JPH03262677A - Printer - Google Patents

Abstract

PURPOSE:To easily judge whether a storage state has been protected over a voltage supply interruption period by an auxiliary power source by a method wherein a state just before a voltage supply is interrupted is compared with a state when the voltage supply is recovered just after the interruption with respect to the printing data storage state. CONSTITUTION:A sum value 230c at the time of a voltage supply interruption is compared and collated with a sum value at the time of a voltage supply recovery. If the both values are equal to each other, the data contents stored in a RAM 230 before and after a period wherein a voltage supply from a power supply 250 is interrupted are coincident with each other. Namely, the data content stored in the RAM 230 is judged to have been protected by a back-up power source by the electric discharge of a capacitor 231. A printing action is continued from printing data just before a voltage supply interruption. On the contrary, if the both sum values are not equal to each other, it is judged that the data content stored in the RAM 230 has been broken during the voltage supply interruption period and is not assured in reliability. Printer is actuated so as to again print out printing data 230a just before the voltage supply interruption.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device, and in particular, to a printing device that is provided with a storage medium for storing print data, and in which an auxiliary memory is added to the storage medium in response to cutoff of voltage supply from a power source. The present invention relates to a printing device to which voltage supply from a power supply is started.

[Prior Art] It goes without saying that the transmission of digital data in electronic computers, communication lines, and other systems requires extremely high reliability, but as a practical matter, errors can occur due to various failures. is unavoidable.

The above-mentioned disturbances may be due, for example, to an unstable supply of voltage from the power supply.

One common method for improving reliability in such cases is a sum check.

For example, whether or not the contents of data stored in the memory are protected even after a certain period of time has passed can be determined by performing the above-mentioned thumb check. That is, assuming that no data is input or output to the memory within the certain period of time, the sum of the contents of the data stored in the memory is calculated and stored in advance as a sum value. After the specified period of time has elapsed, the sum value is calculated again in the same manner and compared with the previously determined sum value. If both values match, the data content is protected within the specified period of time. However, if they do not match, it can be determined that the data content was not protected.

Now, the conventional ECR (abbreviation for electronic cash register)
In a printing device connected to a computer, data to be printed is first stored in a printing buffer and then printed on a special paper and output.

The storage device including the printing buffer is supplied with auxiliary power by a battery or the like even when the voltage supply from the power supply is cut off, so that the stored contents are guaranteed. Therefore, it was considered unnecessary to perform the above-mentioned thumb check to confirm the soundness of the stored data after the power-off period has elapsed.

[Problems to be Solved by the Invention] As described above, in a conventional printing device connected to an ECR, the printing buffer is backed up by a battery or the like even during a period when the voltage supply from the power source is cut off.

However, when power is supplied by a capacitor etc. for a short period of time instead of a backup battery,
Or, if the power supply capacity of the backup battery is not sufficient to maintain the stored contents of the print buffer during the power cutoff period, the print data stored in the print buffer will be kept in good condition after the voltage cutoff period. There was a problem that the gender could not be guaranteed. In other words, even if the printing device returns to a printable state by restarting the voltage supply (power recovery) immediately after the voltage supply cutoff period from the power supply and prints the data that was stored in the print buffer immediately before the power cutoff, , there was a problem that there was no guarantee that correct data would be printed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a printing apparatus that is equipped with a storage device in which data for printing is stored, and that is capable of supplying voltage from an auxiliary power source to the storage device during a certain period of time during which the voltage supply from the power source is cut off. In this case, when the voltage supply is restarted immediately after the voltage supply cutoff period, it can be determined whether the printing data stored in the storage device immediately before the voltage supply cutoff has been protected over the voltage supply cutoff period. The purpose of the present invention is to provide a printing device.

Means for Solving Problem U] A printing device according to the present invention is a printing device that is provided with a storage medium that stores print data and is supplied with voltage from an auxiliary power source in response to interruption of voltage supply from a power source. In detail, a power-off detection means for detecting that the voltage supplied from the power source is cut off, and a method for storing data in the storage medium in response to the detection of the voltage supply cut-off by the power-off detection means. a first calculation means for calculating the sum of the print data calculated by the first calculation means; a storage means for storing the sum of the print data calculated by the first calculation means in the storage medium; and a voltage supply from the power source is cut off. a power supply recovery detection means for detecting a subsequent resumption (recovery) of voltage supply from the power supply, and a printout stored in the storage medium in response to the detection of the resumption of voltage supply from the power supply by the power supply recovery detection means; A second calculation means for calculating the sum of data, further comparing the sum by the first calculation means and the sum by the second calculation means,
and means for determining whether or not the print data stored in the storage medium was protected during the period when the voltage supply from the power source was cut off.

