JP2007131012A - Recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus in a simple structure with no increase in circuit scale, which can provide each actuator of recording heads with various kinds of recording waveform signals, afford gradation controls and optimize recording, and transmit a variety of recording waveform signals in a smaller number of signal lines to the recording head on a carriage. <P>SOLUTION: Printing data including selection data for each one of a plurality of actuators relative to a head driver 21 is transmitted from a main circuit of the recording apparatus body. A selector 33 in the head driver 21 selects a predetermined recording waveform signal among plural kinds of recording waveform signals A, B and C repeatedly outputted in a predetermined cycle based on the selection data, as a result of which, a dot recording is performed. Consequently, a delicate density gradation control can be managed by adding only the selection data to the printing data in a less amount of information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording apparatus such as an inkjet recording apparatus.

  2. Description of the Related Art Conventionally, as a recording apparatus, there is known an inkjet recording apparatus that performs printing by ejecting ink droplets while moving an inkjet head mounted on a carriage along a recording medium at a predetermined interval. .

  Such an ink jet recording apparatus includes a head driver 21 as shown in FIG. 13, for example, which receives print data and various control signals from a main body circuit (not shown). There is one that drives an ink jet head (called a print head) having an ink jet nozzle. The head driver 21 includes a serial-parallel converter (shift register or the like) 31, a latch circuit 32, an AND gate 39, a driver 34, and the like. The serial-parallel converter 31 converts serially transmitted print data into parallel data.

  The latch circuit 32 latches each parallel data according to a latch signal. Each AND gate 39 takes a logical product of each parallel data output from the latch circuit 32 and the transferred print waveform (clock), and generates each drive data as a result of the logical product. . The driver 34 generates a drive signal suitable for the print head based on each drive data, and outputs the drive signal to the electrodes of the ink chambers of the print head. As a result, the actuator constituting the print head is deformed, the pressure in the ink chamber fluctuates, and ink is ejected to perform dot printing.

  By the way, in the conventional head driver configuration as described above, a plurality of types of print waveform signals are not prepared. Therefore, the ink droplet size of each dot is controlled for each head channel (nozzle), for example, The gradation is not controllable. In addition, when performing dot printing, it is preferable to change the current printing waveform (referred to as history control) depending on whether or not the ink is ejected at the preceding and following ejection timings due to the influence of residual vibration of the head drive. As is known, it is not easy to perform droplet control for each nozzle by supplying a print head with various types of print waveform signals with a simple configuration.

  The present invention has been made in view of the above points, and can provide various types of recording waveform signals for each actuator of the recording head with a simple configuration without increasing the circuit scale, and gradation control. And a recording apparatus capable of transmitting a variety of recording waveform signals to a recording head on a carriage with a smaller number of signal lines. With the goal.

  According to the first aspect of the present invention, there is provided a recording head having a plurality of actuators for performing dot recording, a driving circuit for outputting a driving pulse to the actuator of the recording head, and selection data for each of the plurality of actuators with respect to the driving circuit. A main body circuit that transmits a drive signal including a waveform generation circuit that generates a plurality of types of recording waveform signals, and the drive circuit selects the selected data from a plurality of recording waveform signals generated by the waveform generation circuit The recording apparatus has a selection means for selecting a predetermined recording waveform signal based on the above and outputs a drive pulse having the selected recording waveform.

In the first aspect of the present invention, a drive signal including selection data is transmitted from the main body main circuit to the drive circuit for each of the plurality of actuators, and the selection means in the drive circuit uses a plurality of types of recordings generated by the waveform generation circuit. A predetermined recording waveform signal is selected from the waveform signals based on selection data included in the driving signal, and a driving pulse having the selected recording waveform is output to perform dot recording. This makes it possible to select an appropriate recording waveform from a plurality of types of recording waveform signals in units of dots by simply adding selection data that requires a small amount of information to the drive signal. Control is possible.
According to a second aspect of the present invention, in the recording apparatus according to the first aspect, the selection means of the drive circuit is provided for each actuator.

  In the second aspect of the invention, a predetermined recording waveform signal is selected for each actuator based on selection data included in the drive signal transmitted to each of the plurality of actuators.

  According to a third aspect of the present invention, in the recording apparatus of the first or second aspect, the waveform generating circuit generates a plurality of types of recording waveform signals having different numbers of pulses.

  In the invention of claim 3, a variety of recording waveform signals can be generated. Therefore, by selecting an appropriate recording waveform from among them, fine gradation control, history control, etc. can be performed accurately. Is possible.

  According to a fourth aspect of the present invention, in the recording apparatus according to any one of the first to third aspects, the waveform generating circuit repeatedly outputs a plurality of types of recording waveform signals at a constant period.

  In the invention of claim 4, the recording waveform signal itself becomes a recording timing signal, and a separate timing signal is not required.

