JP2009035012A - Printing apparatus having a plurality of print heads - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an art capable of coping with a malfunction of a constituent element related to print heads in a printing apparatus capable of mounting a plurality of the print heads. <P>SOLUTION: A plurality of the print heads 60 and driving control parts 330 each provided corresponding to a predetermined number of the print heads 60 of one or more can be mounted on a carriage 1. A plurality of data processing parts 320 for each transferring data to the driving control parts 330 can be mounted on a printing apparatus main body 300. A circuit set composed of a predetermined number of the print heads 60, a driving control part 330, and a data processing part 320 is configured so as to be attachable and detachable arbitrarily by a set each. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing apparatus that performs printing by ejecting ink from a print head.

  In recent years, so-called inkjet printers have become widespread as computer output devices. Recently, printers have been proposed that use a large number of print heads to print large-sized printed materials such as A1 and A0 plates at high speed.

  However, in a printing apparatus having a large number of print heads, there is a problem that it is not easy to solve the problems when some of the print heads and components such as the drive control circuit thereof are defective. Further, when a large number of print heads are provided, there is a problem of how various signals are transmitted between the printer main body and the drive circuit of each print head.

  The present invention has been made in order to solve the above-described conventional problems, and provides a technique capable of easily dealing with a malfunction of a component related to a print head in a printing apparatus capable of mounting a large number of print heads. For the purpose.

  In order to achieve the above object, a printing apparatus of the present invention is a printing apparatus that performs printing by ejecting ink from a printing head, and each of the printing apparatus includes a plurality of printing heads and one or more predetermined number of printing heads. Correspondingly provided, a plurality of drive control units for driving the predetermined number of print heads and a plurality of data processing units for respectively transferring data to the plurality of drive control units can be mounted. The circuit set including the predetermined number of print heads, one drive control unit, and one data processing unit can be arbitrarily attached and detached one by one.

  In this printing apparatus, a predetermined number of print heads, data processing units, and drive control units can be attached and detached as one circuit set. Therefore, when a problem occurs in the circuit set, for example, it can be easily replaced by replacing the circuit set with a new one. Can deal with defects.

  In the printing apparatus, a circuit set selected from a plurality of different circuit sets can be attached and detached as a circuit set composed of the predetermined number of print heads, one drive control unit, and one data processing unit. There may be.

  According to this configuration, since a circuit set can be arbitrarily selected from a plurality of types of circuit sets, it is possible to easily construct a printing apparatus according to a user's request.

  The print head and the drive control unit may be mounted on a carriage that moves when printing is performed.

  According to this configuration, since the wiring connecting the print head and the drive control unit is on the carriage, the amount of wiring connecting the carriage and the main body of the printing apparatus can be reduced.

  The plurality of data processing units are mounted on a main body of the printing apparatus, and the corresponding data processing unit and the drive control unit are configured to transmit a clock signal line for transmitting a clock signal and a flag signal for transmitting a flag signal. The flag signal line and a serial data signal line for serially transmitting data are connected by a flexible cable, and the data processing unit and the drive control unit are connected via the flexible cable (i ) Drive signal waveform data representing a drive signal waveform for driving the print head, (ii) a print timing signal for notifying the timing of ink discharge, and (iii) a print signal indicating the ink discharge state from each nozzle. Can be selectively transmitted from the data control unit to the drive control unit.

  This printing device can transmit drive signal waveform data, print timing signals, and print signals via flexible cables according to the respective timings, so it is necessary to operate a large number of print heads with a small number of signal lines. It is possible to transmit a proper signal appropriately.

  The print timing signal is preferably transmitted from the data processing unit to the drive control unit every time each nozzle of one nozzle group provided in one print head ejects one pixel of ink. .

  According to this configuration, since printing can be performed at an appropriate timing for each nozzle group, even when a large number of print heads are used, it is possible to execute good printing with little dot misalignment. Is possible.

  In the above configuration, it is preferable that a print signal indicating an ink discharge state from each nozzle of the nozzle group is transmitted from the data processing unit to the drive control unit following the print timing signal related to one nozzle group.

  According to this configuration, a print signal can be supplied to each nozzle in accordance with an appropriate print timing.

  The flexible cable includes only the clock signal line, the flag signal line, and the serial data signal line as signal lines for transmitting a change in signal level between the data processing unit and the drive control unit. preferable.

  According to this configuration, the size of the flexible cable can be reduced, and its routing is facilitated.

  Each of the clock signal line, the flag signal line, and the serial data signal line is preferably configured as a signal line pair that transmits each signal in a differential manner.

  According to this configuration, it is possible to transmit a signal at high speed.

  The data processing unit and the drive control unit are arranged in an ink tank provided on the carriage when the carriage is in one of two non-printable ranges at both ends of the carriage movable range. It is also possible to communicate information related to the amount of ink.

  According to this configuration, since the communication of the print signal is not performed in the non-printable range, the ink amount can be communicated without hindering the printing operation.

  A head suction unit for sucking ink from one print head and cleaning the nozzles of the print head may be arbitrarily detachable one by one.

  According to this configuration, only the necessary number of head suction units can be mounted.

  The present invention can be realized in various forms, for example, a printing method and a printing apparatus, a printing control method and a printing control apparatus, a computer program for realizing the functions of the method or the apparatus, The present invention can be realized in the form of a recording medium that records a computer program, a data signal that includes the computer program and is embodied in a carrier wave, and the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Overall configuration of the device:
B. Bi-directional communication configuration and operation:
C. Ink amount related information communication:
D. Variations:

A. Overall configuration of the device:
FIG. 1 is a perspective view schematically showing a configuration of a printer 200 as an embodiment of the present invention. The printer 200 is a printer corresponding to a relatively large printing paper P such as JIS standard A row 0 paper, B row 0 paper, or roll paper. The printing paper P is supplied from the paper feeding unit 210 to the printing unit 220. The printing unit 220 performs printing by ejecting ink onto the supplied printing paper P. The printing paper P printed by the printing unit 220 is discharged to the paper discharge unit 230.

