JP2006102962A - Printer and its printing control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which can prevent a shutoff of power supply consequent to an increase of a power supply temperature of a power supply and can also obtain an optimum printing performance according to a power supply capacity, and to provide a printing control method. <P>SOLUTION: A temperature detector 25 which detects a surface temperature of an element in the power supply 50 is set. Temperature information outputted from the temperature detector 25 is monitored by a temperature monitoring part 17. When the power supply temperature becomes a predetermined precaution temperature region, the temperature monitoring part 17 designates a printing control condition which reduces a printing load according to the power supply temperature, and outputs the condition to a printing condition setting part 15. The printing condition setting part 15 outputs predetermined control information to a printing control part 13 and a transfer control part 16 in accordance with the printing control condition. The printing control part 13 and the transfer control part carry out printing control for printing printing data on the basis of the control information from the printing condition setting part 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing apparatus that performs printing control according to power supply capacity (power capacity), and more particularly, to a printing apparatus and a printing control method that can perform efficient printing according to the state of a power supply.

  For example, in a thermal line printer, a print head having print dots arranged in a horizontal row in line with the print width in the row direction is arranged so as to face the platen, and is passed between the platen and the print head by a conveyance motor. As the printing paper is conveyed, the printing dots are driven to generate heat, and the portion of the printing paper that is in contact with the generated printing dots is colored black to perform printing. Such a line of 1 dot height corresponding to the printing dots aligned in the horizontal direction is referred to as a “1 dot line”. The number of print dots that are driven when printing one dot line differs depending on the print data. For example, when printing the longest straight line in the horizontal direction, all the printing dots in one dot line are printed, so all the printing dots in one dot line are driven.

  At this time, if the printing load is large enough to drive all the printing dots in one dot line at the same time and the printing density is high, printing of one dot line is completed with one driving pulse. However, when many printing dots are driven at the same time, a large head driving current is instantaneously consumed. Driving many printing dots of one dot line at the same time makes it possible to increase the printing speed. However, on the other hand, since a large head driving current flows, a power source having a large power source capacity is required.

  When high-density printing or high-speed printing is performed using a power supply with insufficient power supply capacity, a large current exceeding the power supply capacity may flow instantaneously and cause a large voltage drop. Such a decrease in voltage may lead to deterioration in print quality such as when the print density becomes thin or the print density becomes uneven. In the power supply itself, if a large current exceeding the power supply capacity flows, depending on the circuit configuration, a safety device may be activated to cut off the power supply, and further, it will not easily return from the state where the power supply is cut off. There are also things.

In the conventional technology, due to the demand for downsizing of the apparatus and reduction of power consumption, print data to be printed before printing is executed in order to prevent a large amount of current from being consumed instantaneously while keeping the power supply capacity small. When there are a large number of dots to be printed in one dot line, divided printing is performed by dividing the printing dot of one dot line into a plurality of units, and driving and printing by giving a driving pulse to each unit a plurality of times. (See Patent Document 1). In the case of divided printing, printing dots of one dot line are driven in a plurality of times, so that the conveyance speed of the printing paper is also suppressed, and the printing speed becomes slow. However, since the printing speed is reduced, the power consumption of the transport motor is also suppressed, and the power consumption is further suppressed. In addition, there is a conventional technique in which control is performed to reduce the printing speed when the rate of time change of voltage drop is equal to or greater than a predetermined value in a serial printer (see Patent Document 2).
JP 2001-84371 A Japanese Patent Laid-Open No. 5-4402

  However, since the printing control according to Patent Document 1 does not feed back the actual power supply state, the actual power supply state cannot be accurately grasped. Therefore, depending on the installation environment or the like, such as when the room temperature is high or when a large load current is flowed instantaneously or continuously, the temperature of the element may be higher than usual, and in the worst case, the power supply may be broken. Or in these cases, while the printing device is printing, the safety device in the power supply suddenly operates to cut off the power supply, and the load current is reduced from the state where the power supply is cut off. However, there are things that can't be restored easily without returning naturally.

