JPH0645742U - Thermal recording device - Google Patents

Abstract

(57) [Abstract] [Purpose] Even in a thermal recording apparatus in which the voltage application time is controlled by the temperature of the recording device, when using an unstable power source such as a battery power source, the print density becomes thin due to the voltage drop. Prevent this. [Configuration] A means for measuring an applied voltage value is provided, and the voltage application time to the heating resistor is controlled by two parameters of the temperature of the recording device and the applied voltage value.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermal recording device, and more particularly to a thermal recording device driven mainly by a battery in a ship or the like.

[0002]

[Prior art]

 FIG. 3 is a block diagram showing the configuration of a conventional thermal recording apparatus of this type. In the figure, 1 is a thermal head provided in the recording unit, 2 is a control device for controlling the whole, 3 is a battery power source, Is an A / D conversion circuit for converting the temperature of the thermal head 1 into a digital value, 5 is an application control unit for applying a voltage from the power supply 3 to the heating element of the thermal head 1 according to the application time determined by the control device 2, and 6 is printing The data. As is well known, a thermal recording device using a thermal head prints by heating a heating resistor at a predetermined temperature, and it is necessary to ensure a certain printing quality. Are in control. That is, when the temperature of the thermal head is low, the application time is long, and when it is high, the printing time is short to make the print density uniform.

[0003]

[Problems to be solved by the device]

 As described above, the conventional thermal recording device controls the voltage application time only by the temperature of the thermal head (the temperature of the recording device), so if the power supply itself is unstable, good print quality is achieved. There is a problem that can not keep. For example, when it is mounted on a ship or the like and is driven by a battery power source, the applied voltage drops during use of the old battery and the print density becomes thin. Further, when the data having many black characters is printed when the applied voltage is lowered to some extent, the voltage is further lowered and the print density becomes thin. In particular, such problems often occur in battery power supplies because the voltage drops immediately when the battery is old or the environmental temperature is low.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a thermal recording apparatus capable of ensuring good print quality even when used with an unstable power source such as a battery power source. .

[0005]

[Means for Solving the Problems]

 The thermal recording apparatus according to the present invention is characterized in that it is provided with means for correcting the power supply voltage when the power supply voltage is not sufficient.

[0006]

[Action]

 In the present invention, when the power supply voltage is not sufficient, a means for correcting this is provided, and not only the temperature of the recording device but also the voltage value supplied to the thermal head is added to the parameter for controlling the printing time. Ensure good print quality even when used with an unstable power supply. Therefore, for example, when used by connecting to the battery power source of a small vessel, the print density does not decrease even if the battery is old and cannot supply a sufficient voltage, and conversely if the power supply voltage is sufficient. By suppressing unnecessary power consumption, the battery power can last longer.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a thermal recording apparatus according to the present invention. The same reference numerals as those in FIG. 3 showing a conventional apparatus indicate the same or corresponding portions, but the apparatus in this embodiment measures an applied voltage The voltage value is input to the A / D conversion circuit 3, converted into a digital value, and sent to the control device 2. Then, in the control device 2, an appropriate voltage application time is selected based on the input temperature information and voltage value information, for example, using a parameter table as shown in FIG. Power is applied to the heating element of the thermal head 1.

Next, the operation will be described. At the start of recording, if the temperature information output from the A / D conversion circuit 4 is low, the thermal data of the thermal head 1 is warmed up by the controller 2, so the print data 6 is set to one line of all black data. The application controller 5 applies a voltage based on the print data to perform printing. Then, during recording, the table of FIG. 3 is referred to based on the temperature information and the applied voltage information output from the A / D conversion circuit 4, the printing time is selected, and the application control unit 5 is selected at this printing time. Applies voltage and prints. As described above, in this embodiment, the optimum application time is selected by the two parameters of the recording device temperature and the applied voltage, and printing is performed. The set values in the parameter table shown in FIG. 2 are set in advance by experiments.

[0009]

[Effect of device]

 As described above, the thermal recording device of the present invention controls the printing time also by the voltage value of the applied voltage, so that the print density becomes thin even when the output voltage is lowered by the battery power source. This also has the effect of preventing unnecessary power consumption even when the output voltage is above the specified value, and making the battery power source last longer. Since no additional hardware is required, the configuration is simple and there is no cost increase.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a parameter table in the present embodiment.

FIG. 3 is a block diagram showing a conventional device.

[Explanation of symbols]

 1 Thermal Head 2 Control Device 3 Battery Power Supply 4 A / D Conversion Circuit 5 Application Control Section 6 Print Data

Claims (1)

[Scope of utility model registration request] 1. A thermal recording apparatus for controlling a voltage application time to a heating resistor according to a temperature of a recording device to make print density uniform, comprising means for measuring an applied voltage value, and the temperature and the applied voltage of the recording device. A thermal recording device that controls the voltage application time to the heating resistor by two parameters, ie, the value and the print density, to make the print density uniform.