JPH079687A - Small printing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a small printing device capable of obtaining a constant print density without being affected by a change in battery voltage. A printing means 6 driven by a NiCd battery 1, a voltage measuring means 2 for measuring an output voltage of the NiCd battery 1, and a print pulse width data storage means 3 for storing proper print pulse width data corresponding to the output voltage. A voltage-to-print pulse width conversion means 4 for selecting an appropriate print pulse width from the print pulse width data storage means 3 based on the measurement result of the voltage measurement means 2, and a print output from the voltage-to-print pulse width conversion means 4. CPU 5 for controlling the printing means 6 with the pulse width
And made up a small printer. [Effect] It is possible to obtain a constant print density without being affected by fluctuations in the battery voltage, and it is possible to obtain a desired print density according to changes in paper quality and ink ribbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable compact printing apparatus for printing on check paper or the like.

[0002]

2. Description of the Related Art In recent years, downsizing of electronic devices and business
With the shift to A, the spread of portable electronic devices is remarkable. In particular, a small printing device such as a check issuing machine having both a deposit management function and a check issuing function is a very convenient electronic device, and thus further spread thereof is desired. However, at present, many problems to be overcome such as improvement of print density remain in the small printing device.

A print density control means in a conventional small-sized printing apparatus will be described below by taking an electronic typewriter as an example.

FIGS. 5A and 5B schematically show a print density control signal. As a means for controlling the print density of an electronic typewriter that constantly obtains a constant voltage from a power source, a method of controlling the energization time of a current flowing through a print head as shown in FIG. ), A method of controlling the voltage supplied to the print head has been known.

[0005]

However, according to the above-mentioned conventional method, in a portable small-sized printing apparatus using a battery as a power source, since it is easily affected by fluctuations in the power source voltage, it is impossible to secure a constant print density. This is one of the bottleneck for commercialization, especially for check issuing machines and the like, which require printing quality of a certain level or more.

Therefore, an object of the present invention is to provide a small-sized printing apparatus capable of maintaining a constant print density without being affected by a change in battery voltage.

[0007]

To this end, the present invention provides printing means driven by a power supply battery, voltage measuring means for measuring the output voltage of the power supply battery, and proper printing pulse width data corresponding to the output voltage. The stored print pulse width data storage means, the voltage-to-print pulse width conversion means for selecting an appropriate print pulse width from the print pulse width storage means based on the measurement result of the voltage measurement means, and the voltage-to-voltage print pulse width conversion means. A small-sized printing apparatus is configured by a printing control unit that controls the printing unit with a printing pulse width output from the printing unit.
The print pulse width data storage means stores a plurality of print pulse width data groups corresponding to a plurality of print densities according to the paper quality and the type of ink of the ink ribbon.

[0008]

With the above structure, a constant print density can be obtained without being affected by the voltage change of the power supply battery. Further, a desired print density can be obtained according to the change of paper quality and ink ribbon.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a compact printer according to an embodiment of the present invention. Reference numeral 1 is a NiCd battery as a power supply battery for driving each part of the small printing apparatus. Two
Is a voltage measuring means for measuring the output voltage of the NiCd battery 1, 3 is a print pulse width data storage means for storing a plurality of conversion tables storing proper print pulse width data corresponding to the output voltage, and 4 is a voltage measuring means 2 It is a voltage-to-print pulse width conversion means for selecting appropriate print pulse width data from the print pulse width data storage means 3 based on the measurement data of. Reference numeral 5 is a central processing unit (CPU) that controls the printing means 6 based on the selected print pulse width data, and 7 is a conversion table of the print pulse width data storage means 3 according to the paper quality, the type of ink ribbon, and the like. It is a conversion table selection means for switching. Reference numeral 8 is an input means such as a keyboard for inputting print data, 9 is a display means composed of an LCD for displaying the data, and 10 is a paper feed means for conveying the print paper. 11 is an RO that stores the control data of the small printing device
M and 12 are RAMs for storing input data.

Next, the printing means 6 will be described with reference to FIGS. 2 (a) and 2 (b). FIG. 2A is a perspective view of a printer unit 20 of a check issuing machine as an example of a small printing device,
FIG. 2B is a plan view of the same. 40 is an ink ribbon. 29 is a shuttle head whose printing direction is downward,
In the shuttle head 29, impact dot type printing units 13 are arranged in parallel in the sub-scanning direction N1. The printing unit 13 prints downward. The shuttle head 29 is supported by the frame 15 so as to be slidable in the sub-scanning direction N1 by the shaft 14 passing through the shuttle head 29. 16 is a paper feed roller, 1
Reference numeral 7 is a DC motor, 18 is an encoder attached to one shaft of the DC motor 17, and 19 is a photo sensor.

Reference numeral 21 is a cylindrical cam having a groove 22 on its surface.
Is provided. Reference numeral 23 denotes a balancer, and the projections 24 provided on the shuttle head 29 and the projections 25 provided on the balancer 23 are positioned at the positions opposite to each other in the groove 22.
Is engaged with. 26 is a gear box for transmitting power to the cylindrical cam 21, 27 is a gear train for transmitting power of the cylindrical cam 21 to the ink ribbon 40, and 28 is a ribbon driving shaft.

