JPS58212969A - Thermal recording device - Google Patents

Abstract

PURPOSE:To obtain a thermal recording device, which is provided with a detecting means that judges the kinds of recording mediums and a means that can switch electric power to be applied to a recording head, and which can automatically perform heating with an optimum calorific value even in heat sensitive recording wherein heat sensitive paper is used and in thermal transfer recording wherein ink ribbon is used. CONSTITUTION:For example, a reflecting type photosensor 27 is provided on the paper path on the upstream side of a platen roller 12. A photosensor 28 is provided over ink film 11. When the photosensor detects the presence of the paper, a microcomputer CPU operates the photosensor 28. When the fact that ordinary paper and the ink film 11 are loaded in this device is detected by the level of reflected light, the CPU selects an electric power supplying signal to a heating body at a high level signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal recording device, and particularly to a thermal recording device that generates heat depending on recorded data. 1 [! Thermal transfer recording involves applying heat to an ink film using a recording head and transferring the molten ink from the ink film to a recording medium overlaid on the ink film.
The present invention relates to a thermal recording apparatus that performs both thermal recording using thermal recording paper that causes thermal changes.

Although various T5 green methods have been proposed for facsimile machines, printers, etc., the thermal recording method is comparatively more commonly adopted because it is easy to downsize and provides high reliability. However, thermal recording has a drawback in terms of preservation. In thermal recording, there is a known technology in which optical fixing is used to fix heat-sensitive recording paper in order to improve the storage stability of records, but at the current stage, sufficient recording quality cannot yet be obtained with this technology. The problem is that there is no.

Recently, thermal transfer recording has been proposed as a recording method that solves the above-mentioned difficulties. Thermal transfer recording uses an ink film impregnated with ink that melts with heat, and a current is passed through the thermal head according to the recording data to melt the ink at the position in contact with the thermal head while scanning the thermal head and/or the recording paper. This is a recording method in which molten ink is thermally transferred to a predetermined position on recording paper.

By the way, the thermal transfer recording method and the thermal recording method differ in principle only in the recording medium, so for example, if a recording medium equipped with an ink film is installed in a conventional thermal recording method recording device, the thermal transfer recording method can be used with the same configuration. It can be changed to a recording device. Therefore, if the user were to be able to select the recording medium according to the purpose, it would be possible to use thermal transfer recording when storage stability is an issue, and thermal recording during normal recording. The degree of freedom in using the device is increased.

However, in reality, as shown in FIG. 1, the relationship between the electric power applied to the thermal head and the recording density differs depending on the recording medium, and in particular, it differs greatly between thermal recording paper and thermal transfer paper. For example, if the power applied to the thermal head per minimum recording unit (dot) is 1.2 W, and if an ink film with a thickness of 12 μm capacitor paper as the base material and plain paper are used as the recording medium, the first
As shown in the figure, a maximum recording density of 1.0 can be obtained, but when thermal paper is used as a recording medium, a recording density of only 0.5 can be obtained as shown in FIG.

When using these two types of recording media, if the power applied to the thermal head is 1.6W per dot, 2
A recording density of 1.0 is obtained for both kinds of recording media. However, in that case, unnecessary power is consumed during thermal transfer recording using an ink filler whose base material is 12μ thick capacitor paper and plain paper as a recording medium, and the applied power is 1°2W. The recording quality will be lower than in the previous case. In this type of recording, it is preferable to apply the minimum necessary power to the recording head.

The first object of the present invention is to provide a thermal recording device capable of performing both thermal recording and thermal transfer recording, and the second object is to provide a thermal recording device capable of performing both thermal recording and thermal transfer recording. and (2) to provide a thermal recording device that provides high recording quality.

In order to achieve the L month (1) goal, the present invention includes a +1f function that switches the power applied to the thermal head between two or more types, and includes a detection means for determining the type of recording medium.
The electric power applied to the thermal head is switched automatically according to the detection data of the detection means f or according to a switch operation by a person. As a result, if the preferred power according to the types of recording media to be used is set in the driving means of the rth thermal head, the optimal power will be set automatically by the recording medium detection means or in response to a switch operation. The thermal head is driven by the applied power and good recording can be performed.

