JPH10297010A - Thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermal transfer printer employing an ink ribbon in which the image quality is enhanced by preventing wrinkle of ribbon, uneven print, white out, and the like. SOLUTION: The thermal transfer printer performs printing of a print medium on a platen 28 using a thermal print head 46. The thermal transfer printer comprises a temperature sensor 150 for detecting the temperature of the thermal print head 46. Based on a detection signal from the temperature sensor 150 and a data on a printing thermal energy data table 148, the CPU 128 in a control means 44 controls the printing thermal energy being applied to the thermal print head 46 depending on the temperature rise thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer for printing characters used on a signboard or the like on a sheet member.

[0002]

2. Description of the Related Art A cover having a thermal print head disposed on a casing is openably and closably attached, and an ink ribbon cassette is detachably mounted on the cover. When the cover is closed, the thermal print head causes the ink ribbon and the print medium to be removed. From above, press against the platen roller on the casing side,
A thermal transfer printer in which a print medium and an ink ribbon are fed in a predetermined direction in this state so that printing is performed on the print medium is conventionally known.

[0003]

In a thermal print head, the head temperature increases when printing is performed continuously. However, with the same printing thermal energy, there is a problem that as the temperature of the thermal print head increases, wrinkles are generated on the ink ribbon, white spots occur, and printing unevenness occurs, and the image quality deteriorates. . An object of the present invention is to solve the above problems.

[0004]

According to the present invention, a platen roller (28) linked to a rotary drive system is disposed on a casing (2), and printing is performed before and after the platen roller (28). A transport path for feeding the medium in the front-rear direction is provided, and the thermal print head (46) is pressed against the platen roller (28) from above the ink ribbon (114) and the print medium (138). And sending the print medium (138) in a predetermined direction on the conveyance path by rotating a driving roller on the conveyance path, and feeding the ribbon (114) in a predetermined direction, and the platen roller by the thermal print head (46). (2
8) In a thermal transfer printer adapted to print on the print medium (138) above, the thermal print head (4
6) printing on the thermal print head (46) in response to the temperature rise of the thermal print head (46) based on a detection signal of the temperature sensor (150) for detecting the temperature of the temperature sensor (150); Control means for controlling the heat energy to an appropriate value set in advance.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail with reference to embodiments shown in the accompanying drawings. FIG.
In the figure, reference numeral 2 denotes a casing of the thermal transfer printer, in which a paper feed motor 4 (see FIG. 1) is built. A roll paper feed shaft 6 is supported at the lower portion of the casing 2, and a roll paper loading roller 8 is rotatably supported opposite the roll paper feed shaft 6. The roll paper feed shaft 6 has a pair of rollers 12, 14 (having a concave groove for detachably receiving the disk-shaped side plates 10a, 10a of the roll paper holder 10 so that the roll paper holder 10 does not shake laterally. (See FIG. 8).

The above-mentioned concave groove is a concave groove 1 for receiving both side plates 10a, 10a of a holder 10 for a wide large roll paper.
6, 18 and a small roll paper holder 1 with a narrow paper width
A groove 20 for receiving both side plates 10a ', 10a'
22 are provided. 24 and 26 are paper feed rollers,
Reference numeral 28 denotes a platen roller,
And are connected to the paper feed motor 4 respectively. Pressing rollers 32 and 34 movably supported in the direction of contact and separation with respect to the paper feed rollers 24 and 26 are rotatably opposed to each other. Reference numeral 36 denotes an automatic cutter unit for cutting a sheet, and is configured such that a blade (not shown) is driven by an automatic cutter motor 38 built in the casing 2. Reference numeral 40 denotes a paper width sensor that detects whether or not a paper is disposed above. The sensor 4
Numeral 0 is attached to a substrate 30 fixed to the casing 2. A cover 42 is rotatably supported on the casing 2 by a shaft 44.

