JPH079686A - Electronic system using inkjet printer and control method thereof - Google Patents

Abstract

(57) [Abstract] [Object] The present invention provides an inkjet printer,
An object of the present invention is to obtain an inkjet printer that is capable of stable ink ejection and has high reliability, and an electronic system equipped with the inkjet printer. An inkjet head 1 having a plurality of nozzles for ejecting ink droplets, a clock 4, a pause time measuring means 12, a pause time judging means 13, a recovery processing means 6 for controlling recovery processing for the nozzles, and a power source. A switch 5 is provided, and the time from the last stop of the printer operation until the power switch is turned on is measured by the pause time measuring means 12, and this is judged by the pause time judging means 13. If the predetermined time is exceeded, a warning is displayed. If it does not exceed, the electronic system using the inkjet printer is characterized by having a control means for controlling the ink ejection by the recovery processing means 6 in accordance with the down time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to an ink jet printer and an electronic system equipped with the same.

[0002]

2. Description of the Related Art Conventionally, many ink jet printers have been proposed because of advantages such as low noise at the time of printing, small and lightweight device, and low power consumption.

However, these ink jet printers,
Particularly, in the on-demand type ink jet printer, if the printing inoperative state continues for a long time, the viscosity of the ink in the nozzle portion increases, which causes ejection failure of the ink when the next printing is started. Even if the ejection failure does not occur, the ejected ink amount becomes smaller than the normal ejection amount,
There is a problem in that the printing dot diameter is different and the printing quality is degraded.

As a conventional technique for solving the problems of these ink jet printers, for example, Japanese Patent Publication No. 61-5610.
9 and Japanese Patent Publication No. 3-59832.

In all cases, the technique is to detect a predetermined print inoperative time or a discharge interruption time when the power is turned on, and perform recovery processing such as preliminary discharge and idle discharge to prepare for the next print operation.

Further, there has been proposed a device equipped with a nozzle capping mechanism or the like in order to prevent clogging of the nozzle while the power is off.

[0007]

However, in all of these conventional examples, the recovery process is performed immediately before the printing process in response to the pause of the nozzles only when the power is on, so that the printing process time becomes long. However, there is a problem that the actual printing speed becomes slow.

[0008] Moreover, the leaving time after power-off is 2 weeks,
Alternatively, in the case of a long period such as one month or more, the nozzles of the inkjet head may be clogged, and there is the inconvenience that printing is started without the user being aware of this.

Further, regardless of whether the pause time due to the user turning off the power is long or short, the amount of ink ejected when the power is turned on is set assuming that the expected pause time is sufficiently long. In addition to the increase in ink consumption required for the above, there is a problem that the power consumption also increases and the efficiency is low.

As described above, the conventional technique still has problems in response to various demands for high speed, high efficiency and high reliability of the ink jet printer.

The object of the present invention is to solve these problems,
An object of the present invention is to provide an inkjet printer that prevents malfunction of the inkjet head.

Another object of the present invention is to obtain a reliable ink jet printer which does not slow down the printing speed substantially, has a long ink life, is efficient, and ensures reliable and stable ink ejection. is there.

[0013]

An electronic system using an ink jet printer of the present invention is a main power source and an on-demand device for forming characters, symbols and the like by ejecting ink droplets driven by the main power source from nozzles of an ink jet head. In an electronic system using an inkjet printer of the type, a battery power source different from the main power source, a timing unit driven by this battery power source, and a period from the operation stop of the printer to the next power-on using the timing unit. A pause time measuring means for measuring a time to substantially measure a pause time of the inkjet head, a means for determining the pause time, an output means for outputting information, and a nozzle for ejecting a predetermined amount of ink from the nozzle. It has a recovery processing means to prevent the clogging of the Time If you have exceeded the predetermined time and outputs warning information to said output means, characterized by discharging a predetermined amount of ink in response to the pause time unless exceeded.

Further, the present invention provides an electronic system using an ink jet printer which has an AC power source as a power source and forms characters, symbols and the like by ejecting ink droplets from nozzles of an ink jet head. When the AC printer is turned on, the idle time is determined by using a time measuring means that operates even when the power is turned off, and the idle time is determined in synchronization with the AC power being turned on. A method for controlling an electronic system using an ink jet printer is characterized in that warning information is output and a predetermined amount of ink is ejected within a predetermined time according to the rest time.

