIC 43 detects the power-on operation and activates the printer 1. Thus, as shown in FIG. 3, the printer 1 includes a DC unit 97, a stop determination unit 91, a next control determination unit 92, a conveyance control execution unit 93, an ink discharge control execution unit 94, an error control execution unit 95, and the like. Realized.

When the external I / F 41 receives print data from the host computer 2 connected thereto, the next control determination unit 92 of the printer 1 starts printing based on the print data.

The host computer 2 generates, for example, an image for printing a predetermined image on a predetermined paper P, converts the print image into an image for each ink color, performs halftone processing on each ink color image, Rasterize color halftone image. The host computer 2 uses the data after the rasterization process as print data to the printer 1
To send.

In addition to this, for example, the host computer 2 may transmit image data to be printed and printing conditions such as paper P and layout to the printer 1. In this case, in the printer 1, the ASIC 43 may generate print data after rasterization processing from the received image data and printing conditions.

FIG. 5 is a timing chart showing control from paper feeding to printing of the printer 1 according to the first embodiment.

When the next control determination unit 92 starts printing, it first determines whether or not the printer 1 is in a printable state. Specifically, for example, the next control determination unit 92 acquires detection information based on detection signals from the PW sensor 51, the linear encoder 52, the rotary encoder 53, and the like from the ASIC 43, and whether or not these detection information is normal. Judging.

If it is determined that the printer 1 is in a printable state, the next control determination unit 92 first instructs the ink discharge control unit 94 to execute, and moves the carriage 32 to a position where the PW sensor 51 can detect the paper P. Move. The DC unit 97 outputs a control signal to the CR motor 63, and the CR motor 63 rotates at a speed according to the control of the CR motor driver 62. C
The carriage 32 moves in a direction perpendicular to the paper surface of FIG. 1 by the rotational driving force of the R motor 63.

As shown in FIG. 4, the carriage 32 moves in a direction substantially perpendicular to the transport direction of the paper P.
The PW sensor 51 can detect the paper P if the paper P is transported to a position facing it. Therefore, the range indicated by the dotted arrow in FIG. 3 is the range in which the PW sensor 51 can detect the paper P. The ink discharge control unit 94 can set the PW at any position within this range.
The carriage 32 is moved so that the sensor 51 is positioned.

When the carriage 32 is moved so that the PW sensor 51 can detect the paper P, the next control determination unit 92 designates the paper feed table 82 and instructs the conveyance control execution unit 93 to execute it. The conveyance control execution unit 93 uses the paper supply table 82 to start paper supply control for conveying the paper P on the paper supply tray 10 to the printing area.

In the paper feed control using the paper feed table 82, the transport control execution unit 93 includes the PF motor 65.
Executes control to accelerate or decelerate the speed. Specifically, as indicated by the detection speed of the rotary encoder 53 during the paper feed control period in FIG.
The first acceleration control that accelerates the vehicle to the maximum control speed, the first constant speed control that maintains the maximum control speed, the deceleration control that decelerates from the maximum control speed to a predetermined low intermediate speed, and the intermediate speed that is maintained The second constant speed control to be performed, the second acceleration control to accelerate from the intermediate speed to the maximum control speed again, and the third constant speed control to maintain the maximum control speed are executed.

By this series of acceleration / deceleration control, the LD roller 14, the PF roller 16, and the paper discharge roller 18.
Rotates according to the rotation of the PF motor 65. In the second constant speed control, the gap cam 20 is separated from the nip portion 13c of the separating member 13, and the nip portion 13c
4 abuts. The speed of the second constant speed control is lower than the maximum control speed. Therefore, the opening operation sound of the hopper spring 12 generated when the nip portion 13c of the separating member 13 abuts against the LD roller 14 is, for example, compared with the case where the nip portion 13c abuts against the LD roller 14 at the maximum control speed. Get smaller. The user of the printer 1 does not feel uncomfortable with a loud sound.

Further, the sheet P on the sheet feeding tray 10 is brought into contact with the nip portion 13 c against the LD roller 14.
The front end portion is sandwiched between the nip portion 13 c and the LD roller 14. By the second constant speed control, the second acceleration control, and the third constant speed control, the paper P on the paper feed tray 10 is conveyed according to the rotation of the LD roller 14. The leading edge of the paper P is the PF roller 14 and the driven roller 2.
3 is nipped. Thereafter, when the LD roller 14 completes one rotation, the rotation is stopped. At this time, the nip portion 13 c is in contact with the gap cam 20 and is separated from the LD roller 14. The paper P is conveyed by the rotation of the PF roller 14.

