Printhead and printing apparatus

Abstract

To raise the temperature of a recording head and ink in a short time by performing short pulse heating without transferring selection data to the recording head.SOLUTION: An OR circuit that performs an OR operation on the heat data latched by the heat data shift register and a level of the data signal, a heat data latch circuit that latches an output of the OR circuit based on a latch signal, and a latch counter that performs counting based on the latch signal and the data signal, wherein short-pulse heating control is performed on a heater determined from a plurality of heaters based on the count value of the latch counter and the value latched by the heat data latch circuit.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to temperature control in a print head of an inkjet printing apparatus. [Background technology]

[0002] In order to achieve optimal ink ejection performance during printing, the print head of an inkjet printing device performs heating control to raise the temperature of the print head and ink to the optimum temperature for ejection before printing. Heating control uses a heater for ejecting ink that is provided in the print head. The heater is driven to raise the temperature of the print head and ink to a level that does not cause ink to be ejected (such a temperature increase is hereinafter referred to as short pulse heating).

[0003] Patent Document 1 discloses a configuration in which the recording head can latch only the group selection number transferred from the controller in order to shorten the time required for short-pulse heating. This configuration shortens the time required for transferring the selection data, thereby shortening the time required for short-pulse heating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-113243 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, when a single signal line is used to control selection data for multiple nozzle rows, a group selection signal is required for each nozzle row. Therefore, as the print head size increases, the amount of selection data that needs to be transferred during short-pulse heating increases. As a result, the time required for short-pulse heating increases.

[0006] In view of the above problems, the present disclosure has an object to perform short pulse heating without transferring selection data to the print head, thereby raising the temperature of the print head and ink in a short time. [Means for solving the problem]

[0007] One embodiment of the present invention relates to a heating control system including a plurality of heaters, a shift register that receives and latches a data signal in synchronization with a clock signal, the shift register including a group selection number shift register and a heat data shift register, an OR circuit that ORs the heat data latched in the heat data shift register with the level of the data signal, a heat data latch circuit that latches the output of the OR circuit based on a latch signal, and a latch counter that counts based on the latch signal and the data signal, and performs short pulse heating control on a heater selected from the plurality of heaters based on the count value of the latch counter and the value latched in the heat data latch circuit. The recording head is characterized by the above. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to perform short pulse heating without transferring selection data to the print head, thereby achieving a temperature rise of the print head and ink in a short time. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration related to heating control of a print head. [Figure 2] Conventional short pulse heating control timing chart [Figure 3] Timing chart of short pulse heating control in the first embodiment [Figure 4] 10 is a timing chart showing the operation of a latch counter in a printhead according to the first embodiment; [Figure 5] FIG. 1 is a diagram showing a circuit configuration within a print head according to a first embodiment; [Figure 6]1 is a timing chart showing an operation during short pulse heating in the first embodiment; [Figure 7] 1 is a timing chart showing an operation during short pulse heating in the first embodiment; [Figure 8] 1 is a timing chart showing an operation during short pulse heating in the first embodiment; [Figure 9] FIG. 10 is a diagram showing the circuit configuration within a print head according to a second embodiment. [Figure 10] Timing chart showing the operation of the circuit shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The circuitry within the printhead and the operation of the circuitry within the printhead for achieving temperature rise control of the printhead and ink in a short period of time will be described below with reference to the drawings.

[0011] [First embodiment] <Configuration for driving the recording head> Fig. 1(A) is a simple block diagram of an inkjet recording apparatus. Fig. 1(B) is a schematic diagram of a recording head. Note that Fig. 1(A) does not show all of the components of the inkjet recording apparatus.

[0012] As shown in Figure 1A, an inkjet recording device has a recording head, which has a heater drive circuit. The recording head has a plurality of nozzle rows 101, each of which includes a plurality of nozzles 102. A heater corresponding to each of the nozzles 102 is provided, that is, a heater for generating the thermal energy required to eject ink.