In one preferred embodiment of the invention, a reflective optical sensor is used as the detection means. In thermal transfer recording, the ink layer or ink filler provided on the recording medium is black, so the reflectance of light on that surface is low; Since the accuracy is high, an optical sensor is used to determine the type of paper in both cases.

Hereinafter, the present invention will be described in detail with reference to the drawings. 2nd a
The figure shows a mechanical part of a recording apparatus according to an embodiment. This will be explained with reference to FIG. The second embodiment is configured as a type of facsimile recording device. The recording paper is regular paper and is stacked in the hopper IO. 11 is an ink film 11, and this ink film 11 passes between the thermal navel F1 and the platen roller 12,
It is wound around a feed roll 13 and a take-up roll 14.

The ink film 11 used in 22 has a thickness of I2.
The base material is μ capacitor paper, and the surface is coated with ink that melts with heat.

The thermal head 1 has 216 recording blocks arranged in the width direction, that is, in the direction perpendicular to the plane of the drawing, so that recording can be performed without mechanical scanning in the width direction of the recording medium. Each recording block has eight heating elements arranged in the scanning direction of the recording paper. In other words, the thermal head 1 has a total of 1728 heating elements. The thermal head 1 is fixed. The platen roller 12 is rotatably supported by a support member 15.

The support member 15 is rotatable about the point "■" as a fulcrum.
(cage, - tension coil spring 1 with fixed end
6, is coupled to the plunger 17a of the electromagnetic actuator 17. The electromagnetic actuator 17 has a solenoid inside, and the force generated by the solenoid is used to pull the plunger 17a. 18 is a stopper that restricts the movement range of the support member 15. The platen roller 12 is equipped with a pulley, and a stepping motor 19 is connected to the pulley.
A timing belt 2o connected to the timing belt 2o is wound around the timing belt 2o.

Reference numeral 21 denotes a paper feed roller, which is connected to a drive source via an electric clutch. 22 is a registration roller. The ink film 11 is sandwiched between two rotatable rollers 23 and 24 in front of the thermal head l. roller 2
3 is in contact with a pad 25, and a tension coil spring 26 is coupled to the support member of the pad 25.

The magnitude of the force of the second spring 26 is such that it gives the roller 23 a force greater than the braking force required to separate the paper and the ink film 11 when the ink is transferred to the paper and the paper and the ink film 11 are in close contact. It is set so that it is wet.

A reflective photosensor 27 for detecting paper is provided in the paper path of the -1- flow of the platen roller 12, and a photosensor 28 is provided above the ink film 11. 2
9 and 3o are conveyance rollers, and timing bells 1 to 31 connected to a stepping motor 19 are coupled to the conveyance port □-ra 3o. 32 is a paper guide, and 33 is a paper discharge tray.

FIG. 2b shows the electrical circuitry of the recording device of FIG. 2a. This will be explained with reference to FIG. 2b. In this embodiment, a single-chip microcomputer 8048 manufactured by Intel Corporation is used as the control means. This microcomputer C
The PU is connected to the facsimile system bus via ports DBO to []B7, and receives and receives data to be recorded via these ports. The aforementioned reflective photosensors 27 and 28 are connected to the test input ports I-'I''0 and 1 of the CPU, respectively.The photosensors 27 and 28 are light-emitting diodes and photo-sensors. A driving circuit MDVI for driving the solenoid S1.1 of the paper feed clutch is connected to the CPU output jiff-l□P20, and an electromagnetic actuator is connected to the output capo-1-P2. The microcomputer CP LJ and the thermal bed 1 drive circuit i-IO are connected to the drive circuit D2 which drives the solenoid SL2 of CPTJ.
P10~P]7. P22. P23. P24 and l)
Connected via 27U. Recorded data i.e. 8
Bit pixel data is output from ports PIO to P17. A motor drive circuit MD that drives the stepping motor 19 is connected to output ports P25 and P26 of the CPU.

