JP5281862B2 - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer capable of achieving accurate protection of a power supply, preventing the power supply from being interrupted, and suppressing split printing caused by excessive protection of the power supply. <P>SOLUTION: The printer includes: a printing element drive part that drives a plurality of printing elements; a monitoring part that monitors drive time of the plurality of printing elements; a current amount calculation part that calculates a current amount required by the printing element drive part based on the drive time monitored by the monitoring part; the power supply that supplies current to the printing element drive part; and a controller that stops the drive of the printing element drive part when the current amount calculated by the current amount calculation part reaches or exceeds a current upper limit value of the power supply and the current level of the printing element being driven is a fixed value. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a printer that prints and outputs image data on a recording medium based on predetermined control.

  2. Description of the Related Art Conventionally, in some printers, a control LSI outputs a drive signal for each pin to a head driver in order to impact each pin of the print head. The drive signal is generated by the following method. First, received data consisting of print data from a host PC connected to the printer is converted into a print image such as characters. Next, print data is output to the control LSI at every print timing of the set print DPI. The print data output to the control LSI becomes valid from the next print timing, and the drive of the print head pin where the print data exists is executed. Since the impact timing differs for each pin, the drive timing is not the same.

  Here, the drive timing of each pin depends on various conditions such as the distance between the print head and the platen, the difference between the single pin or the continuous pin, the temperature of the print head, and voltage fluctuation, and the drive start timing and drive end timing. Are different. In addition, since the separation distances between the print head pins are different, a time difference occurs when impacting the same position. For this reason, depending on the print DPI, the basic print timing itself may be shifted to the next timing. Therefore, as shown in FIG. 1, drive signals for each pin are output at various timings and at various drive times between the basic print timing and the next print timing.

  In addition, a current amount of about 1 A per pin is required for driving a print head pin to which a current for driving the print head is supplied from a power supply unit provided in the printer. For this reason, in order to drive all 24 pins simultaneously, a current amount of about 24 A is required. However, the amount of current that can be supplied from the power supply unit is limited due to cost, over rating of electrical components, and the like. Therefore, in a conventional printer, the number of simultaneous impact pins is detected and control is performed according to the number of simultaneous impact pins in order to use the printer within a range that does not exceed the current output allowable amount of the power supply unit.

  As a method of detecting the number of simultaneous impact pins, the number of simultaneous pins is simply calculated from the print data set at the print timing. Specifically, it is determined whether or not the number of simultaneous impact pins does not exceed the power capacity by counting information for 24 print data set at the print timing without considering the drive timing of each pin. Thus, the control is performed (see, for example, Patent Document 1).

JP-A-7-52413

  However, the above-described configuration has a problem in the conventional method for detecting the number of simultaneous impact pins. This will be specifically described with reference to FIG. The number of impacts at the basic printing timing (1) shown in FIG. 2 is six, and the number of impacts at the basic printing timing (2) is three. Here, if the number of simultaneous impacts is 7 and the maximum allowable current is (A) as the printer specifications, the printing operation in the first half area (A) is possible, but the printing operation in the second half area (I). There is a problem that the power supply cannot be protected because the current exceeds the maximum allowable current (A) of the power supply.

  Further, when the number of simultaneous impacts is 7, the printing operation cannot be performed as described above. However, when the number of simultaneous impacts is 6 as shown in FIG. In this case, since it is determined that the current allowable maximum value of the power source is exceeded, printing is performed in divided portions. In the case of FIG. 3, even-numbered pins are masked. Under the above-described conditions, there is a problem that the printing speed is lowered because the divided printing is performed even though the area (U) and the area (E) are sufficiently within the current allowable range.

  Accordingly, in view of the above-described technical problems, the present invention provides a printer that can accurately protect a power supply, can avoid the interruption of the power supply, and can suppress divided printing due to excessive protection of the power supply. Objective.

In order to solve the above-described problems, a printer according to the present invention includes a printing element driving unit that drives a plurality of printing elements by printing data, and a printing control unit that outputs a driving signal for each printing element to the printing element driving unit. The print control unit includes: a current level count cycle setting unit that sets a count cycle for calculating a current level of each print element; and the print element driving unit based on the print data. A printing unit that outputs a driving timing signal for each printing element; a count cycle setting value that is provided for each printing element and that is output from the current level count cycle setting unit; and a driving timing signal that is output from the printing unit. based on the oFF signal, at the time of the said count cycle setting value partial counts from being turned on the printing element drive unit, a current to said print elements A current level generation unit that outputs a bell, and a total level calculation unit that adds the current level value input from the current level generation unit for each printing element at each timing when the current level value changes and outputs the sum as a total current level And the total current level output by the total level calculation unit and a predetermined threshold value, and when the total current level exceeds the threshold value, only for a printing element having a constant current level. And a means for stopping the driving by the printing element driving section.