  The paper feeding unit 210 includes a roll paper holder 211 on which roll paper as the printing paper P can be set. The roll paper holder 211 includes a spindle 212 that holds the roll paper, and a first spindle receiver 213 and a second spindle receiver 214 on which the spindle 212 can be attached / detached and suspended. The two spindle receivers 213 and 214 are respectively provided on two support pillars 215 provided on the upper part of the printer 200. Both ends of the spindle 212 are mounted on the first spindle receiver 213 and the second spindle receiver 214 after the roll paper is mounted in the center.

  The paper discharge unit 230 includes a take-up holder 231 capable of taking up roll paper. The take-up holder 231 includes a spindle 232 that takes up the roll paper printed by the printing unit 220, and a first spindle receiver 233 and a second spindle receiver 234 that allow the spindle 232 to be attached and detached and suspended. The two spindle receivers 233 and 234 are respectively provided on two support columns 235 provided at the lower part of the printer 200. Both ends of the spindle 232 are mounted on the first spindle receiver 233 and the second spindle receiver 234, and can be rotated by a driving means (not shown). The spindle 212 may be rotated by driving means to wind up the printing paper P. Further, as will be described later, a paper feeding unit such as a paper discharge roller may be provided in the printing unit 220, and the printing paper P may be discharged by driving the paper feeding unit.

  On the upper surface of the printing unit 220, an input / output unit 240 including a key capable of inputting a print mode or the like and a display unit is provided.

  FIG. 2 is an explanatory diagram illustrating the configuration of the printing unit 220. The printing unit 220 includes a carriage 1 on which a plurality of print heads (described later) are installed. A plurality of sub-tank sets 3S for temporarily storing ink used by the print head are mounted on the carriage 1. The carriage 1 is connected to a drive belt 101 driven by a carriage motor 100, and can be moved along the main scanning direction MS by being guided by a main scanning guide member 102. A first inspection unit 10A and a second inspection unit 10B that perform nozzle discharge inspection are provided at both ends of the printing paper P in the movement range of the carriage 1 in the main scanning direction. Next to the second inspection unit 10B, there are provided a wiper unit 30 for wiping the nozzles, a cap unit 20 for sealing the nozzle group for cleaning, and a main tank 9 for supplying ink to the sub tank set 3S. It has been.

  When printing is performed, the carriage 1 performs printing by ejecting ink from the nozzles onto the printing paper P while moving in the main scanning direction. When performing a nozzle ejection test, the carriage 1 moves to a position facing the first inspection unit 10A or the second inspection unit 10B and performs a nozzle ejection test. When performing nozzle wiping, the carriage 1 moves to a position facing the wiper unit 30 to perform nozzle wiping. When performing cleaning using the cap 21, the carriage 1 moves to a position facing the cap portion 20 to clean the nozzle.

  The sub tank set 3 </ b> S and the main tank 9 are connected by an ink supply path 103. In this embodiment, there are six types of ink sub-tanks 3a to 3f of black K, cyan C, light cyan LC, magenta M, light magenta LM, and yellow Y. These six sub tanks 3a to 3f are connected to the corresponding six main tanks 9a to 9f, respectively. However, the number of usable inks is not limited to six, and four types of ink (for example, black K, cyan C, magenta M, yellow Y) and seven types of ink (for example, black K, light black LK, cyan C). , Light cyan LC, magenta M, light magenta LM, yellow Y) can also be used.

  FIG. 3 is an explanatory diagram showing the arrangement of nozzles on the lower surface of one print head 60. The print head 60 has six nozzle groups 60a to 60f. In this embodiment, different ink is assigned to each nozzle group, but the same ink may be ejected from a plurality of nozzle groups.

  The light emitting unit 11 and the light receiving unit 12 constitute an inspection unit 13 for performing an inspection (hereinafter referred to as “ejection inspection”) as to whether or not ink is normally ejected from each nozzle. A plurality of such inspection units are provided in each of the first inspection unit 10A and the second inspection unit 10B. Note that these inspection units 10A and 10B may be omitted.

  FIG. 4 is an explanatory diagram for explaining the outline of the carriage 1. In this embodiment, a large number of print heads 60 are arranged on the carriage 1. As a result, it is possible to print a relatively wide area at a time, and printing can be performed at high speed even when a relatively large printing paper is used. Each print head 60 can be replaced independently.

  FIG. 5 is an explanatory diagram for explaining the outline of the sub tank 3 mounted on the carriage 1. On the carriage 1, one sub tank set 3 </ b> S is arranged for each print head 60. In this embodiment, since all the sub tank sets 3S cannot be two-dimensionally arranged on the carriage 1, each sub tank set 3S is divided into two stages of sub tank plates 1A and 1B provided on the carriage 1. It is installed. Note that the number of plates is not limited to two, and one plate or three or more plates may be provided according to the number of sub-tanks 3.

  FIG. 6 is a partial cross-sectional view of the printing unit 220 including the carriage 1. The printing paper P supplied from the paper feeding unit 210 (FIG. 1) passes through a conveyance path provided from the rear upper part (upper right in FIG. 6) to the front lower part (lower left in FIG. 6) of the printer 200 to the paper discharging part 230. Discharged.

  On the printing paper conveyance path, in order from the paper feeding unit 210 side, a paper feeding guide 105, a paper feeding roller 106, and a driven roller 107 disposed facing the paper feeding roller 106 are provided to be inclined. A printing stage 108, a carriage 1 disposed so as to face the printing stage 108, a paper discharge guide 109, and a paper discharge roller 110 disposed so as to face the paper discharge guide 109 are provided.

  The paper feed guide 105, the printing stage 108, and the paper discharge guide 109 are each formed flat and act as a printing paper conveyance surface. Therefore, since the printing paper P is conveyed in a flat state, even when a relatively large paper is used, it is possible to prevent the printing paper P from being undulated and disturbing the printed image.

