JP2003001862A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer which can make correction factors constantly best suited to different kinds of batteries and bring about the proper quality of printing, by solving a problem such that the quality of the printing is sometimes deteriorated when there are great differences in internal resistance value among the batteries different in kind from one another. SOLUTION: Current-carrying time is made optimum by an in-battery resistance calculating means for calculating internal resistance of the battery from a voltage in non-operation and a voltage in previous phase hold and a correction-factor changing means for changing the correction factor of a current- carrying-time-of-thermal-head correcting means according to the calculated internal resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery-powered portable printer.

[0002]

2. Description of the Related Art In recent years, a large number of battery-driven printing devices have been used. Ni-C as the battery
There are d batteries, Ni-MH, lithium ion batteries, alkaline dry batteries, etc., but they have different internal resistances. Further, in a lithium ion battery or the like, the internal resistance changes greatly with temperature.

Conventionally, for a battery having a large internal resistance and a large voltage drop, for example, the one described in Japanese Patent Laid-Open No. 11-321045 is known as a means for effectively utilizing the battery. FIG. 4 is a flowchart showing the operation of the printing device according to the publication. A description will be given below with reference to FIG.

When the power is turned on, after various initial settings are made, the thermal printer stands by in a state in which it is not performing printing or paper feeding operation (hereinafter referred to as non-operation). The battery voltage during this non-operation is detected (hereinafter this value is referred to as V0). Further, when the non-operation state is continued, the voltage is periodically detected and the value of V0 is updated. When a print command arrives, the thermal printer starts the printing operation, energizes the stepping motor in the last energized phase last time (hereinafter referred to as "pre-phase hold"), and detects the voltage at the previous phase hold (hereinafter this value). Is called V1). Then, dV = | V0-V1 | is calculated from the detected voltages V0 and V1 and divided by the current value passed through the stepping motor to calculate the internal resistance of the battery. Further, the voltage (hereinafter, this value is referred to as V2) during the printing operation is calculated from the number of simultaneously colored dots to be printed next and the motor current, and V2 is equal to or higher than the minimum voltage of the battery (hereinafter, this value is referred to as Vlimit). if there is,
Perform printing operation. When the printing operation is completed, the operation returns to the operation of detecting the battery voltage during non-operation.

On the other hand, if V2 is less than or equal to Vlimit, the number of simultaneously colored dots is reduced by a predetermined value (hereinafter, this value is referred to as N), and V2 is calculated again with the updated number of simultaneously colored dots. Repeat until When V2 is equal to or higher than Vlimit, the printing operation is performed, and when the printing operation is completed, the operation returns to the operation of detecting the battery voltage during non-operation. When this value is equal to or smaller than the minimum number of simultaneously-colored dots (hereinafter, this value is referred to as n) when the number of simultaneously-colored dots is reduced, printing is stopped and a voltage error signal is output. In this way, when the remaining capacity of the battery is high, it is possible to obtain a sufficient printing speed without deteriorating the printing quality, and when the remaining capacity of the battery is low, the number of simultaneously colored dots is reduced to suppress the voltage drop. Since printing is possible, the battery can be used effectively.

[0006]

However, since the printing apparatus shown in the above-mentioned prior art has a printing condition for a specific type of battery, the printing quality is good for the corresponding battery, but the type of battery is different and the internal battery is different. There is a problem that the print quality may be deteriorated when the resistance values are greatly different.

[0007]

In order to solve this problem, the printing apparatus according to the present invention is a thermal head energization time correction for correcting the energization time of the thermal head according to the temperature voltage, the number of divisions, the number of dots that develop color at the same time, and the like. Means, a voltage detecting means for detecting a voltage during non-operation and a voltage during hold of the previous phase of the stepping motor at the start of printing, and an internal resistance of the battery from the voltage during non-operation and the voltage during hold of the previous phase. It comprises a battery internal resistance calculating means for calculating and a correction rate changing means for changing the correction rate of the thermal head energization time correcting means by the internal resistance calculated by the battery internal resistance calculating means. According to the present invention, by detecting the internal resistance and changing the correction rate, the optimum correction rate can always be obtained for different types of batteries.
Good print quality can be obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a thermal head energization time correction means for correcting the energization time of the thermal head according to the temperature voltage, the number of divisions, the number of dots that develop color simultaneously, and the like. Voltage detecting means for detecting the voltage during operation and the voltage during the previous phase hold of the stepping motor at the start of printing, and the internal battery for calculating the internal resistance of the battery from the voltage during the non-operation and the voltage during the previous phase hold Since the resistance calculation means and the correction rate changing means for changing the correction rate of the thermal head energization time correction means by the internal resistance calculated by the battery internal resistance calculation means are provided, the internal resistance is calculated and corrected. By changing the rate,
This has the effect that the optimum correction rate can always be obtained for different types of batteries, and good print quality can be obtained.

