JP4581598B2 - Electronic equipment with time management function - Google Patents

Description

  The present invention relates to an electronic device having a function of managing time using a time counted by an internal clock and a time given from an external device.

  As a conventional example of this type of electronic device, for example, there is an ink jet printer described in Patent Document 1. This printer is connected to an external device and receives time information from the external device when printing is performed or when a head cleaning is requested. The time information stored in the RAM is updated with the received time information. In addition, there is a timer inside this printer, and this internal timer continuously counts the time, and the counted time is added to the time information in the RAM. As a result, the RAM holds time information that substantially matches the time information counted by the external device.

  The time management function inside the printer may be backed up by a rechargeable battery. In that case, the time count in the printer is continued even while the printer is turned off.

JP 2002-144451 A

  The time information managed in the printer as described above is used for the following control. For example, based on the time information, the elapsed time from the time when the previous head cleaning was performed to the present is calculated, and based on the elapsed time, it is determined whether the time to perform head cleaning has arrived. The amount of evaporation of the waste ink discharged from the head to the waste ink absorber by the head cleaning (the amount of waste ink remaining in the waste ink absorber) is calculated.

  Needless to say, the time information or the elapsed time information managed in the printer must be accurate for the above-described control based on the elapsed time to be properly performed. However, due to the following problems (1) and (2), the accuracy of time information or elapsed time information in the printer is impaired.

  (1) When the printer is turned off for a long time, the backup battery is completely discharged and the time management function in the printer is stopped. Even if the power is turned on after that and the time management function is restarted, the time information held in the printer is no longer consistent with the time information held previously. Therefore, it becomes impossible to grasp the elapsed time before the power supply is turned off. For example, if the previous head cleaning was performed before the power supply was turned off, the elapsed time from the previous head cleaning execution time to the present time is unknown, so it is determined when the next head cleaning should be performed, and waste ink evaporation The amount cannot be calculated accurately.

  (2) Even if the problem (1) occurs, if the time information is received again from the external device after the power is turned on, the time information in the printer is corrected by the time information from the external device. Sex is restored again. However, in the case of a printer that is rarely connected to an external device and frequently turned off for a long period of time, the accuracy of head cleaning determination and waste ink evaporation amount calculation becomes extremely poor.

  For this reason, conventionally, when designing a function for regular head cleaning and waste ink leakage prevention, a design having a margin with an appropriate margin has been performed by allowing a certain degree of reduction in control accuracy. However, this causes an increase in manufacturing cost and running cost.

  Accordingly, an object of the present invention is to increase the accuracy of time information managed in an electronic device in a printer or other electronic device.

  Another object is to increase the reliability of control (for example, the above-described head cleaning determination and waste ink evaporation amount calculation) processed based on time information managed in the electronic device.

  According to one aspect of the present invention, an electronic device that can be connected to an external device that intermittently sends absolute time information operates with power from a power source during a power-on period of the electronic device, and a power-off period The clock means that operates with the electric power stored in the capacitor and continuously counts the internal time, and when the information on the absolute time is received from the external device, the clock means is corrected using the information. An internal clock correcting means for making the internal time correspond to the absolute time, a time storage means for storing a processing time acquired from the clock means when a predetermined process is executed in the electronic device, and the internal When the clock means is corrected by the clock correction means, the processing time held in the processing time storage means is corrected by the same correction width as the clock means. And a storage time adjustment means to adapt the processing time to the absolute time.

  According to this electronic apparatus, when the information on the absolute time is provided from the external device, the internal time from the clock means is corrected by the information so as to correspond to the absolute time. When a predetermined process (for example, power supply turn-off, power supply turn-on, head cleaning in the case of an ink jet printer) is executed in the electronic device, a processing time that is an internal time at the time of execution is stored. When the clock means is corrected to correspond to the absolute time, the stored processing time is also corrected to correspond to the absolute time. As a result, the stored processing times are arranged on the same time axis as the internal time. For example, if the internal time is on the absolute time axis, the stored processing time is also on the absolute time axis, and if the internal time is on the relative time axis, the stored processing time is also on the relative time axis. It will be on top. Arranging on the same time axis in this way makes it possible to accurately obtain the elapsed time between both time points using the internal time and the stored processing time. As a result, the reliability of the control processed based on the elapsed time is improved.

  In a preferred embodiment, by calculating a difference between the processing time stored in the processing time storage unit and the current time acquired from the clock unit at the current time point, the execution time of the predetermined process is performed until the present time. An elapsed time calculating means for calculating the elapsed time is further provided.

  In a preferred embodiment, the elapsed time calculating means calculates the elapsed time when a specific operation (for example, head cleaning in the case of an ink jet printer) is performed on the electronic device and immediately before power-off. To do. By calculating the elapsed time at least at this timing, even if the power supply is repeatedly turned on and off, and the clock means may stop during the power-off period, the elapsed time from the execution time of the specific work is to some extent It is possible to grasp with accuracy. As a result, the reliability of control based on the elapsed time, such as when the next specific operation should be performed, is increased. Here, the specific work may include, for example, head cleaning in the case of an ink jet printer.

  In a preferred embodiment, the specific operation, power supply turn-on, and power supply turn-off are employed as the predetermined process. By storing at least the execution times of these processes, even if the power supply is repeatedly turned on and off and the clock means may stop during the power supply off period, the elapsed time from the execution time of the specific work can be calculated. It is possible to grasp with good accuracy. As a result, the reliability of control based on the elapsed time, such as when the next specific operation should be performed, is increased.

  In a preferred embodiment, there is further provided an internal time determination means for determining whether or not the internal time corresponds to the absolute time and storing the determination result. By determining whether the internal time corresponds to the absolute time, the elapsed time is calculated based on the internal time corresponding to the absolute time, and based on the internal time (relative time) not corresponding to the absolute time Thus, it is possible to select a calculation method suitable for each case when calculating the elapsed time. As a result, the reliability of control based on the elapsed time is increased.

  In a preferred embodiment, the internal time determination means performs the determination immediately after power-on and when the clock means is corrected by the internal clock correction means. The switching time at which the internal time corresponds to the absolute time or no longer corresponds to the time when the clock means is corrected or the time when the power supply is turned on, so there is no delay by making a determination at these times. A timely discrimination result is obtained.

In a preferred embodiment, there is further provided a clock stop judging means for judging whether the clock means has been stopped or continuously operated during the power-off period, and storing the judgment result. The internal time discriminating means immediately after the power is turned on,
(1) If the determination result indicates stop, a determination result that the internal time does not correspond to the absolute time is issued;
(2) If the determination result indicates a continuation operation, a determination result according to the determination result stored at the previous power-off time is issued,
When the clock means is corrected by the internal clock correction means, a determination result is output that the internal time corresponds to the absolute time. Thereby, an accurate discrimination result is obtained.