  Further, the case of Document 2 also has the same problem as that of Document 1 in that the temperature information of the power source cannot be grasped, and the power supply is suddenly cut off during printing and printing cannot be performed. Cannot be reliably prevented from becoming unable to return easily. The worst is the power supply destruction. In particular, in a POS system in which a large number of customers form a queue and are waiting for payment, the fact that the printing device suddenly shuts down during receipt printing and cannot print will return the printer to a printable state after waiting for a long time. Will be a big problem. In addition, even when the power returns to the natural state, if the printing is stopped frequently while printing the receipt, it takes time and the paper feed pitch is disturbed, resulting in deterioration of the printing quality.

  The present invention has been made in view of the above-described problems of the prior art, and is capable of efficiently printing according to the power capability while preventing the power supply from being interrupted or damaged due to an excessive load during printing of the printing apparatus. An object of the present invention is to provide a printing apparatus and a printing control method capable of performing the above.

  The present invention achieves the above object by providing a temperature sensor in an element in a power supply and controlling a printing load in accordance with a temperature rise of the element due to a load current of the power supply. That is, the state of the power supply actually used is grasped from the temperature of the element in the power supply, and when the temperature of the element rises above a predetermined value, the printing load is controlled so as to reduce the printing load step by step. Thus, the above-described problem is achieved by performing print control that achieves an appropriate print load according to the power supply capability while suppressing the print load exceeding the limit of the power supply capability. The “printing ratio” used in this specification has the same meaning as so-called “printing ratio”, “printing ratio”, and “printing duty”. May also be referred to.

  A printing apparatus according to a first aspect of the present invention includes a temperature detector provided on a predetermined element in a power source and outputting temperature information of the element, and an element based on the temperature information received from the temperature detector. A printing condition selection unit that selects a printing control condition according to the temperature of the printing unit, and a printing control unit and a conveyance control unit that control the driving of the print head and the conveyance motor based on the selected printing control condition. And In this aspect, the temperature information of the element in the power supply is monitored in real time, and when the element temperature falls within a predetermined warning temperature range, the print control condition is changed so as to reduce the printing load. Thereby, the output current in the power supply can be suppressed.

  In the printing apparatus according to another aspect of the present invention, the printing condition setting unit divides the temperature range of the element into a plurality of elements, and assigns a printing control condition for sequentially reducing the printing load each time the temperature classification increases. It is characterized by. In this aspect, the temperature region of the element is divided into a plurality of areas, and different printing conditions are set for each of the areas to gradually reduce the printing load. As a result, the power source can be used efficiently without reducing the load more than necessary.

  In the printing apparatus according to another aspect of the present invention, the printing control condition is configured by a plurality of control data for controlling the printing speed, the number of dots that are simultaneously driven by the printing head, the driving time to the printing head, and the energization amount to the conveyance motor. The printing condition setting unit selects one printing control condition that matches the temperature information classification, and stores the selected printing control condition in a nonvolatile manner. By storing in advance a plurality of printing control conditions corresponding to various power supply capacities, it becomes easy to set printing conditions suitable for the power supply. Also, by storing more print control conditions, the accuracy of the print control conditions that match the power supply capability is improved.

  In the printing apparatus according to another aspect of the present invention, the printing control condition is that the printing speed, the number of simultaneously driven dots of the print head, the drive time to the print head, the energization to the transport motor, according to the printing ratio of one dot line. It is characterized by comprising a plurality of control data for controlling the amount according to the capability of the power source. In a line printer, one dot line is divided into multiple print dot units, and divided printing is performed by giving a drive pulse multiple times for each unit, so the printing load can be greatly reduced, so one dot line It is efficient to set print control conditions based on the print ratio.

  In the printing apparatus according to another aspect of the present invention, the print control unit and the conveyance control unit acquire control data corresponding to a print ratio of print data to be printed from the selected print control condition, and the control data Based on the above, the drive operation of the print head and the carry motor is controlled.