  According to a fifth aspect of the present invention, in the recording apparatus according to any one of the first to fourth aspects, the recording head and the drive circuit are mounted on a carriage movable along the recording medium, and the main body main circuit and waveform generation The circuit is provided in a recording apparatus main body that accommodates the carriage, and the driving signal and the recording waveform signal are transmitted to the driving circuit via a flexible cable provided between the recording apparatus main body and the carriage. is there.

  In the invention of claim 5, the waveform generating circuit is provided in the recording apparatus main body, and the drive signal and the recording waveform signal are transmitted from the recording apparatus main body side to the carriage side drive circuit via the flexible cable. Therefore, no waveform generation circuit is required on the carriage side, and the configuration on the carriage side is simplified.

  According to a sixth aspect of the present invention, in the recording apparatus according to the fifth aspect, the drive circuit has conversion means for converting the drive signal serially transmitted from the main body main circuit into parallel, and the parallel-converted drives A signal and a plurality of recording waveform signals generated by the waveform generation circuit are input to the selection means, and the recording waveform signal is selected based on the driving signals.

  According to a sixth aspect of the present invention, each selection means of the drive circuit selects a recording waveform signal based on the selection data included in the input driving signal, and the recording head performs a recording operation based on the selected recording waveform signal. I do.

  According to a seventh aspect of the present invention, in the recording apparatus according to any one of the first to fourth aspects, the recording head, the drive circuit, and the waveform generation circuit are mounted on a carriage movable along a recording medium, and the main body main The circuit is provided in a recording apparatus main body that accommodates the carriage, and the driving signal is transmitted to the driving circuit via a flexible cable provided between the recording apparatus main body and the carriage.

  In the seventh aspect of the invention, the driving signal is transmitted from the recording apparatus main body side to the driving circuit on the carriage side via the flexible cable, and the recording waveform signal is generated by the waveform generating circuit mounted on the carriage. For this reason, since the recording waveform signal does not need to be transmitted through the flexible cable, the number of signal lines required for the flexible cable can be reduced.

  According to an eighth aspect of the present invention, in the recording apparatus of the seventh aspect, waveform data is serially transmitted from the apparatus main body side to the waveform generating circuit.

  In the invention of claim 8, desired waveform data can be transmitted from the apparatus main body side to the waveform generation circuit at an appropriate timing. This makes it possible to select an appropriate recording waveform according to the use environment of the apparatus, the characteristics of the recording head, and the like.

  According to a ninth aspect of the present invention, in the recording apparatus according to any one of the first to eighth aspects, the recording head is an ink jet head that ejects ink droplets for each actuator.

  In the ninth aspect of the invention, the amount of ejected ink droplets can be easily controlled by finely controlling the drive for each actuator.

  According to a tenth aspect of the present invention, in the recording apparatus according to the ninth aspect, the actuator of the recording head ejects ink droplets by increasing / decreasing the volume of an ink chamber containing ink based on the drive pulse. .

  In the invention of claim 10, the amount of ink droplets ejected can be finely controlled by increasing or decreasing the volume of the ink chamber.

  The invention of claim 11 is a recording apparatus for transmitting a plurality of types of recording waveform signals from a main body main circuit to a driving circuit for driving a recording head mounted on a carriage, and is provided in the main body main circuit. A compression circuit that compresses a pulse waveform of a recording waveform signal, and a recording waveform signal that is provided in the carriage, receives a signal from the compression circuit, expands the pulse waveform of the compressed signal, and is transmitted from the main circuit main circuit Is provided with a decompression circuit. Here, the carriage moves based on control data such as print data in a state where the print head is mounted.

  In the eleventh aspect of the present invention, the pulse waveforms of a plurality of types of recording waveform signals from the main circuit of the main body are first compressed by the compression circuit, and the number of signals after the compression processing is less than the number of signals. The number is transmitted to the recording head mounted on the carriage. On the carriage, the pulse waveform of the compressed signal is expanded by the expansion circuit, the recording waveform signal transmitted from the main circuit is reproduced, and the recording head is controlled based on the recording waveform signal.

  According to a twelfth aspect of the invention, in the recording apparatus of the eleventh aspect, the recording head mounted on the carriage is an inkjet head, and a plurality of types of recording waveform signals from the main body main circuit are a plurality of types of recording waveform signals from the inkjet head. 4 is a drive pulse signal for selectively ejecting ink droplets in the manner described above. Here, ejecting ink droplets in a plurality of types means that the number of droplets is different.

  In the twelfth aspect of the present invention, the pulse waveforms of a plurality of types of recording waveform signals are compressed and expanded, and the main body main circuit is connected to the inkjet head on the carriage with a smaller number of signal lines than the types of signals. The ink droplets are selectively ejected from the inkjet head in a plurality of types based on the drive pulse signal transmitted.