  According to the printer of the present invention, it is possible to prevent the power from being cut off, and to suppress divided printing due to excessive protection of the power.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments according to a printer of the invention will be described with reference to the drawings. The printer of the present invention is not limited to the following description, and can be changed as appropriate without departing from the gist of the present invention.

[First Embodiment]
First, control of the printer according to the first embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram of the print control unit 101 provided in the control LSI for controlling the printer.

  The print control unit 101 is a control unit, and includes a control register group 102, a print data transfer column count unit 107, a print unit 108, a 1-pin current level generation unit 111 to a 24-pin current level generation unit 134, and a total level calculation unit. 135, a comparison unit 136, a level 1 OFF unit 137, a next pass print data storage unit 138, an interrupt generation unit 139, and a column number counter holding unit 140. Hereinafter, each component constituting the print control unit 101 will be specifically described with reference to FIG.

  The control register group 102 in the print control unit 101 includes a current level count cycle setting register 103, a threshold setting register 104, a print DP1 setting register 105, and a print data setting register 106. Various setting values in the print control unit 101 are set. Store and monitor. The current level count cycle setting register 103 sets a count cycle for calculating a current level in each pin that is a printing element. The count cycle setting value output from the current level count cycle setting register 103 is output to a 1-pin current level generation unit 111 to a 24-pin current level generation unit 134, which will be described later. The threshold setting register 104 sets the maximum allowable amount of current value as threshold information. Note that the maximum allowable amount is set by adding a certain amount of margin in advance, so that even when the threshold is exceeded, the power supply is not immediately shut off. The print DPI setting register 105 sets a print DPI based on a print command received from a host PC (not shown). The generation timing related to the basic printing timing is generated from the set value. The print data setting register 106 sets print data to be printed at each basic print timing. The print data transfer column count unit 107 counts transfer columns related to the print data and outputs the count to the column number counter holding unit 140.

  The print unit 108 in the print control unit 101 outputs a DT1 signal to a head driver (not shown) based on the print data set at the basic print timing, thereby performing an impact related to ON / OFF of DT1 and a print head pin. Works. The 1-pin current level generation unit 111 includes a 1-pin timer 109 and a 1-pin drive current level holding unit 110. The 1-pin timer 109 is based on the current level generation cycle setting value input from the current level count cycle setting register 103 and the ON / OFF flag of DT1 input from the printing unit 108. When turned on, the counter starts and counts for the period of the current level generation period set value. Thereafter, the count up flag is output and the re-counting is repeated. The 1-pin drive current level holding unit 110 receives the count UP flag, raises the current level counter, and then outputs it to the total level calculation unit 135, which is a current amount calculation unit, as an output related to the current level value. Note that when the 1-pin drive is turned off, the counters of the 1-pin timer 109 and the 1-pin drive current level holding unit 110 are reset to wait for the next drive. The 2-pin current level generation unit 112 to the 24-pin current level generation unit 134 are the same as the configuration and operation of the 1-pin current level generation unit 111, and thus description thereof is omitted. The total level calculation unit 135 adds the current levels related to pins 1 to 24 input from the 1-pin current level generation unit 111 to 24-pin current level generation unit 134 and adds them to the total current level, which will be described later. Output to the comparator 136.

  The comparison unit 136 in the print control unit 101 compares the total current level input from the total level calculation unit 135 with the threshold set in the threshold setting register 104 and outputs the comparison result to the level 1 OFF unit 137. . Further, the level 1 OFF unit 137 is configured so that even when the pin is in the middle of driving when the total current level exceeds the threshold value in the comparison result input from the comparator 136 and the current current level is level 1. Forcibly turns off the operation. Specifically, the drive is turned off by outputting OFF information related to DT1 to the printing unit 108. Note that the next pass print data storage unit 138, the interrupt generation unit 139, and the column number counter holding unit 140 are notified that the pin drive is turned off. Further, when notified from the level 1 OFF unit 137 that the drive is turned off, the next pass print data storage unit 138 holds the pin that is turned off during the drive as print data that is not printed. The print data held in the next-pass print data storage unit 138 is used as print data for the second and subsequent passes of divided printing. Further, when notified from the level 1 OFF unit 137 that the drive is turned off, the interrupt generation unit 139 generates an interrupt signal. From the interrupt signal, the CPU knows that the operation has been turned off during driving. Further, when notified from the level 1 OFF unit 137 that the drive has been turned off, the column number counter holding unit 140 holds information indicating the column number of the pin that was turned off during the drive. The number of columns held by the column number counter holding unit 140 is the print start column number for the second pass of divided printing.