[0015]

With this means, it is possible to measure the rest time of the ink jet printer even if the power switch is off by the time measuring means having a clock or the like which is driven by a battery power source different from the main power source, and this time measurement result is dealt with. By controlling the number of times the ink is ejected by a recovery process that prevents clogging of the inkjet head, the ink is ejected from the inkjet head in response to the degree of increase in viscosity caused by evaporation of the ink solvent in the nozzle, The ink viscosity and density at the nozzles are set to a printable state before printing is started, and the processing time immediately before printing is shortened. That is, the viscosity and concentration of the ink are kept constant regardless of the idle time of the inkjet head. This stabilizes the ejection amount and ejection speed of the ink from the nozzle and the reflectance of the ink on the recording medium. Therefore, reliable and stable ink ejection can be obtained at the time of printing, printing quality is stable, and highly reliable printing is performed.

Immediately after predicting that printing will be executed when the power is turned on, the state of the head is checked, and if the pause time exceeds a predetermined time, information for instructing replacement of the head is displayed on a display or the like. If it does not exceed the output, the recovery action is performed according to the pause time. Therefore, the recovery action need not be performed during the printing operation, the time required for printing is shortened, and the substantial printing speed is improved.

[0017]

EXAMPLES First, the relationship between the chemical properties of ink used in an ink jet printer and the recovery process will be verified below. FIG. 7 is a diagram showing the relationship between the minimum required number of times of ink ejection for the recovery process of the inkjet head used in the present invention (vertical axis) and the non-printing time (horizontal axis) due to leaving or the like. The ink used in the present invention contains, as an example, ethylene glycol, water, and a dye as main components,
Since it contains ethylene glycol, it has the characteristic that the viscosity becomes higher as the temperature becomes lower than the temperature, and because the solvent such as water evaporates and dries, the viscosity becomes higher as it is left for a long time. Is as follows.

The relationship between the non-printing time (leaving time) and the number of ink ejections in the recovery processing operation is approximately proportional as shown in the figure within a short time period (for example, within 8 hours), and is the same as the previous ink ejection. If the non-printing time is long, it is necessary to set a large number of ink ejections. On the contrary, when it is short, the number of ink ejections can be set to be small. This proportional relationship is due to the physical or chemical characteristics of the inkjet head or the ink used, as well as the temperature and
Determined by environmental conditions such as humidity.

The relationship between the standing time during low temperature drying (5 ° C. and 35%) and the number of ink ejections during the refresh operation is shown by the alternate long and short dash line 70 in FIG. 95%) is indicated by a chain double-dashed line 72.

The cause of such characteristics can be explained as follows. That is, the rate of increase in the viscosity of the ink in the nozzle portion due to the evaporation of the ink solvent is highest during drying with low relative humidity. Furthermore, due to the temperature dependence of the ink viscosity, the amount of ink droplets ejected per recovery process from the nozzle by the pressure generating element (piezoelectric element, heating resistor, etc.) of the inkjet head decreases as the temperature decreases. Therefore, from the safety side of nozzle clogging, the low temperature drying is the most severe, so it is preferable to determine the operating conditions for the recovery process based on this value.

Further, within a long time range (for example, 8 hours or more), the required number of ink ejections is 100 to 200.
With a relatively large number of departures, it is roughly constant regardless of the standing time. This is because if the leaving time is a long time such as 8 hours or more, most of the ink in the flow path in the inkjet head may be discharged and replaced with new ink, and in this case, the ink required for recovery The number of ejections is not the time required to thicken the ink in the nozzle,
This is because it is determined by the volume of ink in the flow path of the inkjet head (which is uniquely determined by the inkjet head and is constant), and is constant regardless of the standing time with a relatively large number. Therefore, the maximum value of the number of ink ejections necessary for the refresh operation is determined by this, and regardless of the standing time, if the ink ejection amount is equal to or more than this, it is possible to always ensure good and reliable ink ejection and print quality. it can. In fact, gradually after 8 hours,
When the solidification of the ink progresses due to drying or the like and it is left for a long period of one month or more, it is necessary to recover it by a physical method. In order to prevent these problems, generally, the inkjet head is detachable so that it is stored in a closed container when it is not used for a long period of time, or the printer is equipped with a head capping mechanism. The present invention has been made for the purpose of maximizing the use of the above ink characteristics, and will be described below with reference to the drawings. In all the drawings, the same reference numerals indicate the same constituent elements.