In a preferred embodiment, in response to the specific work executed by the electronic device, means for calculating result data according to the result of the specific work,
(1) calculating absolute time base result data in response to the specific operation performed when the internal time corresponds to the absolute time;
(2) calculating relative time base result data in response to the predetermined operation performed when the internal time does not correspond to the absolute time;
(3) Work result management means for separately managing the absolute time base result data and the relative time base result data is further provided.

  In this way, data corresponding to the execution result of a specific work (for example, head cleaning in the case of an ink jet printer) (for example, data obtained by calculating the amount of waste ink absorbed by the ink absorber by the head cleaning) is used as the specific work. The result data of a specific operation (for example, calculation data of the amount of waste ink in the ink absorber) is distinguished and calculated separately depending on whether or not the internal time corresponding to the execution of the time corresponds to the absolute time The calculation accuracy of is improved.

  In a preferred embodiment, when the elapsed time is calculated by the elapsed time calculation means, the work result management means sets the absolute time base result data and the relative time base result data to the calculated elapsed time. Correct accordingly. In this way, the result data of the specific work is corrected according to the elapsed time (for example, the evaporation data according to the elapsed time is subtracted from the calculation data of the waste ink amount) to calculate the result data of the specific work. Accuracy is improved. In particular, it is possible to adopt different correction methods according to the difference in properties between absolute time base and relative time base by separately performing correction on absolute time base result data and correction on relative time base result data. Data calculation accuracy is improved.

  In a preferred embodiment, the apparatus further comprises work result judging means for judging whether there is no problem in the result of the specific work based on data obtained by combining the absolute time base result data and the relative time base result data. It is done. For example, in the case of an inkjet printer, it can be determined whether waste ink overflow does not occur based on a value obtained by adding absolute time-based waste ink amount calculation data and relative time-based waste ink amount calculation data. .

In a preferred embodiment, the elapsed time calculating means includes
(1) means for calculating a first elapsed time in which a time length of a power-off period in which the stop of the clock means has occurred can be counted;
(2) means for calculating a second elapsed time during which the time length of the power-off period in which the clock means has stopped cannot be counted. Then, the work result management means checks whether or not the internal time corresponds to the absolute time at the time of calculation of the elapsed time, and as a result of the check,
(1) When the absolute time is supported,
A. Correcting the absolute time base result data according to the first elapsed time;
B. Correcting the relative time base result data according to the second elapsed time;
(2) If the absolute time is not supported, the absolute time base result data and the relative time base result data are corrected according to the second elapsed time.

  Thus, when the result data is corrected according to the elapsed time, whether the internal time at the time of calculating the elapsed time corresponds to the absolute time, and whether the correction target is the absolute time base result data or the relative time base result By changing the applied elapsed time depending on the data, each result data can be corrected with high accuracy. Therefore, determination control based on the result data corrected according to the elapsed time (for example, determination control of the possibility of overflow of waste ink based on the amount of waste ink corrected by the evaporation amount according to the elapsed time in an inkjet printer) ) Reliability is improved.

  In a preferred embodiment, the elapsed time calculating means does not correspond to the absolute time when the internal time does not correspond to the absolute time due to the clock means being stopped during a power-off period. When the elapsed time is calculated based on time, and then the internal time and the processing time are corrected to correspond to the absolute time according to the information received from the external device, the absolute time corresponds to the absolute time The elapsed time is calculated based on the internal time and the processing time, and the elapsed time calculated based on the internal time not corresponding to the absolute time is invalidated. As a result, if the clock means stops during the long power-off period and the absolute time becomes unknown, the elapsed time is calculated for the time being based on the relative time output by the clock means. If the information is received, the elapsed time based on the absolute time is recalculated and it is assumed that there is no elapsed time based on the relative time. Therefore, the accuracy of the control processed based on the elapsed time is improved. improves.

  ADVANTAGE OF THE INVENTION According to this invention, the precision of the time information managed within an electronic device increases in a printer and other electronic devices.

  According to the preferred embodiment of the present invention, the reliability of the control processed based on the time information managed in the electronic device is increased.

  FIG. 1 shows the overall hardware configuration of an inkjet printer according to an embodiment of an electronic apparatus according to the present invention.

  As shown in FIG. 1, an inkjet printer (hereinafter referred to as a printer) 100 can be connected to an external device (for example, a printer client such as a personal computer, a digital camera, or a mobile phone, or an image source device) 200. The external device 200 continuously counts absolute time itself (typically, a time substantially equivalent to standard time), and uses time information indicating the current time as a predetermined communication time with the printer 100 (for example, a printer). Time information corresponding to the current absolute time is transmitted to the printer 100 when a print job or image data is transmitted to the printer 100 or when a time inquiry is received from the printer 100. The current absolute time information transmitted from the external device 200 to the printer 100 is hereinafter referred to as TI (Time Index).

  The printer 100 includes a printing mechanism 110 that is a mechanism for performing a printing operation. The printing mechanism 110 includes a print head 111, an ink tank 112, a head maintenance mechanism 113, a carriage mechanism 113, an ink absorber 115, a paper feed mechanism 116, and the like. The head maintenance mechanism 113 performs various maintenance operations on the print head 111, for example, filling of the print head 111 with ink when the new ink tank 112 is mounted, cleaning of the print head 111 (removing ink clogs of inkjet nozzles, head This is a mechanism for removing dirt on the surface, and includes a head protection cap, an ink suction pump, a wiper, and the like. The ink absorber 115 is a sponge-like object that absorbs waste ink discharged from the print head 111 when maintenance of the print head 111 is performed, and prevents the waste ink from leaking into the printer 10. . The carriage mechanism 114 is a mechanism that moves the print head 111 by running a carriage (not shown) on which the print head 111 is mounted along a shaft.

  The printer 100 also includes a controller 120 for controlling the printing mechanism 110. The controller 120 includes a CPU 122, a RAM 124, and an EEPROM (nonvolatile memory) 126. The function of the controller 120, particularly various control functions according to the principles of the present invention, will be described in detail later.

  The printer 100 also has an RTC (real time clock circuit) 130 for continuously counting time within the printer 100. Hereinafter, the time continuously counted by the RTC 130 is referred to as an RTC time. The RTC time counted by the RTC 130 is read by the CPU 122 periodically (for example, at one hour intervals). The RTC time counted by the RTC 130 can be set to a time designated by the CPU 122 by an instruction from the CPU 122.

