JP2008100483A - Head substrate, recording head, and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head substrate which enables a sure and high-speed data transmission, and also to provide a recording head using the head substrate, and a recorder using the recording head. <P>SOLUTION: The recording head and the recorder are constituted such that a plurality of data lines and a synchronizing signal for a clock or the like, which are needed between a conventional recorder and a recording head, are eliminated. The synchronizing signal and high-frequency data (recording data) are multiplexed in the recorder, and the function of internally reproducing the synchronizing signal is incorporated in head units 101-104, so that the high frequency data is internally developed and processed. A low-voltage differential transmission (LVDS) line 300 is used for a transmission line, and noise to cause a malfunction in transferring the high-frequency data is thereby prevented from occurring so that the transmission line is protected from the noise. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a head substrate, a recording head, and a recording apparatus. In particular, for example, the present invention relates to an inkjet head substrate in which a large number of recording elements are arranged, a recording head having a configuration in which a plurality of the head substrates are arranged, and a recording apparatus using the recording head.

  2. Description of the Related Art Conventionally, recording apparatuses that record information such as desired characters and images on a sheet-like recording medium such as paper or film have been widely used as information output apparatuses in, for example, word processors, personal computers, and facsimiles. . These recording devices are used in modern business offices and other office processing departments, and also as printers for personal use. While high density and high speed recording are strongly desired for these recording apparatuses, development and improvement have been attempted in order to achieve further cost reduction or high definition.

  Among the recording apparatuses described above, there is an ink jet recording apparatus that performs recording by ejecting ink from an ejection port disposed on a recording element as low-noise non-impact recording. Inkjet recording apparatuses are capable of high-density and high-speed recording due to their structural characteristics, and are widely used as low-cost color printers. An ink jet recording apparatus uses a recording head equipped with a recording element such as an electrothermal conversion element that generates ejection energy for ejecting ink from the ejection port and ejects ink according to desired recording information. And record.

  As a configuration of the recording head, a recording head in which a plurality of recording elements are arranged in one row or in a plurality of rows is conventionally known. In such a recording head, several or several tens of driving integrated circuits that can be driven simultaneously with N recording elements as one block are mounted on the same substrate. Arbitrary recording can be performed on a recording medium such as recording paper by aligning image data corresponding to each recording element, inputting the data to a recording head, and driving the recording element.

  Now, with the recent high-definition and high-quality recording, the performance of the recording head has been greatly improved. On the other hand, the number of recording elements has increased along with the higher definition and higher image quality, or the number of simultaneous driving of the recording elements has increased in order to improve the recording speed. In addition, the performance of the recording element itself has also advanced, and it is possible to eject several pl of ink with a pulse width of about 1 μsec. This is achieved by using a functional element (such as a MOS-FET driver) that switches a large current at high speed.

  In addition to this, improvement is similarly achieved in image data transfer for selectively energizing a recording element. The transfer frequency of image data from the apparatus main body to the recording head has already exceeded 10 MHz. Further, in order to achieve high-speed data transfer, it has been devised that image data can be shifted by a shift register at both the rising edge and falling edge of the image data transfer clock. In addition to this, when the transfer of the image data is not completed within the ink discharge period from the printing element, the image data transfer is made parallel and parallel processing at the same clock frequency is performed.

  Furthermore, so-called full-line recording heads, which have a configuration in which these recording heads are one unit and a plurality of units are arranged, have appeared. Since the full line recording head is configured by arranging several or several tens of units having usually several thousand recording elements, the amount of image data becomes enormous.

  In particular, in a full-line recording head, it is essential that the functions of each unit operate individually and reliably. For this reason, the scale of the circuit for controlling the unit increases, and the number of signal lines and power supply lines tends to increase accordingly.

  In particular, in a full-line recording head employing an ink jet system, the number of recording elements that are driven simultaneously increases, so that each nozzle is subjected to mutual pressure interference due to the pressure generated during ink ejection. This pressure interference (crosstalk) may cause a change in recording density. For this reason, after the recording element is driven, the drive control is also complicated, such as providing a pause time to avoid heat dissipation to some extent or crosstalk.

  In addition, there is an increasing demand for drive control in accordance with the amount of recording agent used in a cartridge containing a recording agent such as ink, particularly the amount of ink cartridge used in an ink jet recording head. This requirement is diverse, such as differences depending on ink color information and manufacturing date, differences due to ink viscosity, and differences depending on usage.