  An invention according to claim 13 is the recording apparatus according to claim 11, wherein the compression circuit detects an rising edge and a falling edge of each edge of the pulse waveform of the recording waveform signal, and generates an edge information pulse; A first delay circuit that shifts the edge information pulses generated by the edge detection circuit so as not to overlap with each other; and an encoder that converts the edge information pulses into a high-efficiency code notation.

  In the invention of claim 13, the rising and falling edges of each edge of the pulse waveform of the drive signal are detected by the edge detection circuit to generate an edge information pulse, and the generated edge information pulse is the first edge pulse. The edge information pulses are shifted so as not to overlap each other in the delay circuit, and the pulse waveform of the recording waveform signal is compressed by the high efficiency code notation (for example, binary notation, ternary notation) by the encoder. The number of signal lines smaller than the number of types of recording waveform signals enables transmission to the recording head on the carriage.

  According to a fourteenth aspect of the present invention, in the recording apparatus according to the thirteenth aspect, the expansion circuit performs recording based on a decoder that cancels the high-efficiency code notation of the edge information pulse, and an edge information pulse from which the high-efficiency code notation is canceled And a pulse reproduction circuit for generating a waveform signal.

  In the invention of claim 14, the pulse waveform of the compressed recording waveform signal is obtained by canceling the high-efficiency code notation of the edge information pulse at the decoder on the carriage and releasing the high-efficiency code notation. Based on the information pulse, a pulse waveform of the control pulse signal is generated by the pulse reproduction circuit and sent to the recording head on the carriage.

  According to a fifteenth aspect of the present invention, in the recording apparatus according to the fourteenth aspect, the decompression circuit is based on a shift of an edge information pulse shifted by the first delay circuit between the decoder and the pulse reproduction circuit. A second delay circuit for returning is provided.

  In the fifteenth aspect of the present invention, the shift of the edge information pulse shifted in the first delay circuit on the main body main circuit side is restored by the second delay circuit prior to the drive signal from the pulse regeneration circuit.

  As described above, according to the first aspect of the present invention, the drive signal including the selection data is transmitted to the drive circuit of the recording head for each of the plurality of actuators, and the plurality of signals generated by the waveform generation circuit based on the selection data. Since a predetermined recording waveform signal is selected from various types of recording waveform signals, an appropriate recording waveform can be selected by adding a small amount of selection data, and a fine density level can be selected. Key control and history control are possible.

  According to the second aspect of the present invention, since the drive circuit selection means is provided for each actuator, a predetermined recording waveform signal can be selected for each actuator, and gradation control in units of nozzles is possible. It becomes.

  According to the invention of claim 3, since a plurality of types of recording waveform signals having different numbers of pulses are generated, fine gradation control and history control can be performed by selecting an appropriate recording waveform. It becomes.

  According to the invention of claim 4, since a plurality of types of recording waveform signals are repeatedly output at a constant period, the signals themselves become recording timing signals, and no separate timing signals are required.

  According to the fifth aspect of the invention, since the drive signal and the recording waveform signal are transmitted from the recording apparatus main body side to the carriage side drive circuit via the flexible cable, no waveform generation circuit is required on the carriage side. The configuration of is simplified.

  According to the invention of claim 6, since the recording waveform signal is selected based on the selection data included in the input drive signal and the recording operation is performed based on the selection, only by adding selection data with a small amount of information, An appropriate recording waveform can be selected.

  According to the seventh aspect of the present invention, the drive signal is transmitted from the recording apparatus main body side to the carriage side drive circuit via the flexible cable, and the recording waveform signal is generated by the waveform generation circuit mounted on the carriage. It is not necessary to transmit the waveform signal via the flexible cable, and the number of signal lines required for the flexible cable can be reduced.

  According to the invention of claim 8, since desired waveform data can be serially transmitted from the apparatus main body side to the waveform generation circuit, an appropriate recording waveform is used in accordance with the use environment of the apparatus and the characteristics of the recording head. Recording operation is possible.

  According to the ninth aspect of the present invention, since the recording head is an ink jet head that ejects ink droplets for each actuator, the amount of ejected ink droplets can be easily controlled by finely controlling each actuator. be able to.

  According to the invention of claim 10, since the actuator of the recording head increases or decreases the volume of the ink chamber that stores ink based on the drive pulse, the ink droplet is ejected. Can be controlled.

  According to the eleventh aspect of the present invention, a plurality of types of recording waveform signals from the main body main circuit are compressed by the compression circuit, and the pulse waveforms of the recording waveform signals are sent to the recording head mounted on the carriage. In the decompression circuit, the compressed signal is decompressed, and the pulse waveform of the recording waveform signal transmitted from the main circuit of the main body is reproduced and transmitted to the recording head. By reducing the number of signal lines to be connected to the number of types of recording waveform signals, the movement load of the carriage can be reduced.

  According to the twelfth aspect of the invention, a plurality of types of ink droplets are selectively ejected from the recording head based on the recording waveform signal that is compressed and expanded from the main body main circuit. A plurality of types of ink droplets can be selectively ejected from the recording head by a number of signal lines smaller than the number of signals corresponding to the number of types of droplets.