[0013] In this embodiment, the nozzles in the nozzle array are divided into groups. Fig. 1(B) illustrates an example in which the nozzles in one nozzle array are divided into 16 groups (groups 0 to 16), but the number of groups is not limited to 16 in this example. The heater drive circuit of the print head is driven by a latch signal, a clock signal, a data signal, and a heater drive signal transferred from the controller.

[0014] <Conventional short pulse heating control> Figure 2 is a timing chart of conventional short pulse heating control. The printhead receives a data signal transferred in serial format from the controller in synchronization with a clock signal (clock synchronization), and latches the received data at the rising edge of the latch signal (t201). A nozzle is selected based on the latched data, and heating control of the heater corresponding to the selected nozzle is performed based on the heater drive signal. Note that for each value of the data signal in Figure 2, '0' to '7' indicate heat data for recording or short pulse heating. Also, 'G0' to 'G5' indicate group designation numbers.

[0015] <Short Pulse Heating Control in This Embodiment> In contrast to conventional short pulse heating control (FIG. 2), FIG. 3 is a timing chart of short pulse heating control in this embodiment. In this embodiment, there is no need to receive a data signal from the controller in clock synchronization; instead, the nozzle is selectively determined by the level of the data signal at the falling edge of the latch signal (t301) and the level of the data signal at the rising edge of the latch signal (t302). This eliminates the need for the data signal transferred from the controller that was conventionally required to select the nozzle, and as a result, the time required to transfer the data signal is eliminated, making it possible to shorten the short pulse heating time. This will be described in more detail later.

[0016] <Configuration of heater drive circuit> 5 shows the configuration of the heater drive circuit in the print head in this embodiment. This circuit configuration will be explained below with reference to FIGS.

[0017] The heater drive circuit has a shift register 501 that latches data transferred from the controller on both edges of a clock signal. The shift register 501 includes a group selection number shift register 502 and a heat data shift register 503. The shift register 501 receives and latches the data signal in serial format in synchronization with the clock signal.

[0018] The heater drive circuit also has a latch counter 506, a latch count adder 507, and a group selection number latch circuit 508. The latch counter 506 counts up when the data signal is at a high level at the falling edge of the latch signal, and clears the count value to 0 when the data signal is at a low level at the falling edge of the latch signal (see FIG. 4). The latch count adder 507 adds the group selection number latched in the group selection number shift register 502 to the count value of the latch counter. The group selection number latch circuit 508 latches the value of the latch count adder at the rising edge of the latch signal.

[0019] The heater driving circuit further includes a heat data OR circuit 504 and a heat data latch circuit 505. The heat data OR circuit 504 performs an OR operation on the heat data latched in the heat data shift register 503 and the level of the data signal. The heat data latch circuit 505 latches the heat data ORed by the heat data OR circuit 504 at the rising edge of the latch signal.

[0020] This embodiment is characterized in that the heater drive circuit has the above-described configuration, and with this configuration, the heater determined by the output of the group selection number latch circuit 508 and the output of the heat data latch circuit 505 is driven by the heater drive signal.

[0021] <Operation during short pulse heating> Hereinafter, the operation of the drive circuit having the configuration explained in FIG. 5 during short pulse heating will be explained with reference to FIG.

[0022] Because the data signal is low when the latch signal falls (t601), the value of the latch counter 506 becomes 0. When the latch signal rises (t602), the value obtained by adding the value of the group selection number shift register 502 and the value of the latch counter 506 is latched in the group selection number latch circuit 508. Also, because the data signal is high when the latch signal rises (t602), all data is latched as '1' in the heat data latch circuit 505 by the heat data OR circuit 504. As a result of the above, all heaters corresponding to the nozzles of group number 0 are driven by the heater drive pulse signal 607.

[0023] Next, when the latch signal falls (t603), the data signal is at a high level, so the latch counter 506 counts up. When the latch signal rises (t604), the value obtained by adding the value of the group selection number shift register 502 and the value of the latch counter 506 is latched in the group selection number latch circuit 508. Also, when the latch signal rises (t604), the data signal is high, so all data is latched as '1' in the heat data latch circuit 505 by the heat data OR circuit 504. Subsequent operations are similar to those described above.