A thermal print head 46 has a built-in temperature sensor 150 made of a thermistor and a holder 48.
It is fixed to. One of the holders 48 is rotatably supported on a shaft 50 by the cover 42, and is urged clockwise in FIG. 2 by a coil spring 52. The holder 4
A shaft 54 projects from the shaft 8, and a receiving member 56 is slidably fitted on the shaft 54. The receiving member 56 is urged by a coil spring 58 in a projecting direction with the holder 48 as a fulcrum. The receiving member 56 includes the holder 4.
8, elastically contacts the lower surface of an elevating body 64 supported by a guide shaft 60 and a shaft 62 disposed on the cover 42 so as to be able to move up and down by a biasing force in a clockwise direction in FIG. .

Next, with reference to FIG. 9, a description will be given of the elevating mechanism of the thermal print head 46 and the ribbon feeding mechanism. Reference numeral 66 denotes a substrate fixed to the cover 42, on which a head elevating motor 68 comprising a stepping motor is provided.
Has been fixed. The motor 68 is also used as a ribbon feed motor. A shaft 70 is rotatably supported on the substrate 66, and a one-way clutch 76 with two-stage gears 72 and 74 and a torque limiter 80 with a gear 78 are mounted on the shaft 70. The shaft 70 has a two-stage gear 8.
2 and 84 are rotatably supported, and the gear 82 meshes with a gear 86 fixed to the output shaft of the motor 68.

Reference numeral 62 denotes a shaft rotatably supported on the substrate 66. A one-way clutch 92 having two-stage gears 88 and 90 is mounted on the shaft. An eccentric cam 91 is fixed to the shaft 62. . The gear 88 of the one-way clutch 92 meshes with the gear 84, and the gear 90 meshes with the gear 72. A roller 94 (see FIG. 3) is rotatably supported by the elevating body 64. A U-shaped groove is formed on the side and upper part of the elevating body 64, and one groove is slidably fitted to a guide shaft 60 laid on the substrate 66, and the other groove is As shown in FIG.
As shown in FIG. The elevating body 64 is supported by the shaft 62 and the guide shaft 60 so as to be vertically movable.

The receiving member 56 is in elastic contact with the projecting curved bottom surface 64 a of the elevating body 64 by the force of the spring 52. Reference numeral 96 denotes a torque limiter fixed to the substrate 66, and a gear 100 is fixed to an input shaft 98 of the torque limiter.
Reference numeral 102 denotes a gear, which is fixed to a shaft 104 rotatably supported on the substrate 66. A gear 106 is fixed to the shaft 104, and the gear 106 is engaged with the gear 78. Gears 108 and 110 are rotatably supported by the cover 42. The gear 108 meshes with the gear 102, and the gear 110 meshes with the gear 100. A fitting recess is formed in the cover 42 for fitting and holding the ribbon cassette 112 in a detachable manner. In the ribbon cassette 112, a ribbon supply reel 116 around which a color ribbon 114 is wound and a ribbon take-up reel 118 are rotatably housed.
Gears 120 and 122 are connected as shown in FIG.

When the ribbon cassette 112 is mounted in the fitting recess of the cover 42, the ribbon 114 stretched between the reels 116 and 118 is just
6, the gear 120 on the ribbon supply reel 116 meshes with the gear 110 for tension application, and the gear 122 on the take-up reel 118 meshes with the output gear 108. . The thermal print head 46 is connected to a head data control circuit 124 (see FIG. 1) built in the casing 2. The D and C motors 38 for the automatic cutter, the sheet feed stepping motor 4, and the head elevating stepping motor 68 are connected to a motor control circuit 126, respectively.

The head data control circuit 124 and the motor control circuit 126 are respectively connected to a CPU 128 built in the casing 2 and controlled by the CPU. A data input device 142 is connected to the CPU 128 via an interface 130, and character information, color information, and other print information can be input to the CPU 128 from a keyboard of the data input device 142. I have. Casing 2
In addition to the paper width sensor 40, a cutter sensor 132 for detecting the position of the cutter, a head elevation sensor 134 for detecting the elevation position of the thermal print head 46, and the ribbon 1
14, a ribbon sensor 136 for detecting the presence or absence of
A cover open sensor 138 and the like for detecting the open / close position are provided, and these are connected to the CPU 128.
The temperature sensor 150 is also connected to the CPU 128. The force of pushing up the receiving member 56 of the coil spring 58 is set stronger than the force of pulling up the holder 48 of the coil spring 52.