  A plurality of subtanks 3 are mounted on the two-stage subtank plates 1A and 1B on the carriage 1, respectively. Each sub tank 3 has a valve 4. The print head 60 and the sub tank 3 are connected by an ink supply path 5 that passes through a valve 4. In this embodiment, since one print head 60 has six nozzle groups, six sub tanks 3 a to 3 f (FIG. 2) are connected to one print head 60. For the six nozzle groups of one print head 60, the supply of ink can be stopped individually by opening and closing the valve 4 as appropriate.

  The installation position of each sub tank 3 is set such that the relationship between the height of the sub tank 3 and the height of the corresponding print head 60 is substantially constant regardless of the position of the print head 60. By doing so, the difference in water head difference between the sub tank 3 and the print head 60 can be reduced. Therefore, the difference in ink ejection amount due to the difference in water head difference can be reduced, and uniform print image quality can be obtained. Further, the installation position of each sub tank 3 may be finely adjusted. Even when the ink discharge amount of the print head varies, it is possible to adjust the water head difference by adjusting the installation position of the sub-tank 3 to adjust the ink discharge amount.

B. Bi-directional communication configuration and operation:
FIG. 7 is a block diagram illustrating a circuit configuration related to bidirectional communication between the printer main body 300 and the carriage 1. In this specification, the “printer main body” means a portion of the various components of the printer 200 that does not move while being installed at the installation location.

  The printer main body 300 includes one main control unit 310 and a plurality of data processing units 320 respectively corresponding to the plurality of print heads 60 on the carriage 1. The carriage 1 is provided with a plurality of drive control units 330 corresponding to the plurality of print heads 60, respectively. The corresponding data processing unit 320 and the drive control unit 330 are connected by a single flexible cable 340. In the present embodiment, as shown in FIG. 4, since 17 print heads 60 are provided, 17 flexible cables 340 are disposed between the printer main body 300 and the carriage 1. In place of the flexible cable 340, a twisted pair cable or a shielded cable can be used.

  The main control unit 310 is a control circuit that controls the entire printer. The data processing unit 320 is a control circuit for performing bidirectional communication between the printer main body 300 and the carriage 1. The drive control unit 330 is a control circuit for performing bidirectional communication with the data processing unit 320 and performing control for causing the print head 60 to eject ink.

  In the present embodiment, one print head 60, one drive control unit 330, and one data processing unit 320 constitute one circuit set, and this circuit set can be attached and detached arbitrarily one by one. it can. Therefore, for example, even when a problem occurs in some of the print heads 60, the drive control unit 330, the data processing unit 320, etc., it is not necessary to repair all the circuit sets on the carriage. There is an advantage that it only needs to be replaced. Note that the number of print heads 60 constituting one circuit set can be set to an arbitrary predetermined number of 1 or more. For example, one circuit set may be configured by three print heads 60, one drive control unit 330, and one data processing unit 320.

  In addition, as the circuit set, it is preferable that the circuit set is configured so that a circuit set can be arbitrarily selected from a plurality of types of sets having at least some different configurations. For example, a plurality of types of circuit sets having different numbers of print heads 60 constituting one circuit set may be selected. In this way, it is possible to easily construct a printing apparatus according to the user's request.

  FIG. 8 is a block diagram showing the internal configuration of the data processing unit 320 and the drive control unit 330. The data processing unit 320 includes a control circuit 400, a differential driver 410, an SRAM 420, and an interface 430. The control circuit 400 is configured as a gate array, and includes a data latch 402, a waveform selection latch 404, and a counter 406 therein.

  The drive control unit 330 includes a control circuit 500, a differential driver 510, an SRAM 520, an interface 530, and a drive signal generation circuit 540. The control circuit 500 includes a PTS pulse generation circuit 502 and a mask signal generation circuit 504. The control circuit 500 also has latches and counters similar to the control circuit 400 on the main body side, but is not shown.

  The control circuit 400 and the differential driver 410 constitute a transmission / reception unit (data processing unit) on the main body side. The control circuit 500 and the differential driver 510 constitute a transmission / reception unit (drive control unit) on the carriage side. The PTS pulse generation circuit 502, the mask signal generation circuit 504, and the drive signal generation circuit 540 constitute a head drive control unit.

  A flexible cable 340 connected between the interfaces 430 and 530 transmits a clock signal line for transmitting the clock signal SCLK, a flag signal line pair for transmitting the flag signal FLG, and serially transmitting data DATA. A serial signal line pair. Note that in this specification, the same reference numerals are used as the reference numerals indicating signals and the signal lines (or signal line pairs).

  In this embodiment, the flexible cable 340 only includes a ground wiring (not shown) in addition to the above-described three types of signal line pairs SCLK, FLG, and DATA. In general, power supply wiring such as ground wiring is not a signal line for transmitting a change in signal level. That is, the flexible cable 340 includes only three types of signal line pairs SCLK, FLG, and DATA as signal lines for transmitting a change in signal level, so that the size of the flexible cable 340 itself is kept small. . As described above, in the printer of this embodiment, the 17 flexible cables 340 are provided corresponding to the 17 print heads 60. Therefore, as the size of each flexible cable 340 increases, the main body 300 and the carriage 1 are increased. A large space is required to arrange signal lines between the two. In this embodiment, by limiting the number of signal lines constituting each flexible cable 340 to as few as possible, the space required for cable routing is reduced, and as a result, the size of the printer itself is also reduced.

  The nozzle groups 60a to 60f of the print head 60 drive the drive elements of the nozzles in accordance with the common drive signal COM supplied from the drive signal generation circuit 540 and the mask signal MSK supplied from the mask signal generation circuit 504. Driver circuits 61a to 61f are provided. The function of these circuits will be described later. Note that the mask signal generation circuit 504 may be provided not in the control circuit 500 but in each of the driver circuits 61a to 61f of each nozzle group.

  FIG. 9 is a block diagram showing the internal configuration of the differential drivers 410 and 510. The differential driver 410 on the main body side includes first and second three-state buffers 411 and 412, a differential amplifier 413, and first and second inverters (knot circuits) 414 and 415. . The carriage-side differential driver 510 also has the same configuration.