[0024] The operation described above makes it possible to update the group selection number without transferring data for selecting nozzles from the controller. Therefore, control can be performed based solely on the length of the heater drive pulse signal, without relying on the transfer time of the data signal from the controller, and it is possible to shorten the time it takes for the print head and ink to heat up using short pulse heating control.

[0025] Hereinafter, another operation during short pulse heating in the drive circuit having the configuration explained in FIG. 5 will be explained with reference to FIGS.

[0026] First, the operation of starting short pulse heating from the group with group selection number 5 will be described with reference to Figure 7. A data signal indicating group selection number 5 is transferred from the controller, and group selection number 5 is latched into group selection number shift register 502 in the printhead (t701). Because the data signal is low when the latch signal falls (t702), the value of latch counter 506 becomes 0.

[0027] At the rising edge of the latch signal (t703), the value of the group selection number shift register 502 (5 in this example) is added to the value of the latch counter 506 (0 in this example), and the result is latched in the group selection number latch circuit 508. In other words, the group selection number 5 is latched in the group selection number latch circuit 508. Also, because the data signal is High at the rising edge of the latch signal (t703), all data is latched as '1' in the heat data latch circuit 505 by the heat data OR circuit 504. As a result of the above, all heaters corresponding to the nozzles in group number 5 are driven by the heater drive pulse signal 710.

[0028] Subsequently, when the latch signal falls (t704), the data signal is at a high level, so the latch counter 506 counts up. When the latch signal rises (t705), the value obtained by adding the value of the group selection number shift register 502 (5 in this example) and the value of the latch counter 506 (1 in this example) is latched in the group selection number latch circuit 508. In other words, the group selection number 6 is latched in the group selection number latch circuit 508. Also, when the latch signal rises (t705), the data signal is at a high level, so all data is latched as '1' in the heat data latch circuit 505 by the heat data OR circuit 504. Subsequent operations are similar to those described above.

[0029] The operation described above makes it possible to specify the group selection number at which short pulse heating begins from the controller, and thereafter update the group selection number without transferring data for selecting nozzles. Therefore, control can be performed that relies solely on the length of the heater drive pulse signal, rather than on the transfer time of the data signal from the controller, making it possible to shorten the time it takes for the print head and ink to heat up under short pulse heating control.

[0030] Next, the operation of performing short pulse heating control for arbitrary data will be described with reference to FIG.

[0031] The controller transfers data indicating heat data 0xA5 and a data signal indicating group designation number 5. Then, the heat data 0xA5 is latched into the heat data shift register 503 in the print head, and the group selection number 5 is latched into the group selection number shift register 502 (t801). Because the data signal is low at the falling edge of the latch (t802), the value of the latch counter 506 becomes 0.

[0032] At the rising edge of the latch signal (t803), the value of the group selection number shift register 502 (5 in this example) and the value of the latch counter 506 (0 in this example) are added together and latched in the group selection number latch circuit 508. That is, the group selection number 5 is latched in the group selection number latch circuit 508. Also, because the data signal is low at the rising edge of the latch signal (t803), the value of the heat data shift register 503 is latched in the heat data latch circuit 505. That is, 0xA5 is latched in the heat data latch circuit 505. Through the above operations, the heater selected based on the group number 5 and the heat data 0xA5 is driven by the heater drive pulse signal 810.

[0033] Next, when the latch signal falls (t804), the data signal is at a high level, so the latch counter 506 counts up. When the latch signal rises (t805), the value obtained by adding the value of the group selection number shift register 502 (5 in this example) and the value of the latch counter 506 (1 in this example) is latched in the group selection number latch circuit 508. That is, the group selection number 6 is latched in the group selection number latch circuit 508. Also, when the latch signal rises (t805), the data signal is at a low level, so the value of the heat data shift register 503 is latched in the heat data latch circuit 505. That is, 0xA5 is latched in the heat data latch circuit 505. Subsequent operations are similar to those described above.

