KR100205294B1 - Print head checking apparatus of inkjet printer - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a printhead checking method of an inkjet printer.

2. Technical problem to be solved by the invention

By checking the state of the head drive of the inkjet printer, it is convenient to know the cause of the abnormal printing of the head.

3. Summary of Solution to Invention

A head including a plurality of nozzles, a head driver for driving the nozzles, a head drive check device for generating a head drive check signal indicating nozzle operation when the nozzle is driven, and nozzles according to a head check command. A control unit of the inkjet printer constituting check data for all nozzles by sequentially searching for a head check signal and determining that the nozzle is in operation when the nozzle is driven, and determining that the nozzle is inferior when the nozzle is not driven; When the head check command is transmitted from the user, the head check command is transmitted to the inkjet printer, and the host receives the check data from the inkjet printer.

4. Important uses of the invention

It is useful for checking the print head of an inkjet printer.

Description

Printhead checker of inkjet printer

The present invention relates to an inkjet printer, and more particularly, to a head check apparatus of an inkjet printer.

In general, a printer employing a wire dot method, a thermal transfer method, or an inkjet method in a method of forming an image on a recording medium such as paper or OHP (Over Head Project) film uses a unique recording head. Among the above printers, the recording head of the inkjet printer includes a plurality of nozzles formed by minute ejection holes for ink injection. The ink in the nozzles is heated and expanded by a heating element provided corresponding to each nozzle, so that the ink is ejected to the outside of the nozzle and attached to the recording medium.

Accordingly, the inkjet printer selectively heats the nozzle of the recording head corresponding to the image to be recorded to eject ink in the nozzle to form an image on the recording medium. At this time, the driving of the nozzle is controlled by the head driving device.

Such heads fail to print normally when the head itself, that is, the nozzles are clogged or damaged, or the head drive that drives the nozzles of the head is damaged.

As described above, there are two reasons why the head does not print normally, and its countermeasure differs depending on each cause.

For example, when the head fails to print normally in the manufacturing process, the manufacturer repairs the head drive if the head fails to print normally due to damage to the head drive. If the head fails to print normally due to damage to the head itself, the ink cartridge is replaced.

On the other hand, when the head does not print normally while the user is using the inkjet printer, the user should request a repair to the service center if the head fails to print normally due to damage of the head drive, and If that doesn't work, replace the ink cartridge.

In this way, the countermeasure differs depending on the cause of the head not printing normally. Nevertheless, the conventional head check merely performed the presence or absence of the print head and the type of head, that is, the division of the color or mono head.

Accordingly, the manufacturer performed printing for each inkjet printer, and then visually checked the head driving device and the printing condition of the head. Then, the user vaguely replaced the ink cartridge with a new ink cartridge or asked a service center for repair if the printing condition of the inkjet printer was poor.

As described above, the head check of the conventional inkjet printer simply checked the presence and type of the head. Accordingly, the manufacturer has been inconvenient to check the printing state of the head driving device and the head with the naked eye after performing printing for each inkjet printer. In addition, if the user has a poor printing condition during use of the inkjet printer, the user may inexpensively replace the ink cartridge with a new ink cartridge or request a service center for repair.

Accordingly, it is an object of the present invention to provide a head check apparatus of an ink jet printer that allows the user to conveniently know the cause of the abnormal printing of the head by checking the state of the head driving apparatus of the ink jet printer.

1 is a block diagram of a typical host.

2 is a flowchart in a host of a printhead checking method of an inkjet printer according to a preferred embodiment of the present invention.

Figure 3 shows an example of displaying the state of the nozzle drive device of the inkjet printer according to the preferred embodiment of the present invention on a monitor of the host.

4 is a block diagram of an inkjet printer having a printhead checker according to a preferred embodiment of the present invention.

5 is a detailed circuit diagram of the printhead check apparatus.

6 is a flowchart of an inkjet printer in a printhead checking method of an inkjet printer according to a preferred embodiment of the present invention.

7 is a pattern diagram for checking a print head of an inkjet printer.