The CPU 128, the head data control circuit 124, and the motor control circuit 126 constitute control means 144 for controlling the thermal transfer printer. The storage device (memory) 146 of the control means 144 stores a print thermal energy data table 148 which defines print thermal energy data (parameters) corresponding to each of a plurality of temperature levels of the thermal print head 46. ing. In the data table 148, for example, between 13 degrees C and 15 degrees C, the first line of printing is 160 (μJ), and the second and subsequent lines are 110 (μJ).
J) Between 15 ° C. and 17 ° C., the printing thermal energy suitable for the temperature of the thermal printing head 46, such as 160 (μJ) for the first line of the printing and 105 (μJ) for the second and subsequent lines. Parameters are set. still,
The optimum value of the data of the printing thermal energy is set by an experiment. In this case, the optimum value may be set in consideration of the paper width, the color of the ink ribbon, and other factors.

Next, the operation of the present embodiment will be described.
When the new ribbon cassette 112 is mounted on the cover 42, as shown in FIG. 5, the cover 42 is swung about the shaft 44 in a counterclockwise direction until it is locked by the stopper at a predetermined angular position. The cover 42 is set substantially upright.
In this state, remove the old ribbon cassette from the cover 42,
A new ribbon cassette 112 is fitted and mounted in the inner fitting concave portion of the cover 42. At this time, the ribbon 114 disposed between the reels 116 and 118 of the ribbon cassette 112
The thermal print head 46 is arranged to face the printing surface. Further, the respective gears 120 and 122 of the ribbon cassette 112 are
As shown in FIG. 6, the gears mesh with the corresponding gears 110 and 108.

Next, the cover 42 is swung clockwise about a shaft 44 in FIG.
Is locked to the casing 2. When the power switch is turned on, an initial operation (initial setting operation) is performed, the thermal print head 46 is set in a state of being raised with respect to the platen roller 28, and the leading end 138a of the roll paper 138 is moved to the position shown in FIG. As shown in (1), it is set at a predetermined position before the platen roller 28. On the other hand, when the power switch is turned on, the CPU 128
Roll paper 138
Is determined whether the paper width of the standard type (large) or the narrow type. Further, the control means 144 selects a value of power thermal energy, that is, a value of print thermal energy according to the paper width and the temperature of the head 46 from preset values based on the signal of the sensor 152. In the present embodiment, the roll paper 13
Reference numeral 8 denotes a configuration in which two types of the standard type and the narrow paper type can be used. However, the present invention is not particularly limited to the two types, but may be various types, and a paper width sensor may be prepared accordingly. You may do it.

In the monochromatic printing, when the printing operation is started, the leading end of the roll paper 138 is located at the discharge port 1 from the position where the platen roller 28 and the thermal print head 46 are pressed against each other.
The paper feed motor 4 is rotated forward to the position where the roll paper 138 is moved to the side of the roll paper 138, and the roll paper 138 is conveyed. Next, the motor 68 for raising and lowering the head is rotated in the reverse direction, and the thermal print head 46 is lowered to bring the thermal print head 46 into pressure contact with the platen roller 28. Next, the paper feed motor 4 is rotated forward.