The thermal head drive circuit HD shown in Fig. 2))
and details of the thermal head 1 are shown. This will be explained with reference to FIG. The thermal head I is equipped with 1728 heating elements R1 to R1728. The heating elements R1 to R1728 are arranged in groups of 8, and those in corresponding positions of the groups are commonly connected at one end and connected to the image signal driver 2, and at the other end, each group is connected to the common driver 3. and
Image signals for one line are applied to the image signal driver 2 in groups of eight, and the image signals applied to the image signal driver 2 are
Each time the heating elements of the next group are changed to the next group, the common driver 3 connects the heating elements of the next group to a predetermined power supply line. Image signals of group divisions (8 pixels) are input from port PIO-P17 of the microcomputer CPU. The common driver 3 includes AND gates A1 to A21.
6, a signal corresponding to "groove" is applied. anime game 1
- The group selection circuit 6 and the heat generation energy control circuit 7 are connected to A1-A216. Group selection circuit 6
A recording command pulse that notifies the start of recording one line, and a clock pulse that is emitted every time the image signal of the group is set to ports PIO to []I1 are applied to the , and the group is selected in synchronization with the arrival of the tarok pulse. Face '116
sequentially outputs ON energizing signals to AND gates A216 to Δl.

In the heating egg lugie control circuit s7, two mono-multivibrators 7c and 7d with different set times are provided, and 7c and 7d are vibrated by 1 every time a clock pulse is applied. Mono multivibrators 7c and 7d are activated according to the applied power selection signal output from the CPU.
One of the outputs is selected, and its output pulse is applied to AND gates A1 to A216. In other words, depending on the applied power selection signal, the mono multivibrator 7c or 7
Since a pulse signal with a time width set to d is applied to the AND gates A1 to A216 every time a clock pulse arrives, the unit recording time (
The power per dot is set according to the applied power selection signal. Output end of mono multivibrator 7G and 7d. At the falling edge of the signal, that is, when the recording activation for one block is completed, the output end of the gate 7h becomes high level II, and a transfer request for the next recording take is issued.

Figure 4 shows motor drive times 1 in Figure 21)! jl M l)
9 details at I are shown. This will be explained with reference to FIG.

In this embodiment, a universal controller IC, PMM8713 manufactured by Sanyo Denki, is used in the phase excitation distribution circuit. Then, pull up pins 5.6 and 7 of the PMM8713 to H to select the 1-2 phase excitation mode for the 4-phase motor. Output ends Φl, Φ2. Φ3 and Φ
4 are connected to power amplifiers AI, A2 .
A3 and A4 are connected to the power amplifier Al-A4.
The output ends (collectors) of the stepping motor 19 have excitation coils 19a, 19b, 19c and 19d, respectively.
Connect it to one end. The other ends of the excitation coils I9a to +9d are connected to each other and connected to a transistor T via a resistor R.
It is connected to the collector of r l. The resistance value of resistor R is
:l/J of DC resistance r of 8 excitation coils 19a''-19d
It is set to 1x.

The MCI4538 is a monomulti I (2) made by MoI Roller, and its input end (bin 5) is the PMM871 (
:υ (input pulse monitor), and the output terminal is connected to Tri via the transistor ']' r2. The emitter terminal of T'rl is connected to the DC constant voltage for driving the motor → -Vd. is applied to the collector end of Trl, and a DC constant voltage element V h (V
d > V l+ ) 'l is applied. Direction indication signal CW/CCW sent by CPU is CW (hour d1 direction)
When a temp pulse is applied to the Ck terminal of the PMM8713, the excitation phases Φ1 to Φ4 sequentially become the excitation level (TI), and the transistors of the amplifiers Δ1 to Δ4 are turned on accordingly. On the other hand, when the stamp pulse is manually applied, PMM8713 outputs a pulse signal to the CO terminal,
As a result, a pulse signal of a predetermined width appears at the output end of the MC14538. The pulse signal turns on the transistors Tr2 and Trl for a predetermined time, and current flows through the resistor R to the excitation coils 19a to 19d connected to the one of the amplifiers A1 to A4 that is turned on.