According to an aspect of the present invention, a head including a plurality of nozzles, a head driver for driving the nozzles, and a head drive check signal indicating that the nozzles are driven when the head driver drives the nozzles are provided. According to the head drive check device and the head check command, the nozzles are sequentially driven one by one, the head drive check signal is searched every time the nozzle is driven, and when the nozzle is driven, the nozzle is determined to be good. It is determined that the nozzle is bad, the control unit of the inkjet printer constituting the check data for all the nozzles, and when the head check command is sent from the user, and transmits the head check command to the inkjet printer, and receives the check data from the inkjet printer to display Characterized in that composed of a host .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the annexed drawings, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a block diagram of a typical host. The CPU (Central Processing Unit) 10 of the conventional host executes a set program and performs overall control of the host. The input / output interface 12 interfaces signals input and output between the CPU 10, the input device 14, the inkjet printer 16, the modem 18, and the auxiliary storage device 20. The input device 14 is a device for inputting various information or commands to the CPU 10 and may be a keyboard or a mouse. The inkjet printer 16 prints an image according to the print data provided by the CPU 10 as an output device. The modem 18 transmits and receives data through an external telephone line. As the auxiliary memory device 20, a hard disk drive, a floppy disk drive, or the like is used. The memory 22 is composed of a ROM and a RAM and stores an execution program of the CPU 10 and processing data of the CPU 10. The display controller 24 displays the various processing information of the CPU 10 on the monitor 26 under the control of the CPU 10. The monitor 26 displays an image under the control of the display controller 24.

The memory 22 stores a processing program at the host of the printhead checking method according to the preferred embodiment of the present invention. 2 is a flowchart of the processing program. The CPU 10 of the host performs step 28 of FIG. 2 when the user inputs a printhead check command through the input device 14. In step (28), the CPU 10 transmits a printhead check command to the inkjet printer 16 via the input / output interface 12. The CPU 10 performs step 30 when transmission of the printhead check command is completed. In step (30), the CPU 10 searches whether the printhead check data is received from the inkjet printer 16. At this time, if the CPU 10 receives the printhead check data from the inkjet printer 16, the CPU 10 performs step 32, and if it does not receive the printhead check data, it performs step 30 again. In step 32, the CPU 10 searches for the received printhead check data. The printhead check data is data obtained by checking the state of the first nozzle driving device of the printhead to the Nth nozzle driving device. Accordingly, the CPU 10 individually displays the states of the first nozzle driving device to the Nth nozzle driving device so that the user can conveniently recognize the state of the first nozzle driving device to the Nth nozzle driving device.

In order to display the state of the nozzle driving apparatus as described above, the CPU 10 provides the display controller 24 with data for displaying the state of the nozzle driving apparatus. The display controller 24 provides and displays data to the monitor 26 for displaying the state of the nozzle drive. 3 shows the state of the nozzle driving device displayed on the monitor 26. The state of the nozzle drive device shown in FIG. 3 is in good condition (shown as' OK ') of the first nozzle drive device and the third to Nth nozzle drive devices, and the second nozzle drive device is bad (' NG). Shown).

By displaying as described above, the user can conveniently recognize the state of the nozzle driving device. In addition, comparing the printed pattern to be described later and the state of the nozzle driving device can accurately check the state of the head and the state of the head driving device.

Figure 4 shows a block diagram of an inkjet printer with a printhead checker in accordance with a preferred embodiment of the present invention. The control unit 34 of the inkjet printer 16 executes a program stored in the memory 54 and controls each unit of the inkjet printer 16. The host interface driver 56 controls the transmission and reception of data between the host and the inkjet printer 16. The memory 54 includes a ROM for storing a control program and various initial data and a RAM for temporarily storing data according to an operation of the controller 34.

The carriage motor driving device 36 controls the driving of the carriage motor 38 under the control of the control unit 34. The carriage motor 38 is driven under the control of the carriage motor driving device 36 to move the print head 46. The line feed motor driving device 40 controls the driving of the line feed motor 42 under the control of the controller 34. The line feed motor 42 moves paper according to the control of the line feed motor driving device 40.

The operation panel driver 50 displays on the display device of the operation panel 52 according to the display data generated from the control unit 34, and controls the key input data generated as a user inputs the operation panel 52. Provide to 34. The operation panel 52 has a plurality of keys for inputting various commands to the control unit 52 and a display device for displaying various states of the inkjet printer under the control of the operation panel driving device 50.

The print head drive device 44 controls the driving of the print head 46 under the control of the control unit 34. The print head 46 performs printing by ejecting ink under the control of the print head drive 44. The print head driving device 44 typically receives a head driving signal from the control unit 34 and controls a switching unit for cutting off or connecting a power supply path of a heating element according to the head driving signal, and the plurality of head driving units. It consists of a drive transistor of the switching unit for the conduction or non-conduction according to the control of the head driving unit, the switching unit for blocking or connecting the power supply path of the heating element, and a plurality of heating elements corresponding to the drive transistor, the drive transistor When conducting, it consists of a heating unit that receives power from the power supply unit and heats it.