  The first and second three-state buffers 411 and 412 are transmission and reception buffer circuits, respectively. A switch signal SW is supplied from the control circuit 400 to the control terminal of the first three-state buffer 411, and the switch signal SW is inverted by the inverter 414 to the control terminal of the second three-state buffer 412. A signal is being supplied. Accordingly, the differential driver 410 is set to either the transmission state or the reception state according to the level of the switch signal SW.

  Data Dout transmitted from the control circuit 400 on the main body side to the control circuit 500 on the carriage side is first input to the input terminal of the first three-state buffer 411. The output of the first three-state buffer 411 and the inverted output obtained by inverting this by the inverter 415 are transmitted to the differential driver 510 on the carriage side through two signal lines 416 and 417. The two signal lines 416 and 417 constitute a serial data signal line pair DATA for data transmission. Two input terminals of the differential amplifier 413 are connected to the serial data signal line pair DATA. The output of the differential amplifier 413 is supplied to the second three-state buffer 412. Data Din transmitted from the carriage-side control circuit 500 to the main body-side control circuit 400 is supplied to the control circuit 400 via the second three-state buffer 412.

  As shown in the lower part of FIG. 9, the data signal transmitted via the serial data signal line pair DATA is a signal having waveforms inverted from each other, and is transmitted in a so-called differential method. Thus, by transmitting a signal by a differential method, it is possible to transmit a signal at high speed while reducing transmission errors. The differential driver 410 includes circuit elements for transmitting the clock signal CLK and the flag signal FLG (FIG. 8), but is omitted in FIG. 9 for convenience of illustration.

The following various data and signals are transmitted from the main body side to the carriage side via the flexible cable 340.
(I) Drive signal waveform data representing a drive signal waveform for driving the print head 60.
(Ii) A print timing signal for notifying the timing of ink ejection.
(Iii) A print signal indicating an ink discharge state at each nozzle.

  FIGS. 10A to 10H are timing charts showing various signals used for ink ejection. As shown in FIG. 10A, the print timing signal PTS is a signal for indicating the timing at which each nozzle ejects ink for one pixel, and is generated for each pixel. However, normally, one print timing signal PTS is commonly used for a plurality of nozzles of one nozzle group. In this embodiment, since six nozzle groups 60 a to 60 f are provided in one print head 60 (FIG. 3), six print timing signals PTS are generated for one print head 60.

  The common drive signal COM shown in FIG. 10B is a signal generated by three pulses W1, W2, and W3 having different waveforms in three partial sections in one pixel section. Such a common drive signal COM is generated by D / A converting the drive signal waveform data stored in the SRAM 520 by the drive signal generation circuit 540 (FIG. 8) on the carriage. The drive signal waveform data is data indicating the waveform of the common drive signal COM for one pixel, and is supplied in advance from the main control unit 310 of the printer main body. In this embodiment, the drive signal generation circuit 540 generates six types of common drive signals COM to be supplied to the six nozzle groups 60a to 60f. For this reason, the SRAM 520 stores six or more types of drive waveform data. This signal is called a “common drive signal” because it is used in common for a plurality of nozzles of the same nozzle group.

  As shown in FIGS. 10C and 10D, when recording small dots, other pulses are masked so as to leave only the second pulse W2 in accordance with the mask signal MSK. The waveform of the mask signal MSK is generated by the mask signal generation circuit 504 (FIG. 8) according to the print signal SI supplied from the main body side. Similarly, when recording a medium dot, only the first pulse W1 is left and other pulses are masked (FIGS. 10E and 10F), and when recording a large dot, the third pulse is used. Other pulses are masked leaving only W3 (FIGS. 10G and 10H). In this way, by performing mask processing of the common drive signal COM in accordance with the print signal SI indicating the dot recording state of each pixel, any one of the three types of dots having different sizes at each pixel position is selectively selected. Can be recorded. Note that various other waveforms can be employed as the waveform of the common drive signal COM.

When transmitting the print timing signal PTS, the print signal SI, and the drive waveform data, first, the following signals are supplied from the main control unit 310 to the data processing unit 320 (FIG. 8).
(1) Clock signal CLK: a synchronous clock used for transmitting a signal from the main control unit 310 to the data processing unit 320.
(2) Serial data signal SD: This signal represents data and is held inside the control circuit 400.
(3) Data latch signal DLAT: A signal indicating the timing at which the data latch 402 holds print data, waveform data, etc. supplied as a serial signal.
(4) Waveform selection latch signal WLAT: a signal indicating the timing at which the waveform number supplied as a serial signal is held in the waveform selection latch 404.
(5) Transmission (W) / Reception (R) designation signal R / W: A signal indicating whether the data processing unit 320 is operated in a transmission state or a reception state.
(6) Reset signal RESET: a signal for resetting various circuit elements in the control circuit 400.
(7) Print timing signal PTS: A signal for notifying the timing of ink ejection.

  When the drive signal waveform data, the print timing signal PTS, the print signal, and the like are supplied from the main control unit 310 to the data processing unit 320 by these signals, the data processing unit 320 includes the latches 402 and 404 in the control circuit 400. The data is temporarily stored in the SRAM 420. The stored data is then transmitted to the drive controller 330 immediately thereafter.

  11 and 12 are timing charts showing a method of transferring drive waveform data from the main body side circuit to the carriage side circuit. FIGS. 11A, 11B, and 11C respectively show three types of signals SCLK, FLG, and DATA transmitted via the flexible cable 340 (FIG. 8). The flag signal FLG is set to 0 level (L level) when driving waveform data is transferred. The data signal DATA is transmitted by 1 bit for each cycle of the clock signal SCLK. In this embodiment, in principle, the 8-bit B0 to B7 data signal DATA is transmitted as one unit. Here, bit B0 means the least significant bit, and bit B7 means the most significant bit.