  In order to cope with the above problems and requirements, for example, a configuration as disclosed in Patent Document 1 has been proposed. That is, the recording head includes means for detecting the temperature of the recording head, means for arbitrarily changing the driving method with an external input signal, and means for detecting the difference of the recording head due to manufacturing variations, and if necessary, the information is provided. To take out and control. In addition, a circuit configuration in which a recording element group is divided into a plurality of blocks including a predetermined number of recording elements and time-division driving is performed for each block has been put into practical use. As described above, in the print head peripheral circuit, as the printing apparatus is highly functionalized, various control methods have been adopted and the processing system has become complicated.

  In the recording apparatus using the recording head as described above, the number of recording elements provided in the recording head tends to increase in order to increase the recording speed and the recording density. For this reason, the number of time-division drive blocks increases, and the number of control signal lines increases even when a decoder circuit or the like is used. For example, when a clock signal having a logic level of 5V or 3.3V is transferred at a speed of several tens of MHz, the influence of the radiation noise on the peripheral device and the influence on the control signal line of the recording apparatus increase.

  Furthermore, the recording apparatus must perform high-speed switching of a large current passing through the recording element. Switching noise (inductive electromotive force) due to the functional element is generated beyond the logic level from the power supply terminal, and affects the logical signal sequence wiring near the functional element. This state has become apparent in the form of abnormal recording due to malfunction of the logic circuit in image data, clock signals, control data lines, and the like, and has become a problem in the configuration of the recording apparatus.

  As a countermeasure against such noise, there is a method such as separating the ground terminal of the logic circuit and the ground terminal of the power supply line as much as possible and short-circuiting at the power supply terminal of the recording device. The influence of noise is increasing. The carriage on which the recording head is mounted is moved at high speed by a carriage motor in the recording apparatus, and the noise level that jumps in is changed with the movement of the flexible cable wiring board connecting the carriage and the recording apparatus main body. The higher the image quality and functions, the more complicated the configuration of the recording head and the surrounding control devices, so the control unit of the recording device itself becomes complicated to control such as countermeasures against malfunction due to noise. come. For this reason, a large load is generated in the control unit of the recording apparatus main body on which the recording head is mounted.

  For example, it is necessary to manage / execute a control sequence such as changing the drive pattern according to the operation mode of the recording head. If there is a large manufacturing variation or lot difference between recording heads, the difference in the recording state may be reflected in the image remarkably, so it is necessary to manage and calibrate them. Furthermore, it is also necessary to always perform data communication between the recording apparatus and the recording head, such as discriminating the model of the head and sequentially monitoring the driving status. Such noise jumping into the control data line is a fatal malfunction factor for the recording apparatus. Furthermore, a mutual EMI (electromagnetic interference) countermeasure is required in which peripheral devices are affected by noise radiated from the entire recording apparatus.

  In order to cope with the above problem, there has been a method of providing two differential input terminals for each terminal as described in Patent Document 2 so far. This cancels out common mode dive noise. However, in this method, the signal is passed through the two-terminal transmission line at a signal level equivalent to the control logic level of the printing apparatus main body and the logic circuit in the carriage or printing head. In this case, it is inevitable that the data rate is lowered due to the waveform deterioration due to the inductance and impedance of the transmission line. This causes a problem that radiation noise that causes malfunction of not only the recording apparatus but also its peripheral devices occurs, such as the influence of EMI due to high-frequency transfer increases.

  In view of this point, Patent Documents 3 and 4 disclose the configuration of a recording apparatus using a low voltage differential signal (LVDS) line. This method according to the LVDS technology can be said to be an effective method from the viewpoint of EMI countermeasures.

  FIG. 10 is a diagram illustrating a general configuration when the LVDS technique is applied to transfer between a recording head and a recording apparatus.

  In this case, data, a clock, a latch signal, and the like transmitted from the recording apparatus 400 by the LVDS transceiver 401 are received by the LVDS receiver 201 of the recording head 200. Each of these signals is input to the head controller 202 to control the driving of the head driving circuit 203. Through this transmission line, a timing signal for arbitrarily accessing the memory 203 and the sensor 204 as information of the print head is communicated according to a specific protocol. For example, when it is desired to acquire information from the memory 204, the LVDS line 300 is used for transmission of memory access command data. Also, when acquiring sensor information, the LVDS line 300 is used for transmission of sensor access command data.