  According to a thirteenth aspect of the present invention, the compression circuit detects the rising edge and the falling edge of each edge of the pulse waveform of the drive signal and generates an edge information pulse, and the edge information pulse generated by the edge detection circuit Since the first delay circuit that shifts the edge information pulses so as not to overlap each other and the encoder that expresses the edge information pulse with a high-efficiency code, the drive signal is compressed with a simple circuit configuration, and the signal The number of lines can be less than the number of signals.

  According to the invention of claim 14, the decompression circuit includes a decoder for canceling the high efficiency code notation of the edge information pulse, and a pulse regeneration circuit for generating a drive signal based on the edge information pulse for which the high efficiency code notation is cancelled. Therefore, the compressed drive signal can be reproduced with a simple circuit configuration, and the recording head can be controlled without any difference from the case of using the same number of signal lines as the number of signals. .

  According to the fifteenth aspect of the present invention, the second delay circuit for returning the shift of the edge information pulse shifted by the first delay circuit is provided between the decoder and the pulse regeneration circuit. Prior to the drive signal by the reproduction circuit, the shift of the edge information pulse shifted by the first delay circuit can be restored.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the recording head mounted on the carriage is an inkjet head, and a plurality of types of drive signals from the main circuit of the main body drive to selectively eject a plurality of types of ink droplets from the inkjet head. A description will be given of a pulse signal applied to an ink jet recording apparatus.

  FIG. 1 is a block diagram showing an electrical configuration of the ink jet recording apparatus according to the first embodiment. The control device of the ink jet recording apparatus includes a main body main circuit, that is, a microcomputer 11 having a one-chip configuration, a ROM 12, a RAM 13 and a gate array 22. The microcomputer 11 includes an operation panel 14 for a user to give a print instruction, a motor drive circuit 15 for driving a CR motor 506 (to be described later), a motor drive circuit 16 for driving an LF motor 510 (to be described later), A paper sensor 17 that detects the leading edge of a recording sheet P as a recording medium, which will be described later, and an origin sensor 18 that detects the origin position of a carriage, which will be described later, are connected.

  The print head 3 is driven by a head driver 21 (drive circuit), and the head driver 21 is controlled by a control circuit 22 including a gate array. The print head 3 and the head driver 21 are mounted on a carriage 2 (FIG. 2) described later, and the gate array 22 and the head driver 21 are connected via a harness cable 28. Although not shown, the print head 3 ejects ink droplets from nozzles by individually increasing / decreasing the volume of each ink chamber containing a plurality of inks by driving an actuator composed of a piezoelectric element, an electrostrictive element, and the like. Electrodes for driving the actuator are provided for each nozzle, and the electrodes are connected to the head driver 21. The head driver 21 generates a pulse waveform suitable for the print head 3 based on the control of the gate array 22 and applies it to each electrode. An encoder sensor 29 that detects the position of the carriage 2 is connected to the gate array 22.

  The microcomputer (one-chip microcomputer) 11 and the ROM 12, RAM 13, and gate array 22 are connected through an address bus 23 and a data bus 24. The microcomputer 11 generates a print timing signal and a reset signal according to a program stored in advance in the ROM 12 and transfers each signal to the gate array 22.

  The gate array 22 print data (drive signal) for forming the image data on a recording medium based on the image data stored in the image memory 25 in accordance with the print timing signal and the control signal from the encoder sensor 29. Then, a transfer clock that is synchronized with the print data, a latch signal, and a print waveform signal (clock) are generated, and these signals are transferred to the head driver 21. The gate array 22 stores image data transferred from an external device such as the host computer 26 via the Centro interface 27 in the image memory 25. The gate array 22 generates a Centro data reception interrupt signal based on the Centro data transferred from the host computer 26 or the like via the Centro interface 27 and transfers the signal to the microcomputer 11. Each signal that connects the gate array 22 and the head driver 21 is transferred via a harness cable 28 (flexible cable) that connects the head driver 21 and the gate array 22.

  FIG. 2 is a perspective view showing a main body configuration of the ink jet recording apparatus. The guide rod 501 and the guide member 502 are fixed to the printer frame 503. The carriage 2 is slidably supported by the guide rod 501 and the guide member 502, fixed to the belt 505, and driven by a carriage motor (CR motor) 506 to reciprocate. The belt 505 is wound around pulleys 507 arranged in the vicinity of both ends of the long guide rod 501 and the guide member 502. One pulley 507 is connected to the drive shaft of the CR motor 506.

  A print head unit 508 including a print head 3 and a head driver 21 composed of a one-chip IC is attached to the carriage 2. The head driver 21 is connected to the gate array 22 (FIG. 1) via a flexible harness cable 28. An ink cartridge 509 as an ink supply source that supplies ink to each nozzle of the print head 3 is detachably mounted on the rear portion of the print head unit 508. A transport mechanism LF that transports the print paper P is disposed at a position facing the print head 3. The transport mechanism LF transports the printing paper P by the rotation of a platen roller 511 that rotates by driving a transport motor (LF motor) 510. A roller shaft 512 of the platen roller 511 is rotatably supported by the printer frame 503.