  Next, a printing operation according to the printer of this embodiment will be specifically described with reference to FIGS. 5 to 8 are flowcharts related to the printing operation of the printer.

  A sequence related to the printing operation of the printer is started based on the printing instruction. When proceeding to the procedure 1, the setting data is written in the control register group 102 provided in the print control unit 101 (S1). Next, when proceeding to step 2, the print control unit 101 receives print data from a host device (not shown) or the like (S2). Next, when the procedure proceeds to step 3, printing is activated, and a scanning unit (not shown) connected to the carriage unit for scanning a carriage unit (not shown) which is a printing element driving unit on which a printing head (not shown) is mounted is scanned. The pacing motor starts rotating. In the following description, the spacing motor is referred to as an SP motor. When the SP motor rotates and the carriage unit is scanned to the position immediately before the first dot position, the basic print timing occurs at that position. Specifically, since the firmware program has previously set the control LSI so that the basic print timing is generated at the position, the basic print timing is generated at the position (S3).

  Since steps 4 to 14 are common to all pins 1 to 24, the processing of 1 pin will be described. When proceeding from step 3 to step 4, the current level of each pin is cleared to 1 before the basic print timing occurs (S4). Next, when proceeding to step 5, the timer of each pin is cleared to 0 before the basic print timing occurs (S5). Next, when the procedure proceeds to step 6, the basic printing timing is generated and the timing becomes a trigger, and when the drive of the 1 pin is activated, the drive signal (DT1 signal) is turned on in the printing unit 108 (Yes). If the 1-pin drive is not activated (No), the process returns to step 6 (S6). Next, in step 7, the 1-pin timer 109 is started and the 1-pin timer 109 is incremented (S7). Next, when the procedure proceeds to step 8, it is determined whether or not the 1-pin timer 109 has the same value as the value set in the current level count cycle setting register 103. If the value is the same (Yes), the procedure proceeds to step 9. If not the same value (No), the process returns to step 7 (S8). Next, when proceeding to step 9, the current level is increased from the current level 1 to the current level 2 by incrementing the current level value of the 1-pin drive current level holding unit 110.

  Steps 7 to 9 described above are repeated until the 1-pin drive is turned off. In addition, drive ON information is input in step 6 or the current level value is increased in step 9 and at the same time, the current level is output to the total level calculation unit 135. Next, when proceeding to step 10, the printing unit 108 determines whether or not the drive signal is turned off. If it is turned off (Yes), the process returns to step 5, and if it is not turned off (No), the procedure is performed. Return to 4 (S10). Next, when proceeding to the procedure 11, all current levels of the 1st pin to the 24th pin are added in the total level calculation unit 135, and the added information is output to the comparator 136 (S11). Next, when the procedure proceeds to step 12, the calculated value in the total level calculation unit 135 is compared with the threshold set in the threshold setting register 104. If the calculated value is equal to or less than the threshold (Yes), the procedure returns to step 11 and the calculated value is If it exceeds the threshold (No), the process proceeds to step 13 (S12).

  Proceeding to step 13, it is determined whether or not the current level of the 1 pin being driven is 1. If the current level of 1 pin is 1 (Yes), proceeding to step 14 and proceeding to step 1 If the level is not 1 (No), the process returns to step 5 (S13). If the current level of pin 1 is not 1, the drive is continued, and as a result, the calculated value may exceed the threshold value. Therefore, the threshold is set in advance by adding a predetermined margin. In addition, if the drive is turned off except when the current level of pin 1 is 1, there is a possibility that the drive is turned off after the print head pin reaches the print medium, so such a specification is not provided. Next, when the procedure proceeds to step 14, in order to turn off the drive of the pin that is currently turned on, the DT1OFF information is output to the level 1 OFF unit 137, and the procedure proceeds to procedure 10 and procedure 15 (S14). Note that, the procedure 7 to the procedure 9 and the procedure 11 to the procedure 14 are repeated until the 1-pin drive is turned off in the procedure 10. Next, in step 15, the DT1OFF information output from the level 1 OFF unit 137 is converted into an interrupt signal for the CPU in the interrupt generation unit 139 (S15).

