JPH0699606A - Thermal recording device - Google Patents

Abstract

PURPOSE:To enable recording at appropriate density even in the case where arbitrary thermal recording paper having different color development properties is used. CONSTITUTION:Energy to be imparted to a thermal head 4 is varied by an energy varying part 2 in according with a kind of thermal recording paper and the energy coincident with color development properties of pieces each of thermal recording paper are imparted to the thermal head. When the energy to be imparted to the thermal head 4 is varied, printing density of the thermal recording paper printed by the thermal head 4 is detected, compared with predetermined printing density and the energy to be imparted to the thermal head 4 is established, through which printing is performed automatically at an optimum density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording apparatus used in printers, facsimiles and the like, and more particularly to optimization of print density.

[0002]

2. Description of the Related Art A heat-sensitive recording apparatus can record on heat-sensitive recording paper by simply applying heat to a thermal head. Since the recording mechanism is simpler than other recording methods, it is widely used in printers, facsimiles and the like. Has been done. A plurality of heat-sensitive recording papers used in this heat-sensitive recording apparatus are commercially available with different color-developing characteristics. When different heat-sensitive recording papers are used for recording, the color-developing densities are different and proper recording density cannot be obtained.

In order to solve such a problem, the drive time of the thermal head for a plurality of types of thermal recording paper is stored in advance in a plurality of drive time storage sections, and the switch is switched according to the thermal recording paper to be used. By selecting the drive time storage section by changing the, and changing the drive time of the thermal head, a thermal recording device that keeps the color density uniform without being affected by different color development characteristics depending on the type of thermal recording paper, For example, it is disclosed in Japanese Patent Laid-Open No. 3-104660.

[0004]

However, in order to store the driving time of the thermal head for a plurality of types of thermal recording papers in advance, it is necessary to check the color forming characteristics of the thermal recording papers. The investigation was not easy. In addition, a large amount of memory is required to store the thermal head drive time for each thermal recording paper,
Since the apparatus itself is expensive, there is a limit to the type of thermal recording paper that can be stored.

Therefore, when a recording paper other than the thermal recording paper designated by the user is used, an appropriate print density cannot be obtained, and the user cannot use any thermal recording paper.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to obtain a heat-sensitive recording apparatus capable of recording at an appropriate density even when using any heat-sensitive recording paper having different coloring characteristics. It is what

[0007]

A thermal recording apparatus according to the present invention has an energy variable section and an energy setting section, and the energy variable section can arbitrarily change the energy given to a thermal head for recording characters and images. However, the energy setting unit sets the energy output by the energy variable unit.

A thermal recording apparatus according to a second aspect of the present invention has a density sensor and an energy variable section, the density sensor is provided downstream of the thermal head on the thermal surface side of the thermal recording paper, and in the thermal head. It is characterized in that the print density of the printed thermal paper is detected, and the energy changing unit changes and outputs the energy given to the thermal head based on the print density set in advance and the print density detected by the density sensor.

Further, each of the above thermal recording devices has a temperature characteristic storage section and a temperature sensor, and the characteristic of the energy ratio with respect to temperature is stored in advance in the temperature characteristic storage section, and the temperature sensor is used for the thermal head at the time of recording. The energy variable unit detects the temperature or the temperature inside or near the device, and the energy variable unit reads the energy ratio stored in the temperature characteristic storage unit according to the temperature at the time of recording detected by the temperature sensor, and the thermal head according to the read energy ratio. It is preferable to correct and output the energy given to.

Further, when setting the energy to be applied to the thermal head, it is preferable to output a constant pattern to record on the thermal recording paper and set the energy based on the recording.

[0011]

According to the present invention, the energy applied to the thermal head is varied by the energy varying section based on the energy set in the energy setting section according to the type of the thermal recording sheet, so that the energy suitable for each thermal recording sheet can be obtained. Output to thermal head.

When the energy to be applied to the thermal head is varied, the density sensor detects the print density of the thermal recording paper printed by the thermal head and sends it to the energy variable section, which then sets the preset print density. The energy applied to the thermal head is automatically set to an appropriate value based on the print density detected by the density sensor.