Since the invention according to claim 2 of the present invention has the correction rate changing means for changing the correction rate of the simultaneous coloring dot number correcting means according to the number of dots which are colored simultaneously, the internal resistance is calculated. By changing the correction rate of the number of simultaneous color dots correction means, it is possible to always obtain the optimum correction rate for different types of batteries in response to the difference in voltage drop due to the number of simultaneous color dots, and to obtain good print quality. It has the effect that can be obtained.

Since the invention according to claim 3 of the present invention has the correction rate changing means for changing the correction rate of the voltage correcting means, the internal resistance is calculated to change the correction rate of the voltage correcting means. As a result, for different types of batteries, the optimum correction rate can be set in accordance with the difference in voltage drop, and good printing quality can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

(First Embodiment) FIG. 1 is a block diagram showing the arrangement of a printing apparatus according to the first embodiment of the present invention.
In FIG. 1, the inside of the CPU 1 is composed of a voltage detection means 2, a battery internal resistance calculation means 3, a thermal head energization time correction rate changing means 4, a thermal head energization time correction means 5, and a control means 6. Thermal head 7 for CPU1
And a motor drive circuit 8 to which a stepping motor 9 is connected
And are connected.

The operation of the embodiment will be described below with reference to FIG.

In FIG. 1, CPU 1 is a power source (not shown).
When is turned on, after performing various initial settings, the thermal printer (not shown) stands by in a state in which printing or paper feeding operation is not performed (hereinafter referred to as non-operation). The battery voltage at the time of non-operation is detected by the voltage detecting means 2 (hereinafter, this value is called V0). Further, when the non-operation state is continued, the voltage is periodically detected and the value of V0 is updated.

When a print command arrives, the thermal printer starts a print operation, and the CPU 1 sends a signal to the motor drive circuit 8 of constant current drive by the control means 6 in the phase where the stepping motor 9 was last energized. 9
(Hereinafter, this is referred to as "pre-phase hold"), and at the same time, the voltage detection means 2 detects the voltage at the time of holding the previous phase (hereinafter, this value is referred to as V1).

Further, the battery internal resistance calculating means 3 calculates dV = | V0-V1 | from the detected voltages V0 and V1 and divides it by the current value passed through the stepping motor 9 to calculate the internal resistance of the battery (hereinafter This value is called r). The thermal head energization time correction rate changing means 4 changes the correction rate of the thermal head energization time correction means 5 for each calculated value of r by a table provided in advance, and determines the energization time of the thermal head 7 according to the changed correction rate. Then, the control means 6 energizes the thermal head 7.

As described above, the battery voltage during non-operation and the battery voltage during the previous phase hold are detected, the internal resistance of the battery is calculated, and the correction table to be used is changed according to the value to change the energization time of the thermal head. By determining, it is possible to always obtain an optimum correction rate for batteries having different internal resistances, and obtain good print quality.

Further, in the present invention, it is not necessary to change the correction rate for each dot line, and since it is sufficient to perform a series of printing operations once, it is possible to carry out with little control load.

In the present invention, the correction rate is changed according to the table provided in advance according to the value of the internal resistance. However, the same effect can be obtained by multiplying the correction rate set as the initial state by a constant determined by the value of the internal resistance. The effect can be obtained.

(Second Embodiment) FIG. 2 is a block diagram showing the arrangement of a printing apparatus according to the second embodiment of the present invention.
2 is a thermal head energization time correction factor changing means 4 of FIG.
Is changed to the simultaneous color dot number correction rate changing means 24.

The operation of the embodiment will be described below with reference to FIG.

The operation until the internal resistance of the battery is calculated is the same as in the first embodiment.

The simultaneous coloring dot number correction rate changing means 24 changes the correction rate of the simultaneous coloring dot number correction of the thermal head energization time correcting means 5 for each calculated value of r by a table provided in advance, and according to the changed correction rate. The energizing time of the thermal head 7 is determined, and the thermal head 7 is energized by the control means 6.