[Operation] Since the printing device according to the present invention is configured as described above,
By capturing the moment when the voltage supply from the power supply to the printing device is cut off, the print data stored in the storage medium at that time will be updated when the voltage supply from the power supply is resumed after a certain arbitrary period of time has elapsed since the power supply cutoff. You can check whether the data content was protected by the voltage supply from the auxiliary power source.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

The printing apparatus 100 in this embodiment employs the dot impact method of a serial printer in which the printing mechanism moves and prints each character, and prints 5 dots (vertical) x 7 dots (horizontal). It is assumed that the characters are selected according to the characters and expressed using 32 digits (32 characters) per line.

FIG. 1 is a schematic diagram showing the functional configuration of a printing apparatus 100 according to an embodiment of the present invention.

In the figure, a printing apparatus 100 is connected to a higher-level control unit via a serial interface 50, and serial data to be printed is input from the higher-level control unit.

The printing apparatus 100 also includes a control section 200 and a printing section 30.
Contains 0.

The control unit 200 includes a CPU (abbreviation for central processing unit) 210 that controls and monitors the operation of the printing apparatus 100 itself, and a ROM (Read Only Memory) that stores data (including programs) required for printing operations.
y) 220 and RAM (Random Acc
ess Memory) 230, the printing section 30
The printing apparatus 100 includes a printer driver 240 that drives and controls the printing apparatus 100, and a power supply 250 that supplies a driving voltage to the printing apparatus 100.

The RAM 230 is charged during the voltage supply period from the power source 250, starts discharging immediately after the power is turned off, and stores data by supplying auxiliary voltage to the RAM 230 for a certain period of time during the power interruption period. A capacitor 231 is connected which acts to protect.

Further, as described above, the printing section 300 is (5×7)
Equipped with a printer function using the dot impact method.

As shown in the figure, the devices within the printing apparatus 100 are interconnected via a bus to speed up mutual data transfer.

In the printing apparatus 100 configured as described above, the CP
The U210 is connected to the upper control unit via the serial interface 50, and the printing unit 30
The print data to be given to 0 is sent from the control unit via the bus. The print data transferred in this way is temporarily stored in the RAM 230, and the print data corresponding to two lines by the dot impact method of the printing unit 300 is stored in the RAM 230, and is periodically processed by the CPU 210. It is read and processed. Therefore, the print data corresponding to two lines stored in the RAM 230 is always updated with data transmitted from the control unit.

On the other hand, the ROM 220 stores character data therein, and is sequentially given print data read out from the RAM 230 by the CPU 210. ROM2 according to
Character data indicating a dot pattern (5.times.7 dots) according to the given print data is read out from 20, and a corresponding code is generated by CPU 210.

The code generated in this way is the printer driver 2
given to 40. In response, the printer driver 240 generates a pulse according to the given code and prints it to the printing unit 300.
give to The printing unit 300 is driven at high speed in response to applied pulses and prints characters on paper using a dot impact method.

FIG. 2 is a schematic diagram of the storage area of the RAM 230 shown in FIG. 1 above.

As shown in the figure, the RAM 230 includes a storage area indicated from address $0000 to address $0OFF,
The breakdown is from address $0010 to address $0
Storage area M1 indicated by OFO and address $0OF
It includes a storage area M2 indicated by F.

The storage area M1 stores print data 230a given from a higher-level control unit and print information 230b including information on the current printing status, ie, to what digit and to what dots are printed. The print data 230a and print information 23
0b is updated as data by the CPU 210 as the printing status of the printing unit 300 progresses.

A sum value 230C of the print data 230a and print information 230b described above is stored in the storage area M2, and the sum value 230C is a value calculated and stored by the CPU 210 immediately after the voltage supply from the power source 250 is cut off. . Note that the storage area M2 is provided outside the storage area M1, and the sum value 230C is stored separately from the print data 230a and print information 230b.

Data indicating the printing status of the printing apparatus 100 is stored in the RAM 230 as described above. The discharge of the capacitor 231 charged in the RAM 230 is started.
Since an auxiliary voltage is supplied to the capacitor 231, the stored data contents can be maintained for a short period of time. Therefore, during the auxiliary power supply period that depends on the capacitance of the capacitor 231, the reliability of the stored data is guaranteed, or after that, the reliability of the stored data decreases significantly and is not guaranteed. Not done.

FIG. 3(a) is a schematic process flow diagram showing the operation of the printing apparatus 100 that is started in response to cutoff of voltage supply from the power supply 250 according to an embodiment of the present invention.

FIG. 3(b) is a schematic process flow diagram showing the operation of the printing apparatus 100 that is started in response to the voltage supply being restored immediately after the voltage supply cutoff in FIG. 3(a).