FIG. 6 is an external view of an electronic desk calculator (hereinafter referred to as a calculator) which is a kind of electronic system equipped with the ink jet printer of the present invention. 41 is a computer case, 4
Reference numeral 2 is a power switch, 43 is a keyboard, 44 is a print selection switch for selecting the use of the printer, and 45 is a liquid crystal display which is a kind of display device. Power switch 42
Even if is turned on, printing is not executed unless the print selection switch is turned on. In this case, the calculation process, results, etc. are only displayed on the liquid crystal display.

FIG. 2 is a circuit block diagram of a calculator using an ink jet printer according to an embodiment of the present invention.
101 is a central processing unit (hereinafter C) that controls the entire calculator.
PU is referred to), 102 is a RAM for temporarily storing data during arithmetic processing, and 103 is a ROM for storing a program, preset predetermined data, and the like. Reference numeral 110 denotes a timepiece driven by a battery power source 111, which is configured to operate even when the power of the printer body or the like is turned off, and can also hold a calendar function and the like. This battery power is also supplied to the RAM, and the data in the RAM is backed up.

Reference numeral 105 is a keyboard for inputting data, 107 is a printer, 106 is a printer driver unit for driving the printer 107, 109 is a calculation process,
A display panel which is a display device for displaying calculation results and the like, and a display driver unit 108 which drives the display panel 109. A print selection switch 105a for selecting whether to print the calculation result or the like is arranged in the keyboard.

The CPU 101 performs processing for input from the keyboard 105 or the like in accordance with the procedure of the program stored in the ROM 103, and transfers the data to be output to the printer 107 to the driver 106 at appropriate times. The printer 107 is driven and controlled by the printer driver unit 106. Input data from the keyboard 105 may be temporarily stored in a memory such as a keyboard buffer.

The ROM 103 stores a table of the relationship between the number of ink ejections and the standing time based on the graph of FIG.

FIG. 1 is a functional block diagram of an embodiment of the present invention. Reference numeral 3 is an ink jet printer, 1 is an ink jet head having a nozzle and a pressure generating element, and ejecting ink droplets from the nozzle to form a letter symbol or the like.
Indicates a drive motor having a function of moving the ink jet head 1 and a print medium such as paper. Reference numeral 5 denotes a power switch for turning on / off the main power of the electronic system equipped with the printer.

Reference numeral 10 is a printing and arithmetic control means for performing printing control, arithmetic control in response to a key input from the key input means 7, and display control of the display means 9 including a liquid crystal panel.

The printing / arithmetic control means 10 executes arithmetic processing in response to the input of the key input 7, and executes control for displaying the calculation process, calculation result and the like on the display means 9. At this time, when the print selection switch 8 for selecting whether to output to the printer in the keyboard is ON, the inkjet head 1 and the drive motor 2 are controlled by the print control signal to execute the print control. Reference numeral 6 is a recovery processing means for performing recovery processing of the inkjet head, which is a drive motor of the printer,
The inkjet head is controlled to execute a predetermined recovery process. The storage unit 11 is usually used when the print calculation control unit performs calculation processing and the like.

A clock 4 is driven by a battery power source (not shown) and can be operated independently of the main power source. The battery power source is also supplied to the storage means 11 as a backup power source. Reference numeral 12 is a pause time measuring means for measuring the time during which the head of the printer is stopped. As an example of measuring the pause time of the printer, it is possible to measure the pause time by calculating from the data of the storage means that stores a predetermined time when the printer is stopped and the current time. Reference numeral 13 denotes a pause time determining means for determining the pause time, which determines whether or not the pause time exceeds a predetermined time. Reference numeral 14 is an interval detecting means for detecting an interval of a predetermined interval using the clock 4.

When the switch of the main power supply is turned on, the rest time measuring means 12 calls the last print end date and time from the backed up storage means 11 and calculates the left time from the present date and time. Based on this leaving time, the recovery processing means is used to execute the ink ejection a number of times corresponding to the leaving time. Further, the time at this time is stored in the storage main stage 11, and when the print selection switch 8 is turned on this time, the recovery processing is similarly executed corresponding to the leaving time.

