JP2009251632A - Printing device, and data writing method for printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing device for writing many data in an image buffer, and for completing the writing of data to be printed with high probability when a supply power source is disconnected during data writing when writing data to be printed in an image buffer and the data writing method of a printing device. <P>SOLUTION: An image buffer 14 for storing image data to be printed is configured of an FeRAM. Since the FeRAM has high speed writing characteristics, even when the power supply of a printer 1 is disconnected during the writing of data to the image buffer 14, large amounts of data are written in an image buffer 14 in the fall period of a power supply voltage from a power supply device 30. Thus, it is possible to increase probability that the writing of the image data can be completed before the image buffer 14 becomes inoperable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a printing apparatus that writes input data into a nonvolatile memory and executes a printing process according to the data written into the nonvolatile memory, and a data writing method for the printing apparatus.

Conventionally, a printer configured to store received print data in a flash memory is known (for example, see Patent Document 1). The printer described in Patent Document 1 is configured to operate with the power stored in the secondary battery, and stores the received print data in the flash memory when sufficient power is not stored in the secondary battery. This prevents the received print data from being lost even if the power is cut off due to power shortage. This
The user is not burdened with unnecessary burdens such as re-sending print data at the time of restart.

JP 2007-261200 A

However, since the writing time of the flash memory is generally relatively long, the printer described in Patent Document 1 has insufficient power accumulated in the secondary battery during the process of writing the received print data to the flash memory. In other words, some of the received print data may be lost because it has not been written to the flash memory. That is,
Even when the flash memory is used as a reception buffer, writing of print data may not be completed, and it may be necessary to retransmit the print data when restarting.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A printing apparatus that writes data to be printed to a storage unit and executes a printing process based on the data stored in the storage unit, and controls the writing of data to the storage unit And a power supply unit having a characteristic that a power supply voltage to be supplied gradually decreases when power is supplied to the storage unit and the control unit and the supply of power is cut off. The storage unit is a ferroelectric memory, and the control unit is driven by a power supply voltage that gradually decreases when power supply by the power supply unit is cut off during writing of data to the storage unit A printing apparatus characterized in that data is continuously written to the printer.

Application Example 2 A data writing method of a printing apparatus that writes data to be printed in a storage unit and executes a printing process based on the data stored in the storage unit, wherein the storage unit is a ferroelectric material The memory is characterized in that when the supply of power is cut off during the writing of data to the storage unit, the data is continuously written to the storage unit driven by a gradually decreasing power supply voltage. Data writing method for printing apparatus.

According to these configurations, the storage unit to which data to be printed is written is a ferroelectric memory whose writing time is much shorter than that of the flash memory, and thus is supplied from the power supply unit during data writing. Even when the power is turned off, a large amount of data can be written to the storage unit while the storage unit is driven by the gradually decreasing power supply voltage. Therefore, when the supply of power is cut off during the writing of data to the storage unit, the possibility of leaving unwritten data is greatly reduced, and the possibility of completing the writing of data is significantly increased.

  Hereinafter, embodiments of the present invention will be described based on examples.

FIG. 1 is a diagram illustrating the configuration of the printer according to the present embodiment. As shown in FIG. 1, a printer 1 as an example of a printing apparatus includes a controller 10, a print engine 20, a power supply device (power supply unit) 30 that supplies power to the controller 10 and the print engine 20,
An operation panel 40 including a display unit such as an LCD (Liquid Crystal Display) and operation buttons.
And. Note that the printer 1 is not receiving power from the outside,
It is operable by power supply from the power supply device 30 inside the printer 1, for example,
This is a portable printer that can be used in mobile applications. Hereinafter, each configuration of the printer 1 will be described.

The controller 10 is a part that controls printing by the print engine 20, and includes a CPU.
11, ROM 12, RAM 13, image buffer (storage unit) 14, DMA controller (control unit) 15, memory I / F 16, panel I / F 17, image processing unit 18,
have. The CPU 11 is a main control device of the controller 10, and performs various controls by executing a control program stored in advance in the ROM 12 using the RAM 13.