The sheet P conveyed by the rotation of the PF roller 14 is conveyed toward the printing area according to the rotation of the PF roller 14. A PW sensor 51 is disposed between the PF roller 14 and the recording head 14. When the light from the light emitting element 101 is reflected by the paper P, the light receiving element 102 of the PW sensor 51 receives the light. The PW sensor 51 sends the detection signal “no paper”
Change from “with paper”.

After starting the third constant speed control based on the paper feed table 82, the transport control execution unit 93
The detection signal of the PW sensor 51 is monitored. When the detection signal of the PW sensor 51 changes from “no paper” to “paper present”, a predetermined constant pulse number is added to the cumulative pulse number of the rotary encoder 53 at the time of the change, Is determined as the start timing of the deceleration control by the paper feed deceleration table 83.

After determining the start timing, the conveyance control execution unit 93 reads the paper feed deceleration table 83 from the ROM 73. When the cumulative number of pulses of the rotary encoder 53 reaches the calculated cumulative number of pulses, the conveyance control execution unit 93 starts speed control by the paper feed deceleration table 83.
In the paper feed deceleration table 83, a target speed curve for decelerating the speed of the PF motor 65 stepwise and finally stopping is stored as a plurality of discrete data.

At the determined start timing, the conveyance control execution unit 93 uses the plurality of discrete pieces of data in the paper feed deceleration table 83 in order from the beginning, so that the detected rotational speed of the rotary encoder 53 follows the speed of the data. In addition, deceleration control by the sheet feeding deceleration table 83 is executed.
The rotational speed of the PF motor 65 is decelerated stepwise according to this control, and the detected rotational speed of the rotary encoder 53 also decreases stepwise following the speed change, and finally becomes the speed “0”. .

In this way, the conveyance control execution unit 93 executes the deceleration control that manages the speed on the basis of the leading edge detection timing of the paper P by the PW sensor 51. The paper P fed to the printing area is fed with high accuracy without causing a large positional shift.

When the above series of paper feed control by the transport control execution unit 93 is completed, the rotation of the PF roller 16 is stopped. The rotary encoder 53 stops outputting pulses. The stop determination unit 91
When it is determined that the paper feeding has been completed, execution is instructed to the ink ejection control unit 94, and the carriage 32 is returned to the home position. The home position of the carriage 32 is set, for example, on the left side of “the range in which the PW sensor 51 can detect the paper P” in FIG.

After returning the carriage 32 to the home position, the stop determination unit 91 confirms that the detection signal of the rotary encoder 53 does not change for a predetermined time, and determines that the printer 1 is in the stop state.

When the paper feed control by the paper feed control unit is completed and the stop determining unit 91 determines that the printer 1 is in the stopped state, the next control determining unit 92 determines whether the printer 1 is in a printable state, A control execution unit to be executed next is determined according to the determination.

For example, when it is determined that there is an abnormality in the printer 1 as in the case where the PW sensor 51 is in a state where there is no paper P even though the paper feed control is finished, the next control determination unit 92 causes the error control execution unit 95 to Instruct execution. For example, the error control execution unit 95 drives the PF motor 65 continuously for a predetermined time to discharge the paper P on the paper transport path to the paper discharge tray 11.

If it is determined that the printer 1 is in a printable state, the next control determination unit 92 designates first ink discharge pattern data in order to discharge ink onto the paper P fed to the print area,
The ink discharge control execution unit 94 is instructed to execute ink discharge control.

The ink ejection control execution unit 94 first reads the carriage speed table 87 from the ROM 73 and starts speed control by the carriage speed table 87. The carriage speed table 87 includes a plurality of discrete target speed curves in which the carriage 32 is accelerated stepwise to a predetermined speed and then controlled at a constant speed for a certain period, and then decelerated and stopped stepwise. Stored as data. The ink ejection control execution unit 94 grasps the moving speed of the carriage 32 from the detection pulse of the linear encoder 52 and controls the speed of the carriage 32 so that the detected speed follows the speed change in the carriage speed table 87.