As a result, the platen roller 28 and the feed rollers 24 and 26 rotate in a predetermined direction, and the roll paper 1
38 is conveyed leftward in FIG. On the other hand, print data is supplied to the thermal print head 46 from the head data control circuit 124 together with print thermal energy suitable for the temperature of the head 46 and the paper width, and the print data is thermally transferred to the roll paper 138 on the platen roller 28. The temperature of the head 46 is monitored at predetermined time intervals by the control means 144, and the printing thermal energy supplied to the head 46 changes each time the temperature of the head 46 changes. During the paper conveyance, the pressure rollers 32 and 34 come into pressure contact with the feed rollers 24 and 26, and follow the rotation of the rollers 24 and 26. On the other hand, during printing, the motor 68 is driven, and the driving force of the motor 68 is changed to the gears 86, 82, 8
4, 88, 90, 72 and the one-way clutch 76 are transmitted to the shaft 70, and the shaft 70 rotates.

At this time, the gears 88 and 90 idle and the shaft 6
2 holds a stationary state. The rotation of the shaft 70 is transmitted to the gear 78 via the torque limiter 80, and the rotation of the gear 78 is transmitted to the gear 106, the shaft 104, the gear 102, and the output gear 1.
08, and transmitted to the take-up reel 118 of the ribbon cassette 112 via the gear 122. As a result, the take-up reel 118 rotates in the ribbon take-up direction. At this time, the supply reel 116 has the gears 120, 110, 10
After zero, the static torque of the torque limiter 96 acts, and the ribbon 114 is wound on the take-up reel 118, while the ribbon 114 is given an appropriate tension.

When printing on the roll paper 138 is one-color printing, when printing of a predetermined length is completed, supply of print data to the thermal print head 46 is stopped, and driving of the paper feed motor 4 and the head elevating motor 68 is stopped. Stop. Next, the head elevating motor 68 rotates in the reverse direction, and the thermal print head 46 ascends from the platen roller 28. Next, the paper driving motor 4 rotates forward, and the roll paper 138 is transported to the cutting position. Next, the auto cutter motor 38 is driven, the roll paper 138 is cut by the auto cutter unit 36, and the printed portion of the roll paper 138 is cut off.

Next, the paper driving motor 4 rotates in the reverse direction,
The leading end 138a of the paper 138 returns to the initial position shown in FIG. When printing on the roll paper 138 is multi-color printing, when printing of one color is completed, supply of print data to the thermal print head 46 is stopped, and driving of the paper feed motor 4 and the head elevating motor 68 is stopped. Next, the CPU 128 supplies a reverse rotation signal to the motor control circuit 126 to drive the head elevating motor 68 to rotate in the reverse direction.

The reverse rotation of the motor 68 causes the gear 86 to rotate in the reverse direction, and the rotation of the gear 86 is transmitted to the shaft 62 via the gear 82, the gear 84, the gear 88, and the one-way clutch 92. At this time, the rotation of the gear 90 is not transmitted to the shaft 70 by the one-way clutch 76, and the shaft 70 maintains the stopped state. When the shaft 62 rotates, the eccentric cam 92 rotates, and the eccentric enlarged portion of the cam 91 comes off the roller 94. As a result, the pressing force of the eccentric cam 91 on the elevating body 64 against the elevating body 64 is released, and the elevating body 64 and the thermal print head 46 are raised by the tensile force of the coil spring 52,
The thermal print head 46 is separated from the platen roller 28 by a predetermined distance upward as shown in FIG. CPU1
When the head elevating sensor 134 detects that the thermal print head 46 has risen to a predetermined position, the driving of the head elevating motor 68 is stopped. Next, the CPU 128 drives the paper feed motor 4 in the reverse rotation direction to return the leading end 138a of the roll paper 138 fed by the printing operation of the first color to the initial position.