  In step 16, the column number counter holding unit 140 latches the number of columns at that time (S16). Next, in step 17, the next pass print data storage unit 138 latches the print data of the print head pin whose drive has been turned off, and returns to step 6 (S17). As for the information described above, data can be acquired by the CPU receiving an interrupt and reading each register. The acquired data is used for printing after the second pass during divided printing. Next, when proceeding from step 3 to step 18, the above-described operation is continued for one line to determine whether or not one-line printing has been completed, and if one-line printing has been completed (Yes), the process proceeds to step 19. If the one-line printing is not completed (No), the process returns to step 18 (S18). Next, when proceeding to step 19, it is determined whether or not there is a pin that has been turned off. If there is a print head pin that has been turned off in the middle of the first line due to the presence or absence of the interrupt described above (Yes). Proceeding to step 20, when there is no print head pin that is turned off (No), the sequence related to the printing operation of the printer is terminated (S19). Next, when the procedure proceeds to step 20, the divided printing of the first pass is terminated and the divided printing of the second pass is executed (S20).

  The total current value in the control LSI relating to the printing operation of the printer described above will be specifically described with reference to FIGS. FIG. 9 shows the current level value and the total current level value of each print head pin related to the control of the printer according to the first embodiment of the present invention. FIG. 10 shows the total amount of current when the threshold value related to the control of the printer according to the first embodiment of the present invention is set to the current level 10. The counter is increased by the timer of each pin and the current value is also increased. Therefore, the current value used in proportion to the sum of the count values of each pin increases. The drive waveform related to the control of the conventional printer described above with reference to FIGS. 1 to 3 is divided by the current level and the total amount of current is also divided in detail in the printer of this embodiment. . Further, when the threshold is set to a current level 10, it is represented in FIG. This is equivalent to the case where the number of simultaneous pins related to the control of the conventional printer is seven. In FIG. 10, the control is performed so that the threshold value is not exceeded in the printing operation related to the conventional printer, and in the printing operation related to the conventional printer described above with reference to FIG. Excessive current control is not performed even in areas where there is no need for divided printing, such as areas (U) and (E), that is, areas where current control is not necessary.

  As described above, according to the printer of the first embodiment, the current level over time after the start of driving is monitored, the current level is counted for all pins, and the current output allowable amount of the power supply unit Based on the comparison with the threshold setting value calculated from the above, it is determined whether or not the allowable current amount has been exceeded. Therefore, compared to conventional printers, the power supply can be protected with high accuracy, so that the power supply can be prevented from being cut off. Furthermore, divided printing due to excessive protection of the power supply can be suppressed, thus improving the printing speed. it can.

[Second Embodiment]
Next, a printer according to a second embodiment of the present invention will be described. Note that the second embodiment is characterized in that it approximates an actual current rise curve by calculating a time constant according to the characteristics of the print head pin, and other configurations related to the printer are the first embodiment. The configuration of the printer described in the embodiment is the same. For this reason, the second embodiment will be specifically described with a focus on a different configuration from the first embodiment.

  First, printer control will be described with reference to FIG. FIG. 11 is a block diagram of the print control unit 201 provided in the control LSI for controlling the printer.

  The print control unit 201 includes a print data transfer column count unit 107, a print unit 108, a total level calculation unit 135, a comparison unit 136, a level 1 OFF unit 137, and next pass print data, which are the same components as in the first embodiment. In addition to the storage unit 138, the interrupt generation unit 139, and the column number counter holding unit 140, the control register group 202, which is a component unique to the second embodiment, and the 1-pin current level generation units 211 to 24 pins The current level generation unit 234 is configured. Hereinafter, among the components constituting the print controller 201, the components specific to the second embodiment will be described in detail with reference to FIG.

  The control register group 202 in the print control unit 201 replaces the current level count cycle setting register 103 according to the first embodiment with a current level 1 count cycle setting register 251 to a current level 5 count according to the second embodiment. It consists of a cycle setting register 255 and a threshold setting register 104, a print DP1 setting register 105, and a print data setting register 106, which are the same components as in the first embodiment, and stores various setting values inside the print control unit 201. It is also a calculation unit. Therefore, the current level 1 count cycle setting register 251 to the current level 5 count cycle setting register 255 will be described.

  The current level 1 count cycle setting register 251 in the control register group 202 sets a first timer count value when each pin is driven ON. Specifically, the time until the current value corresponding to 20% of the maximum current value of the standard head drive related to one pin is increased is set. For example, if the maximum current value of the head drive in the printer is 1 A, the time required for the current value to rise from the current value 0.0 A to 0.2 A corresponding to 20% of 1 A is set. The time until the current value corresponding to 20% of the standard maximum value of the head drive current for one print head pin is increased will be described in detail. The current supplied to the print head has a current rise curve determined based on a time constant defined by an inductor which is an L component of the print head internal coil and a resistor which is an R component. The equation for the time constant is shown in Equation 1, and Table 1 gives an explanation of the symbols used in Equation 1. FIG. 12 shows a current rise curve with a time constant related to the control of the printer.