  In a printing apparatus according to another aspect of the present invention, a plurality of elements in a power source are provided with temperature detectors, and the printing condition selection unit sets printing control conditions based on a combination of temperature information from the plurality of temperature detections. It is characterized by selecting. In this aspect, the print control condition is determined based on the temperatures of the plurality of elements. The warning temperature range varies depending on the performance of each element, the installation position, and the like. Based on these pieces of temperature information, the print control conditions are set more accurately. For example, the temperature of an element that leads to overload may vary depending on the load current characteristics and element characteristics of the printing device. One element has not yet reached the warning temperature range, but the other element has reached the warning temperature range. When it reaches, the printing control condition is changed to perform processing such as reducing the printing load.

  The printing control method for a printing apparatus according to the first aspect of the present invention includes: (a) a step of monitoring a power source temperature composed of the surface temperature of an element in the power source; A step of changing the print control condition according to the power supply temperature, and (c) a step of controlling the drive of the print head and the conveyance motor of the next print data based on the changed print control condition. Features.

According to the present invention, the temperature of the element reflecting the influence of the load current in the power supply is monitored, and the power supply capacity is fully utilized until the element in the power supply reaches the warning temperature range. Controls to reduce the printing load step by step, preventing the power supply from being suddenly interrupted during printing due to the high load current of printing, and suppressing the risk of the power supply being destroyed by the high load current. It is possible to obtain a high printing performance according to the print quality.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1A shows an example in which an AC adapter 50 is used as a power source in the printing apparatus 10. FIG. 1B shows an example of receipt printing. FIG. 1C shows a change in the power supply voltage V (t) accompanying printing of the receipt 60 illustrated in FIG. The change Ptp (t) of the surface temperature of the element (hereinafter referred to as “power supply temperature Ptp”) is illustrated. The surface temperature of the element in the power supply is fixed by mounting a thermistor on the surface of the power supply switching transistor, etc., and applying good thermal conductivity silicon, etc., and applying a 5V voltage inside the power supply to the circuit consisting of the thermistor and resistor It can be known from the obtained divided voltage. This divided voltage is input to the printing apparatus 10 through the cable of the AC adapter 50. Alternatively, it may be a voltage obtained from a temperature detection element that actually cuts off power supply in the power supply.

  In FIG. 1C, V on the vertical axis indicates the output voltage of the power source, ° C indicates the temperature, and t on the horizontal axis indicates the time. In FIG. 1C, the rated voltage of the printing apparatus is 24V (volts), and a safety device that reaches a warning temperature range when the power supply temperature Ptp exceeds 90 ° C and cuts off the power supply when the power supply temperature exceeds 120 ° C is shown. The example which makes it operate | move (limit temperature area) is shown. In this specification, other than FIG. 1, this condition is used as a basic condition, and the control of the print load is started when the warning temperature range is reached (when the power supply temperature Ptp reaches 90 ° C. or more).

  Although FIG. 1A shows an example in which the AC adapter 50 is used, the present invention is not limited to the AC adapter but can be applied to a case where a system power supply is used. Therefore, in the following description, it will be referred to as “power supply 50”, not an AC adapter. In the description of the print control, a description will be given using a print control example of a line printer in which print dots for one dot line are arranged in a horizontal row. However, the present invention is not limited to a line printer, but a serial printer or other printers. It is also applicable to.

  The area A shown in FIGS. 1B and 1C shows a part that has already been printed, the area B shows the part that has been printed recently, and the area C shows the part that will be printed. When the power supply capacity is not sufficient, as the printing load increases, the voltage drop of the output voltage increases and the power supply temperature Ptp increases. As can be seen from FIGS. 1B and 1C, in the case of printing characters and the like shown in the area A, the printing load is not so large, so the voltage drop is small and the power supply temperature Ptp does not rise so much. However, as shown in region B, when printing data with a high print density such as a black-painted image or a barcode (not shown) is printed, the drive current of the print head increases, so the output voltage V As the voltage drop increases, the power supply temperature Ptp also increases.

  The broken line (1) of the power supply voltage V and the power supply temperature Ptp in FIG. 1C shows the voltage V and the temperature Ptp when the same print load as before is applied even when the power supply temperature Ptp rises. A broken line (2) indicates the voltage V and the temperature Ptp when the print load is reduced stepwise according to the temperature when the print load exceeds 90 ° C.