  The printer 100 further includes a main power supply circuit 140 that supplies power to the printing mechanism 110, the controller 120, and the RTC 130 described above. The main power supply circuit 140 receives power from an external power supply 300 such as a commercial 100 VAC power supply, and supplies DC power having a voltage for each part to each part in the printer 100. The main power supply circuit 140 is turned on and off under the control of the CPU 122. Hereinafter, the main power supply circuit 140 may be abbreviated as a power supply.

  The RTC 130 described above receives power from the battery (for example, a large-capacity capacitor or battery) 150 and can continue to operate while the power is off. The battery 150 is charged by the main power circuit 140 while the power is on. However, when the power-off state reaches a predetermined time or longer, the battery 150 is completely discharged and the RTC 130 stops. In the following description, it is assumed that the longest time that the RTC 130 can operate with the battery 150 in the power-off state is 160 hours as an example. Even when the RTC 130 stops during such a long power-off period, if the main power supply circuit 140 is subsequently turned on, the RTC 130 starts operating again. The RTC 130 internally stores operation information indicating whether the operation was stopped during the power-off period or whether the operation was continued without stopping. The CPU 122 refers to the operation information of the RTC 130 after the power is turned on, thereby grasping whether the RTC 130 has been stopped or continuously operated during the power-off period.

  FIG. 2 shows the control functions of the controller 120, particularly various control functions related to the present invention.

  As shown in FIG. 2, the CPU 122 executes a control program incorporated in advance, thereby performing a power-on time control 200, a TI reception time control 202, a carriage maintenance (CM) control 204, and a head maintenance (HM) control. 206 and waste ink control 208 are performed. In the following description, carriage maintenance may be abbreviated as CM and head maintenance may be abbreviated as HM.

  The power-on time control 200 is a time control that is executed when the main power circuit 140 is turned on (immediately after). The TI reception time control 202 is time control that is executed when a TI is received from the external apparatus 200 (immediately after). The power-on time control 200 and the TI reception time control 202 constitute a time management control 203 inside the printer 100. As will be apparent from the specific description later, when the TI is received from the external device 200, the internal time management control 203 corrects the RTC time by the TI so that the RTC time corresponds to the absolute time. To. Also, the internal time management control 203 determines whether or not the RTC time corresponds to the absolute time (that is, only corresponds to the relative time), and determination information (TI described later) indicating the determination result. Flag). Further, the internal time management control 203 determines whether the RTC 130 has been stopped or continuously operated during the previous power-off period when the power is turned on. Process to cope with the unknown length.

  The carriage maintenance control 204 is a control for preventing the solidification or deterioration of the lubricating oil applied to the shaft for the carriage to travel along the carriage mechanism 114 in order to keep the carriage mechanism 114 in an appropriate state. The carriage maintenance control 204 is performed, for example, when the power is turned on (immediately after), and it is determined whether the previous power-off period is longer than a predetermined oil threshold (a threshold time length determined from the viewpoint of preventing solidification of the lubricating oil). If so, the carriage is run to cause the lubricating oil to flow to prevent the lubricating oil from solidifying.

  The head maintenance control 206 is a control for automatically performing head maintenance, particularly cleaning, as timely as possible in order to properly maintain the state of the print head 111. The head maintenance control 206 is performed, for example, when printing is started (immediately before) (may be performed when the power is turned on (immediately after)). The head maintenance control 206 determines whether it is necessary to perform cleaning according to the length of time elapsed since the previous head maintenance execution, and executes it if necessary. Here, for cleaning, multiple types of processes with different levels of work amount are prepared, and when it is determined that cleaning is necessary, what level of cleaning process is performed according to the length of the elapsed time described above Is to be selected.

  The waste ink control 208 calculates the amount of waste ink (remaining amount of waste ink) held from the ink absorber 115 in consideration of the evaporation amount, and based on the calculated waste ink remaining amount, absorbs ink. The head maintenance (especially cleaning) is adjusted so that waste ink does not overflow from the body 115 and leak out. Waste ink control 208 is performed in the head maintenance control 206. The waste ink control 208 is also executed when head maintenance (ink filling when an ink tank is mounted, cleaning according to a user request) is performed according to a user request. As will be apparent from the following description, the waste ink control 208 determines that the remaining amount of waste ink discharged by the head maintenance performed when the RTC time corresponds to the absolute time and the RTC time are relative times. Separately calculate and hold the remaining amount of waste ink discharged by the head maintenance performed when it is compatible, and whether the waste ink overflows based on the total amount of waste ink combined with both Determine whether or not. As a result, highly reliable waste ink leakage prevention control can be performed.

  In order to perform the various controls 200 to 208 described above, the CPU 122 records the following variable data in the RAM 124 and the EEPROM 126.

  That is, as shown in FIG. 2, the RAM 124 stores variable data such as the TI flag 220, the power-off time length 222, the evaporation time length 224, the HM (head maintenance) timer 226, and the power-on time 228. . The EEPROM 126 also includes a previous power-off TI flag 240, a previous HM (head maintenance) time 242, a previous power-off time 244, a previous evaporation calculation time 246, and an absolute time-based waste ink total amount (hereinafter abbreviated as SA). 248, absolute time base waste ink remaining amount (hereinafter sometimes abbreviated as A) 250, relative time base waste ink total amount (hereinafter sometimes abbreviated as SB) 252, and relative time base waste ink. Variable data such as the remaining amount (hereinafter sometimes abbreviated as B) 254 is recorded. These variable data in the EEPROM 126 are retained without being erased even during the power-off period.

  The meanings of the variable data 220 to 226 in the RAM 124 are as follows.

  If it is “1”, the TI flag 220 indicates that the RTC time corresponds to the current absolute time, and if it is “0”, the RTC time does not correspond to the current absolute time ( Corresponding to relative time).

  The power-off time length 222 indicates the time length of the immediately preceding power-off period, and this is used as a material for determining whether or not carriage maintenance should be performed in the carriage maintenance control 204.

  The evaporation time length 224 indicates the elapsed time from the previous execution time of the same calculation to the current execution time at the time of executing the calculation of the waste ink evaporation amount. , RTC time corresponding to absolute time). The evaporation time length 224 is used for calculating the amount of evaporation of waste ink in the waste ink control 208.

