Recording system, recording device and recording head

Abstract

To improve accuracy in inspecting poor connection of a recording head.SOLUTION: A recording system comprises a recording device and a recording head having a recording element, which can be detachably attached to the recording device. The recording device comprises data transmitting means that transmits to the recording head a clock signal with a predetermined cycle and a data signal synchronized with the cock signal. The recording head comprises receiving means that receives the clock signal and the data signal, and information transmitting means that transmits to the recording device information concerning a received result by the receiving means. The data transmitting means sets the predetermined cycle to a first cycle when transmitting control data on the recording element as the data signal, and sets the predetermined cycle to a second cycle longer than the first cycle, when transmitting connection confirmation data for confirming connection of the recording heat to the recording device.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a recording system. [Background technology]

[0002] Printing devices that print images by ejecting ink onto a printing medium are known. In printing devices that have a detachable print head that ejects ink, poor electrical contacts between the print head and the printing device (device body) can occur when the print head is attached. Poor contact can occur, for example, when minute particles of dust get caught between the contacts on the print head and the contacts on the printing device. Poor contact can prevent the control data that drives the printing elements sent from the printing device to the print head from being properly received. Therefore, printing devices equipped with a function for inspecting poor connections have been proposed (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-156032 Summary of the Invention [Problem to be solved by the invention]

[0004] The control data transmitted from the recording device to the recording head is transmitted at high frequencies to improve the recording speed, for example, using differential signaling (LVDS) which is advantageous for high speed. As the signal frequency increases, the time constant caused by the built-in circuit of the recording head can cause erroneous judgments when inspecting for poor contact in the contacts on the signal line for data transmission.

[0005] The present invention provides a technique capable of improving the accuracy of inspection for connection defects in a print head. [Means for solving the problem]

[0006] According to the present invention, A recording device; a recording head detachably attached to the recording device and having a recording element; A recording system comprising: The recording device a data transmitting means for transmitting a clock signal of a predetermined period and a data signal synchronized with the clock signal to the recording head; The recording head includes: receiving means for receiving the clock signal and the data signal; an information transmitting means for transmitting information relating to the reception result of the receiving means to the recording device, The data transmission means When control data for the recording element is transmitted as the data signal, the predetermined period is set as a first period, When connection confirmation data for confirming connection of the printhead to the printing device is transmitted as the data signal, the predetermined period is set to a second period longer than the first period. death , the data signal related to the control data includes a first signal sequence indicating a start of transmission and a second signal sequence related to driving the recording elements, the connection confirmation data includes the first signal sequence but does not include the second signal sequence; A recording system is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique capable of improving the accuracy of inspection for connection defects in a print head. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are external perspective views of a recording system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of a control system of the recording system of FIGS. 1(a) and 1(b). [Figure 3] FIG. 1A is an explanatory diagram of a signal line between an LVDS transmitting circuit and an LVDS receiving circuit, and FIG. 1B is an explanatory diagram showing an example of a wiring defect in the signal line. [Figure 4](a) is an explanatory diagram of a trigger signal, (b) is a diagram showing an example of the configuration of a signal sequence of recording control data, (c) is a diagram showing an example of the configuration of a signal sequence of connection confirmation data, (d) is a diagram showing an example of information indicating the connection determination result (normal), and (e) is a diagram showing an example of information indicating the connection determination result (bad). [Figure 5] 4 is a timing chart showing an example of a signal based on a period (frequency) when recording control data is transmitted. [Figure 6] 1 is a timing chart showing an example of a signal based on a period (frequency) taking into account a time constant. [Figure 7] 6A and 6B are flowcharts showing an example of processing by a control unit of a recording apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] First Embodiment <Recording system overview> Fig. 1(a) is an external perspective view of a recording system according to one embodiment of the present invention, and Fig. 1(b) is a perspective view of the recording system with the upper cover removed. The recording system of this embodiment comprises a recording device 2 and a recording head 11. The recording system can also be called a recording device, and in this case, the recording device 2 can also be called the device main body.

[0011] The recording device 2 is an inkjet printer, and in this embodiment, it is assumed to be a recording device that uses recording media of relatively large sizes such as A0 size or B0 size (so-called large size). However, the present invention is also applicable to recording devices that use recording media of relatively small sizes and recording devices of other types.