  A maintenance / recovery mechanism RM that performs maintenance / recovery of the ink ejection operation of the print head 3 is provided on the side of the transport mechanism LF. The maintenance / recovery mechanism RM includes a suction mechanism 513 and a cap 514. The suction mechanism 513 is a jet that is generated while the print head 3 is in use, such as when the ink dries, bubbles are generated inside the ink head, or ink droplets adhere to the outer surface of the nozzle plate of the nozzle. In order to eliminate the defect, the cap 514 is brought into close contact with the nozzle plate, and ink is sucked from the nozzle. The cap 514 also serves to prevent the ink from drying by covering the outer surface of the nozzle plate when the ink jet recording apparatus is not used.

  FIG. 3 is a block diagram illustrating a first example of the head driver 21. Here, the head driver 21 in the case of driving a 64-channel multi-nozzle head in which 64 ink chambers of the print head 3 are provided is illustrated. The head driver 21 includes a serial-parallel converter 31 (conversion means), a latch circuit 32, a selector 33 (selection means), and a driver 34. The serial-parallel converter 31 is composed of a 64-bit length shift register, inputs print data serially transferred from the gate array 22 in synchronization with the transfer clock, and outputs the print data to each parallel as the transfer clock rises. By converting to data, serial-parallel conversion of the print data is performed, and selection signals sel-0 and sel-1 are set for each channel. Each print data is composed of, for example, 2 bits, and includes a selection signal for selecting a print waveform including non-printing by a combination of the bits.

  The latch circuit 32 latches each parallel data according to the rising edge of the latch signal transferred from the gate array 22.

  Each of the 64 selectors 33 provided for each channel has a plurality of types of print waveform signals (clocks) transferred from the gate array 22 based on each parallel print data (selection signal) output from the latch circuit 32. ) Is selected and output.

  The print waveform signal input to the selector 33 from the gate array 22 can be arbitrarily set on the main circuit side of the main body. Here, three types A, B, and C having different numbers of pulses are prepared. An example is shown in FIG. 7 (details will be described later). These plural types of signals are always output repeatedly at a constant period, and are themselves injection timing signals. A truth table of the selector 33 is shown in FIG. As can be seen from the figure, one of the print waveforms is selected according to the selection signals sel-0 and sel-1 input to the selector 33. That is, when the selection signals sel-0 and sel-1 are 0 and 0, non-printing is selected, when 0 and 1, printing waveform A is selected, when 1, 0 is selected, printing waveform B is selected, and when 1, 1, printing waveform C is selected. To do. Thus, only by adding a 2-bit selection signal, four gradations including non-printing can be obtained for each nozzle. Thus, in FIG. 6, 0 in the column of the waveforms A, B, and C indicates that there is no output, 1 indicates that there is an output, and X indicates that an arbitrary value is acceptable.

  Returning to FIG. 3, each of the 64 drivers 34 generates a pulse waveform of a voltage suitable for the print head based on the waveform signal output from the selector 33, and uses each pulse waveform for each ink of the print head 3. Output to chamber electrode. Incidentally, if the print head 3 is not 64 channels, the bit length of the serial-parallel converter 31 and the number of selectors 33 and drivers 34 may be the same as the number of channels of the print head 3.

  Each print waveform signal A, B, C shown in FIG. 7 has a so-called stop pulse SP added after the ejection pulse train. The stop pulse SP is for suppressing ink vibration at the nozzles remaining after the ink droplets are ejected, and is not ejected by itself. Thus, it is possible to avoid the ink droplets flying undesirably or affecting the flying of the ink droplets in the next dot printing command. Each of the print waveform signals A, B, and C ejects a number of ink droplets corresponding to the number of ejection pulses in response to a 1-dot print command, and has a size corresponding to the number of ink droplets on the print paper P. Forming dots. Therefore, the larger the number of ejection pulses, the larger the dots that are formed. FIG. 7 illustrates a state where ink droplets fly from the nozzles and a state where the ink droplets have landed on the printing paper surface. As described above, since the size of one dot can be controlled, it is possible to easily control the gradation of the print density for each nozzle by selecting the print waveform.

  Note that not only three types of print waveforms but also more types are prepared as described above, so that a large number of gradations can be controlled. Accordingly, it is necessary to increase the number of signal lines for transmitting a print waveform from the gate array 22 to the head driver 21 and to increase the selection signal included in the print data to more than 2 bits. Moreover, the size of each ink droplet may be controlled by preparing a plurality of types of print waveforms having different pulse wave widths.