Further, the ink discharge control execution unit 94 outputs a predetermined voltage from the print head control circuit 61 to the print head 34 based on the ink discharge pattern data during the period of constant speed control based on the carriage speed table 87. Let The ink ejection control execution unit 94 causes the recording head control circuit 61 to output a voltage according to the ink ejection pattern data. Recording head 3
The plurality of four ink ejection nozzles 35 eject ink according to an applied voltage. The ejected ink adheres to the leading edge of the opposing paper P.

When the first ink ejection control by the ink ejection control execution unit 94 is completed and the stop determination unit 91 determines that the printer 1 is stopped, the next control determination unit 92 confirms that the printer 1 is in a printable state. The normal one-time paper feed table 84 is designated, and the conveyance control execution unit 93 is designated.
To execute.

The transport control execution unit 93 executes control for transporting the paper P being fed to the printing area by a predetermined amount in accordance with a normal one-time paper feed table 84. As the PF motor 65 rotates, the PF roller 16 and the paper discharge roller 18 rotate. The paper P fed to the printing area is conveyed by a predetermined amount. Note that the transport amount of the paper P based on the normal one-time paper feed table 84 corresponds to, for example, the arrangement width of the plurality of ink discharge nozzles 35 formed in the recording head 34 in the print medium transport direction. That's fine.

When the sheet feeding control of the conveyance control execution unit 93 based on the normal one-time sheet feeding table 84 is completed and the stop determining unit 91 determines that the sheet is in the stopped state, the next control determining unit 92 determines the second ink. The ejection pattern data is designated, and the ink ejection control execution unit 94 is instructed to execute the ink ejection control. As in the case of the first ink discharge pattern data, the ink discharge control execution unit 94 drives the carriage 32 on the basis of the carriage speed table 87, and in accordance with the second ink discharge pattern data in a constant speed period. Ink is ejected from the ink ejection nozzle 35. Ink adheres to a portion facing the recording head 34 in the printing area of the paper P.

Thereafter, the next control determination unit 92 instructs the conveyance control execution unit 93 to execute one sheet feed control every time the ink discharge control execution unit 94 based on the ink discharge pattern data completes one scan of ink discharge control. In addition, every time one sheet feed control by the conveyance control execution unit 93 is completed, the ink discharge control execution unit 94 instructs the execution of the ink discharge control for one scan. As a result, an image is printed, for example, for each scanning width on the paper P fed to the printing area.

Further, when there is no unprocessed print data or printing for one page is completed, the next control determination unit 92 designates the paper discharge table 86 and the conveyance control execution unit 9.
3 is instructed to execute. The conveyance control execution unit 93 is based on the paper discharge table 86 and the PF motor 6.
5 is rotated for a predetermined time, and the paper P fed to the printing area is discharged to the paper discharge tray 11 by the paper discharge roller 18.

Further, when the next control determination unit 92 instructs the conveyance control execution unit 93 to perform the sheet conveyance control in which the normal one-time sheet feeding table 84 is designated, the PW in the immediately preceding ink discharge control period is used.
It is confirmed whether or not the detection signal of the sensor 51 is “no paper”. The light receiving element 102 of the PW sensor 51 does not receive the reflected light from the paper P of the light emitting element 101 when there is no paper P at the detection position. At this time, even if the carriage 32 is scanned, the detection signal of the PW sensor 51 is “
There is no change from “no paper” to “paper present” and remains “no paper”.

The detection signal of the PW sensor 51 is “no paper” in the immediately preceding ink discharge control period.
If so, the next control determination unit 92 designates the one-time paper feed table 85 that has been decelerated in place of the normal one-time paper feed table 84, and instructs the transport control execution unit 93 to perform the paper transport control. . The next control determination unit 92 starts the deceleration printing control. Deceleration printing control is a control in which the transport amount of paper P is reduced from the normal predetermined transport amount, and ink is ejected from only a part of the ink ejection nozzles 35 within the width of the reduced transport amount. It is. Thus, when the paper P is no longer detected by the PW sensor 51 during the ink ejection control period, the paper P is conveyed little by little, so that the paper P is separated from the PF roller 14 by the elastic force of the PF roller 14 or the like. It becomes difficult to be extruded. As a result, the printing of the rear end portion of the paper P becomes difficult to shift.