  If the printing control for reducing the printing load is not performed when data with high printing density as shown in the area B continues, as shown by the broken line (1), the output voltage becomes lower than the allowable voltage and only causes printing failure. In other words, the power supply temperature Ptp rises and the safety device that cuts off the power supply may be activated.

  The power supply temperature Ptp and the printing load are in a proportional relationship, and when the power supply temperature Ptp increases beyond a predetermined value, it is possible to suppress the increase in the power supply temperature by reducing the printing load. Therefore, when the power supply temperature Ptp reaches a predetermined warning temperature region, it is desirable to reduce the printing load and suppress the increase in the power supply temperature Ptp. In the printing apparatus, it is possible to reduce the instantaneous printing load on the power supply by processing such as increasing the number of divided printings for one dot line or reducing the printing speed. It is also possible to control so that the energization amount to the print head is reduced.

  As indicated by a broken line (2) in FIG. 1C, when the power supply temperature Ptp reaches the warning area, the print load is reduced stepwise according to the value of the power supply temperature Ptp, as shown in the area C. In addition, it is possible to suppress the temperature of the power source temperature Ptp from rising beyond the limit region (120 ° C.). In addition, the voltage drop is suppressed by reducing the printing load. The power supply temperature Ptp is also proportional to the power supply capacity. The operation in the warning area of the power supply temperature Ptp is the limit of the power supply capacity, and it is possible to obtain a high printing performance according to the power supply capacity by giving a printing load in a range where the power supply temperature Ptp does not exceed the warning area. Become.

  FIG. 2 is a functional block diagram of the printing apparatus 10 according to the embodiment of the present invention. The control unit 11 includes a main control unit 12, a print control unit 13, a print buffer 14, a print condition setting unit 15, a conveyance control unit 16, and a temperature monitoring unit 17. Each unit constituting the control unit 11 can be implemented by a CPU, a ROM, a RAM, and a control program and control data stored in the ROM or the RAM.

  The head drive circuit 21 is configured to be able to divide and drive the print head 22 composed of print dots arranged corresponding to one dot line, and can drive each at a time or sequentially. Based on the control of the unit 12, the division printing method of the print head 22 can be selected. As the print head 22, an ink jet head, a thermal head, or an impact head can be used. In the case of a thermal printer, a thermal head is generally used. A drive current is supplied from the power source 50 to the print head 22.

  Based on the control of the main control unit 12, the motor drive circuit 23 drives the rotation of the carry motor by sequentially passing current while switching the drive of each phase of the carry motor 24. The conveyance motor 24 is a motor for feeding (conveying) printing paper, and a normal step motor is used. In the case of a DC motor, the power supply is driven on and off and controlled so as to reach a predetermined speed based on an output signal of a rotation detector (not shown). The drive current for the transport motor 24 is also supplied from the power supply 50.

  A temperature detector 25 such as a thermistor is disposed on an element inside the power supply 50, and detects the surface temperature of the power supply element (power supply temperature Ptp). The temperature detector 25 can be provided in each of a plurality of elements that tend to rise in temperature due to an output current such as a switching transistor, a coil, and a resistor in the power supply 50. In FIG. 2, a temperature detector is arranged outside the power supply 50, but this is for the convenience of drawing, specifically, an element (not shown) in the power supply. Provided on top. As an element in a power supply, it arrange | positions at the surface etc. of a switching regulator, for example. The temperature detector 25 outputs the detected temperature information to the temperature monitoring unit 17 of the control unit 11.

  The temperature monitoring unit 17 stores monitoring information such as a predetermined warning temperature region and a limit temperature region according to each element, and selects a print control condition corresponding to the received temperature information based on the monitoring information. The data is output to the printing condition setting unit 15. The printing condition setting unit 15 outputs control information corresponding to the designated printing control condition to the printing control device 13 and the conveyance control unit 16 based on the printing control condition designated by the temperature monitoring unit 17.