Typically, the switching unit composed of a plurality of drive transistors of the head driving device is a part for finally controlling the driving of each nozzle. Accordingly, by looking at the operation of the switching unit it can be seen the state of the operation of the overall head drive device. Accordingly, in the present invention, it is checked whether the printhead drive device 44 is normal by checking whether each drive transistor of the switching unit operates in response to a command to turn on the nozzle. A signal indicative of the state of the drive transistor of the printhead drive device 44 is provided to the printhead check device 48. The printhead check device 48 generates head drive check data corresponding to a signal indicating a state of the drive transistor and provides the same to the controller 34.

FIG. 5 shows a detailed circuit diagram of the switching section 58 and printhead checker 48 of the printhead drive device. As shown in FIG. 5, one side of the first nozzle heating elements to the nth heating elements NH1 to NHN of the switching unit 58 is provided with a power supply Vh through the resistor R. As shown in FIG. The other sides of the first nozzle heating elements to the Nth nozzle heating elements NH1 to NHN are connected to collectors of the first driving transistor to the Nth driving transistors TR1 to TRN, respectively. The bases of the first to Nth driving transistors TR1 to TRN are provided with signals for driving respective nozzles provided from the head driving units, that is, I1 to IN. The emitters of the first to Nth driving transistors TR1 to TRN are grounded. Accordingly, when a specific signal among the signals of I1 to IN occurs at high potential, the corresponding driving transistor is turned on, and accordingly, the nozzle heating element is heated to inject ink.

This configuration is the same as the conventional switching unit. However, as illustrated in FIG. 5, a signal generated from a node A, that is, a node to which one sides of the first nozzle heating elements to the Nth heating elements NH1 to NHN are connected, is outputted to the outside. The signal generated from the node A is a signal indicating the state of the driving transistor.

The signal generated from the node A is a high potential signal when the first to Nth driving transistors TR1 to TRN are not all conductive, that is, when the signals of I1 to IN are all low potential. Appears. The node A appears as a low potential signal when any one of the first to Nth driving transistors TR1 to TRN is turned on, that is, when any of the signals of I1 to IN have high potential.

Accordingly, the present invention checks whether the head driving device operates normally for each nozzle by looking at the signals generated at the node A while generating the signals I1 to IN at high potential one by one.

The signal generated from the node A is provided to the print head check device 48.

The cathode of the diode D1 of the print head device is connected to the node A, and the anode is connected to the node B. The node B is connected to the power supply Vh through a resistor R and is connected to the cathode of the Zener diode ZD. The anode of the zener diode ZD is connected to the base of the check transistor TRCHK. The collector of the check transistor TRCHK is supplied with a power supply Vh via a resistor R3 and the emitter is grounded. The signal generated from the collector of the check transistor TRCHK is a head drive check signal.

The operation of the printhead checker 48 is as follows. The diode D1 does not conduct when the signal generated at the node A is at high potential, that is, when no driving transistor is conducted. As a result, the control diode ZD is turned on, so that the check transistor TRCHK is turned on. Accordingly, the head drive check signal is generated at a low potential.

The diode D1 conducts when the signal generated at the node A is at low potential, that is, when any of the driving transistors is conducted. As the diode D1 conducts, the zener diode ZD does not conduct, and therefore the check transistor TRCHK does not conduct. Since the check transistor TRCHK is not conductive, the head drive signal is generated at a high potential. The head drive signal is provided to the controller 34.

FIG. 6 shows a flowchart of the ink jet printer according to the preferred embodiment of the present invention for checking the head of the ink jet printer configured as described above. The flow is performed each time a control command is received from the host. When the control command is received from the host, the controller 34 performs step 60. In step 60, the controller 34 searches whether the control command is a printhead check command. At this time, the control unit 34 performs step 62 if the control command is a printhead check command, and performs step 78 if the control command is not a printhead check command.

In step 62, the control unit 34 provides a line feed motor driving signal to load the recording paper into the line feed motor driving device 40. When the recording sheet is loaded, the controller 34 performs step (64). In step (64), the control unit 34 provides a carriage motor driving signal to the carriage movement motor 36 to move the print head 46 to the printing position. When the print head 46 is moved to the printing position, the control unit 34 performs step (66). In step (66), the control unit 34 configures a head driving check pattern.