  Here, when Formula 1 is converted so that time is a solution, it is expressed by Formula 2. The solution t in Expression 2 represents a deviation amount that is a ratio with respect to Vmax related to a current value from V (t−1) to V (t). Therefore, it is necessary to convert the solution t to a value obtained by multiplying the standard t drive time for one print head pin by the solution t. Table 1 shows a calculation example of the current level count cycle setting register value when τ = 1, current max value = 1.0 A, and drive time max value = 300 μsec, and is a standard head related to one print head pin. The time until the current value corresponding to 20% of the maximum drive current value is increased is shown. Based on Equation 2 and Table 2, 40%, 60%, 80%, and 100% which is Vmax are derived and set in the current level 1 count cycle setting register 251 to the current level 5 count cycle setting register 255, respectively.

  The current level 2 count cycle setting register 252 in the control register group 202 sets a time for the current at each pin to rise from 20% to 40%. Similarly, the current level 3 count cycle setting register 253 sets the time for the current in each pin to rise from 40% to 60%. Similarly, the current level 4 count cycle setting register 254 sets the time for the current in each pin to rise from 60% to 80%. Similarly, the current level 5 count cycle setting register 255 sets the time for the current in each pin to rise from 80% to 100%. The time set in each of the current level 1 count cycle setting register 251 to the current level 5 count cycle setting register 255 is a current value for a 1-pin current level generator 211 to a current for 24 pins, which will be described later as a setting value related to the level generation cycle. Each is output to the level generation unit 234.

  The 1-pin current level generation unit 211 in the print control unit 201 is replaced with the 1-pin timer 209 according to the second embodiment instead of the 1-pin timer 109 according to the first embodiment. It comprises a 1-pin drive current level holding unit 110 which is the same component as the embodiment. Therefore, the 1-pin timer 209 will be described. The set values from the current level 1 count cycle setting register 251 to the current level 5 count cycle setting register 255 are input to the 1-pin timer 209, and the timer count value is switched and used according to the current current level. The 2-pin current level generation unit 212 to the 24-pin current level generation unit 234 are the same as the configuration and operation of the 1-pin current level generation unit 211, and thus description thereof is omitted.

  Next, a printing operation according to the printer of this embodiment will be specifically described with reference to FIGS. 13 and 14 show a part of a flowchart relating to the printing operation of the printer.

  A sequence related to the printing operation of the printer is started based on the printing instruction. Note that steps 1 to 7 of the printing operation according to the printer of the second embodiment are the same as the steps 1 to 7 of the printing operation according to the printer of the first embodiment. Similarly, procedures 9 to 20 of the printing operation according to the printer of the second embodiment are the same as the procedures 9 to 20 of the printing operation according to the printer of the first embodiment. Therefore, in the printing operation related to the printer of the second embodiment, the procedure specific to the printing operation related to the printer of the second embodiment is replaced with the procedure 8 related to the printing operation related to the printer of the first embodiment. 21 has the characteristics. The procedure 21 will be specifically described below.

  When proceeding from step 7 to step 21, the timer is started, and the current level count cycle setting register number to be compared changes according to the current current level value. For example, if the current current level is 1, the process proceeds to step 21A, where the 1-pin current level 1 is compared with the value set in the current level 1 count cycle setting register 251, and if the current level is the same (Yes) ) Proceeds to step 9, and the current level is increased from 1 to 2 by incrementing the current level value of the 1-pin drive current level holding unit 110. If the values are not the same (No), the procedure returns to step 7. The operations in the case where the current current level is 2, 3, 3, 4 and 5 are represented by procedure 21B, procedure 21C, procedure 21D and procedure 21E, respectively. The same operation as in the procedure 21A is executed. Further, when the current level is 6, this corresponds to the case where the standard head drive current maximum value of one print head pin is exceeded, so that the current level value remains 6 and is not incremented. Return to step 7 (S21).

  The total current value in the control LSI related to the printing operation of the printer described above will be specifically described with reference to FIGS. 15 and 16. FIG. 15 shows the current level value and the total current level value of each print head pin related to the control of the printer according to the second embodiment of the present invention. FIG. 16 shows the total amount of current when the threshold value for controlling the printer according to the second embodiment of the present invention is set to the current level 14. The drive waveform related to the control of the conventional printer described above with reference to FIGS. 1 to 3 is divided by the current level in the printer of this embodiment by setting the threshold value and driving. The total amount of current is also divided in detail. Further, when the threshold is set to the current level 14, it is represented in FIG. This is equivalent to the case where the number of simultaneous pins related to the control of the conventional printer is seven.