[0012] "Recording" not only includes the formation of meaningful information such as characters and figures, but also includes the formation of images, patterns, designs, etc. on a recording medium, whether meaningful or insignificant, or the processing of the medium, regardless of whether it is manifested in a way that can be perceived visually by humans. In addition, although sheet-like paper is assumed as the "recording medium" in this embodiment, it may also be cloth, plastic film, etc.

[0013] 1(a), a manual insertion slot 88 is provided on the front of the recording device 2, and a roll paper cassette 89 that can be opened and closed to the front is provided below the manual insertion slot 88. Recording media (sheets) are supplied into the recording device 2 from the manual insertion slot 88 or the roll paper cassette 89.

[0014] The recording device 2 comprises a housing 94 supported by two legs 93, a stacker 90 for stacking ejected recording media, and a transparent upper cover 91 that can be opened and closed and allows the interior to be seen through. An operation unit 420 and ink tanks 8 are disposed on the right side of the housing 94.

[0015] 1(b), the recording device 2 includes a transport roller 70 for transporting the recording medium in the direction of arrow B (sub-scanning direction), and a carriage 4 supported so as to be movable back and forth across the width of the recording medium (direction of arrow A, main scanning direction). The transport roller 80, together with a motor and a speed reduction mechanism (not shown), constitutes a transport mechanism, and the recording medium is transported by the rotation of the transport roller 80.

[0016] The carriage 4 is connected to an endless carriage belt 270. The carriage belt 270, together with a carriage motor and pulleys (not shown), constitute a belt transmission mechanism, and the carriage 4 moves as the carriage belt 270 runs. The position of the carriage 4 is detected by a sensor (not shown). The carriage 4 is provided with a plurality of recording heads 11 and a sensor unit 30.

[0017] In this embodiment, color printing can be performed on a printing medium. To this end, a printing head (hereinafter referred to as printing head) 11 consisting of four heads corresponding to the types of ink is mounted on the carriage 4. That is, the printing head 11 is configured, for example, with a K head that ejects K (black) ink, a C head that ejects C (cyan) ink, an M head that ejects M (magenta) ink, and a Y head that ejects Y (yellow) ink. Ink is supplied from an ink tank 8. A recovery unit 9, for example, suctions the ink ejection ports of the printing head 11 to eliminate ink ejection failures caused by clogging of the ejection ports. The printing head 11 may be a unit for each type of ink, or may be a single unit equipped with heads for multiple types of ink.

[0018] In this embodiment, the recording head 11 is detachable from the carriage 4. If the performance of the recording head 11 deteriorates, it is possible to replace the recording head 11. In other words, the old recording head 11 can be removed from the carriage 4, and a new recording head 11 can be attached to the carriage 4.

[0019] The sensor unit 30 is a unit capable of reading an image recorded on a recording medium. The sensor unit 30 is, for example, a reflective optical sensor, and reads the image by detecting the density of the image (e.g., a pattern) formed on the recording medium. By combining the transport of the recording medium in the sub-scanning direction with the movement of the carriage 4 in the main scanning direction, the sensor unit 30 can read an image at any position on the recording medium. The sensor unit 30 can also be used to detect the edges of the recording medium and determine the type of recording medium.

[0020] When an image is recorded on a recording medium with the above configuration, the recording medium is conveyed to a predetermined recording start position by the conveyance roller 70. Thereafter, the operation of ejecting ink while scanning the recording head 11 in the main scanning direction by the carriage 4, and the operation of conveying the recording medium in the sub-scanning direction by the conveyance roller 70 are repeated, thereby recording an image on the entire recording medium.

[0021] That is, recording is performed on the recording medium by moving the carriage 4 in the direction of arrow A shown in FIG. 1B using the belt 270 and a carriage motor (not shown). When the carriage 4 is returned to its position before scanning (home position), the recording medium is conveyed in the sub-scanning direction (the direction of arrow B shown in FIG. 1B) by the conveyance roller 80, and then the carriage 4 is scanned again in the direction of arrow A in FIG. 1B. In this manner, images, characters, etc. are recorded on the recording medium. The above operation is further repeated, and when recording on one sheet of recording medium is completed, the recording medium is ejected into the stacker 90, completing recording on one sheet. As described above, the recording device 2 of this embodiment is a serial inkjet printer that performs recording by scanning the recording head 11, but the present invention is also applicable to a full-line head recording device.