  The printing control unit 13 and the conveyance control unit 16 perform printing control and conveyance control based on the control information from the printing condition setting unit 15. The printing apparatus 10 includes various control logic circuits such as switches and sensors in addition to these, but portions that are not important for the description of the present invention are omitted.

(Control of printing operation)
The main control unit 12 controls each unit in the control unit 11 and the entire printing apparatus 10. The print control unit 13 develops the received print data into bit data of the print image based on the print data and control data received from the host device such as a PC or a POS terminal device, and transfers and stores them in the print buffer 14. Print data (print dot data) that has been bit-patterned from the print buffer 14 is read out in units of dot lines, or divided into multiple print data units that can be transferred by the configuration and wiring of the shift register of the print head 22. Is output to the head drive circuit 21. Based on the drive control of the print control unit 13, the head drive circuit 21 divides a print head 22 that is divided into two, three, four, or the like into print dot units in one dot line simultaneously or sequentially for a predetermined time. (The drive current is passed through the predetermined divided printing dots). In this way, printing of one dot line is executed.

  At this time, the current value consumed by the print head differs depending on how many print dots in one dot line are printed simultaneously. In the case of a printing pattern having a high printing density such that the entire area becomes black as shown in the area B of FIG. 1B, almost all printing dots of one dot line are printed, and the head driving current is also increased. growing. If such a pattern with high printing density continues continuously and is performed at high speed printing, a large current will continue to flow in a short time. If the capacity of the power supply 50 is small, the temperature of the element tends to rise easily and quickly. The alert temperature range is reached. At the same time, a large voltage drop occurs.

  In such a case, if one dot line is divided into a plurality of print dot units and a control called division control is performed in which time is shifted for each division, the number of print dots that are driven simultaneously is reduced. As described above, the current that flows instantaneously can be reduced by dividing the number of times of outputting the current for printing one dot line into a plurality of times. In addition, since printing is performed while the printing paper is being conveyed by the conveyance motor, in such divided printing, it takes time to print one dot line, so it is necessary to reduce the paper feed speed. For this reason, normally, the paper feed speed is reduced in accordance with the number of print divisions, so the drive current of the carry motor also decreases during division printing. Further, regardless of the division printing, it is possible to suppress the driving current of the carry motor and reduce the printing load as a whole by reducing the paper feeding speed. It is also possible to reduce the printing load by reducing the drive time of the print head 22 within a range in which the print contents can be determined.

(Power supply temperature monitoring)
The temperature of the element in the power supply 50 is detected by the temperature sensor 25 and output to the temperature monitoring unit 17. When the temperature of the element (power supply temperature Ptp) rises and reaches a warning area, the temperature monitoring unit 17 changes the printing control condition so as to reduce the printing load.

  FIG. 3 shows an example of the relationship between the monitoring information stored in the temperature monitoring unit 17 and the printing control conditions. In FIG. 3, similarly to FIG. 1C, the power source temperature Ptp is 91 ° C. to 120 ° C. as the warning temperature region, and the temperature exceeding 120 ° C. is the limit temperature region. When the temperature is 90 ° C. or lower, the printing temperature is not controlled as a normal temperature range. When the temperature exceeds 90 ° C, the printing control conditions are sequentially changed in units of 10 ° C. When the temperature exceeds 120 ° C, the operation of the printing apparatus is stopped to protect the power supply. In the present invention, the printing conditions are controlled so as not to exceed 120 ° C., and the operation of the printing apparatus is not stopped for power protection.

  The warning temperature region, the limit temperature region, and the printing conditions are appropriately determined depending on the type of power supply and the type of element. For example, depending on the type of power supply and the type of element, various load tests are performed a considerable number of times, temperature change data of each element according to the load, temperature data at which the element breaks are collected, and based on these data, It is desirable to set the warning temperature area, the number of warning area sections, the limit temperature area, and the printing conditions. When the temperature detectors 25 are provided for a plurality of elements, one print control condition is selected based on a combination of temperature information of each element. In the following description, it is assumed that the four types of printing conditions in FIG. 3 are selected.