Further, the characteristic of the energy ratio with respect to temperature is stored in the temperature characteristic storage unit, and the energy variable unit reads and sets the energy ratio according to the temperature at the time of recording detected by the temperature sensor from the temperature characteristic storage unit. Corrected energy,
Optimal energy corresponding to the temperature at that time is output to the thermal head.

Further, when the energy to be applied to the thermal head is set, a constant pattern is output to record on the thermosensitive recording paper, and the energy is set based on the recording, so that the constant reference is always made. To set the energy.

[0015]

1 is a block diagram showing an embodiment of the present invention. As shown in the figure, the thermal recording apparatus has an energy setting switch 1, an energy variable section 2, a control section 3, a thermal head 4 and an operating section 5. The energy setting switch 1 is composed of, for example, a slide switch attached to the main body of the apparatus or a key switch attached to the operation unit 5, and when the thermal head 4 records characters and images on a thermosensitive recording paper, the pulse width and drive Thermal head 4 for voltage
It sets the value of energy to be given to the energy variable unit 2 and is connected to the energy variable unit 2. The energy variable section 2 is a servo according to the energy value set by the energy setting switch 1.
The energy applied to the round head 4 is changed,
It is connected to the control unit 3. The control unit 3 applies energy to the thermal head 4 in response to a drive signal from the operation unit 5 to control the recording operation of the thermal head 4.

When recording characters and images on the thermal recording paper newly replaced by the thermal recording device having the above-mentioned structure with the thermal head 4, the user first operates the energy setting switch 1 for use. An energy value corresponding to the color development characteristic of the thermal recording paper is set and sent to the energy variable section 2. The energy changing unit 2 changes the energy given to the thermal head 4 according to the energy value set by the energy setting switch 1 and sends it to the control unit 3. In this state, the operation section 5 is operated to start recording. When the control section 3 receives the recording start signal from the operation section 5, the control section 3 gives the energy sent from the energy varying section 2 to the thermal head 4 while
To record characters and images on thermal recording paper. After that,
The recording operation is repeated while supplying energy corresponding to the energy value set by the energy setting switch 1 to the thermal head 4 until the set thermal recording paper is exhausted. When the set thermosensitive recording paper is used up and replaced with a new thermosensitive recording paper, the energy setting switch 1 sets the energy value according to the color development characteristics of the thermosensitive recording paper.

In this way, the thermal head 4 can always be supplied with energy in accordance with the color-developing characteristics of the thermosensitive recording paper to be used. Therefore, even if the type of thermosensitive recording paper used is different, the optimum color density is always provided. Thus, it is possible to record characters and images on the thermosensitive recording paper with uniform printing density.

In the above embodiment, the energy applied to the thermal head 4 is set in accordance with the coloring characteristics of the thermal recording paper used. However, as shown in the block diagram of FIG. By providing the generator 6 and confirming the density of the pattern recorded on the thermosensitive recording paper and varying the energy applied to the thermal head 4, the optimum density recording is performed even when the color development characteristic of the thermosensitive recording paper is unknown. be able to.

When the pattern generating section 6 is provided in this way, as shown in the flow chart of FIG. 3, when the thermosensitive recording paper is replaced and the density is set according to the new thermosensitive recording paper. (Step S1), the recording start button after selecting the density setting mode with the operation unit 5 is turned on and a recording start signal is sent to the control unit 3 (step S2). When the recording start signal is sent, the control unit 3 causes the pattern generation unit 6 to generate a predetermined pattern, and controls the thermal head 4 to start recording the pattern on a new thermal recording paper. (Step S3). The user adjusts the set value of the energy setting switch 1 so as to obtain the optimum print density while confirming the density of the recorded pattern (step S4). By adjusting the energy setting switch 1, the energy changing unit 2 changes the energy applied to the thermal head 4 and sends it to the control unit 3. The controller 3 records the pattern while sending the sent energy to the thermal head 4. When the density of the recorded pattern reaches the optimum density (step S5), the adjustment of the energy setting switch 1 is stopped, the recording stop button of the operation unit 5 is turned on, and the pattern is recorded. The thermosensitive recording paper is ejected and the pattern recording is completed (steps S6 and S7). After that, a normal recording operation is performed (step S8).