  As described above, according to the printer according to the second embodiment, the current level with the lapse of time from the start of the drive is calculated after approximating the actual current rise curve by calculating the time constant according to the characteristics of the print head pin. It is determined whether or not the allowable current amount has been exceeded based on the comparison between the current level counted for all pins and the threshold setting value calculated from the current output allowable amount of the power supply unit. For this reason, compared with the printer of the first embodiment, the power supply can be protected with higher accuracy, so that the power supply can be prevented from being cut off. Further, the divided printing due to the excessive power supply protection can be suppressed. The printing speed can be improved.

[Third Embodiment]
Next, a printer according to a third embodiment of the invention will be described. The third embodiment is characterized in that current control is performed in accordance with the current output specification of the power supply, and other configurations related to the printer are described in the first and second embodiments. The configuration is the same as that of the printer. For this reason, the third embodiment will be specifically described with a focus on the configuration different from the first and second embodiments.

  First, printer control will be described with reference to FIG. FIG. 17 shows a block diagram of a print control unit 301 provided in a control LSI for controlling the printer.

  The print control unit 301 includes the same components as those in the first and second embodiments, the print data transfer column count unit 107, the print unit 108, the total level calculation unit 135, the comparison unit 136, the level 1 OFF unit 137, and the next pass. Print data storage unit 138, interrupt generation unit 139, column number counter holding unit 140, and 1-pin current level generation unit 211 to 24-pin current level generation unit 234, which are the same components as in the second embodiment. In addition, the control register group 302, the average comparator 362, the average timer 363, and the interrupt factor register unit 364, which are components unique to the third embodiment. Hereinafter, among the components constituting the print controller 301, the components unique to the third embodiment will be described in detail with reference to FIG.

  The control register group 302 in the print control unit 301 includes a threshold setting register 104, a print DP1 setting register 105, and a print data setting register 106, which are the same components as those in the first and second embodiments, and the second embodiment. In addition to the current level 1 count cycle setting register 251 to the current level 5 count cycle setting register 255, which are the same components as those in the embodiment, the average threshold setting register 360, which is a specific component in the third embodiment, and the average Timer setting register 361. Therefore, the average threshold setting register 360 and the average timer setting register 361 will be described. The average threshold setting register 360 is a register for setting an average threshold corresponding to the average current allowable output value of the power source. The average timer setting register 361 is a register for setting a timer value according to the average allowable current output time of the power source.

  The average comparator 362 in the print control unit 301 is a block that compares the output value of the total level calculation unit 135 with the average threshold set in the average threshold setting register 360. If the output value of the total level calculation unit 135 exceeds the average threshold set in the average threshold setting register 360, a timer ON flag is output to the average timer 363 described later. When the output value of the total level calculation unit 135 falls below the average threshold set in the average threshold setting register 360, the timer ON flag is reset. The average timer 363 activates the timer using the timer ON flag output from the average comparator 362 as a trigger. When the timer is incremented and becomes the same value as the value set in the average timer setting register 361, the information is transmitted to the level 1 OFF unit 137. When the average threshold value is below, the timer is reset with the reset of the timer ON flag.

  The interrupt factor register unit 364 in the print control unit 301 is a register that holds what detection system is detected for current output. Here, in order to facilitate understanding of the register, general output specifications of a power supply unit mounted on a printer or the like will be described. There are mainly two specifications for the current output requirement from the power supply section. The first is a limitation based on the peak current value described in the prior art, the first embodiment, and the second embodiment. When the maximum current value exceeds the maximum value that can be output by the power supply unit, the power supply is shut off. It is a specification to be done. The second is a restriction based on the average current value. When the thermal derating of the element used on the power supply unit or the range of ASO (Area of Safe Operation) which is a safe operation area is exceeded, the power supply is cut off. It is a specification. Therefore, when a certain amount of current is continuously output, the state is limited based on the average current value. Therefore, a certain amount of current is set in the average threshold setting register 360 and less than the duration. By setting the timer setting value in the average timer setting register 361, it is possible to prevent the power source from being shut off due to the restriction based on the average current value. The interrupt factor register unit 364 is a register that holds which detection system detects that the power supply is shut off in the restriction based on the peak current value or the restriction based on the average current value.