[0022] <Control system configuration> 2 is a block diagram of the control system of the printing system of this embodiment. The printing apparatus 2 is provided with a control unit 100, and the printhead 11 has a built-in head circuit 200.

[0023] The control unit 100 has the following configuration: A CPU 101 controls the entire recording device 2. The CPU 101 controls the operation of the entire recording device 2 by executing an operation control program stored in a ROM 106. The operation unit 420 is, for example, a touch panel, and the CPU 101 detects inputs thereto and controls display.

[0024] A host I / F (interface) 103 connects the printing apparatus 2 and the host computer 300, and transmits and receives data between them. Print job data received from the host computer 300 via the host I / F 103 is stored in RAM. 108 The host interface 103 performs communication using a serial communication method such as USB or a network communication method such as 1000Base-TX.

[0025] The RAM 108 is connected to the system bus via a RAM controller 109 that controls access to the RAM 108. The RAM 108 functions as a work memory when the operation control program executed by the CPU 101 is executed. The RAM 108 also functions as a buffer memory for storing print job data and various intermediate data generated during the execution of the print process.

[0026] The ROM 106 is connected to the system bus via a ROM controller that controls access to the ROM 106. The ROM 106 is a memory that stores the operation control program executed by the CPU 101, various data for recording control, various screen data to be displayed on the operation unit 420, etc. The operation control program includes a program for controlling the printer engine 208 and a connection check program. The connection check program is a program that determines whether the recording head 11 is properly attached to the recording device 2, and an example of the processing will be described later.

[0027] The HDD 104 functions as a mass storage device for the recording device 2 and can be used to store recording job data received from the host computer 300, for example.

[0028] The image processing circuit 102 converts the print job data received from the host computer 300 into image data to be output to a recording medium and stores the image data in the RAM 108. For example, the image processing circuit 102 performs color space conversion processing, gamma correction processing, quantization processing using an error diffusion method, etc. on the image data transmitted from the host computer 300 as the print job data.

[0029] The printer engine 110 includes a motor that drives the conveying roller 80. Yakki Motor for moving the cartridge 4, recording device 2 The printer engine 110 includes various actuators and sensors. The printer engine 110 is connected to the system bus via an I / F (interface) 111, and its operation is controlled by the CPU 101.

[0030] The print control data generation circuit 112 generates print control data for causing the print head 11 to eject ink. For example, the print control data generation circuit 112 reads image data from the RAM 108 in accordance with an ejection timing signal generated from a signal indicating the position of the carriage 4. The print control data generation circuit 112 then performs data processing according to various drive formats for the nozzles of the print head 11 to generate print control data. The generated print control data may be temporarily stored in the RAM 108. The print control data is converted into a serial signal and transmitted from the LVDS transmission circuit 113 to the print head 11. Heat data based on a divided pulse width modulation drive method may be transmitted together with the print control data. The divided pulse width modulation drive method is a method in which, for example, the pulse applied to the print element (heater) is not a single pulse, but is configured with a pre-pulse that preheats the ink directly above the heater and a main pulse that causes the ink to bubble.

[0031] LVDS transmitter circuit 113 (Data transmission means) is a signal transmission circuit of a differential transmission system, which transmits a differential transmission signal. The connection check data generation circuit 114 generates connection check data for checking the connection of the recording head 11 to the recording device 2. The connection check data is converted into a serial signal and transmitted from the LVDS transmission circuit 113 to the recording head 11.

[0032] The head circuit 200 has the following configuration: 2 00, data is transmitted and received using a differential transmission method using an LVDS signal line 115 between the LVDS transmitting circuit 113 and the LVDS receiving circuit 202. Data is transmitted and received in a single-ended format on other communication paths.