Since the LVDS technology is an effective configuration for EMI, there is an advantage that troubles of the recording head and the recording apparatus can be reduced due to problems such as noise on the LVDS line and other communication lines.
Japanese Patent Application Laid-Open No. 7-241992 JP-A-10-166583 JP 2002-326348 A Japanese Patent Laid-Open No. 2005-199665 JP 2002-225271 A

  However, there are several problems in applying the conventional technique using LVDS to a recording apparatus.

  As shown in FIG. 10, since the LVDS line always supplies two inverted pair signals, if the number of data signal lines is increased as the number of recording elements is increased, the number of terminals is doubled. End up. An increase in the number of terminals results in an increase in cost and connection reliability of the recording apparatus and the recording head. Originally, since the LVDS line is a line capable of high-speed transfer, it can be dealt with by increasing the transfer speed without providing many data signal lines.

  However, in reality, since the maximum operating frequency of the circuit mounted on the recording head side is about several tens of MHz, no measures have been taken to make data, clock terminals, etc. compatible with transmission / reception of substantial high-frequency signals. Regarding the coupling between the recording apparatus and the recording head, the carriage on which the recording head is mounted frequently moves. Therefore, the characteristic transmission line of the recording apparatus is indispensable to reduce the number of terminals to the limit and to improve the connection reliability.

  For example, if the clock signal is smoothed for EMI countermeasures, noise may enter the part where the rising speed is slow, and the recording apparatus or the recording head may malfunction. In the future, recording apparatuses and recording heads that will be further increased in speed are required to solve such problems. Particularly in a recording apparatus, it is an important issue to transfer the amount of recorded information accompanying the increase in the number of recording elements at a high speed with a small number of terminals. It is important to.

  Further, a configuration disclosed in Patent Document 5 is known for a full line recording head. For example, FIG. 5 of Patent Document 5 shows a clock and data LVDS transmission line wired from a printing apparatus to a control circuit in a full-line printing head. Specifically, this configuration is a configuration in which a serial data stream and its corresponding clock signal are received by the LVDS line. The LVDS technique is effective as an EMI countermeasure as described above, and is effective for a full-line recording head.

  However, when this transmission line is driven at a high frequency, there is a possibility that the data transmitted on a separate line from the clock cannot be accurately synchronized due to clock jitter or the like. The full line recording head handles a huge amount of image data, and the LVDS line requires high frequency transfer of about several hundred MHz. If the image data is not synchronized, the image is defective and the high-quality image is damaged.

  The present invention has been made in view of the above conventional example, and an object thereof is to provide a head substrate capable of reliably performing high-speed data transfer. Another object of the present invention is to provide a recording head using the head substrate and a recording apparatus using the recording head.

  In order to achieve the above object, the head substrate of the present invention has the following configuration.

  That is, a head substrate including a plurality of recording elements and a plurality of driving elements for driving the plurality of recording elements, and receives a serial signal including a recording signal serially transferred from the outside via a differential transmission line. In synchronization with a differential signal receiver, a clock generation circuit that generates a clock signal used inside the head substrate from a serial signal received by the differential signal receiver, and a clock signal reproduced by the clock generation circuit, And a shift register for inputting the recording signal received by the differential signal receiver.

  According to another aspect of the invention, there is provided a recording head characterized in that a plurality of head substrates having the above-described configuration are arranged in the arrangement direction of a plurality of recording elements.

  According to still another aspect of the invention, there is provided a recording apparatus that performs recording on a recording medium using the recording head, wherein the generation unit generates a recording signal supplied to the recording head as a parallel signal, and the generation unit generates the recording signal. Conversion means for converting the parallel signal and the clock signal accompanying the signal into a multiplexed serial signal, and transfer means for transferring the serial signal converted by the conversion means to the recording head via a differential transmission line And a recording device.

  Therefore, according to the present invention, the recording signal transferred by the differential transmission line is processed at high speed in the head substrate in synchronization with the clock signal generated in the head substrate based on the information of the differential transmission line. There is an effect that can be.