FIG. 5a shows a schematic operation timing of the device shown in FIG. 2a, and FIG. 5b shows the microcomputer CP shown in FIG. 2b.
The operation of U is shown. The operation of the device will now be described with reference also to Figures 5a and 5b.

The microcomputer CPU first sets the port P20 to a high level H, energizes the solenoids Sl and I of the paper feed clutch, and drives the paper feed roller 21. The paper in the hopper 10 is now fed out, and the fed paper is sent to the registration roller 22.
is conveyed to the platen row 512 side via. When the photosensor 27 detects paper, the CPIJ then reads the entire length of 1 m from the photosensor 28. In the state shown in Figure 1,
Since plain paper and ink film 11 are installed in the apparatus, the output level of the first sensor 28 for detecting reflected light is high.

When the output level of the photosensor 28 is H, the CPU sets the applied power selection signal to a high level H.

In other words, the time width for energizing the thermal head 1 during the period in which the mono-multivibrator 7d is selected and one dot is recorded is 8T2. In the second embodiment, Δ゛J゛2 is
In the case of thermal transfer recording, this is set to the time required to apply the minimum necessary power to the thermal head 1 to obtain a recording density of 1 minute. On the other hand, when thermal recording paper, which undergoes a chemical change due to heat, is used as a recording medium, since the thermal recording paper is white, the reflected light is strong, and the first sensor 28
output level becomes low. When the output level of the photosensor 28 is low, the CPU sets the applied power selection signal to low level L, selects the mono multivibrator 7c, and sets the thermal head's A4 period per recording dot to ΔT1. Set. ΔTl is set to the time required to apply the minimum necessary power to the thermal head l to obtain a sufficient recording density when thermal recording paper is used.

The CPU detects paper after the photo sensor 27 detects the paper.

The program counts the time and waits until the time T required for the paper to advance to a predetermined position has elapsed.

When the paper reaches the predetermined position, the CPU outputs high level I to port P21, and solenoid S1. ．． 2 to press the platen roller 12 against the paper and bring the paper, ink film 11 and thermal head l into close contact. Next, driving of the motor 19 is started, and thereafter, the CPU'U outputs step pulses to the motor drive circuit 8MD at predetermined intervals.

The stepping motor 19 now rotates at a predetermined speed, and the platen roller 12 and conveyance roller 30 are driven at the same circumferential speed via the timing healds 20 and 31. Turn off the paper feed clutch solenoid SLI to stop the paper feed roller.

Next, the recording command signal is output with the Nippo IP 22 set to a high level I. This sets the flip-flop of the group selection circuit 6. Here, it is checked whether there is pixel data to be recorded in the next recording line. If the next recording line is a line with no recording data, such as margins between lines of text, CP T, J are ball l-P.
21, the platen roller 12 is retracted, and it waits until a line with recording data is reached. When the platen roller 12 retreats, the paper is drawn and fed by the conveyance rollers 29 and 30, but the ink film 11 is
Since tension is applied at and 25, the ink film 11 and the paper are separated and only the paper is conveyed. In other words, the ink film 11 does not move on lines where printing is not performed.

When there is recording data, the CPU outputs clock pulses to the thermal head drive circuits IB II +-, +. As a result, the counter for the group selection time g6 counts up, and a predetermined group of the common driver 3 is selected. This clock pulse also triggers the 1,000' multivibrators 7c and 7d, turning on a predetermined common driver while the pulse of the selected one of these is being output. Here C110 bow 1-P]
Since the pixel data output when there was a previous data transfer request is sent to O to P17, the heat generating element selected according to the pixel data of the heat generating elm mezotogel loop selected by the common driver. A predetermined current flows through. When the set time of the selected mono-multivibrator has elapsed and its output level becomes L, a request to transfer the next pixel data is issued. When this transfer request is made, the CP
U sets pixel data to be recorded next in boats PIO to P17. Since the flip-flop of the group selection circuit 6 is reset each time recording of each line is completed, if the next recording line exists, a recording command is output every time recording of each line is completed. When all recording has been completed, the platen 12 is retracted, the stepping motor 19 is turned on, and the stepping motor 19
Stops driving.