In this way, the battery voltage during non-operation and the battery voltage during the previous phase hold are detected to calculate the internal resistance of the battery, and the correction table for the number of simultaneously colored dots to be used is changed according to the calculated internal resistance to determine the thermal resistance. By determining the energization time of the head, it is possible to always obtain an optimum correction rate for batteries with different internal resistances, especially for the difference in voltage drop due to the change in the number of simultaneously colored dots, and obtain good print quality. be able to.

In the present invention, the correction rate for the simultaneous color dot number correction is changed according to the table provided in advance according to the internal resistance value. However, a constant determined by the internal resistance value is multiplied by the correction rate set as the initial state. Even if it does so, the same effect can be obtained.

(Third Embodiment) FIG. 3 is a block diagram showing the arrangement of a printing apparatus according to the third embodiment of the present invention.
FIG. 3 shows the thermal head energization time correction factor changing means 4 of FIG.
To the voltage correction factor changing means 34.

The operation of the embodiment will be described below with reference to FIG.

The operation until the internal resistance of the battery is calculated is the same as in the first embodiment.

The voltage correction rate changing means 34 changes the correction rate of the voltage correction of the thermal head energization time correction means 5 for each calculated value of r according to a table provided in advance, and the energization time of the thermal head 7 is changed according to the changed correction rate. Then, the control means 6 energizes the thermal head 7.

In this way, the battery voltage during non-operation and the battery voltage during the previous phase hold are detected, the battery internal resistance is calculated, and the correction table of the voltage correction to be used is changed according to the value to change the correction table of the thermal head. By determining the energization time, it is possible to always obtain the optimum correction rate by performing the voltage correction in consideration of the voltage drop especially for the batteries having different internal resistances, and it is possible to obtain the good print quality.

In the present invention, the correction rate for voltage correction is changed according to the table provided in advance according to the value of the internal resistance. However, a constant determined by the value of the internal resistance is multiplied by the correction rate set as the initial state. Also has the same effect.

[0032]

As described above, the printing apparatus of the present invention is
By detecting the battery voltage during non-operation and the battery voltage during the previous phase hold, calculating the battery internal resistance, and changing the correction table to be used according to that value to determine the energizing time of the thermal head It is possible to obtain an advantageous effect that it is possible to always obtain an optimum correction rate for batteries having different resistances and obtain good print quality.

Further, the battery voltage during non-operation and the battery voltage during the previous phase hold are detected, the battery internal resistance is calculated, and the correction table of the number of simultaneously colored dots to be used is changed according to the calculated value to change the thermal head. By determining the energization time, it is possible to always obtain an optimum correction rate for batteries with different internal resistances, especially for the difference in voltage drop due to the change in the number of simultaneous colored dots, and to obtain good print quality. The advantageous effect that it is possible is obtained.

Further, the battery voltage during non-operation and the battery voltage during the previous phase hold are detected to calculate the battery internal resistance,
By changing the correction table of the voltage correction to be used according to the value and determining the energizing time of the thermal head, the voltage correction that considers especially the voltage drop is performed for the batteries with different internal resistances so that the optimum correction rate is always obtained. And an advantageous effect that good printing quality can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a printing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a printing device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a printing device according to a third embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of a conventional printing device.

[Explanation of symbols]

1 CPU 2 Voltage detection means 3 Battery internal resistance calculation means 4 Thermal head energization time correction factor changing means 5 Thermal head energization time correction means 6 Control means 7 thermal head 8 Motor drive circuit 9 Stepping motor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirofumi Komiya             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshiki Takeda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2C055 CC00 CC03                 2C066 AA14 AB01 AB09 CB01 CB03                       CB05 CB06 CB09

Claims (3)

[Claims] 1. A thermal head energization time correction means for correcting the energization time of the thermal head according to temperature voltage, the number of divisions, the number of dots that develop color at the same time, and a non-operating voltage and a front phase of a stepping motor at the time of printing start. The voltage detection means for detecting the voltage during the hold, the battery internal resistance calculation means for calculating the internal resistance of the battery from the non-operating voltage and the voltage during the previous phase hold, and the battery internal resistance calculation means A printing apparatus having a configuration of a correction rate changing means for changing the correction rate of the thermal head energization time correction means by an internal resistance. 2. The printing apparatus according to claim 1, further comprising a correction rate changing unit that changes the correction rate of the simultaneous color dot number correction unit according to the number of dots that are colored simultaneously. 3. The printer according to claim 1, further comprising a correction factor changing unit that changes the correction factor of the voltage correcting unit.