  As a result, signal transfer at a higher speed than before can be achieved, so that it is possible to cope with a further increase in the number of recording elements and a higher density in the future recording head. In addition, such high-speed and large-capacity data transfer is possible with only one transmission line.

  Further, by performing differential transmission at, for example, a low voltage, there is an advantage that radiation noise is reduced regardless of high-speed data transfer. The noise jumping into the high-frequency data in the transmission line can be offset, and the occurrence of abnormality in the data transmitted to the recording head can be prevented, and the resistance to noise can be improved.

  Furthermore, since the recording apparatus can process the transfer of the recording signal at a higher speed, the processing time in the processor and the control circuit can be greatly reduced. In addition, it is possible to realize a highly reliable recording apparatus that is not easily affected by radiation noise or external noise.

  Hereinafter, preferred embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the already demonstrated part and duplication description is abbreviate | omitted.

  In this specification, “recording” (sometimes referred to as “printing”) is not limited to the case of forming significant information such as characters and graphics, but may be significant. It also represents the case where an image, a pattern, a pattern, etc. are widely formed on a recording medium, or the medium is processed, regardless of whether it is manifested so that humans can perceive it visually. .

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Further, “ink” (sometimes referred to as “liquid”) should be interpreted widely as in the definition of “recording (printing)”. Therefore, by being applied on the recording medium, it is used for formation of images, patterns, patterns, etc., processing of the recording medium, or ink processing (for example, solidification or insolubilization of the colorant in the ink applied to the recording medium). It shall represent a liquid that can be made.

  Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port or a liquid channel communicating with the ejection port and an element that generates energy used for ink ejection.

  The recording head substrate (head substrate) used below does not indicate a simple substrate made of a silicon semiconductor but indicates a configuration in which each element, wiring, and the like are further provided.

  Further, the term “on the substrate” means not only the element substrate but also the surface of the element substrate and the inside of the element substrate near the surface. The term “built-in” as used in the present invention is not a word indicating that each separate element is simply arranged separately on the surface of the substrate. It shows that it is integrally formed and manufactured on top.

<Basic configuration of recording apparatus (FIG. 1)>
FIG. 1 is an external perspective view showing a configuration of a main part of an ink jet recording apparatus IJRA which is a typical embodiment of the present invention. As shown in FIG. 1, the ink jet recording apparatus of this embodiment records a recording head (full line recording head) IJH that ejects ink jets over a range that covers the entire width of a recording medium such as continuous sheet recording paper P, for example. It has a configuration arranged in the paper transport direction. Ink is ejected toward the recording paper P from the ejection ports IN of these recording heads IJH at a predetermined timing.

  In this embodiment, the recording sheet P, which is a foldable continuous sheet, is driven in the VS direction shown in FIG. 1 by the control from the control circuit described below, and is recorded on the recording sheet. Is made. In FIG. 1, reference numeral 5018 denotes a conveyance roller, and 5019, together with the conveyance roller 5018, holds the continuous sheet recording paper P at the recording position, and the recording paper P is linked to the conveyance roller 5018 driven by a drive motor (not shown). A discharge-side roller that conveys in the direction of arrow VS.

  In FIG. 1, as a configuration for performing monochrome recording, a configuration in which one full line recording head IJH is provided to eject black (K) ink is illustrated. When performing color recording, at least four full line recordings corresponding to at least yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (K) ink used for color recording. A head is provided along the conveyance direction of the recording paper.

  For example, two full-line recording heads that eject ink of the same color may be provided for high-quality recording and high-speed recording. Such a configuration will be specifically described in the following several embodiments.

  Furthermore, the recording medium used in the recording apparatus may be a continuous sheet as shown in the figure or a cut sheet.

<Control Configuration of Recording Apparatus (FIG. 2)>
FIG. 2 is a block diagram showing a control configuration of the recording apparatus shown in FIG.

  In FIG. 2, 1700 is an interface for inputting a recording signal from an external device such as a host computer, 1701 is an MPU, 1702 is a ROM for storing a control program (including a character font if necessary) executed by the MPU 1701. Reference numeral 1703 denotes a DRAM that temporarily stores various data (such as the recording signal and recording data supplied to the recording head). Reference numeral 1704 denotes a gate array (GA) that controls supply of recording data to the recording head IJH, and also performs data transfer control among the interface 1701, MPU 1701, and RAM 1703. Reference numeral 1708 denotes a conveyance motor for conveying the recording paper (continuous sheet in this embodiment). Reference numeral 1705 denotes a head driver for driving the recording head IJH, and 1706 denotes a motor driver for driving the transport motor 1708. Data is supplied from the head driver to the recording head via an LVDS line 300 described later.