[0034] As explained above, in this embodiment, it is possible to specify heat data for heating with short pulse heating from the controller, and after specifying the heat data, it is possible to update the group selection number without transferring selection data for selecting nozzles. Therefore, since control can be performed based only on the length of the heater drive pulse signal, without relying on the transfer time of the data signal from the controller, it is possible to shorten the time it takes for the print head and ink to heat up using short pulse heating control.

[0035] [Second embodiment] Fig. 9 shows the configuration of a heater drive circuit in a print head in this embodiment. This circuit configuration will be explained below with reference to Fig. 9. The heater drive circuit of this embodiment is characterized by not having an adder, and in this respect it differs from the first embodiment (see latch count adder 507 in Fig. 5).

[0036] The heater driving circuit has a shift register 901 that latches data transferred from the controller at both edges of a clock signal. The shift register 901 includes a group selection number shift register 902 and a heat data shift register 903.

[0037] The heater drive circuit also has a latch counter 906 and a group selection number latch circuit 908. The latch counter 906 counts up when the data signal is at high level at the falling edge of the latch signal, and loads the value of the group selection number shift register 902 when the data signal is at low level at the falling edge of the latch signal. The group selection number latch circuit 908 latches the value of the latch counter at the rising edge of the latch signal.

[0038] The heater driving circuit further includes a heat data OR circuit 904 and a heat data latch circuit 905. The heat data OR circuit 904 performs an OR operation on the heat data latched in the heat data shift register 903 and the level of the data signal. The heat data latch circuit 905 latches the heat data ORed by the heat data OR circuit 904 at the rising edge of the latch signal.

[0039] The heater drive circuit of this embodiment has the above configuration and is characterized in that a heater determined by the output of the group selection number latch circuit 908 and the output of the heat data latch circuit 905 is driven by a heater drive signal.

[0040] <Operation during short pulse heating> Hereinafter, the operation of the drive circuit having the configuration explained in FIG. 9 during short pulse heating will be explained with reference to FIG.

[0041] Because the data signal is low when the latch signal falls (t1001), the value of the group selection number shift register 1002 is loaded into the latch counter. Because the data signal is high when the latch signal rises (t1002), the value of the latch counter is latched into the group selection number latch circuit 908. Also, because the data signal is high when the latch signal rises (t1002), all data is latched as '1' into the heat data latch circuit 1005 by the heat data OR circuit 1004. As a result of the above, all heaters corresponding to group number 0 are driven by the heater drive pulse signal 1007.

[0042] Next, when the latch signal falls (t1003), the data signal is at a high level, so the latch counter 906 counts up. When the latch signal rises (t1004), the value of the latch counter is latched in the group selection number latch circuit 908. Also, when the latch signal rises (t1004), the data signal is at a high level, so all data is latched as '1' in the heat data latch circuit 1005 by the heat data OR circuit 1004. Subsequent operations are similar to those described above.

[0043] The operation described above makes it possible to update the group selection number without transferring data for selecting nozzles from the controller. Therefore, control can be performed based solely on the length of the heater drive pulse signal, without relying on the transfer time of the data signal from the controller, and it is possible to shorten the time it takes for the print head and ink to heat up using short pulse heating control.

[0044] It should be noted that other operations during short pulse heating in the drive circuit having the configuration explained in FIG. 9 are the same as those in the first embodiment, and therefore explanations thereof will be omitted.

[0045] [Other embodiments] The present disclosure 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. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0046] [Technical Features of the Disclosure] The present disclosure includes the following configurations.