The processing flows shown in FIGS. 3(a) and 3(b) are stored in advance in the ROM 220 as a program and executed by the CPU 220.
It is activated by interrupt control of 0 and starts execution.

That is, when the CPU 210 receives an interrupt request signal output when the power supply 250 is abnormal, it sends an interrupt affirmation signal to the interrupt cause side, that is, the power supply 250. In response, the cause side receives the interrupt affirmation signal, and upon confirming this, stops outputting the interrupt request signal. Thereafter, interrupt processing based on reception of the interrupt request signal by the CPU 210 is executed.

Now, the printing apparatus 100 is continuing its normal printing operation, and suddenly the voltage supply from the power supply 250 is cut off, and then it recovers from the voltage supply cutoff state and returns to the normal printing operation again. Assume that it is processed as follows.

First, step 510 in FIG. 3(a) (in the figure, SI
(abbreviated as PO), the CPU 210 outputs a power interruption detection signal (Po
We r Fa i l signal (hereinafter abbreviated as signal PF)
It is determined whether or not the signal is detected at a signal level of "HIGH". In other words, the CPU 210 determines that the signal PF is at the signal level "HI".
While the signal PF is not detected at the signal level "GH", the determination process of step 310 is repeated, but when the signal PF is detected at the signal level "HIGH", the process branches to the next step S20.

As described above, the CPU 210 receives the signal level "HIGH" input of the signal PF as an interrupt request signal, and starts executing the processing from step S20 onwards.

First, the printing operation is stopped in step S20.

In other words, the print data 230a is stored in the RAM 230, but the CPU 210 inputs and outputs the data to and from the RAM 230 in order to maintain the print data 230a stored in the RAM 230 in the state at which the voltage supply from the power supply 250 was cut off. Control so that all operations are stopped all at once. At this time, the printing operation of the printing unit 300 is also interrupted because the voltage supply from the power source 250 is cut off.

Thereafter, in the process of step S30, the data (included in the print information 230b) stored in the stack of the CPU 210 is stored in the storage area M1 of the RAM 230.

Next, in the process of step S40, in response to the completion of the process of step S30 described above, the memory area Ml of the RAM 230 is
The total sum of data of print data 230a and print information 230b stored in is calculated. In other words, power supply 2
Two lines of print data 230a are transmitted from the host control unit and stored in the RAM 230 immediately before the power supply is cut off from 50, and the print data 230a is printed to which digit and to what dot immediately before the voltage supply is cut off. A sum value of the data of the print information 230b is calculated.

Next, in the process of step S50, the above-mentioned step S
The value obtained by adding (A
It is stored in F as a sum value 230c.

Note that even if the voltage supply from the power supply 250 is cut off, the data content stored in the RAM 230 can be maintained for a certain period of time thereafter (a period depending on the capacitance of the capacitor 231).

The CPU 210 responded to the voltage supply interruption as described above.
By executing the interrupt process, the sum value 230c is calculated and stored.

Next, a description will be given of the processing performed when the voltage supply from the power supply 250 is restored immediately after the power cutoff.

When the voltage supply from the power supply 250 is restored, FIG. 3(b)
The CPU 210 starts executing the process.

When the CPU 210 receives a signal to start supplying voltage from the power supply 250 in step 5100, the process proceeds to step 82.
00 Execute the processing shown below.

First, in step 5200, when the voltage supply is restored, the RA
Calculate the total sum of data stored in the storage area M1 of M230, add (AA)H to it in the same way as step S50 in FIG. It is temporarily stored in a register within the CPU 210 as a sum value.

Next, in step 5300 and step 5400, the sum value 230c at the time of voltage supply cutoff read from the address $0OFF in the RAM 230, and the sum value 230c at step 520 described above.
The sum value obtained at 0 and temporarily stored in the register at the time of voltage supply recovery is compared and verified.

Now, in the comparison and determination process of step 5400, the sum value 230c at the time of voltage supply interruption and the sum value at the time of voltage supply restoration are compared and verified, and if the two sum values are equal, step 55
The process branches to step 00, but if the two values are not equal, the process branches to step 8200 and subsequent steps.

In the process of step 5500, the above-mentioned step 5
In response to the comparison result at step 400, the print information 230b stored in the RAM 230 is returned to the stack of the CPU 210, and the printing process from immediately before the voltage supply is cut off is continued. That is, the CPU 210 processes the print data 230a in the RAM 230 based on the print information 230b returned to the stack. The print data 230a processed in this way is given to the printing section 300, and
The printing operation in the printing unit 300 is controlled to continue from the state immediately before the voltage supply was cut off.

Therefore, the characters to be printed will be printed following the character immediately before the voltage supply is cut off.