  The operation outline of the control circuit will be described. When a recording signal is input to the interface 1700, the recording signal is converted into recording data for printing between the gate array 1704 and the MPU 1701. Then, the motor driver 1706 is driven, and the recording head IJH is driven in accordance with the recording data sent to the head driver 1705 to perform a recording operation.

  Next, the actual configuration of the full line recording head will be described.

  FIG. 3 is a schematic diagram showing the arrangement of the head units constituting the full line recording head.

  As shown in FIG. 3, in the full line recording head of this embodiment, a plurality of head units having a predetermined number of nozzle groups are arranged while being shifted in the nozzle row direction. In the case of FIG. 3, a total of 10 head units 101 to 110 are arranged to realize a nozzle group having a long recording width as a whole. Each head unit has a head substrate to be described later.

  Next, several embodiments of the configuration of the head unit of the full-line recording head mounted on the recording apparatus having the above configuration and the connection configuration of the recording apparatus will be described.

  FIG. 4 is a functional block diagram showing the configuration of the recording head, the head unit constituting the recording head, and the recording apparatus.

  4, the same components as those already described with reference to FIGS. 2 and 10 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 4, the head units 101... Including the head controller 202 are connected by a bus in the LVDS line 300 and are individually controlled by high-frequency data from the recording apparatus. An LVDS transceiver 401a is provided on the recording apparatus side, and each head unit of the recording head is provided with an LVDS receiver 201a. Further, power is supplied from the power supply 1710 to each head unit of the recording head IJH under the control of the power supply control unit 1711.

  Specific data is selectively received by each head unit according to the head unit selection information included in the high-frequency data. In the case of the configuration shown in FIG. 4, the transfer rate of high-frequency data in the LVDS line 300 is several hundreds Mbit / sec. For this reason, in order to synchronize with the clock signal in the head unit, synchronization with the internal clock is achieved using a PLL or the like. Since the transfer speed of the feedback information from the recording head IJH to the recording apparatus is not so high, there is no problem, so a normal logic circuit level is applied.

  FIG. 5 is a functional block diagram showing a detailed configuration built on the head substrate inside the head unit. In this figure, the configuration of the head substrate corresponding to the head unit 101 is representatively shown, but the same head substrate is also provided in other head units.

  Each terminal of the head substrate 120 is provided as shown in FIG. The head unit 101 including the head substrate is provided with a flexible substrate (not shown) connected to each terminal on the outer periphery of the head substrate. A plurality of power supply terminals VH and GNDH shown in FIG. 5 are a power supply terminal for supplying a recording current to the recording element and a ground terminal for the feedback current.

  The recording current per recording element is several tens of mA and exceeds 1 A when 10 elements or more are energized simultaneously. For this reason, two systems are distributed and arranged in units of recording element arrays constituted by recording elements 16 such as 1280 electrothermal conversion elements provided on both sides of the ink supply port 17. These 1280 recording elements are indicated by A1 to A1280 and B1 to B1280. VDD is a power supply terminal for driving the semiconductor circuit, and GNDL is a ground terminal thereof. Note that although only one of these terminals is shown in FIG. 5, it may be added as appropriate in accordance with the configuration of the semiconductor circuit.

  In the configuration shown in FIG. 5, there is only one differential transmission line indicated by DATA + and DATA− as data signal input lines.

  In this embodiment, the data sent through the differential transmission line is high-frequency data, and the data corresponding to the recording elements after the differential receiver 2 is recording data. As other signal lines, there are only two pulse signal input lines for supplying energy for arbitrarily driving the recording elements from the recording apparatus side. The two breakdowns are ODD and EVEN terminals that can drive the recording elements 16 separately at odd and even positions in the same recording element array. Since this terminal is a negative logic signal, it is connected to the AND circuit 14 in the head unit via the inverting buffers 12 and 13.