By recording the constant pattern and confirming the print density in this way, the energy can always be set based on a constant reference.

In each of the above-described embodiments, the case where the user adjusts the set value of the energy setting switch 1 to change the energy applied to the thermal head 4 has been described. However, the density recorded on the thermosensitive recording paper is changed to the density. It is also possible to set the energy detected by the sensor and automatically applied to the thermal head 4.

FIGS. 4 and 5 show an embodiment in which the energy applied to the thermal head 4 is automatically set. FIG. 4 is a block diagram and FIG. 5 is an arrangement diagram showing an outline of the recording unit.
As shown in FIG. 4, a density selection switch 7 and a density sensor 8 are connected to the energy variable section 2. Concentration sensor 8
5, is provided on the downstream side of the thermal head 4 in the passage of the thermosensitive recording paper 11 sent by the platen roller 9 and the discharge roller 10, and the output of the density and density sensor of FIG. As shown in the characteristic diagram, when a character or an image is recorded on the thermosensitive recording paper 11, an output voltage corresponding to the density is sent to the energy variable section 2. With the density selection switch 7, the thermal recording paper 1
When the character and the image are recorded on 1, the optimum color density is selected as "1.3" as shown in FIG. 6, and when the optimum color density "1.3" is recorded on the thermal recording paper 11. Then, the output voltage V ₀ is sent from the concentration sensor 8 to the energy variable unit 2. The energy varying unit 2 varies the energy applied to the thermal head 4 so that the output voltage of the density sensor 8 becomes the voltage V ₀ corresponding to the optimum color density "1.3".

In the thermal recording device having the above-mentioned structure,
For example, as shown in the energy and density characteristic diagram of FIG. 7, the energy Ea to be given to the thermal head 4 is sent out from the energy variable section 2 to obtain the optimum density for the thermal recording paper 11a having the coloring characteristic shown in FIG. The operation when the thermosensitive recording paper 11a disappears in the state of recording and the thermosensitive recording paper 11b is replaced with the thermosensitive recording paper 11b having the coloring characteristic b different from that of the thermosensitive recording paper 11a will be described.

In the density setting mode in which the heat-sensitive recording paper 11a is replaced with the heat-sensitive recording paper 11b, the pattern generated in the pattern generating section 6 is applied while applying the energy Ea to the thermal head 4. When recorded on 11b, the color density of the thermal recording paper 11b becomes about "0.7", and the density sensor 8
The output voltage V ₁ is sent to the energy variable unit 2. The energy variable section 2 uses the voltage V ₁ sent from the density sensor 8 and the optimum color density "1.3" set in the density setting switch 7.
Comparing the voltage V ₀ corresponding to, varying the energy to be output according to the difference of the voltage V ₀ and the voltage V _1. Then, the energy Eb when the voltage V ₁ sent from the density sensor 8 becomes equal to the voltage V ₀ is set as the optimum energy of the exchanged thermosensitive recording paper 11b and sent to the control unit 3 to end the density setting mode.

By performing this density setting every time the thermosensitive recording paper 11 is replaced, as shown in FIG. 7, even if the thermosensitive recording papers 11a to 11n having different coloring characteristics from a to n are used, the thermal head is used. Optimum energy can always be given to the four.

The color development characteristics of the thermal recording paper 11 differ depending on the temperature of the surrounding environment. Therefore, as shown in FIG. 8, a temperature characteristic storage unit 12 and a temperature sensor 13 for measuring the temperature inside or outside the apparatus or in the vicinity of the thermal head 4 are provided, and the temperature sensor 13 measures the temperature according to the temperature of the operating environment. -It is preferable to correct the energy applied to the round head 4.