  In addition to performing gradation control, it is possible to improve the printing quality by appropriately selecting the printing waveform depending on the presence or absence (history) of the preceding and following dots. An example is shown in FIG. In the drawing, the dot immediately before and after the dot to be printed is indicated by a black circle when there is a dot, and a white circle with a broken line when there is no dot, and the corresponding dot under each of the conditions (a) to (d) The printing waveform of the ejection pulse for the dot is appropriately selected. When there is no dot immediately before and immediately after (a), for example, as shown on the right side of FIG. 8, a printing waveform having a predetermined wave width w1 is selected, and there is a dot immediately before and there is no dot immediately after (b). If there is a dot immediately before and after (d), select the print waveform with wave width w2, and if there is no dot immediately before and there is a dot immediately after (c), select the print waveform with wave width w3 To do. Here, each wave width has a relationship of w1> w3> w2. Note that the type of print waveform is not limited to the above, and the wave height (voltage value) is changed, the number of pulses and the wave width or wave height are combined, and depending on various conditions such as the shape of the ink flow path, It may be different. In addition, the print waveform output from the gate array 22 can be corrected according to environmental conditions such as temperature, or an arbitrary print waveform can be input from the outside through the I / F and the gate array 22 to intentionally control dots. It can also be done. For example, when draft printing is performed with dots thinned out, printing quality is not so required, so it is possible to select high-speed printing without adding a stop pulse.

  FIG. 4 is a block diagram illustrating a second example of the head driver 21. In the first example described above, the print waveform signal is generated by the main body main circuit provided on the apparatus main body side. However, in the second example shown below, the head driver mounted on the carriage 2 is shown. 21 is provided with a plurality (three in this case) of waveform generators 35a, 35b, and 35c (waveform generation circuits). Further, the head driver 21 includes a serial-parallel converter 31 (conversion means), a latch circuit 32, a selector 33 (selection means), and a driver 34 similar to those in the first example. From the gate array 22 on the apparatus main body side, a print data / waveform data signal including print data and waveform data, a transfer clock synchronized with those data, a latch signal, a transfer data selection signal for selecting print data and waveform data, and The ejection timing signal output at a constant cycle is transmitted to the head driver 21 on the carriage via the flexible harness cable 28.

  In the section in which the transfer data selection signal is low (in the timing chart of FIG. 5, the waveform data setting section), the gate array 22 on the apparatus body side print waveform signals A and B including non-printing in the print data / waveform data signal. , C are included, and the waveform generators 35a, 35b, and 35c are loaded separately. Then, the waveform generators 35a, 35b, and 35c synchronize the print waveform signals A, B, and C with respect to each of the 64 selectors 33 based on the loaded waveform data. Output.

  The transfer data selection signal is set to low when a page break occurs in a print operation or when a print command for new print data is input, and the gate array 22 sets each waveform data A, B, C according to the environmental temperature or the like. It is possible to transmit the print waveform corrected to the optimum state by setting the wave width and the presence or absence of the stop pulse.

  When the transfer data selection signal becomes high, the print data can be loaded into the serial-parallel converter 31 (printing section in FIG. 5), and the gate array 22 has 64 print data / waveform data. One dot print data (128 bits) for the actuator is included and output to the serial-parallel converter 31. Thereafter, as in the first example, the print data is serial-parallel converted and latched in the latch circuit 32 in synchronization with the latch signal. Thereafter, in each selector 33, one of the print waveforms A, B, and C output from the waveform generator 35 is selected according to the selection signals sel-0 and sel-1.

  In the head driver 21 according to the second example, since the waveform generator 35 is provided in the head driver 21 mounted on the carriage 2, it is necessary to transmit the print waveform signal from the main body circuit via the harness cable 28. Since there is no signal line, the number of signal lines required for the cable is small. The print data and the waveform data are transmitted through the same signal line, but separate signal lines may be used. In that case, the transfer clocks are also different.

  FIG. 9 is a block diagram showing a control system of the ink jet recording apparatus according to the second embodiment. In the present embodiment, in the first example of the embodiment, if the number of print waveform signals is increased, the number of signal lines must be increased. However, a large number of print waveform signals are not increased without increasing the number of signal lines. Is configured to transmit. In this embodiment, eight types of printing waveforms 1 to 7 can be selected including non-printing.

  The main body main circuit is provided with a compression circuit 111 for compressing a pulse waveform of the print waveform signal (see print waveforms 1 to 7 in FIG. 10), while the carriage 2 receives a signal from the compression circuit 111, An expansion circuit 121 is provided that expands the pulse waveform of the compressed signal and reproduces the pulse waveform of the print waveform signal transmitted from the main body main circuit. In addition to the selector 33, a serial-parallel converter 31, a latch circuit 32, and a driver 34 are provided on the carriage 2 in the same manner as in the above embodiment, and print data, a transfer clock, a latch signal, and the like are input. The

  Therefore, the pulse waveforms of a plurality of types of print waveform signals from the main body main circuit are first compressed by the compression circuit 111 and transmitted to the head driver 21 mounted on the carriage 2. On the carriage 2, the pulse waveform of the compressed signal is expanded by the expansion circuit 121, and the pulse waveform of the print waveform signal transmitted from the main body main circuit is reproduced. Based on this, the printing from the main body main circuit is performed. One of a plurality of print waveforms is selected based on the data, and the print head 3 is driven and controlled.