[0033] LVDS receiver circuit 202 (Means of receiving)It receives the signal sequence of the recording control data transmitted from the LVDS transmission circuit 113, deserializes it, and outputs it to the control circuit 201. The control circuit 201 controls the drive circuit 204 based on the recording control data and drives the recording element 205. The recording element 205 is provided for each ink ejection port and is an element that ejects ink by supplying power, and in particular, is an electrothermal conversion element (heater). The electrothermal conversion element heats by energization to foam the ink, and ejects the ink from the ink ejection port with the foaming energy. Note that the recording element 205 may be other recording elements such as a piezo element instead of the electrothermal conversion element.

[0034] Reception result transmission circuit 203 (Means of transmitting information) is an information transmission circuit that transmits information related to the reception result of the signal sequence by the LVDS reception circuit 202 to the control unit 100. More specifically, the reception result transmission circuit 203 is a signal sequence determination circuit that monitors the signal sequence received by the LVDS reception circuit 202 and transmits information indicating whether there is an error in the signal sequence to the control unit 100.

[0035] The memory 206 is a non-volatile memory that stores the individual information of the recording head 11 and the like, and is, for example, a ROM. The memory 206 is connected to the control unit 100 via a memory controller that controls its access, and the CPU 101 can acquire the information stored in the memory 206.

[0036] <LVDS signal line> FIG. 3(a) is an explanatory diagram of the LVDS signal line 115. The LVDS signal line 115 includes a signal line for a CLK+ signal, a signal line for a CLK- signal, a signal line for a DATA+ signal, and a signal line for a DATA- signal. The CLK+ signal and the CLK- signal are clock signals whose + and - are inverted relative to each other. The DATA+ signal and the DATA- signal are data signals whose + and - are inverted relative to each other. Contacts C1 to C4 are present on each signal line. When the printhead 11 is attached to the carriage 4, the signal lines are electrically connected at the contacts C1 to C4. A termination resistor 202a is connected between the signal line for the CLK+ signal and the signal line for the CLK- signal. Furthermore, a termination resistor 202b is connected between the signal line for the DATA+ signal and the signal line for the DATA- signal. The resistance values ​​of the termination resistors 202a and 202b are, for example, 100 Ω.

[0037] <Checking for poor connections> If a foreign object gets caught in the contacts C1 to C4, causing poor contact, data transmission from the control unit 100 to the print head 11 will be hindered. For example, this may occur if the electrical connection is interrupted at contact C4, as shown in Figure 3(b). In the following, an inspection for poor connection of the print head 11 to the recording device 2 will be described.

[0038] 4(a) to 4(e) are diagrams illustrating the operation of the reception result transmission circuit 203. Fig. 4(a) shows an example of a trigger signal transmitted from the LVDS transmission circuit 113. The period between a trigger signal 21 and the next trigger signal 22 is one unit of the determination period.

[0039] Figure 4(b) shows the signal arrangement structure (data format) of the recording control data. The recording control data consists of a start command 23 (First signal sequence) , multiple recorded data 24 (Second signal sequence), and CRC command 25. The start command 23 is a signal sequence indicating the start of transmission, and the recording data 24 is a signal sequence corresponding to the actual control data of the recording element 205. Figure 4(c) shows the signal arrangement structure of the connection confirmation data. In this embodiment, a method is adopted in which the reception result transmitting circuit 203 does not need to recognize in advance whether the signal sequence received by the LVDS receiving circuit 202 is recording control data or connection confirmation data. The connection confirmation data includes only the start command 23 in the recording control data.

[0040] If the connection of the recording head 11 to the recording device 2 is normal, the recording head 11 expects the recording data 24 and CRC command 25 following the start command 23. However, if the connection confirmation data is received, the CRC command 25 does not arrive between the trigger signal 21 and the next trigger signal 22. In this case, the reception result transmission circuit 203 sets the reception error flag to "1" as shown in Figure 4(d). The default value of the reception error flag (when reception is normal) is "0", and "1" indicates that there is an error in the received signal sequence.