  The HM timer 226 indicates an elapsed time having the same meaning as the evaporation time length 224, and is used for calculating the evaporation amount of waste ink. However, the HM timer 226 is calculated based on the relative time (strictly speaking, the RTC time corresponding to the relative time). As will be apparent from the following description, when the RTC 130 is stopped due to the capacitor discharge during the power-off period, the length of the power-off period is unknown, but the unknown power-off period length is the HM timer 226. Is not included in the elapsed time indicated by. As a result, the unknown power-off period length is excluded from the calculation of the waste ink evaporation amount, and the reliability of the waste ink control 208 is improved.

  The power-on time 228 is an RTC time when the power is turned on.

  The meaning of the variable data 240 to 254 in the EEPROM 126 is as follows.

  The previous power-off TI flag 240 indicates the value of the TI flag 220 at the time of the previous power-off (that is, whether the RTC time indicates an absolute time or a relative time). The previous HM time 242 indicates the time when the previous head maintenance was executed. The previous power-off time 244 indicates the time when the previous power-off was performed. The previous evaporation calculation time 246 indicates the time when the previous evaporation amount calculation was executed (the time when the previous waste ink control 208 was executed).

  The absolute time base waste ink total amount (SA) 248 is discharged to the ink absorber 115 by the head maintenance performed when the RTC time corresponds to the absolute time (when the TI flag 220 is “1”). Indicates the total amount of ink. The absolute time base waste ink remaining amount (A) 250 indicates the remaining amount of SA248 excluding the evaporation amount.

  The relative time base waste ink total amount (SB) 252 is discharged to the ink absorber 115 by the head maintenance performed when the RTC time corresponds to the relative time (when the TI flag 220 is “0”). Indicates the total amount of ink. The relative time base waste ink remaining amount (B) 254 indicates the remaining amount of the SB 252 excluding the evaporation amount.

  Hereinafter, specific flows of the various controls 200 to 208 performed by the CPU 122 will be described.

  FIG. 3 shows the flow of the power-on time control 200.

  As shown in step S300 of FIG. 3, the power-on time control 200 is started immediately after the power source (main power circuit 140) is turned on. In step S <b> 302, it is determined based on the operation information held by the RTC 130 whether the RTC 130 has been continuously operated during the immediately preceding power-off period or has been stopped due to the capacitor discharge.

  If it is determined in step S302 that the RTC 130 has been continuously operated, the control proceeds to step S304, the elapsed time from the previous power-off time 244 to the current RTC time (current time) is calculated, and the calculated elapsed time is calculated. Is recorded as the power-off time length 222. In step 304, the current RTC time (current time) is set in the HM timer.

  In step 308, the previous power-off TI flag 240 is checked. If the previous power-off TI flag 240 has a value of “1”, it means that the RTC time corresponds to the absolute time at the previous power-off (that is, the TI was received). In that case, the value “1” is set in the TI flag 220. This means that the RTC time still corresponds to the absolute time. On the other hand, if the result of step 308 is that the previous power-off TI flag 240 is “0”, the RTC time corresponds to the relative time at the previous power-off (that is, the TI was not received). ). In that case, the value “0” is set in the TI flag 220. This means that the RTC time still corresponds to the relative time.

  If it is determined as a result of step S302 described above that the RTC 130 has stopped during the previous power-off period, the control proceeds to step S320. In this case, the power-off time length is not exactly known, but it is understood that it is longer than the maximum backup time length of the battery 150 (for example, 160 hours). Therefore, in step S320, the estimated minimum value (eg, 161 hours) of the power-off time length is set as the power-off time length 222. In this case, since the RTC time is also an unreliable value, the initial value “0” is set as the RTC time in the RTC 130 in Step 322, and the initial value “0” of the RTC time is also set in the HM timer 226 in Step 324. Is set. As a result, the RTC 130 starts time counting with the power supply turn-on time as the origin of the relative time. In step 312, the value “0” is set in the TI flag 220. This means that the current RTC time corresponds to the relative time.

  With the above power-on time control 200, the property of the time managed inside the printer, whether the current RTC time corresponds to the same absolute time as TI or the relative time, is TI. It will be identified by the flag 220. When the RTC 130 continues to operate during the power-off period, the exact time length of the power-off period is recorded as the power-off time length 222. On the other hand, when the RTC 130 stops during the power-off period, the minimum time length (for example, 161 hours) of the power-off period estimated from the backup capability (for example, 160 hours) of the battery is recorded as the power-off time length 222. Will be. Further, when the RTC 130 stops during the power-off period, the RTC time is counted again with the subsequent power-on time as the origin.

  FIG. 4 shows a flow of the TI reception time control 202.

  As shown in step S400 of FIG. 4, immediately after the TI is received from the external device 200, the TI reception time control 202 is started. In step 402, it is checked whether or not the current TI reception is the first reception after the power is turned on.

  As a result, if it is the first reception, in step S404, the RTC 130 is set as the RTC time with the absolute time (TI corresponding time) corresponding to the received TI (that is, the RTC time is set to the TI corresponding time). Modified to match). Here, the TI corresponding time is a value obtained by converting an absolute time indicated by the TI, for example, 13:15 on October 1, 2004, into a count value of the RTC 130 which is a ring counter having a fixed number of years. If the time difference between the RTC time and the received TI is as small as the normal variation of the time managed by the external device 200 (for example, within 24 hours), the time difference is The RTC time can be regarded as corresponding to the correct absolute time. Thus, if the time difference is so small, step 404 may be passed.

  If a TI is received, a value “1” is set in the TI flag 220 in step 406. This means that the current RTC time corresponds to the absolute time.

  In step S408, it is checked whether the current TI reception is the first reception after the printer 100 is shipped from the factory. As a result, if it is determined that it is not the first reception, the HM timer 226, the power-on time 228, the previous HM time 242, the previous power-off time 244, and the previous evaporation calculation time 246 are the RTC time in step 404. And the TI corresponding time and the difference (that is, the same correction width as that of the RTC time) are corrected. For example, if 100 hours is added to the RTC time in step 404, the HM timer 226, the power-on time 228, the previous HM time 242, the previous power-off time 244, and the previous evaporation calculation time 246 are also added to 100 hours. Is done. As a result of this correction, the HM timer 226, the power-on time 228, the previous HM time 242, the previous power-off time 244, and the previous evaporation calculation time 246 become values on the time axis of the same absolute time as the RTC time. The difference between these values indicates a meaningful elapsed time (for example, the difference between the corrected previous power-off time 244 and the RTC time indicates the elapsed time from the previous power-off to the present). On the other hand, if it is determined in step S408 that the reception is the first reception after shipment from the factory, the correction in step 410 is passed. In the case of the first reception after shipment, the values of the HM timer 226, the previous HM time 242, the previous power-off time 244, and the previous evaporation calculation time 246 are indefinite, so it is meaningless to correct this. .