After instructing the conveyance control execution unit 93 to perform conveyance control designating the one-time decelerated paper feed table 85, the next control determining unit 92 only determines the width of the conveyance amount in the one-time decelerated paper feed table 85. Ink discharge pattern data for decelerating printing for discharging ink is generated. The next control determination unit 92 divides, for example, the ink discharge pattern data at the normal paper feed amount for each of the decelerated transport amounts, and generates a plurality of decelerated printing ink discharge pattern data having the divided pattern data. It only has to be generated. It should be noted that in the ink discharge pattern data for each deceleration printing, data for prohibiting ink discharge from the nozzles may be added to the data other than the divided pattern data. The next control determination unit 92 divides all unprocessed ink ejection pattern data, and generates a plurality of ink ejection pattern data for reduced-speed printing.

When the conveyance control execution unit 93 based on the decelerated one-time paper feed table 85 completes the conveyance control of the paper P, and the stop determination unit 91 determines that the sheet is stopped, the next control determination unit 92 generates The first ink discharge pattern data among the plurality of ink discharge pattern data for deceleration printing is designated, and execution is instructed to the ink discharge control execution unit 94.

The ink ejection control execution unit 94 is based on the carriage speed table 87 and the carriage 32.
In the constant speed period, ink is ejected from some of the plurality of ink ejection nozzles 35 based on the designated first ink ejection pattern data for decelerating printing.

Thereafter, the next control determination unit 92 performs one decelerated paper feed control based on the decelerated one paper feed table 85 each time ink ejection control for one scan based on the ink ejection pattern data for decelerated printing is completed. And instructing the execution of the ink ejection control for one scan based on the ink ejection pattern data for the decelerating printing every time the paper feeding control for one decelerated is completed. As a result, an image is printed on the paper P fed to the printing area, for example, for each transport amount by the paper feed table 85 once decelerated.

Further, when the ink ejection control for the number of generated ink ejection pattern data for deceleration printing is completed, the next control determination unit 92 designates the paper ejection table 86 and instructs the conveyance control execution unit 93 to perform the ejection. The conveyance control execution unit 93 rotates the PF motor 65 for a predetermined time based on the paper discharge table 86, and discharges the paper P fed to the printing area by the paper discharge roller 18.
To discharge.

As described above, in this embodiment, the PW sensor 51 provided in the carriage 32 is used for the paper P.
Is no longer detected, control is started to reduce the paper feed amount of the paper P once from a normal predetermined transport amount. Therefore, for example, the paper P between the LD roller 14 and the PF roller 16 is assumed.
As compared with the case where the deceleration control is started based on the detection of the sheet by the sensor for detecting the sheet speed, the decelerated sheet feed can be reduced.

In this embodiment, the carriage 32 is driven so that the PW sensor 51 provided on the carriage 32 can detect the paper P, and the paper feed deceleration table 83 is based on the paper detection of the PW sensor 51. Deceleration control based on is started. The paper P is accurately fed without causing a large positional shift to the printing area. Moreover, since the sheet P is decelerated and stopped after the PW sensor 51 provided on the carriage 32 detects the absence of the sheet, for example, the sheet P is detected by a sensor that detects the sheet P between the LD roller 14 and the PF roller 16. Based on the detection, the decelerated paper feed can be reduced as compared with the case where the deceleration control based on the sheet feeding deceleration table 83 is started. Even if, for example, the paper feeding is started without positioning the PW sensor 51, it is not necessary to drive the paper P intermittently in order to confirm the paper P by the PW sensor 51 during the paper feeding.

As a result, in the printer 1 of this embodiment, the speed reduction paper feeding period at the time of paper feeding and one paper feeding at a time is minimized, so that the effect of shortening the printing time of one sheet can be maximized. .

In this embodiment, the interval between the detection position of the paper P detected by the PW sensor 51 and the plurality of ink discharge nozzles 35 of the recording head 34 is the same as the plurality of ink discharge nozzles 35.
Is greater than or equal to the width in the print medium conveyance direction. The conveyance amount of the sheet P in the ink discharge control period is as follows:
As long as there is no blank space where printing is not performed, the width is usually equal to or smaller than the width of the plurality of ink discharge nozzles 35 in the print medium conveyance direction. Therefore, when the detection state of the PW sensor 51 changes from the presence of paper to the absence of paper, the paper P is always disposed in the print area of the recording head 34 facing the plurality of ink ejection nozzles 35. The ink ejected from the plurality of ink ejection nozzles 35 is
It adheres to the paper P. In addition, since the detection of the sheet P to be decelerated is performed during the scan for ink ejection control of the carriage 32, it is not necessary to separately perform this detection scan, and the decelerated sheet feeding period is shortened. The effect of shortening the printing time is not impaired.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes can be made without departing from the scope of the invention. is there.