Since the printer may be stopped even after the print selection switch 8 is turned on, during this period, the interval detection means 13 detects whether the printer is in use at every predetermined time of the clock, and if the printer is not in use, a predetermined time is reached. Ink is ejected a number of times corresponding to the interval. For example, 15
In the case of minute intervals, ink ejection is performed five times as shown in FIG.

FIG. 3 is a flow chart showing the control method of the embodiment of the present invention.

In step S1, the printer memory or the like is initialized. At this time, the memory backed up by the battery power source is not initialized and only confirmation is made for any abnormality. First, in step S2, the printer pause time is detected from the previous printer stop time and the current time stored in a predetermined area of the RAM, and in step S3, if this exceeds the predetermined period, step S2
In step 1, a warning is displayed on the display panel to prompt the operator to perform a predetermined operation, and after this confirmation is made in step S22, the process proceeds to step S4 to execute a recovery processing subroutine. Thereafter, in step S5, the stop time of the printer is written and stored in a predetermined RAM area.

This warning display may be executed by the display, or may be a warning sound from a buzzer. In response to this, the operator carries out a designated predetermined work, for example, to remove the clogging of the nozzle by physical means, or to replace the inkjet head when there is no prospect of recovery.

The recovery processing subroutine is achieved by executing steps SS1 to SS3 of the recovery processing operation routine shown in FIG. When the recovery processing operation is designated, the head carriage is moved to a predetermined location where the ink ejected by the ink ejection can be absorbed in step SS1, and a predetermined amount of ink is ejected in step SS2.
After that, in step SS3, the head carriage is returned to the original carriage position, and the recovery processing operation ends.

In step S6, it is confirmed that the print selection switch is on. If it is off, the process proceeds to step S7, and display and arithmetic processing are executed in synchronization with key input or the like. Thereafter, the same processing is repeated until the print selection switch is turned on, and the display-centered calculation is repeated.

When the print selection switch is turned on in step S6, first, the recovery processing subroutine in step S11 and the print pause time setting in step S12 are executed, and in step S13 the clock reaches the predetermined time by the interval detection means. If it has been detected, it is confirmed in step S14 whether or not printing is in progress. If printing is not in progress, recovery processing in step S15 and step S1 are performed.
The print pause time set in step 6 is executed, and the process proceeds to the display and calculation process in step S17, and the print process in step S18, S
19 print rest time setting is executed, and thereafter, the power supply is cut off in steps S13 to S19 or step S2.
Repeat until the print selection switch of 0 is turned off. If it is not on time in step S13, the process proceeds to step S17, and the processing such as display, calculation or printing is repeated. Even when the main power is turned off, the rest time at that time is always stored in the non-volatile memory after printing is completed, so the rest time of the printer, that is, the head leaving time from the previous time can be easily calculated when the power is turned on next time. It

FIG. 5 is a timing chart describing the operation according to these embodiments of the present invention. Reference numeral 60a indicates turning on the main power source, and 60b indicates turning on the print selection switch. Reference numeral 60c is an operation of the pause time measuring means, 60d is an output signal of the interval detecting means, 60e is a print signal,
Reference numerals 60f respectively indicate recovery processing signals.

The rest time Tr is detected by c1, and the recovery process f1 is executed in synchronization with the main power-on. Similarly, the recovery process f2 is executed in synchronization with the turning on of the print selection switch. After that, the outputs c1 to c7 of the interval detection means
The print signal is confirmed at the timing of, and if the printing is not executed, the recovery process is executed at the timings of f3, f5, f6, and f9.
Recovery processing is not performed at 7 and f8.

The print selection switch 8 is generally of two types. One is a type which is connected to a printer on hardware and cannot supply power or signals to the printer unless this switch is turned on. The other type is a type that can be accessed from the CPU even if the power supply is under the control of the CPU and the print selection switch is not turned on.

In the former example, the initialization or recovery process of the printer unit immediately after the power is turned on cannot be executed. In this case, these processes must be executed when the print selection switch is turned on. In the flow chart, the steps S2, S3 and S4 are moved to the step S11 and executed.

The interval detecting means after the power is turned on in this embodiment can be formed by using a built-in timer or the like in the CPU, and can also be formed by hardware using a capacitor.

Further, the recovery process in the present embodiment may be performed for the nozzle to be printed, or if it is performed for a plurality of nozzles or for all nozzles, it is not against the gist of the present invention.