  If it is determined in step 402 described above that the reception is not the first reception after the power is turned on (reception after the second time), steps S404 to S410 are passed. In this case, the RTC time has already been corrected by the TI and corresponds to the correct current absolute time, so there is no need to correct it again.

  By the TI reception time control 202 described above, the RTC time, the HM timer 226, the power-on time 228, the previous HM time 242, the previous power-off time 244, the previous evaporation calculation time 246, etc. managed in the printer. The information is set to a value corresponding to the absolute time managed by the external device 200.

  Even if the absolute time becomes unknown due to the stop of the RTC 130, when the TI is received after that, various times such as the RTC time and the stored previous evaporation calculation time are corrected by the TI and are absolute. It changes to the one corresponding to the time. As will be described in detail later, the waste ink control 208 calculates the elapsed time based on the RTC time in order to calculate the evaporation amount of the waste ink. The elapsed time calculated from the RTC time corresponding to the relative time is influenced by the fact that the RTC 130 is stopped during the power-off period, and may not be accurate. On the other hand, the elapsed time calculated by the RTC time corresponding to the absolute time is accurate because it is not affected by such an effect. Even if the elapsed time is calculated at the relative time after the absolute time becomes unknown due to the stop of the RTC 130, the TI is received after that, the RTC time and the stored previous evaporation calculation time are absolute again. If it corresponds to the time, the accurate elapsed time is calculated based on the absolute time, and the incorrect elapsed time calculated in the relative time is invalidated. As described above, the correction of the RTC 130 by the TI makes it possible to accurately grasp the elapsed time, and as a result, the accuracy of the control that is processed based on the elapsed time like the waste ink control 208 is improved.

  FIG. 5 shows the flow of the carriage maintenance control 204.

  As shown in step S500 of FIG. 5, the carriage maintenance control 204 is started immediately after the power is turned on. In step S502, it is determined based on the power-off time length 222 whether the time length of the immediately preceding power-off period is equal to or greater than a predetermined CM (carriage maintenance) threshold. Here, the CM threshold is an appropriate time length as an interval for carriage maintenance, for example, an appropriate interval length for preventing the lubricant applied to the shaft or the like of the carriage mechanism 114 from solidifying, It is shorter than the backup capacity of the battery (for example, 160 hours).

  If the result of step S502 is that the power-off time length 222 is greater than or equal to the CM threshold value, reciprocating travel is performed in step S504 over the full movable range along the carriage shaft. Thereby, the lubricating oil of the carriage mechanism 114 is stretched and flows to prevent solidification.

  According to the above carriage maintenance control 204, when there is a power-off period longer than the CM threshold, carriage maintenance is always executed immediately after the subsequent power-on. In particular, when there is a long power-off period, even if the RTC 130 stops during that time, the carriage maintenance is surely performed immediately after the subsequent power-on.

  FIG. 6 shows the flow of the head maintenance (HM) control 206.

  As shown in step S600 of FIG. 6, this head maintenance control 206 is started immediately before printing. Alternatively, the head maintenance control 206 may be started immediately after the power is turned on. Further, as shown in step S602, the head maintenance control 206 is also started when a head maintenance execution request (for example, a head cleaning execution request or a notification of completion of ink tank installation) is input from the user. The

  If the head maintenance control 206 is started immediately before printing is performed (or immediately after the power is turned on) in step S600, the difference between the previous HM time 242 and the current RTC time (current time) is calculated in step S604. The elapsed time from the head maintenance execution time to the present time is calculated. In step S606, it is determined whether or not the calculated elapsed time falls within (exceeds) a predetermined plurality of levels of HM (head maintenance) thresholds. Is done. Here, the HM threshold value of each level is the length of an interval between head maintenances suitable for executing head maintenance (particularly head cleaning) of each level. The higher the level (the more careful and heavy the cleaning operation), the longer the HM threshold is set.

  As a result of the determination in step S606, if the calculated elapsed time does not correspond to any of the multiple levels of the HM threshold (that is, less than the minimum HM threshold), the head maintenance is not performed and the head maintenance control 206 is terminated. To do. On the other hand, when the calculated elapsed time corresponds to one of the HM thresholds (“corresponding HM threshold” means the maximum HM threshold among HM thresholds equal to or less than the elapsed time), the corresponding HM threshold Control proceeds to step S608 to perform level head maintenance.

  In addition, when the head maintenance control 206 is started by a user request in step 602 described above, the control proceeds to step S608 in order to execute the head maintenance requested by the user.

  In step S608, preliminary waste ink control is executed. Preliminary waste ink control refers to the amount of waste ink remaining in the ink absorber 115 when the head maintenance to be performed is actually performed according to substantially the same calculation procedure as the waste ink control 208 described in detail later. Is a process for predictively calculating whether or not waste ink overflows from the ink absorber 115. In this preliminary waste ink control calculation, an ink discharge amount value determined in advance for each level is used as the amount of ink discharged by the head maintenance. In the waste ink control 208, as will be described later, the variable data in the RAM 124 and the EEPROM 126 is deterministically updated, whereas in the preliminary waste ink control, the variable data is not deterministically updated.

  In step 610, it is determined whether or not there is a possibility of waste ink overflow based on the result of the preliminary waste ink control in step 608. If it is determined that there is such a possibility, the execution of the head maintenance is passed, and the head maintenance control 206 ends. In this case, in the preliminary waste ink control, a predetermined maintenance error process for overflowing the waste ink (for example, a predetermined message is notified to the user) is performed.

  If it is determined in step 610 that there is no possibility of waste ink overflow, control proceeds to step S612, and head maintenance at the level determined in step 606 (or the level requested by the user in step 602). Is executed. In step S612, waste ink control 208 is executed. In this waste ink control 208, the value of the amount of waste ink remaining in the ink absorber 115 as a result of the head maintenance that has just been performed is calculated, and whether or not waste ink overflows from the ink absorber 115 is determined. Is determined. In step S616, the current RTC time (current time) is set as the previous HM time 242.

  By the head maintenance control 206 as described above, an appropriate level of head maintenance is selectively executed according to the length of time elapsed since the previous head maintenance execution before printing or when the power is turned on. Further, whether or not the head maintenance can be performed is controlled so as to prevent the waste ink from overflowing from the ink absorber 115.

  7 and 8 show the flow of the waste ink control 208 connected to each other.