In this case, the temperature-characteristic storage unit 12 stores the characteristics of temperature and energy ratio based on the temperature of 25 ° C. as shown in FIG. 9, for example. In the density setting mode in which the thermosensitive recording paper 11a is replaced with the thermosensitive recording paper 11b, the energy Eb is detected by the density sensor 8 at a temperature of the use environment of 25 ° C.
Is set, and recording is repeated using the thermal recording paper 11b. During this recording, the temperature sensor 13 constantly measures the temperature of the usage environment and sends the measured temperature signal to the energy variable unit 2. The energy variable unit 2 corrects the energy Eb set at the temperature of 25 ° C. based on the sent temperature signal and the temperature-energy ratio characteristic stored in the temperature characteristic storage unit 12.

For example, if the temperature of the operating environment changes to 10 ° C. during repeated recording,
The energy variable unit 2 determines the energy to be sent to the control unit 3 from the signal corresponding to the measured temperature of 10 ° C. and the temperature / energy ratio stored in the temperature characteristic storage unit 12, which is 1.21 of the set energy Eb.
Double.

In this way, the energy applied to the thermal head 4 set in the density setting mode is corrected according to the change in the ambient temperature, so that the thermal recording paper 11 is always recorded with the optimum density. can do.

[0030]

As described above, according to the present invention, the energy applied to the thermal head is varied according to the type of the thermal recording paper, and the energy suitable for each thermal recording paper is applied to the thermal head. Even if the type of thermal recording paper used is different, the optimum color density can always be obtained, and characters and images can be recorded on the thermal recording paper with uniform printing density.

When the energy applied to the thermal head is varied, the print density of the thermal recording paper printed by the thermal head is detected, and the energy applied to the thermal head is set by comparison with the preset print density. By doing so, it is possible to automatically print at the optimum density.

Further, by reading out the energy ratio according to the temperature at the time of recording and correcting the set energy, the optimum energy according to the temperature at the time of recording can be output to the thermal head, which is always optimum. It is possible to record on thermal recording paper at various densities.

Further, when the energy to be applied to the thermal head is set, a constant pattern is output to record on the thermosensitive recording paper, and the energy is set based on the recording, so that the constant reference is always made. Energy can be set.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a second embodiment.

FIG. 3 is a flowchart showing the operation of the second embodiment.

FIG. 4 is a block diagram showing a third embodiment.

FIG. 5 is a layout diagram showing an outline of a third embodiment.

FIG. 6 is a diagram showing the density of the thermal recording paper and the output characteristic of the density sensor.

FIG. 7 is a characteristic diagram of energy and concentration given to the thermal head 4.

FIG. 8 is a block diagram showing a fourth embodiment.

FIG. 9 is a characteristic diagram of temperature and energy ratio.

[Explanation of symbols]

 1 Energy Setting Switch 2 Energy Variable Section 3 Control Section 4 Thermal Head 5 Operation Section 6 Pattern Generation Section 7 Density Selection Switch 8 Density Sensor 11 Thermal Recording Paper 12 Temperature Characteristic Storage Section 13 Temperature Sensor

Claims (4)

[Claims] 1. An energy variable section and an energy setting section, wherein the energy variable section arbitrarily changes energy applied to a thermal head for recording characters and images, and the energy setting section outputs energy output by the energy variable section. A heat-sensitive recording apparatus, characterized by setting. 2. A concentration sensor and an energy variable unit,
The density sensor is provided on the heat-sensitive side of the thermal recording paper downstream of the thermal head, detects the print density of the thermal paper printed by the thermal head, and the energy variable section uses the preset print density and density sensor. A thermal recording apparatus characterized in that the energy applied to the thermal head is varied and output based on the detected print density. 3. A temperature characteristic storage unit and a temperature sensor are provided,
The characteristic of energy ratio to temperature is stored in advance in the temperature characteristic storage unit, the temperature sensor detects the temperature of the thermal head at the time of recording or the temperature inside or near the device, and the energy variable unit records by the temperature sensor. 3. The thermal recording apparatus according to claim 1, wherein the energy ratio stored in the temperature characteristic storage unit is read according to the temperature at the time, and the energy applied to the thermal head is corrected and output according to the read energy ratio. 4. When the energy to be applied to the thermal head is set, a constant pattern is output to record on a thermosensitive recording paper, and the energy is set based on the recording.
The heat-sensitive recording apparatus according to 2 or 3.