FIG. 3 is a perspective view of a check issuing machine in which the printer unit 20 is incorporated. Reference numeral 20 is the printer unit described above. 31 is a main body case, 32 is a case lid, 33
Is a hinge that pivotally attaches the main body case 31 and the case lid 32 to each other. 34 is a flat platen, 35 is a leaf spring, 3
6 is a lid opening / closing lever, 37 is a system stopper of the case lid 32, 38
Is a claw for positioning the check paper 39, 40 is an ink ribbon, 41 is a sub plate that supports the platen 34, and springs the platen 34 to the ink ribbon 40 side by a spring material (not shown) provided on the case lid 32. is there.

Next, the operation of the check issuing machine configured as described above will be described. First, the insertion of the check paper 39 will be described. As shown in FIG. 3, the lid opening / closing lever 36
To open the case lid 32 and insert the check paper 39 into the nail 3.
Position at 8. Next, the case lid 32 is closed to set it. In the case of roll paper, it can be set in the same way as standard paper by inserting it inside the claw 38.

Information input by the input means 8 shown in FIG. 1 is calculated by the CPU 5, and is stored in the ROM 11 and RA.
The rotation amount and the rotation speed are determined based on the data of M12, and the DC motor 17 is rotated by the drive circuit. D
The C motor 17 rotates the cylindrical cam 21 via the gear in the gear box 26. The shuttle head 29 engaged with the groove 22 on the cylindrical cam 21 and the balancer 23 reciprocate in the thrust direction. The rotational force of the DC motor 17 is further transmitted by the gear train 27, and the paper feed roller 1
6, and the ribbon drive shaft 28 is rotated to wind up the engaged ink ribbon 40. The check paper 39 is a leaf spring 3
It is fed by the paper feed roller 16 because it is biased to 5. When printing, the slit on the encoder 18 is read by the photo sensor 19, the CPU 5 calculates the output of the photo sensor 19 and drives the shuttle head 29 by the drive circuit at a constant timing, and the ink ribbon 40
The check paper 39 is printed with the ink soaked in.

Next, the control of the printing means 6 will be described. The output voltage value of the NiCd battery 1 is obtained from the voltage measuring means 2 at the start of printing, and the print pulse width data suitable for the measured voltage value stored in the print pulse width data storage means 3 is converted by the conversion table selecting means 7. It is selected from the table by the voltage-to-print pulse width conversion means 4. Next, based on the selected print pulse width data, the CPU 5
The printing means 6 is controlled by this, and printing is performed on the check paper 39 via the ink ribbon 40.

FIG. 4 is a schematic view of the contents of the voltage-to-print pulse width conversion table. The horizontal axis is the voltage value, and the vertical axis is the printing pulse width. The larger the voltage value, the smaller the printing pulse width, and conversely, the smaller the voltage value, the larger the printing pulse width. .

Further, by selecting an arbitrary conversion table from among several conversion tables by the conversion table selection means 7, it is possible to perform printing corresponding to changes in paper quality and ink ribbon. At this time, when it is desired to reduce the print density, it moves to the lower left A, and when it is desired to increase the print density, the locus of the conversion table in FIG. 4 moves to the upper right B.

[0019]

According to the small-sized printing apparatus of the present invention, it is possible to always obtain a constant print density without being influenced by the fluctuation of the battery voltage, and to print a desired print according to the change of the paper quality or the ink ribbon. Since the density can be obtained, high quality printing can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of a compact printer according to an embodiment of the present invention.

2A is a perspective view of a printer of a check issuing machine according to an embodiment of the present invention. FIG. 2B is a plan view of FIG.

FIG. 3 is a perspective view of a check issuing machine according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining the contents of a voltage-to-print pulse width conversion table in an embodiment of the present invention.

FIG. 5 (a) is an explanatory view of print density control according to energization time in a conventional small-sized printing apparatus.

[Explanation of symbols]

 1 NiCd Battery 2 Voltage Measuring Means 3 Print Pulse Width Data Storage Means 4 Voltage-to-Print Pulse Width Converting Means 5 Central Processing Unit (CPU) 6 Printing Means 7 Conversion Table Selecting Means

Claims (3)

[Claims] 1. A printing unit driven by a power supply battery,
Voltage measurement means for measuring the output voltage of the power supply battery, print pulse width data storage means for storing proper print pulse width data corresponding to the output voltage, and print pulse width data storage based on the measurement result of the voltage measurement means. Voltage-to-print pulse width conversion means for selecting an appropriate print pulse width from the means,
A small-sized printing apparatus comprising: a printing control means for controlling the printing means with a printing pulse width output from the voltage-to-printing pulse width conversion means. 2. The small-sized printing apparatus according to claim 1, wherein the printing means comprises an impact dot printer. 3. The print pulse width data storage means stores a plurality of print pulse width data groups corresponding to a plurality of print densities corresponding to paper quality and ink type of ink ribbon, and selects the print pulse width data group. 3. The miniature printing apparatus according to claim 2, further comprising a selection unit for performing the above.