For example, in the above embodiment, a sheet is conveyed and printed on this sheet. In addition, for example, as a print medium for ejecting ink, for example, a transparent film sheet, a CDR
Various media such as a disk medium such as a DVD and a metal plate such as an aluminum plate can be used.
A disk medium, a metal plate, or the like is not placed on the paper feed tray 10 but may be conveyed straight from the opening provided on the lower side of the paper feed tray 10 to the printing area. Further, the PW sensor 51 is not a reflection type optical type but may be a light passing type optical sensor by providing a light emitting part or a light receiving part on the platen 17 side, or may be a sensor other than the optical type.

For example, in the above embodiment, ink is ejected onto the paper. The printer 1 is an ink jet printer 1. In addition, for example, the printer 1 may be, for example, a laser printer, a photographic printer, a printing apparatus, or the like.

In the above embodiment, the paper feed at the rear end portion of the paper P is executed by the paper feed control in which the paper feed amount is reduced once. In addition, for example, the paper feed at the rear end portion of the paper P may be controlled by the same paper feed amount as usual.

FIG. 6 is a block diagram illustrating a control configuration realized in the printer 1 according to the modification of the first embodiment of the present invention. The ROM 73 of the printer 1 of the modification shown in FIG. 6 stores only a normal one-time paper feed table 84. The normal one-time paper feed table 84 controls the driving of the PF motor 65 so as to be equal to or less than the length of the interval between the detection position of the PW sensor 51 and the print area (“A” in FIG. 1). The ROM 73 does not store the paper feed table 85 once decelerated.

The conveyance control execution unit 121 realized by the CPU 72 of the printer 1 of the modification of FIG.
72 is realized by executing a firmware program stored in the ROM 73. The conveyance control execution unit 121 controls driving of the PF motor 65 and the CR motor 63 via the DC unit 97 and the like realized in the ASIC 43.

Further, the ink discharge control execution unit 122 includes the DC unit 97 and the recording head control circuit 6.
1, ink ejection from a plurality of ink ejection nozzles 35 of the recording head 34 is controlled. In particular, when the detection signal of the PW sensor 51 remains “no paper” during the period in which the carriage 32 is driven for ink ejection control, the ink ejection control execution unit 122 according to the third embodiment performs the next time. Mask setting for ink ejection control is performed. Further, when the mask setting is made, the ink discharge control execution unit 122 selects a part of the plurality of ink discharge nozzles 35 based on the mask setting (specifically, the ink discharge nozzles on the upstream side in the paper transport direction). 3
The ink from 5) is not ejected, that is, masked ink ejection pattern data is generated.

The configuration other than the configuration described above has the same function as the configuration of the same name in the first embodiment, and the same reference numerals as those in the first embodiment are given and the illustration and description thereof are omitted.

  Next, the operation of the modified printer 1 having the above configuration will be described.

The conveyance control execution unit 121 starts driving control of the PF motor 65 in order to convey the paper P on the paper feed tray 10 to the printing area after setting the PW sensor 51 to be located upstream of the printing area. After that, the detection signal of the PW sensor 51 is monitored. When the detection signal of the PW sensor 51 changes from “no paper” to “paper present” level, a predetermined constant pulse number is added to the cumulative pulse number of the rotary encoder 53 at the time of the change, and the cumulative pulse of the addition result is obtained. The timing that is a number is determined as the start timing of the deceleration control. After determining the start timing, the conveyance control execution unit 121 starts the deceleration control based on the sheet feeding deceleration table 83 stored in the ROM 73 and stops the PF motor 65. Thereby, the paper P on the paper feed tray 10 is accurately conveyed to the printing area. That is, the leading end portion of the paper P is supplied to the printing area facing the recording head 34.

The ink discharge control execution unit 122 executes ink discharge control for the paper P fed to the printing area, and the transport control execution unit 121 uses a normal one-time paper feed table 84 stored in the ROM 73. One paper feed control is repeatedly executed. When the detection signal of the PW sensor 51 during ink ejection control remains “no paper” for the first time, the ink ejection control execution unit 122 sets “2” as the mask setting value.

The mask setting value may be stored in the memory outside the ASIC 43, the RAM 74, or the like by the ink ejection control execution unit 122. Further, the mask setting value is reset to “0” by the conveyance control execution unit 121 when, for example, control for feeding a new sheet P to the printing region, and the detection signal of the PW sensor 51 during the ink ejection control is “sheet”. Every time it remains `` None ''
The ink discharge control execution unit 122 adds “1” by one.