  FIG. 11D shows the structure of the data signal DATA when transmitting drive waveform data. The lower 4 bits B0 to B3 are used as a flag for identifying the contents of the data signal DATA. However, these bits B0 to B3 are active low (negative polarity). That is, the least significant bit B0 becomes 0 level (L level) only when the content of the data signal is the data latch signal DLAT. Bit B1 becomes 0 level only when the content of the data signal is waveform selection latch signal WLAT. Bit B2 is 0 level only when the content of the data signal is the transmission / reception designation signal R / W. Bit B3 becomes 0 level only when the content of the data signal is the reset signal RESET. These four types of signals DLAT, WLAT, R / W, and RESET are all supplied from the main control unit 310 (FIG. 8) to the data processing unit 320.

  The upper 4 bits B4 to B7 of the data signal DATA mean the nozzle group number. In the present embodiment, since six nozzle groups 60a to 60f are provided in one print head 60, values of 1 to 6 are used as the nozzle group numbers.

  When transferring the drive waveform data, first, as shown in FIG. 11, 8-bit data indicating the reset signal RESET is transferred to the carriage side. Of the lower 4 bits B0 to B3 of the 8-bit data, only the bit B3 indicating the reset signal RESET is 0 level, and the other bits B0 to B2 are 1 level. The upper 4 bits B4 to B7 indicate the nozzle group number. When the upper 4 bits B4 to B7 indicate the nozzle group number, for example, the most significant bit B7 is always set to 1, and the other 3 bits B4 to B6 are set as binary numbers indicating the nozzle group numbers from 1 to 6. The In the 8-bit data indicating the reset signal RESET in FIG. 11, the nozzle group number is set to 1, which means the first nozzle group 60a (FIG. 3). The 8-bit data indicating the reset signal RESET may not include the nozzle group number.

  When the 8-bit data indicating the reset signal RESET is transferred, the 8-bit data representing the waveform number in binary number is transferred. Here, the “waveform number” is a number assigned to the waveform of the common drive signal COM (FIG. 10) for one pixel. Since the printer of this embodiment can use a plurality of types of common drive signals, the waveform data of each common drive signal is stored in the SRAM 520 (FIG. 8) together with the corresponding waveform number. Which nozzle group uses which waveform data is instructed from the main control unit 310 to the drive control unit 330 together with the print data, as will be described later.

  When the 8-bit data indicating the waveform number is transferred, the 8-bit data indicating the waveform selection latch signal WLAT is subsequently transferred. When the waveform selection latch signal WLAT is received by the carriage-side control circuit 500, the waveform number is held in a latch (not shown) in the control circuit 500, and a storage area for waveform data related to this waveform number is secured in the SRAM 520. The

  Thereafter, as shown in FIGS. 12A to 12C, 16-bit (8 bits × 2) waveform data representing the signal level of the common drive signal in binary is transferred. Subsequently to the 16-bit waveform data, 8-bit data indicating the data latch signal DLAT is transferred. The lower 4 bits B0 to B3 of the 8-bit data indicate the data latch signal DLAT (see FIG. 11D), and the upper 4 bits B4 to B7 indicate the nozzle group number. When the carriage-side control circuit 500 receives the data latch signal DLAT, the waveform data is held in a latch (not shown) in the control circuit 500 and then stored in the SRAM 520.

  24-bit data composed of 16-bit waveform data and 8-bit data latch signal DLAT is repeatedly transferred by the number of waveform data. Thus, when the transfer of all the waveform data representing the waveform of one common drive signal is completed, the data indicating the end of the waveform data is transferred as shown in FIGS. In this example, waveform data in which the lower 12 bits are set to 1 level and all other bits are set to 0 is transferred. When the carriage-side control circuit 500 receives the waveform data, it is determined that the transfer of the waveform data has been completed.

  The transfer of the waveform data shown in FIGS. 11 and 12 is repeatedly executed until the transfer of the waveform data regarding all the common drive signals used for printing is completed. This transfer of waveform data is usually executed when the printer is started. If necessary, the waveform data can be transferred after the printer is activated. For example, a temperature sensor may be provided in the print head, the main control unit 310 may correct the waveform data according to the measured temperature, and the corrected waveform data may be transferred to the drive control unit 330. It is also possible to correct the waveform data in accordance with the ink remaining amount.

  FIG. 13 is a timing chart showing a method for transferring a print signal from the printer body to the carriage. As shown in FIG. 13C, when transferring the print signal, first, 8-bit data indicating the print timing signal PTS is transferred, and subsequently, data indicating the print signal SI is transferred.

  When the print timing signal PTS is transferred, the flag signal FLG is set to 0 level (L level). As shown in FIG. 13D, in the 8-bit data indicating the print timing signal PTS, the most significant bit B7 is set to 1 level, and the other bits B0 to B6 are all set to 0 level. Note that the flag signal FLG is also set to 0 level during the transfer of the drive waveform data shown in FIG. 11, but in this case, the lower 4 bits B0 to B3 are not all set to 0 level, and one of them is It only goes to level 0. On the other hand, when the print timing signal PTS is transferred, all the lower 4 bits B0 to B3 are set to 0 level, so that it can be determined which signal is transferred.

  When the print signal SI is transferred, the flag signal FLG is set to 1 level. The data indicating the print signal SI includes an 8-bit nozzle group designation flag, 180-bit upper bit data, 180-bit lower bit data, and 32-bit waveform number data. The 8-bit nozzle group designation flag is a flag for designating which of the six nozzle groups 60a to 60f included in one print head 60 is a print signal, as shown in FIG. The upper bit data and lower bit data transferred following the head designation flag are the upper bit and the lower bit of the 2-bit print signal for all nozzles included in one nozzle group. In this example, it is assumed that one nozzle group includes 180 nozzles. Correspondingly, upper bit data and lower bit data are each composed of 180 bits. As described with reference to FIG. 10, the print signal SI of the present embodiment indicates four dot recording states of three different sizes of dots (small, medium, and large) and no dot. The print signal SI for one pixel is composed of 2 bits. However, if the print signal SI indicates only the presence or absence of dots, the print signal SI for one pixel may be 1 bit. Further, in the case where five or more dot recording states are indicated, the print signal SI for one pixel is composed of 3 bits or more. In this specification, the dot recording state is also referred to as an ink ejection state. The 32-bit waveform number transmitted last is the waveform number of the common drive signal COM. Note that the waveform number may be omitted.

