JP2007168305A - Secondary battery-driven printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery-driven printer which can identify whether an error is a low battery voltage error or a battery life error as conventionally observed and annunciate the identification result. <P>SOLUTION: The relationship of a potential difference between the voltage of a secondary battery 22 during the turning ON of a power supply and a present secondary battery voltage, with a normal maximum issuance distance, is stored. Then, in case the secondary battery voltage is judged as due to a low battery voltage by a battery detection circuit 21 after printing operation, and the issuance distance during the printing operation is shorter than the normal maximum issuance distance corresponding to the voltage difference between the secondary battery voltage at the time of turning ON the powder supply and the present secondary battery voltage, the battery life is displayed, for example, by turning LED ON and OFF. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a secondary battery driven printer capable of detecting battery life.

  For example, a portable printer uses a secondary battery as a driving power source. Such a secondary battery driven printer displays a low battery error and stops operating when the battery charge capacity is low and the printing operation cannot be performed. Therefore, the user can recognize that replacement with a charged battery is necessary.

In addition, it is known that the life of the secondary battery will deteriorate as the number of times of charging / discharging increases.
JP-A-10-253725

In some printers using a secondary battery as a driving power source, the remaining battery capacity is detected by detecting the battery voltage. Therefore, if you use a battery whose performance has deteriorated due to a large number of charge / discharge cycles,
Even if printing is started from full charge, a low battery error is detected immediately after printing several sheets. For this reason, since the user cannot print the specified number of sheets, it may be determined that the device is abnormal despite the deterioration of the battery.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a secondary battery driven printer capable of distinguishing and notifying whether a conventional low battery error or an error due to battery life is detected. .

  The present invention relates to a battery detection unit for detecting a secondary battery voltage and a secondary detection detected by the battery detection unit at power-on in a printer that prints on a sheet by driving a sheet conveyance unit or a print head with a secondary battery. Means for storing battery voltage, storage means for storing the relationship between the potential difference between the secondary battery voltage when the power is turned on and the current secondary battery voltage, and the normal maximum issuance distance, and counting the issuance distance during the printing operation When the secondary battery voltage is determined to be a low battery by the issuing distance counting means and the battery detecting means after the printing operation, the issuing distance is the secondary battery voltage when the power is turned on and the current secondary battery voltage during the printing operation. And a battery life display means for displaying the battery life when the distance is smaller than the normal maximum issuance distance corresponding to the potential difference.

  According to the present invention, the relationship between the difference between the secondary battery voltage when the power is turned on and the current secondary battery voltage and the normal maximum issuance distance is stored, and the issuance distance is 2 when the power is on during the printing operation. If it is smaller than the normal maximum issuance distance corresponding to the potential difference between the secondary battery voltage and the current secondary battery voltage, it is determined that the error is due to the battery life, so that the notification is made. It is possible to distinguish and report whether the error is due to battery life.

  A secondary battery driven printer according to an embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 11 denotes a CPU (central processing unit) that controls the printer as a whole. The system bus 11a from the CPU 11 includes a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a motor driver 14, a head control circuit 15, a disconnection check circuit 16, a power switch 17, an LED 18, A communication I / F 19, various sensors 20, and a battery voltage detection circuit 21 are connected.

  The battery voltage detection circuit 21 detects the voltage of the secondary battery 22. The output of the secondary battery 22 is stabilized via the regulator circuit 23 and supplied to each element.

  In addition to the control program shown in FIG. 3, the ROM 12 stores the potential difference x between the battery voltage of the secondary battery 22 when the power is turned on and the current battery voltage of the secondary battery 22 as shown in FIG. Is stored in advance.

  The RAM 13 has a counter 13 a that counts the issuance distance a of the recording medium conveyed by the stepping motor 24 and a storage area 13 b that stores the voltage b of the secondary battery detected by the battery voltage detection circuit 21. The issuance distance a is the number of steps in which the sheet is fed by a sheet conveying stepping motor, for example.

  A stepping motor 24 is connected to the motor driver 14.

  Thermal heads 25 are connected to the head control circuit 15 and the disconnection check circuit 16, respectively. The head control circuit 15 outputs a head drive signal to the thermal head 25. The disconnection check circuit 16 checks for disconnection of the heating element of the thermal head 25.