[0041] During the printhead 11 connection confirmation process, the CPU 101 obtains the value of the reception error flag from the reception result transmission circuit 203, and if this value is "1," it determines that the printhead 11 is properly attached to the recording device 2. This is because the connection confirmation data contains only the start command 23 and does not contain the CRC command 25, and therefore if it is properly transmitted to the printhead 11, it is always determined to be a reception error. Conversely, during the printhead 11 connection confirmation process, if the reception error flag is "0," as shown in FIG. 4(e), it can be determined that the printhead 11 is not properly connected. Note that if the recording device 2 is configured to have multiple printheads 11 with different types of ink attached, this connection failure inspection is performed on each printhead 11.

[0042] This mechanism can be used to check for connection defects in the recording head 11, but if the frequency of the clock signal is high (the period is short), it may be affected by the time constant on the LVDS signal line 115, resulting in erroneous judgment. In particular, the differential transmission method is advantageous for high-frequency data transmission, and it is possible to send recording control data from the control unit 100 to the recording head 11 at higher speeds. However, this may be affected by the time constant. Figure 5 is an explanatory diagram.

[0043] 5, CLK_DEF is the voltage difference between the CLK+ signal and the CLK- signal transmitted from the LVDS transmission circuit 113, and is a clock signal with a period T1. The period T1 is the transmission period of the recording control data. DATA_DEF0 is the difference between the DATA+ signal and the DATA- signal transmitted from the LVDS transmission circuit 113. - It is the voltage difference between the signal and the data signal.

[0044] The data signal is synchronized with the clock signal and is delayed by 1 / 4 cycle relative to the clock signal. This delayed signal may be generated by the LVDS transmitter circuit 113 at the source, or by the LVDS receiver circuit 202. The received data signal sequence can be converted into digital data by latching the data signal (DATA_DEF0) at the rising and falling edges of the clock signal (CLK_DEF) and comparing its voltage value with a voltage threshold TH. In the example shown in the figure, "1010" is obtained as the data indicated by the data signal (DATA_DEF0).

[0045] 3(b), if there is poor contact at contact C4, and if there is no parasitic capacitance in the head circuit 200 and the time constant is 0, the potential of the termination resistor 202b becomes equipotential, and the data signal obtained on the LVDS receiving circuit 202 side becomes "0000," as indicated by DATA_DEF1.

[0046] In the example of FIG. 4(c), if the start command is "1010," then in the case of DATA_DEF0 in FIG. 5, the start command is recognized. After that, the CRC command is not received, so the reception result transmission circuit 203 sets the reception error flag to "1." As a result, the CPU 101, which has acquired the reception error flag, determines that the connection of the printhead 11 is normal. In the case of DATA_DEF1 in FIG. 5, the start command is not recognized, so the reception error flag remains at the default value of "0." As a result, the CPU 101, which has acquired the reception error flag, determines that the connection of the printhead 11 is faulty.

[0047] However, in reality, a time constant exists due to the parasitic capacitance within the head circuit 200, the resistance of the signal line, etc., and if the time constant exceeds a certain level, the data signal will be affected. If poor contact occurs at contact C4 as shown in FIG. 3(b), a voltage difference may occur, as shown by DATA_DEF2, unlike DATA_DEF1 in FIG. 5, and data "1010" may be obtained. If the start command is "1010," in the case of DATA_DEF2 in FIG. 5, the start command is recognized, but the CRC command is not received thereafter, so the reception result transmission circuit 203 sets the reception error flag to "1." As a result, the CPU 101, upon receiving the reception error flag, erroneously determines that the connection of the printhead 11 is normal.

[0048] Therefore, in this embodiment, the connection confirmation process for the print head 11 is performed in the period T1 (First Cycle) period T2, which is longer than period T1 (Second Cycle) This makes it possible to prevent erroneous judgments due to the time constant. Figure 6 shows an example of this.

[0049] 5, CLK_DEF is a clock signal that is the voltage difference between the CLK+ signal and the CLK- signal transmitted from the LVDS transmission circuit 113. However, its period T2 is longer than the period T1.

[0050] The period T2 is set to, for example, a time equal to or greater than the period T1 plus a time constant determined through experiments, etc. For example, if the period T1 when transmitting the recording control data is 1.0 nsec (frequency: 1 GHz) and the time constant on the signal line is 0.5 nsec, the period T2 is 2 nsec (frequency: 500 MHz). Expressed as a formula, for example, T2 = T1 + time constant + coefficient, or T2 = T1 + time constant × coefficient (> 1), or T2 = (T1 + time constant) × coefficient (> 1).