Next, the operator manually releases the lock of the cover 42 to the casing 2 and swings the cover 42 in the upright direction as shown in FIG. After replacing the ribbon cassette, the cover 42 is closed horizontally again as shown in FIG. When the CPU 128 confirms that the cover 42 has been closed by the cover open sensor 138, the CPU 128 drives the head lifting / lowering motor 68 in the reverse rotation direction to rotate the eccentric cam 91, and moves the eccentric enlarged portion onto the roller 94. The shaft 54 is pressed down so that the print surface of the thermal print head 46 is
The plate 38 comes into pressure contact with the platen roller 28. next,
The CPU 128 resumes the printing operation, drives the paper feed motor 4 and the head elevating motor 68 in the forward rotation direction again to feed the roll paper 138 and the ribbon 114 in a predetermined direction, and print information is loaded on the thermal print head 46. , The appropriate printing thermal energy corresponding to the width of the paper width and the temperature of the thermal printing head 46 to send the roll paper 13
In step 8, the second color is printed. When all the printing is completed, the CPU 128 performs the cutting process of the roll paper 138 as described above. When cutting is completed,
The roll paper 138 is returned to the initial position. In the present embodiment, roll paper is used as a printing medium, but a sheet member made of a vinyl chloride adhesive sheet, a plastic sheet, or any other material can be used.

[0023]

According to the present invention, as described above, the thermal width of the thermal print head is detected by the sensor, and printing thermal energy suitable for the temperature of the thermal print head is supplied to the thermal print head. This has the effect of preventing generation, printing unevenness, white spots and the like, and improving image quality.

[Brief description of the drawings]

FIG. 1 is an electronic block circuit diagram of a thermal transfer printer.

FIG. 2 is a sectional view of the thermal transfer printer.

FIG. 3 is a sectional view of the thermal transfer printer.

FIG. 4 is a sectional view of a thermal head print elevating mechanism.

FIG. 5 is a sectional view of the thermal transfer printer with a cover opened.

FIG. 6 is a side view of the thermal transfer printer with a cover opened.

FIG. 7 is a plan view of the thermal transfer printer with a cover opened.

FIG. 8 is a rear view of the thermal transfer printer.

FIG. 9 is a plan view of a ribbon feed mechanism and a thermal print head elevating mechanism.

FIG. 10 is a side view of the ribbon cassette.

[Explanation of symbols]

 Reference Signs List 2 casing 4 paper feed motor 6 roll paper feed shaft 8 roll paper placement roller 10 roll paper holder 12 roller 14 roller 16 concave groove 18 concave groove 20 concave groove 22 concave groove 24 paper feed roller 26 paper feed roller 28 platen roller 30 substrate 32 pressure Roller 34 Pressure roller 36 Auto cutter unit 38 Auto cutter motor 40 Paper width sensor 42 Cover 44 Axis 46 Thermal print head 48 Holder 50 Axis 52 Coil spring 54 Axis 56 Receiving member 58 Coil spring 60 Guide axis 62 Axis 64 Elevating body 66 Substrate 68 Head elevating motor 70 shaft 72 gear 74 gear 76 one-way clutch 78 gear 80 torque limiter 82 gear 84 gear 86 gear 88 gear 90 gear 91 eccentric cam 92 one-way clutch 94 low 96 torque limiter 98 input shaft 100 gear 102 gear 104 shaft 106 gear 108 output gear 110 output gear 112 ribbon cassette 114 color ribbon 116 ribbon supply reel 118 ribbon take-up reel 120 gear 122 gear 138 roll paper 138a roll section 140 discharge port 142 input Machine 144 control means 146 storage device 148 data table 150 temperature sensor

Claims (1)

[Claims] A platen roller (28) linked to a rotary drive system is disposed on a casing (2), and a conveyance path for feeding a print medium in the front-rear direction is provided before and after the platen roller (28), and thermal printing is performed. The head (46) is pressed against the platen roller (28) from above the ink ribbon (114) and the print medium (138), and the print medium (138) is rotated by rotation of the platen roller (28) and a drive roller on the transport path. ) Is sent in a predetermined direction on the transport path, and the ribbon (114) is sent in a predetermined direction, and the platen roller (2) is moved by the thermal print head (46).
8) In a thermal transfer printer adapted to print on the print medium (138) above, the thermal print head (4
6) printing on the thermal print head (46) in response to the temperature rise of the thermal print head (46) based on a detection signal of the temperature sensor (150) for detecting the temperature of the temperature sensor (150); A thermal transfer printer provided with control means for controlling thermal energy to an appropriate value set in advance.