  Although the pulse signal is not shown in FIG. 4, the head controller 202 may generate a pulse signal having an optimal pulse width in accordance with information stored in the memory 204. Further, an optimum pulse width signal may be generated by the head controller 202 based on pulse width data obtained by a single differential transmission line indicated by DATA + and DATA−. In addition, the head substrate 120 has an ink supply port 17 that can correspond to two colors (or one color) that penetrates the semiconductor substrate.

  Signals input from the ODD and EVEN terminals are supplied to an AND circuit 14 corresponding to an even / odd recording element, and function in common for a plurality of recording element arrays. Now, 640 recording elements 16 are arranged for each column, and 640-bit drivers 15 corresponding to the number of the recording elements 16 are driven in accordance with recording data, divided drive data, and pulse signals input to the AND circuit 14. The recording data is an output from the latch circuits 7, 8, 9, and 10 corresponding to the recording element array. The divided drive data is input to the latch circuit 6 using the last 4 bits of the data line, and the output is converted into 16 types of outputs by the decoder circuit 11.

  Further, the shift registers 4 and 5 assign data to the latch circuits 6 to 10, respectively. This shift register circuit corresponds to high-speed transfer, which is a feature of the present invention. This shift register, the shift clock generation thereof, and the configuration for controlling the latch signal input to the latch circuit after the expansion are the characteristic configuration of the present invention.

  In the conventional recording head configuration (not shown), the data of the shift register is shifted using a shift clock of about several tens of MHz. In the present invention, the data is processed at a speed twice or more. Conventionally, a clock input exceeding several tens of MHz has caused an increase in the input buffer size of the semiconductor circuit. For this reason, for data transfer with a transfer rate of 50 MHz or higher, the transfer frequency is lowered and data transfer is performed on two or more data lines. Therefore, when the number of recording elements reaches several thousand, the data lines are made parallel by that amount. For this reason, the number of data input terminals has increased.

  On the other hand, in this embodiment, the data line receiver is a differential transmission line, and an LVDS receiver 2 is used as shown in FIG. The differential input signal by DATA + and DATA− is a low voltage of about several hundred mV. These low voltage signals can reduce power consumption on the line, contribute to EMI countermeasures, and reduce the differential buffer size of the input stage. After high frequency data is input into the semiconductor circuit, the internal circuit can be made small so that a function corresponding to the high frequency characteristics can be extracted.

  The most characteristic configuration of this embodiment is that there is no data shift clock input other than the LVDS receiver 2. Even if high-frequency data is input using a differential line, data cannot be expanded unless a clock synchronized with the high-frequency data is input.

  Conventionally, as disclosed in Patent Document 5, the clock line is also received by the LVDS receiver. However, when the frequency becomes higher, jitter on the clock transmission side (subtle shift in clock timing) occurs. There is a possibility that synchronization with high-frequency data may not be achieved. In addition, the number of terminals increases by receiving the clock at two terminals. In consideration of these points, this embodiment is characterized in that a multiplexed clock is reproduced from the data line. In other words, a configuration is adopted in which the clock in the head unit is generated by the clock recovery circuit 3 and the timing control circuit 3a without inputting the clock into the head unit 101.

  FIG. 6 is a circuit diagram showing only the LVDS line and its peripheral circuits shown in FIG.

  FIG. 6 shows the wiring in the recording head as a configuration when the bus is actually connected. The parallel data signals transmitted from the gate array (GA) 1704 and the head driver 1705 on the recording apparatus side are multiplexed by the LVDS transceiver 401a and sent out as a serial signal. On the other hand, after passing through the LVDS receiver 201a of the recording head, a synchronous clock is reproduced from the information, and thereafter, serial-parallel conversion is performed.

  In FIG. 6, parallel signals are indicated by thick arrows.

  In the LVDS configuration of bus connection, there are a single termination configuration and a plurality of (including bidirectional) connections.

  In the former, an LVDS transceiver is installed at one end, an LVDS receiver is connected toward the other end, and a termination resistor is required at the final end. The latter has a configuration in which a terminating resistor is arranged at both ends, and an LVDS transceiver and a receiver are arranged therebetween.

  In this embodiment, the latter example is shown in FIGS.