[0045]

As described above, according to the electronic system equipped with the ink jet printer of the present invention, the idle time of the ink jet head is clocked in synchronization with the turning on of the main power supply, and this time should not exceed the predetermined time. For example, by providing a means to warn the user, printing mistakes can be prevented in advance, and if it is within a predetermined time, by executing the nozzle recovery process corresponding to this time, it can be done for a long time. Even if the inkjet head is left unattended, it is possible to perform recovery processing that corresponds to the time left, and it is possible to minimize the amount of ink that is discarded due to the recovery processing. It is possible to eliminate the waiting time, eliminate the waiting time, increase the substantial printing speed, and realize a comfortable printing environment.

Further, after the recovery processing corresponding to the time from the power-off to the power-on or the print selection switch on, the operation pause time is detected and the recovery processing is executed at predetermined intervals. It is possible to discharge the ink with increased viscosity generated by evaporation of the ink solvent or the like from the inkjet head and keep the ink viscosity and density at the nozzle portion constant. Viscosity of ejected ink
If the density is kept constant, reliable and stable ink ejection from the nozzles will be obtained during printing, and the ink ejection amount and ejection speed and the reflectance of the ink on the recording medium will be stable. The printing quality is stable, highly reliable printing is performed, and it is possible to provide a printer with excellent printing quality and high reliability.

Furthermore, in an electronic system equipped with a clock for displaying the time like a certain kind of calculator, it is not necessary to add a device as a time counting means, and the main power supply is turned off by using this clock. In addition, it is possible to easily measure the downtime of the printer, and it is possible to maintain the quality of the inkjet head very simply.

Further, by using the above-mentioned clock, it can be utilized as a timekeeping means for regularly preventing clogging of the nozzle even after the main power supply is turned on, which contributes to cost reduction of a calculator or the like. is doing.

As described above in detail, the present invention is extremely useful in an electronic system using an ink jet printer.

[Brief description of drawings]

FIG. 1 is a functional configuration diagram of an embodiment of the present invention.

FIG. 2 is a circuit block diagram showing a configuration of a calculator using an inkjet printer according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a method of controlling an electronic system according to an embodiment of the present invention.

FIG. 4 is a flowchart of a head recovery process according to the present invention.

FIG. 5 is a timing chart illustrating an operation of the electronic system according to the exemplary embodiment of the present invention.

FIG. 6 is an external view of a kind of calculator of the electronic system of the present invention.

FIG. 7 shows the number of times ink is ejected from the inkjet head used in the present invention (vertical axis) and the non-printing time due to standing or the like (horizontal axis)
The figure which shows the example of the relationship.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 inkjet head 3 printer 4 clock 6 recovery processing means 7 key input means 8 print selection switch 9 display means 10 print calculation control means 11 storage means 12 pause time measuring means 13 pause time judging means 14 interval detection means 20 power switch 101 CPU ( Central processing unit) 102 RAM 103 ROM 104 timer 105 keyboard 106 printer driver 107 printer 108 display driver 109 display

Claims (2)

[Claims] 1. An electronic system using an on-demand type inkjet printer, which has a main power source and is driven by the main power source to eject ink droplets from nozzles of an inkjet head to form characters, symbols and the like. Another battery power source, a time measuring means driven by this battery power source, and a time from the operation stop of the printer to the next power-on using the time measuring means to measure the idle time of the inkjet head substantially. A pause time measuring means for timing, means for determining the pause time, output means for outputting information, and recovery processing means for discharging a predetermined amount of ink from the nozzle to prevent clogging of the nozzle, Immediately after the main power is turned on, the rest time is determined, and if the rest time exceeds a predetermined time, warning information is output to the output means, An electronic system using an inkjet printer, characterized in that a predetermined amount of ink is ejected according to the pause time if the time is not exceeded. 2. In an electronic system using an inkjet printer, which has an AC power source as a power source and ejects ink droplets from nozzles of an inkjet head to form characters, symbols, etc., the AC power source is turned off. Even when the AC printer is turned on by measuring the rest time of the ink jet printer by using the time measuring means that operates, the rest time is judged, and if it exceeds the predetermined time, the warning information is given. A method of controlling an electronic system using an ink jet printer, characterized in that a predetermined amount of ink is output and a predetermined amount of ink is ejected within a predetermined time.