  The compression circuit 111 detects the rising edge and falling edge of each edge of the pulse waveform of the print waveform signal and generates an edge information pulse, and the edge information pulse generated by the edge detection circuit 112 is mutually transmitted. A first delay circuit 113 that shifts so as not to overlap, and an encoder 114 that expresses the edge information pulse in a high-efficiency code (binary notation in this example), and the number of signal lines at the site of the encoder 114 As a result, the number of signal lines required to transmit a print waveform signal to the print head 3 on the carriage 2 is less than half of the number of signals. Therefore, the number of types of signals to be transmitted can be increased without increasing the number of signal lines in the harness cable 28.

  More specifically, the edge detection circuit 112 detects the rise and fall of each edge of the pulse waveform of the print waveform signal as shown in FIG. 10A, and edge information corresponding to the rise and fall of each edge. Generate a pulse. The first delay circuit 113 shifts the generated edge information pulses so as not to overlap each other as shown in FIG. 10B. The encoder 14 (8-3 encoder) expresses the plurality of edge information pulse trains at a high efficiency code in a pulse train having a smaller number at each pulse generation time. For example, as shown in FIG. 10C, when the outputs from the delay circuits 1 to 7 are expressed as “1” to “7”, respectively, “1” is the lowest column of the outputs of the encoders 1 to 3 ( Only the encoder 1) is turned on, and "3" is converted into binary notation by turning on only the lowest column and its upper column (encoders 1, 2). As described above, the edge information pulse is expressed by a high-efficiency code, so that the pulse waveform of the print waveform signal is compressed and the number of signal lines required to transmit the signal to the head driver 21 is reduced.

  The decompression circuit 121 includes a decoder 122 that cancels the high-efficiency code notation of the edge information pulse by performing the reverse operation to the above, and the second delay circuit 123 on the main body main circuit side as described above. A second delay circuit 123 that restores the shifted edge information pulse to the original, and a pulse regeneration circuit 124 that generates a drive pulse signal based on the edge information pulse from which the high-efficiency code notation is canceled. Here, the reason why the delay processing is performed on each signal is to perform the compression / decompression using the simple encoder 114 and the decoder 122 so that the edge information of the driving waveform does not overlap.

  Therefore, the pulse waveform of the compressed print waveform signal is released on the carriage 2 by the decoder 122 (3-8 decoder) from the high efficiency code notation of the edge information pulse as shown in FIG. The second delay circuit 123 restores the shift of the edge information pulse shifted by the first delay circuit 113 on the main body main circuit side as shown in E of FIG. 10, and then the high efficiency code notation is canceled. Based on the edge information pulse, the pulse reproduction circuit 124 generates a drive waveform of the drive pulse signal as shown in F of FIG. 10 and sends it to the waveform selector 33, which drives the print head 3 on the carriage 2 based on it. Be controlled.

  In the embodiment, either the edge detection circuit or the first delay circuit may be arranged first. As shown in FIG. 11, the edge detection circuit and the first delay circuit are integrated into an edge detection and delay circuit 112A, and the edge information pulse (W in FIG. 12) subjected to delay processing from this circuit 112A is sent to the encoder 114. It is also possible to make it.

  In the embodiment, the edge shifted in the first delay circuit 113 by the second delay circuit 123 in the expansion circuit 121 prior to the reproduction of the drive waveform of the drive pulse signal by the pulse regeneration circuit 124. Although the information pulse shift is restored, the second delay circuit can be omitted as shown in FIG. In this way, as shown by Z in FIG. 12, simultaneous rise and fall of a large number of drive waveforms are avoided, and the drive current of the print head does not concentrate in a certain time.

  In each of the above embodiments, the ink jet recording apparatus has been described. However, the present invention is not limited thereto, and can be applied to a recording apparatus using an impact type print head, a thermal type print head, or the like. . In addition to gradation control of print density, history control, that is, impact type print heads can select the waveform depending on the presence or absence of print data before and after considering vibration remaining in the impact element, and thermal type print heads can also generate heating elements. It is also possible to select the waveform depending on the presence or absence of the previous and subsequent print data in consideration of the heat remaining in the image.