  Next, a printing operation according to the printer of this embodiment will be specifically described with reference to FIG. FIG. 18 shows a part of a flowchart relating to the printing operation of the printer.

  A sequence related to the printing operation of the printer is started based on the printing instruction. It should be noted that the printing operation procedures 1 to 7 relating to the printer of the third embodiment are the same as the printing operation procedures 1 to 7 relating to the printers of the first and second embodiments, respectively. Similarly, the printing operation procedures 9 to 20 relating to the printer of the third embodiment are the same as the printing operation procedures 9 to 20 relating to the printers of the first and second embodiments described above, respectively. . Similarly, the printing operation procedure 21 related to the printer of the third embodiment is the same as the printing operation procedure 21 related to the printer of the second embodiment described above. Therefore, the printing operation according to the printer of the third embodiment is characterized in that the procedures 31 to 34 are added. Hereinafter, the procedures 31 to 34 will be specifically described.

  Proceeding from step 11 to step 31, the calculation result of the total level calculation unit 135 and the average threshold value setting register 360 of the total level calculation unit 135 based on the information on the sum total of the current levels of all the pins calculated in step 11. The set values are compared. If the calculation result does not exceed the average threshold (No), the procedure proceeds to step 32. If the calculation result is equal to or less than the average threshold (Yes), the procedure proceeds to step 33 (S31). Next, when the procedure proceeds to step 32, the timer of the averaging timer 363 is reset, and the procedure returns to step 31 (S32). Next, in step 33, the timer of the average timer 363 is incremented (S33). Next, in step 34, the timer value of the average timer 363 is compared with the set value of the average timer setting register 361, and the timer value of the average timer 363 counts up to the set value of the average timer setting register 361. If not (No), the process returns to step 33, and then increments while the timer value of the average timer 363 exceeds the average threshold. When the timer value of the average timer 363 counts up to the set value of the average timer setting register 361 and the timer value of the average timer 363 exceeds the average threshold (Yes), the process proceeds to step 13. Thereafter, the level 1 OFF unit 137 is notified to turn off the drive of the print head pin whose current level is 1 (S34).

  The total current value in the control LSI related to the printing operation of the printer described above will be specifically described with reference to FIGS. FIG. 19 shows the current level value and the total current level value of each print head pin related to the control of the printer according to the third embodiment of the present invention. FIG. 20 shows the total amount of current when the average threshold for controlling the printer according to the third embodiment of the present invention is set to the current level 10. The drive waveform related to the control of the conventional printer described above with reference to FIGS. 1 to 3 is divided by the current level in the printer of this embodiment by setting the average threshold and driving the drive. The total amount of current is also divided in detail. FIG. 20 shows a case where the average threshold is set to 10 in the case of a conventional printer in which the power supply is shut down by continuing the current amount of 5 simultaneous pins for the power supply allowable limit point (duration). It is a control timing chart.

  As described above, according to the printer according to the third embodiment, by performing the current control according to the current output specification of the power supply unit, in addition to the peak current value protected in the first and second embodiments, The average amount of current can also be protected. For this reason, compared to the printers of the first and second embodiments, the power supply can be protected with higher accuracy, so that the power supply can be prevented from being cut off. Further, the divided printing by the excessive protection of the power supply is also possible. Since it can be suppressed, the printing speed can be improved.

  In addition, regarding the calculation of the time constant in the second embodiment described above, by using a high-spec CPU with a high operating frequency, a CPU excellent in multiplication and division operations such as a DSP (Digital Signal Processor), and the like. Furthermore, a configuration that performs more general and highly efficient control may be employed. In addition, since the LSI circuit scale is enormous in multiplication and division operations, it is not preferable that the time constant is calculated by the control LSI. Therefore, it is preferable that the calculation of the time constant is calculated in advance as a design value for each printer, and the design value can be set on the control LSI. Furthermore, although the basic configuration according to the third embodiment is the same as that of the second embodiment, the basic configuration according to the third embodiment may be the same as that of the first embodiment. good.