FIG. 7 is an explanatory diagram showing an example of a paper feeding state when printing the rear end portion of the paper P in the printer 1 of the modified example of FIG. In FIG. 7A, the detection signal of the PW sensor 51 during ink ejection control by the ink ejection control execution unit 122 in the middle of the scanning direction of the carriage 32 changes from “no paper” to “
FIG. 7B shows a state in which the detection signal of the PW sensor 51 during ink ejection control by the ink ejection control execution unit 122 remains “no paper” for the first time. 7 (C) is a state in which the detection signal of the PW sensor 51 during ink ejection control remains “no paper” for the second time. In the state of FIG. 7B, the control unit 141 sets the mask setting value “2”.

As shown in FIGS. 7B and 7C, when the detection signal of the PW sensor 51 during the ink ejection control by the ink ejection control execution unit 122 remains “no paper”, the paper P is moved in the paper conveyance direction. The end portion passes the detection position by the PW sensor 51. In addition, the paper P is shown in FIG.
When changing from A) to (B) and when changing from FIG. 7 (B) to (C), a predetermined paper whose length is equal to or less than the length of the interval “A” between the detection position of the PW sensor 51 and the printing area It is conveyed by the feed amount.

When the ink ejection control for one scan is completed in the state of FIG.
Confirms that unprinted print data remains. If unprinted print data remains, the next control determination unit 92 instructs the transport control execution unit 121 to perform one paper feed control. The conveyance control execution unit 121 is a normal one-time paper feed table 84 stored in the ROM 73.
Is used to carry out a control for conveying the paper P by a predetermined amount.

Further, when the state changes to the state shown in FIG. 7C by one paper feed control, the ink discharge control execution unit 122 generates the next ink discharge pattern data based on the unprinted print data. At this time, the ink ejection control execution unit 122 refers to a mask setting value stored in a memory (not shown) of the ASIC 43, the RAM 74, or the like. When a value equal to or greater than “2” is set as the mask setting value, the ink discharge control execution unit 122 sets the ink discharge pattern in which the ink discharge of some or all of the plurality of ink discharge nozzles 35 is restricted. Generate data. Specifically, for example, the ink discharge control execution unit 122 prohibits ink discharge from the ink discharge nozzles 35 within a length range corresponding to the following formula 1. In the following formula 1, the paper feed amount is a normal paper feed amount, and A is the length of the interval between the detection position of the paper P by the PW sensor 51 and the print area.

  Range in which ink ejection is limited = paper feed amount x mask setting value -A (1)

When ink discharge pattern data that restricts ink discharge from the ink discharge nozzle 35 within the range of “paper feed amount × 2-A” is generated, the ink discharge control execution unit 122 starts ink discharge control for one scan. . The ink discharge control execution unit 122 supplies the generated ink discharge pattern data to the DC unit 97. The DC unit 97 accelerates the carriage 32 to a predetermined speed, and executes voltage application to a plurality of piezo elements based on the ink ejection pattern data when the carriage 32 enters the printing area in the middle of the scanning direction. Since the plurality of ink ejection nozzles 35 on the downstream side in the paper transport direction are not masked, ink is ejected based on the ink ejection pattern data. When the carriage 32 moves to the vicinity of the other end of the paper P, the DC unit 97 ends the voltage application to the plurality of piezoelectric elements based on the ink ejection pattern data, and stops the carriage 32.

The next control determination unit 92 checks whether or not unprinted print data remains each time ink ejection control for one scan is completed. If unprinted print data remains, the next control determination unit 92 instructs the transport control execution unit 121 to perform paper feed control with a normal paper feed amount. When the paper feed control by the conveyance control execution unit 121 is completed, the ink discharge control execution unit 122 generates the next ink discharge pattern data in which the ink discharge is limited based on the above equation 1 according to the instruction of the next control determination unit 92. Ink ejection control is started. The transport control execution unit 121 and the ink discharge control execution unit 122 basically alternately perform the paper feed control with the normal paper feed amount and the ink discharge control with the ink discharge restricted until there is no unprinted control data. Repeatedly.