  As shown in step S700 of FIG. 7, the waste ink control 208 is executed immediately before the power is turned off and in the head maintenance control 206 described above. In step S702, it is determined whether the previous evaporation calculation time 246 is indefinite. The case where the previous evaporation calculation time 246 is indefinite means that neither the head maintenance nor the power supply turn-off has been performed since the printer 10 was collected at the factory (the waste ink control 208 has been executed once). In this case, it is meaningless to calculate the waste ink evaporation amount. Therefore, in this case, the control passes the processing related to the calculation of the waste ink evaporation amount, and proceeds to step 806 shown in FIG. 8, where the ink amount discharged in the current head maintenance is set to SB (relative time). The total amount of base waste ink) 252 and B (relative time base waste ink remaining amount) 254 are added.

  If the previous evaporation calculation time 246 has been identified as a result of step S702 above (when head maintenance or power supply turn-off has already been performed (when waste ink control 208 has already been performed)). ), The control proceeds to step S704 in order to calculate the evaporation amount of the waste ink. In step S704, it is determined whether or not the current evaporation amount calculation is the first calculation after the power is turned on.

  As a result of step S704, if it is determined that this is the first calculation time after the power supply is turned on, it is determined in step S706 whether the RTC 130 was continuously operating or stopped when the power supply was turned on. If the RTC 130 continues to operate when the power is turned on, the difference between the previous power-off time 244 and the current RTC time (current time) is calculated in step S708, and the difference is set in the HM timer 242. The That is, the elapsed time from the previous power supply turn-off time (that is, the time when the previous evaporation amount calculation was performed) to the present time is set in the HM timer 242. On the other hand, when the RTC 130 is stopped when the power supply is turned on, the current RTC time is not a value that has been counted since the previous power supply turn time, but a value that has been counted since the power supply is turned on. In this case, the difference between the power-on time 228 and the current RTC time (current time) is calculated in step S 710, and the difference is set in the HM timer 242. That is, the elapsed time from the time when the power is turned on until the present is set in the HM timer 242. In short, in the first calculation after the power is turned on, the elapsed time from the time when the previous evaporation amount calculation was performed to the present time, the length of the power off period that was unknown due to the stop of the RTC 130 was excluded. The HM timer 242 is set to a time length that is recognized as having passed.

  On the other hand, if it is determined in step S704 that it is not the first calculation time after the power supply turn-on (in the case of the second or subsequent calculation time after the power supply turn-on), in step S712, the current HM timer 242 (previous waste ink is used). The difference between the previous execution time of waste ink control 208 set in step 732 of the control 208 and the current RTC time (current time) is calculated, and the difference is set in the HM timer 242 again. In other words, in the second and subsequent calculation times after the power is turned on, the elapsed time from the previous execution time of the waste ink control 208 to the present time (which is considered to have surely passed) is set in the HM timer 242. The

  Thereafter, control proceeds to step S714, where TI flag 220 (whether RTC time corresponds to absolute time or relative time) is checked. When the TI flag 220 is “1” (when the RTC time corresponds to the absolute time), the control proceeds to step S716, where the difference between the previous evaporation calculation time 246 and the current RTC time (current time) is calculated. The difference is calculated and the evaporation time length 224 is set. The evaporation time length 224 set in this way is the elapsed time from the previous evaporation calculation execution time to the present time calculated based on the absolute time indicated by the RTC time, and this is the time that is surely passed. It is. In step S718, the previous evaporation calculation time 246 is updated to the current RTC time (current time).

  Thereafter, in step S720, the evaporation amount of the waste ink is calculated as a predetermined function of the evaporation time length 224 set in step S716. For example, the evaporation amount is calculated by multiplying the evaporation time length 224 by a predetermined evaporation coefficient (a value defining the evaporation amount per unit time). Thus, the evaporation amount calculated based on the evaporation time length 224 is subtracted from the current A (absolute time base waste ink remaining amount) 250, and the waste ink remaining amount thus obtained is set to A250 again. .

  Further, in step S722, the evaporation amount of waste ink is calculated as a predetermined function of the HM timer 220 set in step S708, 710, or 712. For example, the evaporation amount is calculated by multiplying the HM timer 220 by the evaporation coefficient. The evaporation amount calculated based on the HM timer 220 in this way is subtracted from the current B (relative time base waste ink remaining amount) 254, and the waste ink remaining amount thus obtained is set to B254 again.

  Here, the meaning of the evaporation time length 224 and the HM timer 220 used as the basis of the evaporation amount calculation in the steps S720 and S722 will be described.

  The evaporation time length 224 is calculated using the RTC time corresponding to the absolute time, and from the previous evaporation amount calculation time (head maintenance execution time or power supply turn-off time) to the current evaporation amount calculation time (head maintenance execution time). The time interval until the time or power supply turn-off time). There is a case where the power-off period is sandwiched between the previous evaporation amount calculation time and the current evaporation amount calculation time. Even if the RTC 130 is stopped during the power-off period, the length of the power-off period is necessarily included in the evaporation time length 224.

  In contrast, the HM timer 220 may be calculated using the RTC time corresponding to the absolute time, or may be calculated using the RTC time corresponding to the relative time. This is determined depending on whether the RTC time corresponds to the absolute time or the relative time when the HM timer 220 is set. The HM timer 220 indicates the next time length.

(1) When calculating the first evaporation after power-on (when head maintenance is performed or when power is turned off) When the RTC 130 is continuously operating during the power-off period The length of the time interval from the previous power-off time to the present time (head maintenance execution time or power-off time).

B. When the RTC 130 stops during the power-off period The length of the time interval from the time when the power is turned on until the present time (when head maintenance is performed or when the power is turned off)

(2) When the second evaporation amount is calculated after the power is turned on (when head maintenance is performed or when the power is turned off) From the previous evaporation amount calculation time (head maintenance execution time) to the current evaporation amount calculation time (head maintenance execution time) Or the length of the time interval until the power is turned off.

  Unlike the evaporation time length 224, the HM timer 220 does not include the time length of the power-off period in which the RTC 130 is stopped. On the other hand, the time length of the power-off period during which the RTC 130 is continuously operating can be included in the HM timer 220.

  The evaporation time length 224 and the HM timer 220 normally have the same value, but differ only in the following cases. This is the case of the first calculation after the power is turned on after the RTC 130 is stopped during the power-off period. In this case, as described above, in the evaporation time length 224, a difference from the previous evaporation calculation time 246 to the current RTC time is set, whereas in the HM timer 220, the current time from the power turn-on time to the current time is set. The difference from the RTC time is set, and it does not include the elapsed time before the power is turned on. By properly using the different evaporation time lengths 224 and the HM timer 220 in this way, as will be described later, the reliability of the values of A250 and B252 is improved.