  As shown in FIG. 3, the recording head is provided with a wiring substrate that is electrically connected to the head substrates of the head units 101 to 110. This configuration may be a printed circuit board or a flexible circuit board. In this wiring board, the interval between the pair wirings is arranged as short as possible so that the bus-connected LVDS functions effectively. In addition, the LVDS wiring is not affected as much as possible from the surroundings. The aforementioned termination resistors are arranged at both ends of the bus wiring, and pull-up and pull-down resistors are added to increase the high-frequency response speed. In this way, large-capacity and high-speed data transfer is achieved with only two pair wires for the high-frequency LVDS bus.

  FIG. 7 is a circuit diagram showing a configuration when the high-frequency LVDS line shown in FIG. 4 is a bidirectional bus.

  G. on the recording apparatus side. A. The parallel data signals from 1704 and the head driver 1705 have a function of multiplexing clocks by the LVDS transceiver 401a and sending them out as serial signals, and converting the received data from serial to parallel on the same line.

  Similarly, the LVDS receiver 201a in the recording head also has serial-parallel conversion and parallel-serial conversion functions. In FIG. 7, parallel bidirectional signals are indicated by thick arrows.

  Also in the bidirectional high-frequency LVDS bus shown in FIG. 7, a wiring configuration similar to that in FIG. 6 can be applied. For example, it is possible to transmit the information of the recording head to the recording apparatus side by this bidirectional bus. As the function is added to the recording head, the amount of information processing increases, so two-way communication such as the configuration shown in FIG. 7 is required.

  With such a bidirectional transmission configuration, it is possible to notify the recording apparatus side whether or not the image data has been correctly sent to the recording head. In addition, if standardization as a general-purpose recording head such as error correction progresses, its application will be widespread, and this type of recording head can be adapted to various apparatuses.

  FIG. 8 is a block diagram illustrating a configuration of a recording head and a recording apparatus according to the second embodiment.

  In FIG. 8, the same components as those already described in FIGS. 2, 4, and 10 are denoted by the same reference numerals, and the description thereof is omitted.

  In this embodiment, the head substrate 101 of the head unit 101 including the head control unit 202 is divided into a plurality of high-frequency LVDS lines without connecting the LVDS lines 300a to 300d by a bus. In this case, since there is a one-to-one correspondence between the LVDS receiver of each head unit and the LVDS transceiver of the recording apparatus, head unit selection information is not added to the high-frequency data from the recording apparatus, and each head unit is individually Be controlled.

  The configuration according to this embodiment is effective when each head unit is relatively large in terms of the number of recording elements, control functions, and the like.

  FIG. 9 is a block diagram illustrating a configuration of a recording head and a recording apparatus according to the third embodiment.

  In FIG. 9, the same components as those already described in FIGS. 2, 4, and 10 are denoted by the same reference numerals, and the description thereof is omitted.

  In this embodiment, the head control unit 202 is provided separately from the recording head IJH. This embodiment is effective when using a recording head in which a plurality of head units having an existing configuration without LVDS are used, and one head control unit 201 controls a plurality of head units 101 to 104 in parallel control. Drive control is performed. The head control unit 202 according to this embodiment is a component such as an ASIC, and is disposed in the vicinity of the recording head separately from the recording head.

  The connection between the head controller and the head substrate of each head unit is a plurality of wiring connections, but the influence of EMI or the like can be reduced by shortening the distance and further separating from the power supply line. Further, the head controller may be directly mounted on the recording head. For example, the head control unit common to the head unit may be executed on the head substrate shown in FIG.

  Furthermore, if packet transmission is performed between the recording head and the recording apparatus main body according to a predetermined transfer protocol, transmission of all transfer control data can be realized by one transmission line. Standardized recording head assemblies provide a variety of uses.

  Needless to say, the configuration of the embodiment described above is not affected by differences in electrical and mechanical configurations, software sequences, and the like as long as the effects of the present invention can be obtained.

  In the embodiment described above, the recording apparatus equipped with the full line recording head has been described as an example. However, the present invention can be applied to a recording apparatus using a recording head mounted on a carriage that reciprocates. In this case, it is possible to adopt a configuration in which a plurality of head substrates corresponding to, for example, ink colors are provided on the carriage.

  Further, in the embodiment described above, a low voltage differential signal (LVDS) line is used as a configuration for realizing high-speed and large-capacity data transmission from the recording apparatus to the recording head, but the present invention is not limited thereto. Absent. For example, a configuration using low current differential transmission (LCDS) instead of the LVDS line may be used. When LCDS is used for the differential transmission line, the information transmission speed in the differential transmission line between the recording apparatus and the recording head is configured to be less than half the information speed developed by the recording head. Is possible.