[0051] DATA_DEF0 is the same as the example in Figure 5, with the DATA+ signal and DATA - The data signal is the voltage difference between the clock signal and the data signal, and is delayed by 1 / 4 cycle relative to the clock signal. As in the example of Figure 5, the data signal (DATA_DEF0) is latched at the rising and falling edges of the clock signal (CLK_DEF), and the voltage value is compared with the voltage threshold TH, thereby converting the received data signal string into digital data "1010".

[0052] DATA_DEF2, like the example in FIG. 5, shows an example in which poor contact occurs at contact C4, as shown in FIG. 3(b), and the time constant affects the data signal. However, by lengthening the period T2, the timing of the voltage fluctuation shifts from the comparison timing with the voltage threshold TH (the rising and falling edges of the clock signal). As a result, the obtained data is "0000," and like the example in DATA_DEF1 in FIG. 5, the reception error flag remains at the default value of "0." As a result, the CPU 101, which has acquired the reception error flag, determines that the connection of the print head 11 is faulty. In this way, this embodiment can improve the accuracy of inspections for poor connections of the print head 11.

[0053] <Processing example> An example of the connection inspection process for the print head 11 executed by the CPU 101 will be described. 7 The process shown in FIG. 1(a) is executed, for example, when the recording device 2 is turned on, or when the user notifies the operation unit 420 that the recording head 11 has been replaced.

[0054] In S1, the CPU 101 causes the connection check data generation circuit 114 to generate connection check data. In the example of FIG. 6, the connection check data generation circuit 114 generates data that includes "1010" as a start command but does not include a CRC command. In S2, the CPU 101 causes the LVDS transmission circuit 113 to transmit the connection check data generated by the connection check data generation circuit 114 to the printhead 11 using the differential voltage method. At this time, the CPU 101 sets (instructs) the LVDS transmission circuit 113 to use a clock signal period T2 for transmitting the connection check data, instead of the period T1 used for transmitting the print control data. A known technique may be used to switch the signal period. In the head circuit 200 of the printhead 11, the LVDS reception circuit 202 receives the connection check data, and the reception result transmission circuit 203 sets the reception error flag to "1" or "0" based on the received data.

[0055] In S3, the CPU acquires a reception error flag from the reception result transmission circuit 203 and determines whether the acquired reception error flag indicates error information ("1"). If it indicates error information, the process proceeds to S4, where the status of the recording device 2 is set to indicate that the recording head 11 is normally connected. If it does not indicate error information, the process proceeds to S5, where the status of the recording device 2 is set to indicate that a connection failure has occurred with the recording head 11. If it is set to indicate a connection failure, the CPU executes a response process, such as notifying the user.

[0056] Second Embodiment In the first embodiment, the period T2 is a uniform period regardless of individual differences between the print heads 11, but it may be set for each print head 11. The time constant differs depending on the individual differences between the print heads 11. By setting the period T2 for each print head 11, it is possible to shorten the inspection time for print heads 11 with small time constants.

[0057] The individual time constants of the recording head 11 can be measured by experiment before shipping, etc. For example, a recording device 2 for measuring the time constant is prepared in advance. The recording head 11 is attached to the prepared recording device 2, and data communication is performed between the recording device 2 and the recording head 11 using the LVDS signal line 115. At this time, the time required for the rise of the signal transmitted from the recording device 2 to the recording head 11 (time constant) is measured using a measuring device. The measured time constant is then stored in the memory 206 of the head circuit 200 as time constant information specific to that recording head 11. (memory means) In this way, after the recording head 11 is distributed, the time constant information can be read from the memory 206 by any recording device 2.

[0058] In this embodiment, an example of the connection inspection process for the print head 11 executed by the CPU 101 will be described. 7 An example of this process is shown in (b) of the flowchart. This process is executed, for example, when the recording device 2 is turned on, or when the user notifies the operation unit 420 that the recording head 11 has been replaced.