  Thus, when the print timing signal PTS and the print signal SI are transferred for one nozzle group, a dot for one pixel is formed by each nozzle of the nozzle group. FIG. 14 is a timing chart showing the timing of ink ejection. As shown in FIG. 14A, when the print timing signal PTS for the first pixel of the black nozzle group is transferred to the carriage-side control circuit 500 in the procedure shown in FIG. 13, a PTS pulse generation circuit (FIG. 8) generates a PTS pulse (FIG. 14B) after a predetermined time delay. At a timing according to the PTS pulse, the mask signal generation circuit 504 (FIG. 8) generates a mask signal MSK (FIG. 14C) from the print signal SI, and the black nozzle driver circuit 61a (FIG. 8). To supply. A switching element (not shown) for each nozzle provided in the driver circuit 61a performs on / off control of the common drive signal COM in accordance with the mask signal MSK, thereby driving a pixel (FIG. 14D). )). At this time, ink droplets corresponding to the mask signal MSK are respectively ejected from the 180 nozzles of the black nozzle group 60a.

  In this way, each time the print timing signal PTS and the print signal SI are supplied from the main body side circuit to the carriage side circuit, dot formation for one pixel is executed by each nozzle of the black nozzle group. 14A shows only the transfer timing of the data of the black nozzle group, but in actuality, other signals are transferred between the signals PTS and SI related to the black nozzle group of FIG. Signals PTS and SI relating to the five nozzle groups are sequentially executed. For this reason, the frequency of the clock signal SCLK that defines the transfer speed between the main body side circuit and the carriage side circuit is set to a sufficiently high frequency (several tens to several hundreds MHz) so that such transfer can be performed. In this embodiment, since data is transmitted serially with such a high frequency clock, it is particularly preferable to transmit each signal in a differential manner.

  As described above, in this embodiment, each print head 60 is used by using the flexible cable 340 including three signal line pairs for transmitting the 1-bit clock signal SCLK, the flag signal FLG, and the data signal DATA. Since the main body side circuit and the carriage side circuit are connected, various data and signals can be transmitted between the main body side circuit and the carriage side circuit at high speed. In particular, during printing, the print timing signal PTS that defines the dot formation timing for one pixel is transferred from the main circuit to the carriage circuit for each nozzle group, so that it is provided in a large number of print heads. Appropriate printing timing can be designated for each of a large number of nozzle groups.

C. Ink amount related information communication:
FIG. 15 is an explanatory diagram showing the configuration of the ink system of the printer 200 of this embodiment. This ink system includes a pressure regulating valve 610 and a pressurizing pump 612 in addition to the sub tank 3a and the main tank 9a. The pressure regulating valve 610 and the pressure pump 612 are used when the main tank 9a is pressurized and ink is supplied from the main tank 9a to the sub tank 3a. The sub tank 3a is provided with an ink remaining amount sensor 620, and the main tank 9a is provided with a pressure sensor 630.

  The ink system further includes a head suction unit 640 for cleaning the print head 60. The head suction unit 640 includes a cap 642 for sealing the lower surface of the print head 60, a suction hose 644, and a suction pump mechanism 646. The cap 642 is the same as the cap 21 shown in FIG. The suction pump mechanism 646 includes a rotating ring 647. A suction hose 644 is wound around the outer periphery of the rotating ring, and protrusions 648 are provided at two locations on the outer periphery. When cleaning the print head 60, the cap 642 is in close contact with the lower surface of the print head 60, and in this state, the rotating ring 647 is driven and rotated by a motor (not shown). As a result, the air and ink in the suction hose 644 are scraped out by the protrusions 648, and the ink is sucked from a large number of nozzles of the print head 60 and discharged to the outside.

  The head suction unit 640 is unitized for one print head 60 and can be attached to and detached from the printer 200 as a unit. Therefore, it is possible to install the head suction units 640 according to the number of print heads 60 mounted on the printer 200, and there is an advantage that it is not necessary to use the head suction units 640 that are not used wastefully.

  FIG. 16 is a flowchart showing a procedure for communicating information related to the ink amount between the carriage side and the main body side in the ink system of FIG. In step S11, the main control unit 310 (FIG. 7) determines whether or not the carriage return is from the forward path to the backward path. In the configuration of FIG. 1 described above, a carriage return from the forward path to the return path occurs when the carriage 1 is at the left end. If it is not a carriage return, step S11 is repeated. In the description of FIG. 16, the carriage return from the forward path to the return path is simply referred to as “carriage return”.

  In the case of a carriage return, in step S12, the drive control unit 330 (FIG. 15) on the carriage acquires the ink remaining amount from the ink remaining amount sensor 620 of the sub tank 3a, and the data processing unit 320 (FIG. 7) on the main body side. ). The data processing unit 320 further transfers this remaining ink amount to the main control unit 310. Note that such acquisition and transfer of the ink remaining amount are performed for all the sub tanks mounted on the carriage 1. The main control unit 310 determines whether or not the ink remaining amount is equal to or less than a predetermined value. When the ink remaining amount exceeds the predetermined value, the main control unit 310 proceeds to step S15 described later. On the other hand, when the ink remaining amount is equal to or smaller than the predetermined value, the main control unit 310 starts an ink filling operation to the sub tank 3a in step S13. Specifically, the main tank 9a is maintained at a predetermined relatively high pressure by using the pressurizing pump 612, the pressure adjusting valve 610, and the pressure sensor 630, thereby supplying ink from the main tank 9a to the sub tank 3a. .

  When the next carriage return occurs after the ink filling operation is started (step S14), the ink remaining amount is transferred from the drive control unit 330 to the data processing unit 320 and further transferred to the main control unit 310 (step S15). The main control unit 310 determines whether or not the sub tank 3a is full based on the remaining ink amount. If the sub tank 3a is full, pressurization by the pump 612 is stopped in step S16. On the other hand, if it is not full, the ink replenishment operation is continued. If printing has not ended, the process returns to step S11, and the operations of steps S11 to S16 described above are repeated.