  Now, after A250 and B252 are calculated, in step S724, SA (absolute time base waste ink total) 248, SB (relative time base waste ink total) 252 and a predetermined residual evaporation rate (no more evaporation is required). The calculated A250 and B254 are not too small (that is, the calculated amount of waste ink evaporation is not too large) based on the limit of the ratio of the remaining amount of waste ink to the total amount of waste ink). Is done. As a result, when it is determined that A250 or B254 is insufficient, A250 or B254 is corrected. For example, SA248 and SB252 are multiplied by the residual evaporation rate, respectively, so that the limit waste ink remaining amount based on SA248 and the limit waste ink remaining amount based on SB252 are calculated. Then, A250 and the limit waste ink remaining amount based on SA248 are compared. If A250 is smaller, A250 is corrected to the same value as the limit waste ink remaining amount based on SA248. Similarly, if B254 is smaller than the limit waste ink remaining amount based on SB252, it is corrected to the same value as the limit waste ink remaining amount based on SB252.

  Thereafter, in step S726, the amount of waste ink newly discharged by the current head maintenance is added to SA248 and A250. The amount of newly discharged waste ink is not added to SB252 and B254. Thereafter, the control proceeds to step S728 described later.

  On the other hand, when it is determined in step S714 that the TI flag 220 is “0” (when the RTC time corresponds to the relative time), the control proceeds to step S800 shown in FIG. In step S800, the previous evaporation calculation time 246 is updated to a value obtained by adding the HM timer 220 set in step S708, 710 or 712 to the previous evaporation calculation time 246.

  In step S802, the evaporation amount is calculated as a function of the HM timer 220. For example, the evaporation amount is calculated by multiplying the HM timer 220 by the evaporation coefficient. Thus, the evaporation amount calculated based on the HM timer 220 is subtracted from the current A250 and B254, respectively, and the remaining amount of waste ink obtained thereby is set to A250 and B254, respectively.

  Thereafter, in step 804, it is checked whether A250 and B254 calculated in step S802 are too small (that is, whether the calculated amount of waste ink evaporation is excessive) in the same manner as in step S724 described above. As a result, A250 or B254 determined to be insufficient is corrected.

  Thereafter, in step S806, the amount of waste ink newly discharged by the current head maintenance is added to SB252 and B254. The amount of newly discharged waste ink is not added to SA248 and A250. Thereafter, the control proceeds to step S728.

  In step S728, A250 and B254 are added to calculate the total waste ink remaining amount, and it is determined whether the total waste ink remaining amount is equal to or greater than a predetermined overflow threshold. Here, the overflow threshold is a value that determines that there is no possibility of overflow of waste ink from the ink absorber 115 if the remaining amount of waste ink is equal to or less than the overflow threshold. As a result of the determination, if the total waste ink remaining amount exceeds the overflow threshold value, predetermined maintenance error control (for example, display of a message to the user) is performed in step 730 in order to deal with waste ink overflow. Thereafter, in step S732, the current RTC time (current time) is set in the HM timer.

  By the waste ink control 208 as described above, the remaining amount of waste ink discharged when the RTC time corresponds to the absolute time is recorded in A250, while the RTC time is set to the relative time in B254. The remaining amount of the waste ink discharged when it is compatible is recorded.

  As shown in steps S720 and S722, when the TI flag is “1” (that is, when the RTC time corresponds to the absolute time), the evaporation time length 224 is used in the evaporation amount calculation of A250. In contrast, the HM timer 220 is used in the calculation of the evaporation amount of B254. The reason is as follows. That is, regarding B254 (that is, the amount of waste ink discharged when the RTC time corresponds to the relative time), when the RTC 130 stops during the power-off period, the time when the ink was discharged. Becomes unknown. In such a case, there is a possibility that an elapse time longer than the elapsed time from the B254 ink discharge time that has become unknown to the present is set in the evaporation time length 224. Therefore, when the evaporation time length 224 is used for calculating the evaporation amount of B254, an evaporation amount larger than the actual amount may be calculated, and as a result, there is a possibility that waste ink overflows. The HM timer 220 represents the time that is considered to have elapsed reliably from the time of power-on to the present. For this reason, the HM timer 224 is used in the calculation of the evaporation amount of B254 in order to calculate only the evaporation amount that is recognized as being surely evaporated, without counting the evaporation amount at the elapsed time that has become unknown. On the other hand, for A250 (that is, the amount of waste ink discharged when the RTC time corresponds to the absolute time), as long as the current RTC time corresponds to the absolute time, the current RTC time and the previous evaporation. The evaporation time length 224, which is the difference from the amount calculation time, represents a value closer to the elapsed time length from the ink discharge time to the present time than the HM timer 220. Therefore, the evaporation time length 224 is used in the evaporation amount calculation of A250.

  Further, as shown in step S802, when the TI flag is “0” (that is, when the RTC time corresponds to the relative time), the evaporation amount calculation for both A250 and B254 is HM. A timer 220 is used. The reason is as follows. In other words, when the current RTC time corresponds to the relative time, if the RTC 130 stops during the previous power-off period, the elapsed time during the power-off period becomes unknown. As long as the RTC time corresponds to the relative time, it is meaningless to calculate the evaporation time length 224 that is the difference between the RTC time and the previous evaporation calculation time 246 (as shown in step S718). Since the RTC time corresponding to the absolute time is set in the evaporation calculation time 246, the difference from the current RTC time corresponding to the relative time is meaningless). The same applies to A250 and B254. In short, when the TI flag is “0”, only the HM timer 220 indicates the time that is surely passed since the previous evaporation amount calculation time. Therefore, only the HM timer 220 is used for the evaporation amount calculation.

  By properly using the evaporation time length 224 and the HM timer 220 as described above, A250, which is a calculated value of the remaining amount of waste ink discharged when the RTC time corresponds to the absolute time, and the RTC time become the relative time. B254, which is a calculated value of the remaining amount of waste ink discharged when it corresponds, is a highly reliable value. By making a determination based on the total waste ink remaining amount obtained by adding A250 and B25, the accuracy and reliability of preventing waste ink overflow can be improved.

  Even when the elapsed time (HM timer 226) is calculated as a relative time after the absolute time becomes unknown due to the stop of the RTC 130 during the power-off period, the TI is subsequently received and the RTC time or If the stored previous evaporation calculation time or the like again corresponds to the absolute time, an accurate elapsed time (evaporation time length 224) is calculated from the absolute time, so the calculation was performed in relative time. The remaining ink remaining amount is calculated using the accurate elapsed time (evaporation time length 224), not the incorrect elapsed time (HM timer 226). As described above, the correction of the RTC 130 by the TI makes it possible to accurately grasp the elapsed time, and as a result, the accuracy of the control that is processed based on the elapsed time like the waste ink control 208 is improved.