The image buffer 14 is a buffer for storing image data to be printed, and its storage element is a FeRAM (Ferroelectric Random Access) which is a ferroelectric memory.
Memory) is used. FeRAM is a non-volatile memory that can read and write data by utilizing the hysteresis characteristics of ferroelectric materials for data storage, and is a flash memory that is widely used as a readable and writable non-volatile memory. Compared to this, a remarkably high speed operation is realized. Specifically, the writing time of a block unit of 64 bytes is about 10 ms in the flash memory, whereas the writing speed of 50 to 100 μs is realized in the FeRAM when converted to the writing time of the same amount of data. Compared with flash memory, the amount of data that can be written to FeRAM per unit time is much larger. In addition, FeRAM can be driven at a low voltage in principle.
. Those that are driven at less than 4 V have been put into practical use. For this reason, FeRAM has a low voltage operation characteristic of operating at a lower voltage than a flash memory requiring a driving voltage of about 3V.

The DMA controller 15 is a part that executes data transfer to the image buffer 14 or the like in accordance with a command from the CPU 11. In this embodiment, the DMA controller 1
The operating voltage of 5 is assumed to be lower than that of FeRAM.

The memory I / F 16 is an interface portion to which a memory card MC including the flash memory FL is detachably attached, and data is read from and written to the flash memory FL via the memory I / F 16. The panel I / F 17 is an interface part connected to the operation panel 40, and outputs a display signal from the controller 10 to the LCD,
An operation signal corresponding to the operation applied to the operation switch is input to the controller 10 via the panel I / F 17.

The image processing unit 18 performs image processing such as color conversion processing for converting image data into CMYK data and halftone processing for converting CMYK data into dot data. The image processing unit 18 performs post-image processing. Is output to the print engine 20 to execute printing by the print engine 20.

The power supply device 30 includes a secondary battery 31 that is charged with power, and a power supply circuit 32 that supplies the power stored in the secondary battery 31 to the controller 10, the print engine 20, and the like. That is, the printer 1 can be operated by the power of the built-in secondary battery 31 without receiving power supply from an external power source. However, when charging or the like, the battery is connected to an external power supply device via a dedicated cable so that the secondary battery 31 is charged with power, and power from the external power supply device is supplied to each part of the printer. The

Here, since the amount of power stored in the secondary battery 31 is finite, if the printer 1 is continuously used without being supplied with external power, the amount of power remaining in the secondary battery 31 is reduced. If it continues to be used, power will be insufficient and the power supplied to the controller 10 and the print engine 20 will be cut off. That is, if the use of the printer 1 with the power of the secondary battery 31 is continued, the power necessary for the operation of the controller 10 and the print engine 20 cannot be supplied at a certain point, and the processing performed in the printer 1 cannot be executed. End up. Therefore, for example, in order to print the image data written in the flash memory FL of the memory card MC, while the image data is being transferred from the flash memory FL to the image buffer 14, There is a possibility that the supply will be cut off.

Therefore, the printer 1 according to the present embodiment stores data in the image buffer 14 that is FeRAM when the power supply from the power supply device 30 is cut off, and the power supply voltage is reduced when the power supply is cut off. Taking advantage of the high-speed write characteristics of FeRAM during the fall time,
A large amount of data is written into the image buffer 14. Specifically, when power supply is cut off due to a shortage of remaining power, the power supply voltage supplied from the power supply device 30 is the same as that shown in FIG. 2 when the power supply from the power supply device 30 is cut off ( After time T0), a voltage drop starts from the power supply voltage VD during normal operation, and the power supply voltage gradually decreases.
In 1, the power supply voltage is almost 0 (V). That is, the power supply voltage supplied from the power supply device 30 is 0 from the normal power supply voltage VD (V) during the falling period ΔT of the times T0 to T1.
A voltage change of the voltage drop characteristic C in which the voltage gradually decreases is generated in (V).

Here, the operating voltage VL of FeRAM is lower than the power supply voltage VD during normal operation (VD> VL).
> 0), the FeRAM operates normally during the period ΔD during which the voltage higher than the operating voltage VL is supplied during the falling period ΔT. In this printer 1, since the operating voltage of the DMA controller 15 is lower than the operating voltage of the FeRAM, during the FeRAM operable period ΔD,
The image buffer 14 and the DMA controller 15 operate and data can be written into the image buffer 14. In the FeRAM operable period ΔD, Fe
Data is written utilizing the high-speed writing characteristics of the RAM.

Next, an operation when printing according to the image data stored in the memory card MC in the printer 1 will be described with reference to FIG. 3 showing an example of data transfer processing to the image buffer 14.