1 is a block diagram showing an electrical configuration of an ink jet recording apparatus according to a first embodiment of the present invention. It is a perspective view which shows the main body structure of an inkjet recording device. It is a block diagram which shows the 1st example of a head driver. It is a block diagram which shows the 2nd example of a head driver. It is a timing chart of operation of the head driver by the 2nd example. It is a figure which shows the truth table of a selector. It is a figure which shows a printing waveform signal, an ink flying state, etc. It is a figure for demonstrating selecting a printing waveform by the presence or absence of a dot. It is a block diagram which shows the control system of the inkjet recording device which concerns on 2nd Embodiment. It is a figure which shows the waveform of the drive signal of the control system shown in FIG. It is a figure similar to FIG. 9 about other embodiment. It is a figure similar to FIG. 10 about other embodiment. It is a block diagram of the conventional head driver.

Explanation of symbols

2 Carriage 3 Print head (recording head)
11 Microcomputer (Main circuit)
21 Head driver (drive circuit)
22 Gate array (Main circuit)
28 Harness cable (flexible cable)
31 Serial-parallel converter (conversion means)
33 Selector (selection means)
35 Waveform generator (waveform generator circuit)
111 compression circuit 111A compression circuit 112 edge detection circuit 112A edge detection and delay circuit 113 first delay circuit 114 encoder 121 expansion circuit 121A expansion circuit 122 decoder 123 second delay circuit 124 pulse regeneration circuit

Claims (15)

A recording head having a plurality of actuators for performing dot recording;
A drive circuit that outputs a drive pulse to the actuator of the recording head, a main body circuit that transmits a drive signal including selection data for each of a plurality of actuators to the drive circuit,
A waveform generation circuit for generating a plurality of types of recording waveform signals, and the drive circuit selects a predetermined recording waveform signal from the plurality of recording waveform signals generated by the waveform generation circuit based on the selection data A recording apparatus having a selection means and outputting a drive pulse having a selected recording waveform. The recording apparatus according to claim 1, wherein a selection unit of the drive circuit is provided for each of the actuators. The recording apparatus according to claim 1, wherein the waveform generation circuit generates a plurality of types of recording waveform signals having different numbers of pulses. The recording apparatus according to any one of claims 1 to 3, wherein the waveform generation circuit repeatedly outputs a plurality of types of recording waveform signals at a constant period. The recording head and the driving circuit are mounted on a carriage movable along a recording medium, and the main body main circuit and the waveform generation circuit are provided in a recording apparatus main body that houses the carriage, and the driving signal and the recording waveform signal The recording apparatus according to claim 1, wherein the recording apparatus is transmitted to a drive circuit via a flexible cable provided between the recording apparatus main body and a carriage. The drive circuit includes conversion means for converting the drive signal serially transmitted from the main body main circuit into parallel, and the drive signal converted in parallel and a plurality of recording waveform signals generated by the waveform generation circuit The recording apparatus according to claim 5, wherein the recording waveform signal is input to a selection unit and the recording waveform signal is selected based on each of the driving signals. The recording head, the drive circuit, and the waveform generation circuit are mounted on a carriage movable along a recording medium, the main body main circuit is provided in a recording apparatus main body that houses the carriage, and the drive signal is the recording signal The recording apparatus according to claim 1, wherein the recording apparatus is transmitted to a drive circuit via a flexible cable provided between the apparatus main body and the carriage. 8. The recording apparatus according to claim 7, wherein waveform data is serially transmitted from the apparatus main body side to the waveform generation circuit. The recording apparatus according to claim 1, wherein the recording head is an ink jet head that ejects ink droplets for each actuator. The recording apparatus according to claim 9, wherein the actuator of the recording head ejects ink droplets by increasing / decreasing a volume of an ink chamber containing ink based on the driving pulse. A recording apparatus for transmitting a plurality of types of recording waveform signals from a main body main circuit to a driving circuit for driving a recording head mounted on a carriage, provided in the main body main circuit, and a pulse waveform of the recording waveform signal A compression circuit that compresses the signal, and a decompression circuit that receives a signal from the compression circuit, decompresses a pulse waveform of the compressed signal, and reproduces a recording waveform signal transmitted from the main body circuit. A recording apparatus comprising: The recording head mounted on the carriage is an inkjet head, and a plurality of types of recording waveform signals from the main body main circuit are driven to selectively eject ink droplets from the inkjet head in a plurality of types. The recording apparatus according to claim 11, wherein the recording apparatus is a pulse signal. The compression circuit detects a rising edge and a falling edge of each edge of the pulse waveform of the recording waveform signal, and generates an edge information pulse and the edge information pulse generated by the edge detection circuit does not overlap each other. The recording apparatus according to claim 11, further comprising: a first delay circuit that shifts the edge information pulse, and an encoder that converts the edge information pulse into a high-efficiency code notation. The decompression circuit includes a decoder that cancels the high-efficiency code notation of the edge information pulse, and a pulse reproduction circuit that generates a recording waveform signal based on the edge information pulse whose high-efficiency code notation is cancelled. The recording apparatus according to claim 13. The decompression circuit is characterized in that a second delay circuit is provided between the decoder and the pulse regeneration circuit to restore the shift of the edge information pulse shifted by the first delay circuit. The recording apparatus according to claim 14.