  Further, in the embodiments described above, the liquid droplets ejected from the recording head are described as ink, and the liquid stored in the ink tank is described as ink. However, the storage is limited to ink. It is not something. For example, a treatment liquid discharged to the recording medium may be accommodated in the ink tank in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

  The above embodiment uses a method that includes means (for example, an electrothermal converter) for generating thermal energy for ink ejection, and causes a change in the state of the ink by the thermal energy, among ink jet recording methods. High density and high definition of recording can be achieved.

  In addition, the ink jet recording apparatus according to the present invention may be used as an image output apparatus for information processing equipment such as a computer, a copying apparatus combined with a reader, or a facsimile apparatus having a transmission / reception function. It may be one taken.

1 is an external perspective view showing an outline of a configuration of an ink jet recording apparatus that is a representative embodiment of the present invention. 3 is a block diagram illustrating a configuration of a control circuit of the recording apparatus. FIG. FIG. 2 is a block diagram illustrating a schematic configuration of a full line recording head. FIG. 3 is a functional block diagram illustrating a configuration of a head unit and a recording apparatus according to the first embodiment of the invention. It is a functional block diagram which shows the detailed structure of a head unit. FIG. 5 is a circuit diagram showing only the LVDS line shown in FIG. 4 and its peripheral circuits. FIG. 5 is a circuit diagram showing a configuration when the high-frequency LVDS line shown in FIG. 4 is a bidirectional bus. FIG. 6 is a block diagram illustrating a configuration of a recording head and a recording apparatus according to a second embodiment. FIG. 10 is a block diagram illustrating a configuration of a recording head and a recording apparatus according to a third embodiment. It is a block diagram which shows the structure of the recording device using the conventional differential transmission line.

Explanation of symbols

2, 201, 201a LVDS receiver 3 clock recovery circuit 3a timing control circuit 4, 5 shift register 6-10 latch circuit 11 decoder circuit 12, 13 inversion buffer circuit 14 for ODD / EVEN terminal AND circuit 15 640 bit driver 16 recording element 17 Ink supply ports 101-110 Head unit 300 LVDS lines 401, 401a LVDS transceiver

Claims (10)

A head substrate comprising a plurality of recording elements and a plurality of drive elements for driving the plurality of recording elements,
A differential signal receiver for receiving a serial signal including a recording signal serially transferred from the outside via a differential transmission line;
A clock generation circuit for generating a clock signal used inside the head substrate from a serial signal received by the differential signal receiver;
A head substrate comprising: a shift register for inputting the recording signal received by the differential signal receiver in synchronization with a clock signal reproduced by the clock generation circuit.   The head substrate according to claim 1, wherein the signal transferred through the differential transmission line is a low-voltage differential signal.   The head substrate according to claim 1, wherein the differential signal receiver is a bidirectional signal transmitting / receiving circuit that transmits a signal to the outside.   4. The head substrate according to claim 1, wherein each of the plurality of recording elements is an electrothermal conversion element that generates thermal energy used for ejecting ink. 5.   5. A recording head, wherein a plurality of head substrates according to claim 1 are arranged in an arrangement direction of the plurality of recording elements.   6. The recording head according to claim 5, wherein a signal for the plurality of head substrates is received via a set of differential transmission lines.   6. The recording head according to claim 5, wherein signals are transferred separately to a differential signal receiver provided on each of the plurality of head substrates via a plurality of sets of differential transmission lines. A recording apparatus that performs recording on a recording medium using the recording head according to any one of claims 5 to 7,
Generating means for generating a recording signal supplied to the recording head as a parallel signal;
Conversion means for converting the parallel signal generated by the generation means and a clock signal accompanying the signal into a multiplexed serial signal;
And a transfer unit configured to transfer the serial signal converted by the conversion unit to the recording head via a differential transmission line.   9. The recording apparatus according to claim 8, wherein the signal transferred by the differential transmission line is a low voltage differential signal.   The recording apparatus according to claim 8, wherein the transfer unit is a bidirectional transceiver that receives a signal transferred from the recording head through the differential transmission line.

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