[0047] (Configuration 1) A print head comprising: a plurality of heaters; a shift register that receives and latches a data signal in synchronization with a clock signal, the shift register including a group selection number shift register and a heat data shift register; an OR circuit that ORs the heat data latched in the heat data shift register with the level of the data signal; a heat data latch circuit that latches the output of the OR circuit based on a latch signal; and a latch counter that counts based on the latch signal and the data signal, wherein short pulse heating control is performed on a heater selected from the plurality of heaters based on the count value of the latch counter and the value latched in the heat data latch circuit. (Configuration 2) The printhead according to configuration 1, characterized in that it is possible to switch the heaters that perform short pulse heating control without transferring the data signal. (Configuration 3) The ink jet head further includes a plurality of nozzle rows, each of which includes a plurality of nozzles, the plurality of nozzles being divided into groups, and each of the plurality of heaters is provided corresponding to each of the plurality of nozzles. 3. The recording head according to configuration 1 or 2. (Configuration 4) A recording head according to any one of configurations 1 to 3, further comprising an adder that adds the group selection number included in the data signal latched in the group selection number shift register and the count value of the latch counter. (Configuration 5) The recording head according to any one of configurations 1 to 4, further comprising a group selection number latch circuit that latches the output of the adder at the rising edge of the latch signal. (Configuration 6) The printhead according to any one of configurations 1 to 5, characterized in that short pulse heating control is performed on a heater selectively determined from among the plurality of heaters based on the value latched in the group selection number latch circuit and the value latched in the heat data latch circuit. (Configuration 7) The recording head according to any one of configurations 1 to 6, wherein the shift register receives the data signal in a serial format. (Configuration 8) The printhead according to any one of configurations 1 to 7, wherein the heat data latch circuit latches the heat data ORed by the OR circuit at the rising edge of the latch signal. (Configuration 9) The recording head according to any one of configurations 1 to 8, wherein the latch counter counts up when the data signal is High at the falling edge of the latch signal. (Configuration 10) The recording head according to any one of configurations 1 to 9, wherein the latch counter clears the count value to 0 when the data signal is low at the falling edge of the latch signal. (Recording device) A recording device having a printhead comprising: a plurality of heaters; a shift register that receives and latches a data signal in synchronization with a clock signal, the shift register including a group selection number shift register and a heat data shift register; an OR circuit that ORs the heat data latched in the heat data shift register with the level of the data signal; a heat data latch circuit that latches the output of the OR circuit based on a latch signal; and a latch counter that counts based on the latch signal and the data signal, wherein short pulse heating control is performed on a heater selected from the plurality of heaters based on the count value of the latch counter and the value latched in the heat data latch circuit. [Explanation of symbols]

[0048] 101 nozzle row 102 nozzle 501 Shift Register 502 Group selection number shift register 503 Heat Data Shift Register 504 Heat data OR circuit 505 Heat Data Latch Circuit 506 Latch Counter

Claims

1. A plurality of heaters; a shift register for receiving and latching a data signal in synchronization with a clock signal, the shift register including a group selection number shift register and a heat data shift register; an OR circuit that performs an OR operation on the heat data latched in the heat data shift register and the level of the data signal; a heat data latch circuit that latches the output of the OR circuit based on a latch signal; a latch counter that counts based on the latch signal and the data signal; and performing short pulse heating control on a heater selected from the plurality of heaters based on the count value of the latch counter and the value latched in the heat data latch circuit; A recording head characterized by:

2. It is possible to switch the heater that performs the short pulse heating control without transferring the data signal.

2. The recording head according to claim 1.

3. further comprising a plurality of nozzle rows, each of the plurality of nozzle rows including a plurality of nozzles, the plurality of nozzles being grouped; Each of the plurality of heaters is provided corresponding to each of the plurality of nozzles.

3. The recording head according to claim 2.

4. further comprising an adder that adds the group selection number included in the data signal latched in the group selection number shift register and the count value of the latch counter; 4. The recording head according to claim 3.

5. further comprising a group selection number latch circuit that latches the output of the adder at the rising edge of the latch signal; 5. The recording head according to claim 4.

6. performing short pulse heating control on a heater selectively determined from among the plurality of heaters based on the value latched in the group selection number latch circuit and the value latched in the heat data latch circuit; 6. The recording head according to claim 5.

7. the shift register receives the data signal in serial form; 7. The recording head according to claim 6.

8. the heat data latch circuit latches the heat data ORed by the OR circuit at the rising edge of the latch signal; 8. The recording head according to claim 7.

9. the latch counter counts up when the data signal is High at the falling edge of the latch signal; 9. The recording head according to claim 8.

10. the latch counter clears the count value to 0 when the data signal is Low at the falling edge of the latch signal; 10. The recording head according to claim 9.

11. A recording apparatus having the recording head according to claim 1.

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