Further, if there is no unprinted control data or the mask setting value is incremented by “1” every time the carriage 32 is scanned before there is no unprinted control data, and the result becomes a predetermined value or more, the next control judgment is made. The unit 92 instructs the transport control execution unit 121 to perform paper discharge control. The next control determination unit 92 instructs the conveyance control execution unit 121 to perform paper discharge control when the ink discharge restriction range calculated by, for example, Equation 1 is equal to or greater than the width of the print region in the paper feed direction. The conveyance control execution unit 121 rotates the PF motor 65 for a predetermined time, and discharges the paper P fed to the printing area to the paper discharge tray 11 by the paper discharge roller 18.

The operations of the printer 1 other than the operations described above are the same as those of the printer 1 according to the first embodiment, and a description thereof will be omitted.

As described above, in the printer 1 of this modified example, based on the detection of the presence or absence of the paper P by the PW sensor 51, the deceleration stop control in the paper feed control by the transport control execution unit 121, the normal at the rear end portion of the paper P Print control and paper discharge control are executed at the above speed. The conveyance control execution unit 121 and the ink discharge control execution unit 122 make use of the feature of the device configuration in which the detection position of the PW sensor 51 is located away from the printing area, and based on the paper detection of the PW sensor 51. Control that restricts ink ejection is executed without reducing the amount of paper transport during printing on the trailing edge of the paper P.

FIG. 8 is an explanatory diagram showing print control on the rear end portion of the paper P by the printer compared with the printer of the modified example of FIG. The printer of this comparative example has a PW sensor 131 disposed in the vicinity of the recording head 34 in the conveyance direction of the paper P. In the PW sensor 131 of this comparative example, the light emitting elements and the light receiving elements are arranged along the transport direction of the paper P. Therefore, in the printer of this comparative example, the interval “between the detection position of the PW sensor 131 and the print area”
The length of A ′ ”is shorter than the length of the interval“ A ”in the modified printer 1 and the paper feed amount in the normal paper feed control.

FIG. 8A shows that the detection signal of the PW sensor 131 during ink ejection control is “no paper”.
FIG. 8B shows a state in which the detection signal of the PW sensor 131 during the ink ejection control remains “no paper” for the first time, and FIG. In this state, the detection signal of the PW sensor 131 during ink ejection control remains “no paper” for the second time. In the state of FIG. 8B, the control unit sets the mask setting value “2”. FIG. 8 (C)
In this state, the control unit sets the mask setting value “3”.

When the ink ejection control in the state of FIG. 8A is completed, the conveyance control execution unit of the comparative example performs the paper feed control with the normal paper feed amount. Therefore, as shown in FIG. 8B, when the detection signal of the PW sensor 131 during ink ejection control remains “no paper” for the first time, the trailing edge of the paper P enters the printing area. There is a possibility.

In FIG. 8A, the PW sensor 131 does not detect the trailing edge of the paper P. Therefore, the ink discharge control execution unit of the comparative example executes normal ink discharge control in a state where the rear end portion of the paper P enters the printing area as shown in FIG. 8B. The plurality of ink ejection nozzles 35 eject ink between the rear end portion of the paper P in the printing area and the upstream side of the printing area in the paper conveyance direction. The ink ejected outside the paper P does not adhere to the paper P. The ink that does not adhere to the paper P becomes a mist that floats inside the printer 1 and contaminates the inside of the printer 1 and the paper P. In the case of the printer of this comparative example, the amount of ink discarded is large.

In the printer of this comparative example, when trying to reduce the amount of ink discarded in the state of FIG. 8B, the paper feed of the paper P when changing from the state of FIG. 8A to the state of FIG. The amount needs to be equal to or less than the length of the interval “A ′” between the detection position of the PW sensor 131 and the print area. If the paper feed amount per time is reduced in this way, the printing time per sheet P increases, and the printing throughput decreases.

Further, in the printer 1 of the modified example of FIG. 6, it is not necessary to reduce the paper feed amount of the paper P at the rear end portion of the paper P by restricting ink ejection by detecting the paper rear edge of the PW sensor 51. The printing speed per sheet P is as high as that for other printing (for example, printing with borders) even in the case of borderless printing. The maximum conveyance speed of the sheet can be increased so as to take advantage of the fact that the interval “A” between the detection position of the sheet P by the PW sensor 51 and the recording head is secured wider than before.

In the printer 1 of the modified example of FIG. 6, the length of the portion of the paper P that is transported at a reduced speed is controlled by controlling the paper feed with the paper feed amount reduced based on the presence / absence of the paper P detected by the PW sensor 51. It is possible to increase the number of printable sheets per unit time by making the most of the effect of shortening the length and increasing the maximum conveyance speed of the paper.