(Setting print control conditions)
When the printing condition is set by the temperature monitoring unit 17, it is output to the printing condition setting unit 15. The printing condition setting unit 15 stores control information (control information pattern) corresponding to various printing control conditions. When the printing control condition is designated, the printing condition setting unit 15 reads out control information for performing printing control according to the designated printing control condition, and outputs it to the printing control unit 13 and the conveyance control unit 16.

  The control information pattern according to the print control condition includes the number of print divisions, the print speed (conveyance speed), the drive current to each print head, etc., according to the print ratio (print duty) of the print data to be printed. This is a combination of control data for controlling the printing load so as to change. That is, as the printing ratio increases, the number of divisions is increased and the printing speed is reduced to reduce the printing load. The printing control conditions 1 to 4 are such that the printing load with respect to the printing ratio is reduced as the number increases.

  A transport motor according to the drive current and transport speed required when printing data with various print ratios (print duty) without division, when printing with two divisions, when printing with four divisions, etc. The drive current is a value unique to the printing apparatus and can be grasped in advance. Therefore, it is possible to set the current consumption and the energization time according to the print data print ratio, print speed, and division print combination so as to have an appropriate print load according to the power supply temperature Ptp.

  An example of control information corresponding to the print control condition stored in the print condition setting unit 15 will be described with reference to FIG. FIG. 4 shows four examples of print control conditions 1 to 4 as graphed images. In FIG. 4, the print control conditions 1 to 4 are shown as “pattern 1” to “pattern 4”, respectively. In the figure, the vertical axis represents the printing speed, and the horizontal axis represents the printing ratio. The numbers (1), (2), and (4) in the figure indicate the number of divisions for 1-dot line printing. (1) is 1 division (no division), (2) is 2 divisions, ( 4) shows four divisions. Cp indicates a switching point for divided printing.

  Pattern 1 is a case of normal printing with a power supply temperature of 90 ° C. or lower, and it is possible to perform printing control that requires a relatively large printing load in accordance with the original capability of the power supply. In this example, one dot line is printed without division (1) until the printing ratio is approximately 50%, and printing control is performed at a printing speed of 150 mm / s. All of the printing ratios 50% to 100% are printed by the two-division printing (2), and the printing speed is gradually decreased according to the printing ratio.

  Pattern 2 is printing control when the power supply temperature is higher than 90 ° C and lower than 100 ° C. Divided printing is the same as pattern 1, but the printing speed is set slower than pattern 1 and the printing load is set. Has been reduced. Pattern 3 is printing control when the power supply temperature is higher than 100 ° C and lower than 110 ° C. In this case, since the power source temperature is considerably high, the printing speed is decreased according to the printing ratio, and when the printing ratio exceeds approximately 15%, two-division printing (2) is performed, and when the printing ratio is 60%, four-division printing (4 ) Is used to control printing, greatly reducing the printing load.

  Pattern 4 is print control when the power supply temperature is higher than 110 ° C., which is just below the limit region, and is 120 ° C. or lower. In this case, since the power supply temperature has almost reached the limit, the printing speed is reduced to 50 mm / s regardless of the printing ratio, and printing by four-division printing (4) is performed so that the power supply temperature is lowered. I have to.

  Although FIG. 3 and FIG. 4 show four examples of printing conditions, it is also possible to set a larger number of printing conditions and execute fine print control. In addition, it is desirable to set appropriate values for the temperature range of the warning temperature region and the temperature range of the limit temperature region according to each power source.

  FIG. 5 shows an example of the processing procedure of the print control method in the case shown in FIGS. First, it is confirmed whether the printing condition is not 1 (S101). If the print control condition is 1 (S101; No), it is next checked whether the power supply temperature is higher than 90 ° C. If it is higher than 90 ° C (S101; Yes), the print control condition is set according to the power supply temperature. It is set (S103).