For example, after the user sets a memory card MC storing image data captured by a digital still camera or the like in the memory I / F 16, an instruction to start printing image data stored in the memory card MC is issued. When input is made to the operation panel 40, the printing process is started. When the processing is started, the CPU 11 designates the start address and end address of the flash memory FL in which the image data to be printed is stored as the transfer target, and transfers the target data from the flash memory FL to the image buffer 14. A command to that effect is issued to the DMA controller 15. As a result, as shown in FIG. 3A, the DMA controller 15 starts data transfer for printing the image data D1 to D5 stored in the flash memory FL, and is first stored at the head address. The image data D1 is read and stored in the image buffer 14. Then, the DMA controller 15 sequentially transfers the image data stored in the flash memory FL and stores it in the image buffer 14.

Here, as shown in FIG. 3B, at the timing before the transfer of the image data D4 is started, the secondary battery 31 falls into a power shortage state, and power is supplied from the power supply device 30 to the controller 10. Shall be disconnected. However, as shown in FIG. 2, during the operable period ΔD between time T0 and time T2 when the power supply is cut off, the image buffer (FeR
AM) 14 and DMA controller 15 are operating and capable of writing data, and due to the high-speed writing characteristics of FeRAM, as shown in FIG. Also, the image data D4 that has not been transferred when the power supply is cut off.
˜D5 are transferred and written to the image buffer 14. Thereby, the data transfer of the image data D1 to D5 to be printed is completed. Then, after the data transfer is completed, when the voltage becomes lower than the operating voltage VL, the operation of the image buffer 14 is stopped and data cannot be written.

As described above, the data transfer can be completed despite the power supply being cut off during the data transfer. For example, when the secondary battery 31 is charged or the printer 1 is supplied with the external power supply. When the printer 1 is restarted, print processing can be executed using the image data stored in the image buffer 14 without receiving an instruction from the user.
That is, the CPU 11 reads out image data from the image buffer 14, and the image processing unit 18.
A process of converting image data into bitmap data in accordance with the print resolution in cooperation with C,
Printing of image data stored in the image buffer 14 is performed by performing color conversion processing for converting to MYK data and halftone processing for converting to dot data, and performing print processing for outputting the processed data to the print engine 20. Can be executed.

If a large amount of untransferred image data remains when the power supply is cut off, the FeRAM
Even with this write characteristic, it is possible that the transfer of all data cannot be completed during the operable period ΔD. In this case, for example, when the printer 1 is restarted by charging the secondary battery 31 or the printer 1 is supplied with external power, the started CPU 11 issues an instruction to the DMA controller 15 and the data is not transferred. Data transfer from the memory card MC to the image buffer 14 is resumed for the image data for the remaining minutes.

As described above, in the printer 1, the memory element of the image buffer 14 is an FeRAM having a high data writing speed, so that when the image data stored in the memory card MC is printed, the memory card Image buffer 14 from flash memory FL of MC
FeRAM operable period Δ even when the power supply is cut off during data transfer to
A lot of data can be written into the image buffer 14 in D. As a result, data writing can be completed with high probability before the image buffer 14 becomes inoperable. In particular, a flash memory widely used as a readable / writable nonvolatile memory is used as the image buffer 14.
Compared with the case of using for the above, it is possible to remarkably increase the possibility that data writing can be completed. Further, when the printer 1 is restarted, the user does not need to reinstruct the printing of the image data stored in the memory card MC.

However, as described in FIG. 3 as an example, the data transfer is started within the FeRAM operable period ΔD after the power supply is cut off, without being limited to the case where the power supply is cut off during the data transfer. Similarly, data writing can be completed with high probability.

Further, since FeRAM has a characteristic that it operates at a lower voltage than a flash memory, the FeRAM operable period ΔD is longer than the flash memory operable period under a constant voltage drop characteristic C. Therefore, more data can be written by the low-voltage operation characteristic in addition to the high-speed writing characteristic. By using the FeRAM having these two characteristics for the image buffer 14, the data can be written with higher probability. The writing can be completed.

Furthermore, at the time of restart, without writing new data to the image buffer 14,
Since there is a high possibility that printing can be performed in accordance with the data already written in the image buffer 14, it is less necessary for the user to instruct reprinting at the time of restart, and convenience for the user is improved.