  As mentioned above, although embodiment of this invention was described, this embodiment is only the illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. The present invention can be implemented in various other modes without departing from the gist thereof.

  For example, in the above embodiment, in step S710 in the waste ink control 208 of FIG. 7, the elapsed time from the time when the power is turned on to the present is set in the HM timer 226. This is to prevent the elapsed time before the power-turn-on, which has become unknown due to the stop of the RTC 130, from being included in the evaporation amount calculation. However, if the RTC 130 stops during the power-off period, it is recognized that at least a time (for example, 161 hours) slightly exceeding the backup capability (for example, 160 hours) of the battery 150 has elapsed during the power-off period. It is done. Therefore, as a modified example, in step S710, a time length slightly exceeding the backup capability (for example, 161 hours) may be added to the elapsed time from the power-on time to the present time.

1 is a block diagram showing an overall hardware configuration of an inkjet printer according to an embodiment of an electronic device according to the present invention. The block diagram which shows the control function of the controller 120, especially the function of various control relevant to this invention. The flowchart which shows the flow of the time control 200 at the time of power-on. The flowchart which shows the flow of time control 202 at the time of TI reception. 7 is a flowchart showing a flow of carriage maintenance control 204. 7 is a flowchart showing the flow of head maintenance (HM) control 206. 9 is a flowchart showing a flow of waste ink control 208 (connected to FIG. 8). 8 is a flowchart showing a flow of waste ink control 208 (connected to FIG. 7).

Explanation of symbols

100: printer, 110: printing mechanism present, 111: print head, 113: head maintenance mechanism, 113: carriage mechanism, 115: ink absorber, 120: controller, 122: CPU, 124: RAM, 126: EEPROM (nonvolatile Memory), 130: RTC (real time clock circuit), 140: main power supply circuit, 150: capacitor, 200: power on time control, 202: TI reception time control, 203: internal time management control, 204: carriage maintenance ( CM) control, 206: head maintenance control, 208: waste ink control.

Claims (4)

In electronic devices that can be connected to external devices that send absolute time information intermittently,
Clock means for operating with power from a power source during the power-on period of the electronic device, operating with power stored in a capacitor during the power-off period, and continuously counting the internal time;
Internal clock correction means for correcting the clock means using the information when the information on the absolute time is received from the external device, and making the internal time correspond to the absolute time;
A processing time storage means for storing a processing time acquired from the clock means when a predetermined process is executed in the electronic device;
When the clock means is corrected by the internal clock correction means, the processing time held in the processing time storage means is corrected by the same correction width as the clock means, and the processing time is set to the absolute time. A corresponding storage time correction means;
By calculating the difference between the processing time stored in the processing time storage means and the current time acquired from the clock means at the current time, the elapsed time from the execution time of the predetermined process to the present is calculated. Elapsed time calculation means,
In response to the specific work executed in the electronic device, means for calculating result data according to the result of the specific work,
(1) calculating absolute time base result data in response to the specific operation performed when the internal time corresponds to the absolute time;
(2) calculating relative time base result data in response to the predetermined work performed when the internal time does not correspond to the absolute time;
(3) Separately holding the absolute time base result data and the relative time base result data ;
(4) Work result management means for correcting the absolute time base result data and the relative time base result data according to the calculated elapsed time when the elapsed time is calculated by the elapsed time calculation means. It equipped with a door,
The elapsed time calculation means includes
(1) means for calculating a first elapsed time in which a time length of a power-off period in which the stop of the clock means has occurred can be counted;
(2) means for calculating a second elapsed time during which the time length of the power-off period in which the clock means has stopped cannot be counted;
Have
The work result management means checks whether the internal time corresponds to the absolute time at the time of calculation of the elapsed time, and as a result of the check,
(1) If it corresponds to the absolute time,
A. Correcting the absolute time base result data according to the first elapsed time;
B. Correcting the relative time base result data according to the second elapsed time;
(2) An electronic device that corrects the absolute time base result data and the relative time base result data according to the second elapsed time when the absolute time is not supported . In electronic devices that can be connected to external devices that send absolute time information intermittently,
Clock means for operating with power from a power source during the power-on period of the electronic device, operating with power stored in a capacitor during the power-off period, and continuously counting the internal time;
Internal clock correction means for correcting the clock means using the information when the information on the absolute time is received from the external device, and making the internal time correspond to the absolute time;
A processing time storage means for storing a processing time acquired from the clock means when a predetermined process is executed in the electronic device;
When the clock means is corrected by the internal clock correction means, the processing time held in the processing time storage means is corrected by the same correction width as the clock means, and the processing time is set to the absolute time. A corresponding storage time correction means;
By calculating the difference between the processing time stored in the processing time storage means and the current time acquired from the clock means at the current time, the elapsed time from the execution time of the predetermined process to the present is calculated. Elapsed time calculation means,
In response to the specific work executed in the electronic device, means for calculating result data according to the result of the specific work,
(1) calculating absolute time base result data in response to the specific operation performed when the internal time corresponds to the absolute time;
(2) calculating relative time base result data in response to the predetermined operation performed when the internal time does not correspond to the absolute time;
(3) Separately holding the absolute time base result data and the relative time base result data ;
(4) Work result management means for calculating the absolute time base result data and the relative time base result data according to the calculated elapsed time when the elapsed time is calculated by the elapsed time calculation means. It equipped with a door,
The elapsed time calculation means, when the internal time does not correspond to the absolute time due to the clock means being stopped during the power-off period, the elapsed time based on the internal time not corresponding to the absolute time If the internal time and the processing time are corrected to correspond to the absolute time according to the information received from the external device after calculating the time, the internal time and the processing corresponding to the absolute time An electronic device that calculates the elapsed time based on time and invalidates the elapsed time calculated based on the internal time that does not correspond to the absolute time .   The work result judging means for judging whether there is no problem in the result of the specific work based on data obtained by combining the absolute time base result data and the relative time base result data. The electronic device described. The electronic device is an inkjet printer;
The specific operation is head maintenance,
The result data is waste ink amount data indicating the amount of waste ink discharged from the print head by the head maintenance and held in the ink absorber,
The work result the correction by the management means, wherein the waste ink amount data, the electronic device of claims 1 to 3, wherein by subtracting the ink evaporation amount corresponding to the elapsed time.

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