  A host computer (not shown) is connected to the communication I / F 19. A print request is output from the host computer.

  Next, the operation of the embodiment of the present invention configured as described above will be described. First, when the power switch 17 is turned on, the processing shown in the flowchart of FIG. 3 is started. First, the count value of the counter 13a is cleared (step S1).

  Next, the battery voltage detection circuit 16 detects the battery voltage of the secondary battery 22, and the battery voltage b is stored in the storage area 13b of the RAM 13 (step S2). That is, the battery voltage b of the secondary battery 22 when the power switch 17 is turned on is stored.

  Next, it is determined whether the battery voltage b is at a low battery level (step S3). This low level is set to a voltage of a predetermined percentage of the voltage value when the secondary battery 22 is fully charged.

  If it is determined “YES” in step S3, the LED 18 is lit red (step S4). This notifies the user that the secondary battery 22 is a low battery.

  On the other hand, if “NO” is determined in the determination in step S3, the print wait state is set (step S5).

  Then, it is determined whether a print request from a host computer (not shown) has been received via the communication I / F 19 (step S6). While it is determined “NO” in the determination of step S6, the printer waits for printing.

  On the other hand, if “YES” is determined in the determination in step S6, it is determined whether the battery voltage b is at a low battery level (step S7).

  If “NO” is determined in the determination in step S7, a printing operation is performed (step S8).

  Then, a process for incrementing the travel distance counter 13a by the printing operation performed in step S8 is performed (step S9). Thereafter, the process returns to step S5.

  On the other hand, if “YES” is determined in the determination in step S7, the current battery voltage, that is, detected in step S7, is determined from the battery voltage b of the secondary battery 22 when the power switch 17 stored in step S2 is turned on. The potential difference x obtained by subtracting the battery voltage is calculated (step S10).

  Then, the normal maximum issuance distance y with respect to the potential difference x is obtained with reference to the data of FIG. 2 stored in the ROM 12 (step S11).

 Then, the normal maximum issuance distance y is compared with the issuance distance a of the recording medium counted by the counter 13a (step S12).

Then, it is determined whether the battery life is reached (step S13). That is, it is determined whether the issue distance a <the normal maximum issue distance y.

  If “YES” is determined in the determination in step S13, the LED 18 blinks in red and it is displayed that the secondary battery has a battery life (step S14).

  On the other hand, if “NO” is determined in the determination in step S13, the process in step S4 described above, that is, the LED 18 is turned on.

  As described above, the relationship between the difference between the secondary battery voltage at power-on and the current secondary battery voltage and the normal maximum issuance distance is stored, and the issuance distance at the time of printing operation is the secondary at the time of power-on. If it is smaller than the normal maximum issuance distance corresponding to the potential difference between the battery voltage and the current secondary battery voltage, it is determined that the error is due to the battery life, so that the notification is made. It is possible to distinguish and notify whether the error is due to the lifetime. In particular, in a printer using a thermal head, the power consumption of the thermal head is large, so that it is possible to accurately determine whether the battery voltage is reduced or the battery life is low due to a low battery.

1 is a block diagram showing a system configuration of a secondary battery driven printer according to an embodiment of the present invention. The figure which shows the relationship between the voltage difference x memorize | stored in ROM which concerns on the same embodiment, and the normal maximum issue distance y. The flowchart for demonstrating the operation | movement of the embodiment.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 11 ... CPU, 12 ... ROM, 15 ... Head control circuit, 21 ... Battery voltage detection circuit, 22 ... Secondary battery, 17 ... Power switch, 18 ... LED.

Claims (1)

In a printer that prints on paper by driving the paper transport unit or print head with a secondary battery,
Battery detection means for detecting a secondary battery voltage;
Means for storing a secondary battery voltage detected by the battery detection means at power-on;
Storage means for storing a relationship between a potential difference between a secondary battery voltage at the time of power-on and a current secondary battery voltage and a normal maximum issuance distance;
Issuance distance counting means for counting the issuance distance during printing operation;
When the secondary battery voltage is determined to be a low battery by the battery detection means after the printing operation, the issue distance corresponds to the potential difference between the secondary battery voltage when the power is turned on and the current secondary battery voltage during the printing operation. A secondary battery-driven printer comprising battery life display means for displaying the battery life when it is smaller than the normal maximum issuance distance.

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