7 shows the head driving check pattern. As shown in FIG. 7, the head driving check pattern is a pattern in which the first nozzle driving device drives only the first nozzle. The check pattern of the second nozzle drive device is such that only the second nozzle is driven. In this way, the pattern is configured so that only one nozzle in one pattern is driven for all the nozzle driving devices.

By constructing the pattern as described above, the head drive check signal generated upon printing of the head drive check pattern for driving the particular nozzle indicates the state of the particular nozzle. Accordingly, when the head drive check signal is high, it indicates that the head drive device for driving the specific nozzle is normal.

When the pattern configuration as described above is finished, the control unit 34 performs step 68. In step 68, the control unit 34 prints the check pattern of the first nozzle driving device. When the printing of the check pattern is finished, the control unit 34 receives step (70), and in step (70), the control unit 34 receives a head drive check signal. If the head drive check signal is high potential, the controller 34 determines that the first nozzle drive device is good. Data on the state of the nozzle driving apparatus is called head driving check data, and the control unit 34 stores the head driving check data. When storing of the head drive check data ends, the controller 34 performs step 74. In step 74, the controller 34 searches whether the printed pattern corresponds to the last nozzle. At this time, the controller 34 performs step 76 if the printed pattern corresponds to the last nozzle, and performs step 68 if the printed pattern does not correspond to the last nozzle to print the pattern corresponding to the next nozzle.

In step 76, the controller 34 transmits the head drive check data to the host. When the transmission of the head drive check data ends, this flow ends.

As described above, when the inkjet printer is used, the inkjet printer checks the driving device of each nozzle when the head check is instructed through the host when the head is not normally printed. In addition, the check result of the driving device of the nozzle may be transmitted to the host to search whether the head driving unit is normal through the monitor of the host. If the user checks the head because the head does not print normally, the head drive may be displayed as good on the monitor. This indicates that the cause of the abnormal factor of the head is not a damage of the head drive but a defect of the head itself.

Therefore, the user or manufacturer can conveniently check the state of the head driving unit and the state of the head.

As described above, the present invention displays the cause of the abnormal factor of the head to the user or the manufacturer when the abnormal factor of the head, the user or manufacturer has an advantage that can be appropriately performed according to the cause of the abnormal factor of the head.

Claims (5)

In the printhead checker of an inkjet printer, A head having a plurality of nozzles, A head drive device for driving the nozzles; A head drive check device for generating a head drive check signal indicating that the nozzles are driven when the head drive device drives the nozzles; According to the head check command, the nozzles are sequentially driven one by one, the head drive check signal is searched every time the nozzle is driven, and when the nozzle is driven, the nozzle is determined to be good, and when the nozzle is not driven, the nozzle is determined to be bad. A control unit of the inkjet printer constituting check data for all nozzles; And a host for transmitting a head check command to an ink jet printer when the head check command is transmitted from the user, and receiving and displaying check data from the ink jet printer. According to claim 1, wherein the head drive device, Is composed of a plurality of heating elements, one side is connected to a power source, generates a sensing signal generated on one side, each heating element portion for heating the corresponding nozzles and spraying ink in the nozzles, Comprising a plurality of drive transistors, the other side of the corresponding heating elements are respectively connected to the collector, the emitter is grounded switching unit, And a head driver for providing a signal for conducting a drive transistor corresponding to a nozzle to be driven according to the image to be printed. According to claim 2, wherein the head drive check device, And a head driving check signal generated when the sensing signal receives the sensing signal and has a low potential. According to claim 2, wherein the head drive check device, A diode which receives the sensing signal as a cathode and an anode is connected to a power source through a resistor to conduct when the sensing signal has a high potential; The cathode is connected to the anode of the diode, the zener diode is conducted when the diode is not conductive, The collector is connected to a power supply, the base is connected to a cathode of the zener diode, and the emitter is grounded to generate a high potential head drive check signal indicating that the nozzle operates normally through the collector when the zener diode is turned on. Print head check apparatus of the inkjet printer, characterized in that it comprises a. According to claim 1, wherein the control unit of the inkjet printer, After the head command is applied, the pattern is configured to sequentially print from the first nozzle to the last nozzle one by one, and the head drive check signal is retrieved for every nozzle pattern print, and the head drive check data for all the nozzles is stored. The printhead check apparatus of the inkjet printer, characterized in that the transmission to the control unit of the host.