The present invention can be used in, for example, an ink jet printer that prints print data from a host computer.

1 is a configuration diagram illustrating a main mechanism configuration of a printer according to a first embodiment of the present invention. FIG. FIG. 2 is a diagram illustrating a main hardware configuration of a control system of the printer in FIG. 1. FIG. 2 is a block diagram illustrating a control configuration realized in the printer of FIG. 1. FIG. 2 is a partially enlarged exploded perspective view of a PW sensor and a carriage in FIG. 1. 2 is a timing chart showing control from paper feeding to printing of the printer of FIG. 1. FIG. 6 is a block diagram of a printer control system according to a modification of the embodiment. FIG. 7 is an explanatory diagram showing paper feeding at the rear end of the paper in the printer of FIG. FIG. 8 is an explanatory diagram showing paper feeding at the trailing edge of the paper in the comparative example of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer, 14 LD roller (a kind of conveyance roller), 16 PF roller (a kind of conveyance roller), 18 Paper discharge roller (a kind of conveyance roller), 32 Carriage, 34 Recording head, 35 Ink discharge nozzle, 51 PW sensor ( Print medium detection sensor), 93 transport control execution unit (control means), 101 light emitting element, 102 light receiving element, 104 resin body, P
Paper (print media)

Claims (7)

A recording head that discharges ink from a plurality of ink discharge nozzles to a printing medium, and a carriage that scans the printing medium conveyed to a printing area facing the recording head;
A transport roller for transporting the print medium fed to the print area by a predetermined transport amount;
A print medium detection sensor disposed on the carriage upstream of the recording head in the transport direction of the print medium and detecting the presence or absence of the print medium;
When the print medium detection sensor detects the presence / absence of the print medium, the conveyance roller is driven by reducing the one-time conveyance amount of the print medium by the conveyance roller from the predetermined conveyance amount. Control means;
A printer comprising: The interval between the print medium detection position detected by the print medium detection sensor and the plurality of ink discharge nozzles of the recording head is at least equal to or larger than the arrangement width of the plurality of ink discharge nozzles in the print medium conveyance direction. The printer according to claim 1. The interval between the print medium detection position detected by the print medium detection sensor and the plurality of ink ejection nozzles of the recording head is at least equal to or greater than the predetermined transport amount of the transport roller,
If the light receiving element of the print medium detection sensor does not receive the reflected light from the print medium during scanning of the carriage when discharging ink from a plurality of ink discharge nozzles to the print medium, The printer according to claim 1, wherein a single conveyance amount of the print medium by the conveyance roller is less than the predetermined conveyance amount. A recording head that discharges ink from a plurality of ink discharge nozzles to a printing medium, and a carriage that scans the printing medium conveyed to a printing area facing the recording head;
A transport roller for transporting the print medium to the print area;
A print medium detection sensor disposed on the carriage upstream of the recording head in the transport direction of the print medium and detecting the presence or absence of the print medium;
Control means for decelerating and stopping the transport roller while managing the transport speed of the print medium by the transport roller when the print medium is detected by the print medium detection sensor;
A printer comprising: The print medium detection sensor is an optical sensor having a light emitting element and a light receiving element that receives light reflected by the print medium of the light emitting element.
In a state where the carriage is moved to a position where the light receiving element can receive the reflected light from the printing medium fed to the printing area, the control means starts conveying the printing medium to the printing area. The printer according to claim 4, wherein the conveyance roller is continuously driven until the light receiving element receives reflected light from the printing medium. A recording head that discharges ink from a plurality of ink discharge nozzles to a print medium, and a carriage that scans the print medium that is conveyed to a print area facing the print head;
A transport roller for transporting the print medium;
A print medium detection sensor disposed on the carriage upstream of the recording head in the transport direction of the print medium and detecting the presence or absence of the print medium;
Control means for shifting to a paper feed control that decelerates the conveyance of the print medium by the conveyance roller according to the detection state of the print medium detection sensor;
A printer comprising: The print medium detection sensor has a resin main body in which a light emitting element and a light receiving element are arranged side by side, the light emitting element and the light receiving element are arranged in a scanning direction of the carriage, and a printing medium conveyance direction of the resin main body The printer according to any one of claims 1 to 6, wherein an upstream surface is arranged so as to be aligned with an upstream surface of the carriage in a print medium conveyance direction.

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