In the above embodiments, the case where regular-sized recording paper was used was described, but roll paper may also be used in the same manner. If roll paper is used, the first sensor 27 shown in FIG. 2a is not necessary, and recording positioning may be determined by, for example, the number of step pulses that drive the stepping motor.

In the embodiment described above, the type of paper is detected by a photo sensor and the power to be applied to the thermal head is automatically set, but this power setting is set according to a switch operation by a person. You can do it like this. This will be explained in the example manufacturing method in that case.

FIG. 6a shows the electrical circuit of the embodiment. To explain with reference to FIG. 6a, in the second embodiment, due to the restriction on the number of ports of the microcomputer CPU, the pixel data is encoded into 3-bit data.
-1) Output from 20 to P22, and a decoder r) 1! on the input side of the thermal head drive circuit HD. : is provided to decode 3-bit data into 8 pixel data. SWI and SW2 are switches for selecting the thermal transfer recording mode and the thermal recording mode. Switches SWl and SW2 are connected to the R-S blip flop F,
The output end of FF is connected to the input port I)23 of CI)IJ. A speaker SP is connected to the output capo-1-P24 of O1'U via an amplifier AM■.
A pulse signal is generated by the programmer at port P24, and sound is generated from the speaker SP. The rest of the configuration is the same as the previous embodiment.

FIG. 6b shows the operation of the microcomputer shown in FIG. 6a. This will be explained with reference to FIG. 6b. FoI sensor 28
The processing up to reading the detection state of j is the same as in the previous embodiment.

When the photo sensor 28 detects black, that is, an ink filler or an ink layer, if the output end Q of the flip-flop FF is set to a high level H by operating the switch sw1 in advance (thermal transfer recording mode), the above-mentioned As in the embodiment, the applied power selection signal is set to a high level H, and the power application time per dot of the thermal head is set to 8T1. Switch SW due to operator error etc.
2 is operated and the output terminal Q of the flip-flop FF is set to a low level I- (thermal recording mode), a pulse is output to ports 1-P24 for a predetermined period of time, a buzzer sounds, and the operator is informed of the mode. Informs you that the settings are incorrect. Then, the applied power selection signal is set to a low level (-), and the power application time per dot of the thermal head is set to 8T2.

When the photo sensor 28 detects white paper, that is, thermal paper, if the thermal recording mode is set, the applied power selection signal is set to low level L, the power application time period Δ'I'2 is set, and the thermal transfer recording is started. If the mode is set, a buzzer sounds for a predetermined period of time to inform the operator of the error in mode setting, the applied power selection signal is set to I■, and the power application time is set to ΔT1. The subsequent processing is the same as in the previous embodiment.

In the embodiment described in 1-1 below, the time for applying the electrical energy to the thermal head per recording dot was set to 8T1 or 8T2 in accordance with the applied force selection signal. The change may be made by changing the magnitude of the current flowing through the thermal head or the magnitude of the voltage applied to the thermal head.

FIG. 7 shows the components used to change the magnitude of the current flowing through the thermal head. In this embodiment, each transistor of the image signal driver 2 is controlled so that the current flowing through each transistor becomes a predetermined value. In other words, each current is detected by the resistors Ra to Rh connected to the emitters of each transistor, and the voltage corresponding to the current is fed back to the operational amplifiers OPa to OPh, and this voltage becomes the output voltage of the D/A converter. It is controlled to be the same. Note that each resistor Ra
The resistance values of R'h are all equal. In the case of the second embodiment, the power applied to the thermal head can be arbitrarily set using digital data set in the D/A converter, so when using various types of recording media, the power applied to the thermal head can be set as desired for each recording medium. Therefore, the optimum power applied to the thermal head can be set.