It is a schematic diagram showing print head pin drive signals output at various timings related to control of a conventional printer. It is a schematic diagram showing the recognition of the number of simultaneous print head pins and the actual amount of current related to the control of a conventional printer. It is a schematic diagram showing the recognition of the number of simultaneous print head pins and the actual amount of current related to the control of a conventional printer. FIG. 3 is a block diagram illustrating a print control unit provided in a control LSI related to control of the printer according to the first embodiment of the present invention. 3 is a flowchart illustrating a flow of a printing operation of the printer according to the first embodiment of the present invention. 3 is a flowchart illustrating a flow of a printing operation of the printer according to the first embodiment of the present invention. 3 is a flowchart illustrating a flow of a printing operation of the printer according to the first embodiment of the present invention. 3 is a flowchart illustrating a flow of a printing operation of the printer according to the first embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a current level value and a total current level value of each print head pin according to the control of the printer of the first embodiment of the present invention. FIG. 6 is a schematic diagram illustrating a total current amount when a threshold value related to control of the printer according to the first embodiment of the present invention is set to a current level of 10; It is a block diagram which shows the printing control part provided in the control LSI which concerns on control of the printer of the 2nd Embodiment of this invention. It is a schematic diagram which shows the electric current rise curve by the time constant which concerns on control of the printer of the 2nd Embodiment of this invention. It is a flowchart which shows the flow of the printing operation of the printer of the 2nd Embodiment of this invention. It is a flowchart which shows the flow of the printing operation of the printer of the 2nd Embodiment of this invention. It is a schematic diagram which shows the current level value and total current level value of each print head pin which concern on control of the printer of the 2nd Embodiment of this invention. It is a schematic diagram which shows the total electric current quantity when the threshold value concerning the control of the printer of the 2nd Embodiment of this invention is set to the current level. It is a block diagram which shows the printing control part provided in the control LSI which concerns on control of the printer of the 3rd Embodiment of this invention. It is a flowchart which shows the flow of the printing operation of the printer of the 3rd Embodiment of this invention. It is a schematic diagram which shows the current level value and total current level value of each print head pin which concern on control of the printer of the 3rd Embodiment of this invention. It is a schematic diagram which shows the total electric current quantity when the threshold value for averaging which concerns on control of the printer of the 3rd Embodiment of this invention is set to the current level 10. FIG.

Explanation of symbols

101 Print Control Unit 102 Control Register Group 103 Current Level Count Period Setting Register 104 Threshold Setting Register 105 Print DP1 Setting Register 106 Print Data Setting Register 107 Print Data Transfer Column Counting Unit 108 Printing Unit 109 1-Pin Timer 110 1-Pin Drive Current Level holding unit 111 1-pin current level generation unit 112 2-pin current level generation unit 134 24-pin current level generation unit 135 Total level calculation unit 136 Comparison unit 137 Level 1 OFF unit 138 Next pass print data storage unit 139 Interrupt generation Unit 140 Column number counter holding unit 201 Print control unit 202 Control register group 209 1-pin timer 211 1-pin current level generation unit 212 2-pin current level generation unit 234 24-pin current level generation unit 251 Current level Count cycle setting register 252 Current level 2 count cycle setting register 253 Current level 3 count cycle setting register 254 Current level 4 count cycle setting register 255 Current level 5 count cycle setting register 301 Print control unit 302 Control register group 360 Threshold setting register for averaging 361 Average timer setting register 362 Average comparator 363 Average timer 364 Interrupt factor register

Claims (4)

A printing element driving unit for driving a plurality of printing elements by printing data;
A printer having a print control unit for outputting a drive signal for each print element to the print element drive unit,
The print control unit
A current level count cycle setting unit for setting a count cycle for calculating the current level of each printing element;
A printing unit that outputs a driving timing signal of each printing element to the printing element driving unit based on the printing data;
Provided for each of the printing elements, the printing element driving unit is turned on based on a count cycle setting value output from the current level counting cycle setting unit and an on / off signal of a driving timing signal output from the printing unit. A current level generator that outputs a current level for the printing element at the time of counting the count cycle set value after
A total level calculation unit that adds the current level value input from the current level generation unit for each printing element at each timing when the current level value changes, and outputs the total current level;
The total current level output by the total level calculation unit is compared with a predetermined threshold value, and when the total current level exceeds the threshold value, only for a printing element whose current level is a constant value, A printer having means for stopping driving by the printing element driving unit.   2. The printer according to claim 1, wherein the amount of current supplied to the printing element driving unit is limited to a certain amount. A calculation unit that calculates the amount of current supplied to the plurality of printing element driving units based on a time constant of the printing element driving unit;
The current level count cycle setting unit includes:
The printer according to claim 1, wherein the count period setting value is set from the current amount calculated by the calculation unit. An average current amount calculating unit that calculates an average current amount supplied to the printing element driving unit;
The print control unit
The total current level output by the total level calculation unit is compared with a threshold set based on the average current amount, and when the total current level exceeds the threshold , the current level is a constant value. 4. The printer according to claim 1 , further comprising a unit that stops driving of the printing element driving unit only for a certain printing element . 5.