  If the print control condition is not 1 (S101; Yes), the print control condition is currently set to 2 or more (temperature control setting in the warning temperature region), so the print control condition is set based on the power supply temperature. Performed (S103). For example, when the print control condition 2 is set and the power supply temperature recovers to a warning temperature range (90 ° C. in the example of FIG. 3) or lower, the print control condition is set to the normal state (print control condition 1). Setting to return to is performed (S103). Conversely, when the power supply temperature is higher than 100 ° C., the printing condition 3 is set (S103).

  Next, control information corresponding to the designated control condition is read and set by the printing condition setting unit 15 (S104). The print control unit 13 and the conveyance control unit 16 calculate the print ratio of the print data scheduled to be printed, determine the number of divided prints, the conveyance speed, and the energization time of the print dots based on this control information (S105). The print drive circuit 21 and the motor drive circuit are controlled to perform printing (106).

  In this way, the power supply temperature is monitored in real time, and the printing control is performed in accordance with the power supply temperature so as to provide a proper printing load that matches the power supply capacity. In addition to preventing this, it is possible to bring out the optimum print performance according to the power supply while maintaining the print quality.

  In the above description, an example using a line printer is shown, but the present invention can also be applied to a serial printer. In this case, the control information specified by the print control conditions includes the drive current of the transfer motor that moves the print head in the horizontal direction and the drive current of the print head.

(A) is an external view showing an example in which a general-purpose AC adapter 50 is used as a power source, (b) is a diagram showing an example of printing on a receipt, and (c) is a diagram of (b). It is a graph which illustrates the change of the power supply voltage V (t) accompanying the example of receipt printing, and the change of the surface temperature of the element in a power supply. It is a functional block diagram of the printing apparatus concerning one Embodiment of this invention. 6 is a table showing an example of the relationship between monitoring information and printing control conditions stored in a temperature monitoring unit 17. Four examples of printing control conditions are shown as graphed images. 6 is a flowchart illustrating an example of a processing procedure of a print control method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printing apparatus 11 Control part 12 Main control part 13 Print control part 14 Print buffer 15 Print condition setting part 16 Conveyance control part 17 Temperature monitoring part 21 Head drive circuit 22 Print head 23 Motor drive circuit 24 Conveyance motor 25 Temperature detector 50 Power supply 60 Receipt

Claims (7)

A temperature detector provided on a predetermined element in a power source and outputting temperature information of the element;
A printing condition selection unit that selects a printing control condition according to the temperature of the element based on the temperature information received from the temperature detector;
Based on the selected print control condition, a print control unit and a conveyance control unit that perform drive control of the print head and the conveyance motor;
A printing apparatus comprising:   2. The printing according to claim 1, wherein the printing condition setting unit divides the temperature range of the element into a plurality and assigns a printing control condition for reducing a printing load each time the temperature classification becomes higher. apparatus.   The printing control condition is configured by a plurality of control data for controlling a printing speed, the number of simultaneously driven dots of the printing head, a driving time to the printing head, and an energization amount to the conveyance motor, and the printing condition setting unit includes a plurality of control data. The printing apparatus according to claim 2, wherein one printing control condition that matches the temperature classification is selected from printing control conditions, and the selected printing control condition is stored in a nonvolatile manner.   The print control condition is to control the printing speed, the number of dots simultaneously driven by the print head, the drive time to the print head, and the energization amount to the carry motor according to the printing ratio of one dot line according to the capability of the power source. The printing apparatus according to claim 2, comprising a plurality of control data.   The print control unit and the transport control unit acquire control data corresponding to a print ratio of print data scheduled to be printed from the selected print control condition, and based on the control data, the print head and the transport control unit The printing apparatus according to claim 3, wherein a driving operation of the motor is controlled. The temperature detector is provided in a plurality of elements in the power source,
The printing apparatus according to claim 1, wherein the printing condition selection unit selects the printing control condition based on a combination of temperature information from the plurality of temperature detections. (A) monitoring the power source temperature comprising the surface temperature of the elements in the power source;
(B) changing the printing control condition according to the power supply temperature when the power supply temperature is in a predetermined monitoring temperature range;
(C) controlling the drive of the print head and the transport motor for the next print data based on the changed print control condition;
A printing control method for a printing apparatus, comprising:

Images