FIG. 8 shows the constituent elements when changing the voltage applied to the thermal head. In this embodiment, the common driver 3 has a
Two transistors each are provided, and the AND gates driving them are three-manufactured ant gates, and either the AND gate gate loop Gl or 62 is selected by the applied power selection signal, and one group of transistors T a 1 , T
b The voltage +Vl applied to the collector of 1...,
Another group of transistors T a 2 , T
One of the voltage elements v2 applied to the collectors of b2... is applied to the heat generating element. For example, when the applied power selection signal becomes a low level L, ant game 1 of group G1 is selected, and among them, group selection time M! The gate selected by I6 outputs a high level H for a period of time Δ'F set for the mono multivibrator after the clock pulse is applied, and the gate 1.
The transistor connected to the output of is turned on, and voltage element V1 is applied to the heating element. Further, when the applied power selection signal becomes high level H, the AND gate of group G2 is selected, and the gate selected by the group selection circuit 6 of that group is
It is turned on for a period of 1', the transistor connected to its gate is turned on, and voltage element 2 is applied to the heating element.

According to the present invention, Jj? In both A recording and thermal transfer recording, optimum recording density and recording quality can be obtained with the minimum necessary power consumption.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the power applied per unit time to the thermal head and the degree of recording &A'a for various recording media, and FIG. 2a is a side view showing the mechanical part of a facsimile recording device embodying the present invention. Figure 2b is a block diagram showing the electric circuit of the device in Figure 2a, Figure 3 is a block diagram showing the thermal head Flψ motion circuit and thermal head in Figure 2b, and Figure 4 is a block diagram showing the motor drive circuit in Figure 2b. Figure 5a is a timing chart showing the general operation of the device shown in Figure 2a, and Figure 5b is a block diagram showing the 21st motor.
) is a flowchart showing the operation of the microcomputer shown in FIG. FIG. 6a is a block diagram of an electric circuit showing another embodiment, and FIG. 6b is a flowchart 1 showing the operation of the microcomputer shown in FIG. 6a. FIGS. 7 and 8 are block diagrams of electric circuits showing other embodiments, respectively. l: Thermal head 2: Image signal driver 3: Common driver 6: Group selection circuit 7: 9! Thermal energy control circuit IO = hopper ll: Ink film 12 nib' Latin roller 13: Feeding roll 14: Winding roll 15: Support portion 16.26: Spring 17: vh1 Magnetic 7:
/Tuator 18 Varnish 1-Brim 19 Varnish chipping dryer (driving means) 20.3]: Timing helmet 21: Paper feed roller 22 Ni registration roller 23.2
4: Roller 25: Pad 27. 28: First sensor 29: Conveyance roller CIJ U: Microcomputer (control means) 11
+1: Thermal head drive means (recording head drive means) Patent applicant Ricoh Co., Ltd.

Claims (6)

[Claims] (1) Recording head t that is activated to generate heat according to recording data
4. In a thermal energy recording device that increases in temperature, there is a detecting means for determining the type of recording medium; a recording head driving means for switching the electric power applied to the recording head between at least two types of power; and a switch operation or a signal output from the detecting means. A thermal recording apparatus comprising: a control means for supplying drive power to a recording head drive means in accordance with the above. (2) The thermal recording device according to claim (1), wherein the detection means is an optical sensor that detects reflected light. (3) The thermal recording device according to claim (I), wherein the control means includes an alarm generation means that issues an alarm when the signal output from the detection means does not match the switch operation. (4) The thermal recording apparatus according to claim 1, wherein the recording head driving means includes a switching element that switches the voltage applied to the recording head. (5) The thermal recording device according to claim 1, wherein the recording head driving means includes a switching element that switches the current applied to the recording head. (6) The thermal recording device according to item (1) of the patent application, wherein the recording head driving means includes a switching means for switching the application time of electric energy applied to the recording head per unit energizing time.