  As described above, in the processing procedure of FIG. 16, the ink remaining amount in the sub tank 3a is communicated from the carriage side to the main body side at the carriage return from the forward path to the return path. Since there is no communication for the print signal at the carriage return, there is an advantage that the printing operation is not hindered even if the ink remaining amount is communicated.

  FIG. 17 is an explanatory diagram showing another configuration of the ink system. This ink system does not include the sub tank 3a and the main tank 9a, but instead, an ink cartridge 700 is mounted on the carriage 1. Accordingly, neither the pressure regulating valve 610 nor the pressurizing pump 612 shown in FIG. 15 exists. The ink cartridge 700 has an IC memory 710 for storing ink cartridge related information including the remaining amount of ink. When the ink in the ink cartridge 700 is consumed, it is replaced with a new cartridge.

  FIG. 18 is a flowchart showing a procedure for communicating information related to the ink amount between the main body side and the carriage side in the ink system of FIG. In step S21, the main control unit 310 determines whether or not the carriage return is from the forward path to the backward path. This step S21 is the same process as step S11 of FIG.

  If it is a carriage return, in step S22, the main control unit 310 transfers the ink ejection amount (ink usage amount) from the ink cartridge 700 to the drive control unit 320 via the data processing unit 320. This ink ejection amount can be obtained by calculating the total number of ink droplets ejected from the cartridge 700 based on the print signal used for printing so far and multiplying this by the weight of the ink droplets. The drive control unit 320 divides the ink discharge amount from the ink remaining amount read from the IC memory 710 of the cartridge 700 and writes the updated ink remaining amount in the IC memory 710.

  In step S <b> 23, the updated ink remaining amount is notified from the drive control unit 330 to the main control unit 310 via the data processing unit 320. In step S24, the main control unit 310 determines whether or not the ink end is reached (that is, whether or not the remaining amount of ink in the cartridge 700 is a predetermined value or less). If it is the ink end, printing is temporarily stopped, and the fact that it is the ink end is displayed on a display unit (not shown) of the printer 200. On the other hand, when the ink end has not been reached, the process returns from step S25 to step S21, and the processes of steps S21 to S24 described above are repeated.

  As described above, the example of FIG. 18 also has an advantage that since the ink discharge amount and the ink remaining amount are communicated at the carriage return, these communications do not hinder the printing operation.

  In the examples of FIGS. 16 and 18, the timing for performing the communication of the ink remaining amount is adjusted to the carriage return from the forward path to the backward path. May be performed. When these carriage returns are performed, the carriage 1 exists in one of the two non-printable ranges at both ends of the movable range of the carriage 1. That is, it is preferable that the communication of the ink remaining amount is performed when the carriage exists in one of these two non-printable ranges.

  In addition, what is to be communicated at the time of carriage return is not limited to the remaining amount of ink or the amount of ink discharged, but generally relates to the amount of ink in the ink tank (sub tank 3a or cartridge 700) mounted on the carriage 1. Communication can be performed on information (referred to as “ink amount related information”).

  Further, instead of communicating ink amount related information for each carriage return as in the examples of FIGS. 16 and 18, ink amount related information is communicated every time a predetermined number of carriage returns are completed. It may be. Further, the ink amount related information may be communicated every time printing of one page is completed.

D. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

D1. Modification 1:
The number of bits and bit arrangement of various signals described in the above embodiments are merely examples, and various other bit numbers and bit arrangements can be adopted for each signal. For example, each signal line of the flexible cable 340 transmits a 1-bit signal, but the data signal line DATA may transfer a data signal of 2 bits or more. However, if the signals transmitted through the flexible cable 340 are all 1-bit serial signals as in the above embodiment, the size of the flexible cable 340 can be reduced, so that a large number of cables can be easily routed. There are advantages. Further, 1-bit serial transmission has an advantage that transmission can be performed at a higher frequency without transmission error.

D2. Modification 2:
In the above embodiment, the print timing signal PTS is generated once every time each nozzle of one nozzle group forms a dot for one pixel. Instead, the print timing signal PTS is provided in one print head 60. The print timing signal PTS may be generated once every time each nozzle of a plurality of nozzle groups forms a dot for one pixel. For example, when one print head 60 has six nozzle groups, in the latter case, the print timing signal PTS is generated at a frequency 1/6 that in the former case. The deviation in printing timing for a plurality of nozzle groups in one print head 60 is equal to the time obtained by dividing the distance in the main scanning direction between the nozzle groups by the main scanning speed (carriage speed). Therefore, if the print timing of the first nozzle group is known, the print timing of other nozzle groups in the same print head can be calculated from the distance between the nozzle groups. Such a print timing shift can be registered in advance in the drive control unit 330, and the print timing for other nozzle groups than the head nozzle group can be determined according to this shift.

D3. Modification 3:
In the above embodiment, all the nozzles belonging to the same nozzle group eject the same ink, but it is also possible to combine a plurality of nozzles ejecting different inks into one nozzle group. Alternatively, a plurality of nozzles that eject the same ink may be divided into two or more nozzle groups. As can be understood from these examples, there is a certain degree of arbitraryness in the way of dividing the nozzle group. However, if the type of ink (ink color, pigment / dye, etc.) is different, the drive waveform to be applied may differ accordingly. In such a case, as in the above embodiment, if all the nozzles belonging to the same nozzle group eject the same ink, there is an advantage that a preferable driving waveform suitable for each ink can be selected.

D4. Modification 4:
In the above embodiment, a part of the configuration realized by hardware may be replaced with software, and conversely, a part of the configuration realized by software may be replaced by hardware. For example, some of the functions of the data processing unit 320 and the drive control unit 330 (FIG. 8) on the main body side can be realized by a computer program.