[0059] CPU101 on S11 (Acquisition method) In step S12, the time constant information is acquired (read) from the memory 206 of the recording head 11. If the time constant information cannot be acquired, it can be determined at that point that the recording head 11 is poorly connected. CPU 101 (setting means) sets the period T2 based on the time constant information acquired in S11. An example of the method for setting the period T2 taking the time constant into consideration is as described in the first embodiment.

[0060] The processes of S13 to S17 are the same as those of S1 to S5 in Fig. 5(a). In S13, the CPU 101 causes the connection confirmation data generation circuit 114 to generate connection confirmation data. In S14, the CPU 101 causes the LVDS transmission circuit 113 to transmit the connection confirmation data generated by the connection confirmation data generation circuit 114 to the recording head 11 using the differential voltage method. At this time, the CPU 101 sets (instructs) the cycle T2 set in S12 as the cycle of the clock signal to the LVDS transmission circuit 113. In the head circuit 200 of the recording head 11, the LVDS reception circuit 202 receives the connection confirmation data, and the reception result transmission circuit 203 sets the reception error flag to "1" or "0" based on the received data.

[0061] In S15, the CPU acquires a reception error flag from the reception result transmission circuit 203 and determines whether the acquired reception error flag indicates error information ("1"). If it indicates error information, the process proceeds to S16, where the status of the recording device 2 is set to indicate that the recording head 11 is normally connected. If it does not indicate error information, the process proceeds to S17, where the status of the recording device 2 is set to indicate that a connection failure has occurred with the recording head 11. If it is set to indicate a connection failure, the CPU executes a response process, such as notifying the user.

[0062] <Other embodiments> The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0063] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0064] 2 recording device, 11 recording head

Claims

1. A recording device; a recording head detachably attached to the recording device and having a recording element; A recording system comprising: The recording device a data transmitting means for transmitting a clock signal of a predetermined period and a data signal synchronized with the clock signal to the recording head; The recording head includes: receiving means for receiving the clock signal and the data signal; an information transmitting means for transmitting information relating to the reception result of the receiving means to the recording device, The data transmission means When control data for the recording element is transmitted as the data signal, the predetermined period is set as a first period, When transmitting connection confirmation data for confirming connection of the print head to the printing device as the data signal, the predetermined period is set to a second period longer than the first period, the data signal related to the control data includes a first signal sequence indicating a start of transmission and a second signal sequence related to driving the recording elements, the connection confirmation data includes the first signal sequence but does not include the second signal sequence; A recording system characterized by:

2. 2. The recording system of claim 1, the data transmitting means transmits differential transmission signals as the clock signal and the data signal. A recording system characterized by:

3. 3. The recording system according to claim 1 or 2, the second period is equal to or longer than the first period plus a time constant of the data signal; A recording system characterized by:

4. 4. The recording system according to claim 3, the recording head includes a storage means for storing time constant information indicating the time constant; The recording device an acquisition means for acquiring the time constant information from the storage means; and a setting means for setting the second period based on the time constant information acquired by the acquisition means. A recording system characterized by:

5. 5. A recording system according to claim 1, the information transmitting means transmits information indicating an error to the recording device when the data signal received by the receiving means includes the first signal sequence but does not include the second signal sequence. A recording system characterized by:

6. A recording device in which a recording head having a recording element is detachable, a data transmitting means for transmitting a clock signal of a predetermined period and a data signal synchronized with the clock signal to the recording head; The data transmission means When control data for the recording element is transmitted as the data signal, the predetermined period is set as a first period, When transmitting connection confirmation data for confirming connection of the print head to the printing device as the data signal, the predetermined period is set to a second period longer than the first period, the data signal related to the control data includes a first signal sequence indicating a start of transmission and a second signal sequence related to driving the recording elements, the connection confirmation data includes the first signal sequence but does not include the second signal sequence; A recording device characterized by:

7. A recording head that is detachable from a recording device and has a recording element, a storage means for storing information that can be acquired by the recording device; a receiving means for receiving a clock signal having a predetermined period and a data signal synchronized with the clock signal, both transmitted from the recording device; an information transmitting means for transmitting information relating to the reception result of the receiving means to the recording device, the storage means stores time constant information indicating a time constant of the data signal; A recording head characterized by:

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