On the other hand, if the two sum values are not equal in the process of step 5400, the process branches to step 5600 and the CP
The U210 controls the printing unit 300 to print a PF mark (for example, a mark "*PF*", etc.) that indicates that the voltage supply from the power supply 250 has been cut off. Since the printing unit 300 prints the PF mark on the printing paper, the user can see the printed PF mark and know that the voltage supply has been cut off during the printing process.

After that, in the next step 5700, the CPU
210 clears (initializes) the storage area M1 of the RAM 230 and outputs a signal requesting retransmission of the print data 230a to the upper control unit. In response to receiving the retransmission request signal, the control unit side controls the RAM 230 when the voltage supply is cut off again.
The print data 230a stored in the print data 230a is transmitted. The thus retransmitted print data 230a at the time of voltage supply interruption is stored again in the storage area M1 of the RAM 230. The print data 230a retransmitted in this way is controlled by the CPU 210 and sent to step $8.
In the process of 00, the dot print is output again via the printing unit 300.

As described above, if the two sum values are equal in the determination process of step 5400, the data contents stored in the RAM 230 are the same before and after the voltage supply interruption period from the power supply 250. It is determined that the data stored in the RAM 230 is protected, and the printing operation continues from the printing immediately before the voltage supply was cut off.

On the other hand, if the two sum values do not match in the determination process of 5400, it is determined that the data stored in the RAM 230 has been damaged during the voltage supply cutoff period and its reliability cannot be guaranteed, and the data printed just before the voltage supply cutoff is It is operating to print out the data 230a again.

Note that during the voltage supply cutoff period from the power supply 250, the RAM 23
Considering that the storage area within 0 will be cleared and that the sum value of the data in the storage area M1 will become 0 by chance, the sum of the data in the storage area M1 will be set to (AA) as described above. A safety measure is taken in which the sum value 230C is the value obtained by adding H.

As described above, in printing devices where the backup function for power supply during power outage is limited to a short time,
RAM23 that stores print data when voltage supply interruption occurs
By comparing and collating the sum value of the data of 0 and the sum value of the data of the RAM 230 obtained immediately after the voltage supply is restored, it is possible to determine whether the RAM 230 has been backed up by the backup function operation, that is, the contents of the stored data. You can easily check whether or not the information was protected.

[Effects of the Invention] As described above, according to the printing device in which the storage medium in which the print data is stored is supplied with voltage from the auxiliary power source for a certain period of time after the voltage supply from the power source is cut off, the print data is Regarding the memory state, the state immediately before the voltage supply is cut off,
By comparing the state with the state immediately after the voltage supply is restored, it can be easily determined whether the storage state has been protected by the auxiliary power supply over the voltage supply cutoff period. Therefore, there is an advantage that it is possible to easily decide whether or not to continue the printing operation when the voltage supply from the power supply is restored after being cut off. As a result of the above effect, after the voltage supply from the power supply is restored, waste such as unconditionally reprinting the same data that was printed before the voltage supply was cut off can be avoided, and based on the above judgment, even if the voltage supply is cut off, After recovery, printing can be continued from the time when the voltage supply was cut off, which is more efficient.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the functional configuration of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the storage area of the RAM shown in FIG. 1. FIG. 3(a) is a schematic processing flow diagram showing the operation of the printing apparatus that is started in response to cutoff of voltage supply from the power source according to an embodiment of the present invention. Third
FIG. 3(b) is a schematic process flow diagram showing the operation of the printing apparatus that is started in response to the voltage supply being restored immediately after the voltage supply cutoff in FIG. 3(a). In the figure, 100 is a printing device, 200 is a control unit, and 210 is a printing device.
is the CPU, 230 is the RAM, 231 is the capacitor, 25
0 is a power supply, 300 is a printing unit, Ml and M2 are storage areas, 230a is print data, 230b is print information, and 230c is a sum value. In each figure, the same reference numerals indicate the same or corresponding parts. (α) Third

Claims (1)

[Scope of Claims] In a printing device that includes a storage medium for storing print data and is supplied with voltage from an auxiliary power supply in response to cutoff of the voltage supplied from the power supply, the voltage supplied from the power supply is cut off. a first calculation means for calculating the sum of print data stored in the storage medium in response to the detection of the voltage interruption by the power interruption detection means; , storage means for storing the sum calculated by the first calculation means in the storage medium; power recovery detection means for detecting power recovery after the voltage from the power source has been cut off; and by the power recovery detection means. a second calculation means for calculating a total sum of print data stored in the storage medium in response to detection of power recovery; and a second calculation means for calculating the sum total calculated by the first calculation means and the second calculation means. and means for comparing the total sum calculated by the means to determine whether or not print data stored in the storage medium during the voltage cutoff period was protected.