1 is a perspective view illustrating an outline of a configuration of a printer 200 as an embodiment of the present invention. 3 is an explanatory diagram illustrating a configuration of a printing unit 220. FIG. FIG. 3 is an explanatory diagram showing an arrangement of nozzles on the lower surface of one print head. 2 is an explanatory diagram for explaining an outline of a carriage. FIG. FIG. 3 is an explanatory diagram for explaining an outline of a sub tank 3 mounted on a carriage 1. FIG. 3 is a partial cross-sectional view of a printing unit 220 including a carriage 1. FIG. 3 is a block diagram illustrating a circuit configuration related to bidirectional communication between the printer main body 300 and the carriage 1. The block diagram which shows the internal structure of the data process 320 and the drive control part 330. FIG. The block diagram which shows the internal structure of the differential drivers 410 and 510. FIG. 6 is a timing chart showing various signals used for ejecting ink. 6 is a timing chart showing a method for transferring drive waveform data from the printer body to the carriage. 6 is a timing chart showing a method for transferring drive waveform data from the printer body to the carriage. 6 is a timing chart showing a method for transferring a print signal from the printer body to the carriage. 6 is a timing chart showing ink ejection timing. FIG. 3 is an explanatory diagram illustrating a configuration of an ink system. 16 is a flowchart showing a procedure for communicating information related to the ink amount between the carriage side and the main body side in the ink system of FIG. 15. FIG. 6 is an explanatory diagram illustrating another configuration of the ink system. 18 is a flowchart showing a procedure for communicating information relating to the ink amount between the carriage side and the main body side in the ink system of FIG. 17.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Carriage 1A ... Sub tank plate 3 ... Sub tank 3S ... Sub tank set 3a-3f ... Sub tank 4 ... Valve 5 ... Ink supply path 9, 9a-9f ... Main tank 10A, 10B ... Inspection part 11 ... Light emission part 12 ... Light receiving part DESCRIPTION OF SYMBOLS 13 ... Inspection unit 20 ... Cap part 30 ... Wiper part 60 ... Print head 60a-60f ... Nozzle group 61a-61f ... Driver circuit 100 ... Carriage motor 101 ... Drive belt 102 ... Main scanning guide member 103 ... Ink supply path 105 ... Supply Paper guide 106 ... Feeding roller 107 ... Following roller 108 ... Printing stage 109 ... Ejecting guide 110 ... Ejecting roller 200 ... Printer 210 ... Feeding unit 211 ... Roll paper holder 212 ... Spindle 215 ... Supporting column 220 ... Printing unit 230 ... paper discharge unit 231 ... holder 232 Spindle 235 ... support pillar 240 ... input / output unit 300 ... printer main body 310 ... main control unit 320 ... data processing unit 330 ... drive control unit 340 ... flexible cable 400 ... control circuit 402 ... data latch 404 ... waveform selection latch 406 ... counter 410 ... Differential driver 413 ... Differential amplifier 414 ... Inverter 415 ... Inverter 416, 417 ... Signal line 420 ... SRAM
430: Interface 500 ... Control circuit 502 ... PTS pulse generation circuit 504 ... Mask signal generation circuit 510 ... Differential driver 520 ... SRAM
530 ... Connector 540 ... Drive signal generation circuit 610 ... Pressure adjustment valve 612 ... Pressure pump 620 ... Ink level sensor 630 ... Pressure sensor 640 ... Head suction unit 642 ... Cap 644 ... Suction hose 646 ... Suction pump mechanism 647 ... Rotating ring 648 ... Protrusion 700 ... Ink cartridge 710 ... IC memory

Claims (10)

A printing apparatus that performs printing by discharging ink from a print head,
Multiple printheads;
A plurality of drive control units provided respectively corresponding to one or more predetermined number of print heads for driving the predetermined number of print heads;
A plurality of data processing units for respectively transferring data to the plurality of drive control units;
Can be installed,
A printing apparatus, wherein a circuit set including the predetermined number of print heads, one drive control unit, and one data processing unit can be arbitrarily attached and detached one by one. The printing apparatus according to claim 1,
A printing apparatus in which a circuit set selected from a plurality of different types of circuit sets is detachable as a circuit set composed of the predetermined number of print heads, one drive control unit, and one data processing unit. The printing apparatus according to claim 1, wherein:
The printing apparatus, wherein the print head and the drive control unit are mounted on a carriage that moves when printing is performed. The printing apparatus according to claim 3,
The plurality of data processing units are mounted on a main body of the printing apparatus,
The corresponding data processing unit and the drive control unit include a clock signal line for transmitting a clock signal, a flag signal line for transmitting a flag signal, and a serial data signal line for serially transmitting data And a flexible cable including
The data processing unit and the drive control unit are connected via the flexible cable.
(I) drive signal waveform data representing a drive signal waveform for driving the print head;
(Ii) a print timing signal for notifying the timing of ink ejection;
(Iii) a print signal indicating an ink discharge state from each nozzle;
Can be selectively transmitted from the data control unit to the drive control unit. The printing apparatus according to claim 4, wherein
The printing apparatus, wherein the print timing signal is transmitted from the data processing unit to the drive control unit every time each nozzle of one nozzle group provided in one print head ejects one pixel of ink. The printing apparatus according to claim 5,
A printing apparatus, wherein a print signal indicating an ink discharge state from each nozzle of the nozzle group is transmitted from the data processing unit to the drive control unit following the print timing signal related to one nozzle group. The printing apparatus according to any one of claims 4 to 6,
The flexible cable includes only the clock signal line, the flag signal line, and the serial data signal line as signal lines for transmitting a change in signal level between the data processing unit and the drive control unit. apparatus. The printing apparatus according to any one of claims 4 to 7,
Each of the clock signal line, the flag signal line, and the serial data signal line is configured as a signal line pair that transmits each signal in a differential manner. The printing apparatus according to any one of claims 3 to 8,
The data processing unit and the drive control unit include ink in an ink tank provided on the carriage when the carriage is in one of two unprintable ranges at both ends of the carriage movable range. A printing device that communicates information related to volume. The printing apparatus according to any one of claims 1 to 9,
A printing apparatus in which a head suction unit for sucking ink from one print head and cleaning the nozzles of the print head can be arbitrarily attached and detached one by one.

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