When the amount of data to be transferred is particularly large, the FeRAM operable period Δ
Although there is a possibility that all data cannot be written in D, since a large amount of image data can be written, the amount of data that needs to be written to the image buffer 14 after the restart is reduced, and this is performed at the time of restart. The time required for data writing can be shortened.

  Although one example of the embodiment has been described above, the following modifications may be made.

(Modification 1) In the above-described embodiment, the portable printer in which the power supply device 30 is built in the printer 1 has been described as an example. However, a stationary printer that operates by receiving power supply from the outside may be used. . In this case, even if a power failure occurs during data writing or the power cable is unexpectedly disconnected, the power supply is suddenly cut off, so that the image buffer 14 is replaced with an FeRAM. It is possible to complete the writing of data to the server with a high probability.

(Modification 2) In the above-described embodiment, the case where image data is input via the memory card MC has been described as an example. However, a host device having a printer driver is connected and printing is performed from the printer driver of the host device. A printer configured to receive image data may be used. In this case, even if the power is turned off during the process of storing the image data received from the printer driver in the image buffer 14, a large amount of data can be written by the high-speed writing characteristics of the FeRAM. Can complete the data writing.

(Modification 3) In the above embodiment, the DMA transfer by the DMA controller 15 is taken as an example, but the CPU (control unit) 11 itself may perform PIO transfer for transferring data.

(Modification 4) In the above embodiment, the operation voltage of the DMA controller 15 has been described as being driven at a voltage lower than that of FeRAM. However, the present invention is not limited to this. When the operating voltage of the DMA controller 15 is higher than that of the FeRAM, the period during which data can be written is limited to the operable period of the DMA controller 15 that is shorter than the operable period ΔD of the FeRAM. A lot of data can be written according to the writing characteristics, and the data writing can be completed with high probability.

(Modification 5) The controller 10 or the CPU 11 is provided with a function unit for detecting a voltage drop of the power supply voltage, and when the voltage drop of the power supply from the power supply device 30 is detected, the CPU 11 sets its operation mode to sleep or By shifting to the standby state, the power consumption in the falling period ΔT may be reduced. In this way, the power supplied during the FeRAM operable period ΔD is intensively supplied to the FeRAM and the DMA controller, so that the operation is stable for data transfer after the power supply is cut off. Can be achieved.

1 is a diagram illustrating a configuration of a printer according to an embodiment. The figure explaining the operation possible period of FeRAM when a power supply is cut | disconnected. It is a figure which showed the example of a process of data transfer, (a) is at the time of a transfer start, (b) is when a power supply is cut off (time T0), (c) is after a power supply is cut off (operation of FeRAM is possible) The figure which showed the state of the data transfer in the period (DELTA) D).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer as printing apparatus, 10 ... Controller, 11 ... CPU, 12 ... ROM,
DESCRIPTION OF SYMBOLS 13 ... RAM, 14 ... Image buffer as a memory | storage part, 15 ... DMA controller as a control part, 16 ... Memory I / F, 17 ... Panel I / F, 18 ... Image processing part, 20 ... Print engine, 30 ... Power supply Power supply device as supply unit, 31 ... secondary battery, 32 ... power supply circuit,
40: Operation panel, MC: Memory card, FL: Flash memory, C: Voltage drop characteristic of power supply voltage when power is cut off, VD: Power supply voltage at normal time, VL: Operating voltage of FeRAM, Δ
T: Falling period, ΔD: FeRAM operable period.

Claims (2)

A printing apparatus that writes data to be printed into a storage unit and executes a printing process based on the data stored in the storage unit,
A control unit that controls writing of data to the storage unit;
A power supply unit having a characteristic that a power supply voltage to be supplied gradually decreases when power for driving is supplied to the storage unit and the control unit and power supply is cut off;
The storage unit is a ferroelectric memory,
The control unit continues to write data to the storage unit that is driven by a gradually decreasing power supply voltage when power supply by the power supply unit is cut off during data writing to the storage unit. A printing apparatus characterized by performing. A data writing method for a printing apparatus that writes data to be printed in a storage unit and executes a printing process based on the data stored in the storage unit,
The storage unit is a ferroelectric memory,
Data of a printing apparatus, wherein data is continuously written to the storage unit that is driven by a gradually decreasing power supply voltage when power supply is cut off during the data writing to the storage unit Writing method.

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