JP2009051154A - Heat transfer printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transfer printing device which facilitates control by software and makes it possible to improve a flexibility in device design. <P>SOLUTION: The heat transfer printing device 1 comprises a conveying path 8 which conveys an ink ribbon 3 for heat transfer printing on which inks with different colors are applied so that the arrangement of a predetermined color may be repeated and a print medium (a card 2), and a thermal head 4 which presses the ink ribbon 3 to the print medium to perform heat transfer printing. The device comprises at least two or more sensors 51 and 52 which identify the colors of the inks by irradiating the ink ribbon 3 with light. The colors of the inks are identified by changing the sensitivity of each sensor and comparing a predetermined threshold value Vth with the output of each sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal transfer printing apparatus having an ink ribbon for thermal transfer printing, and more particularly to a color identification technique for the ink ribbon.

  In a general thermal printer, an ink ribbon for thermal transfer printing is unwound by an ink ribbon roll or the like. And the to-be-printed material conveyed in the same direction as this ink ribbon is piled up, and the ink of the ink ribbon is selectively transferred to the to-be-printed material by the thermal head.

  Some ink ribbons are coated with different colors of ink in a certain order along the transport direction. For example, inks of yellow, magenta, cyan, etc. are repeatedly arranged along the transport direction. As a technique for detecting the color of the ink ribbon, for example, there is a technique disclosed in Patent Document 1.

  Each color detection device of the color ink ribbon for thermal transfer disclosed in Patent Document 1 is a transmission visible sensor (transmission light sensor) and a reflection infrared sensor (reflection light sensor) in order to detect the leading position of each color of the ink ribbon. Is disposed opposite to the ink ribbon. Then, the transmitted light and reflected light are detected, and the start position of each color is detected by detecting the passage of a predetermined time from the detection of a predetermined position of a specific color by a timer.

JP 2000-255150 A (paragraph number [0009])

  However, when both the transmitted light sensor and the reflected light sensor are used as in Patent Document 1, certain restrictions are imposed on the sensor arrangement, and the degree of freedom in device design may be impaired. Further, when color detection is performed using a timer, the timing control of the two sensors becomes complicated, which may hinder the simplification of software incorporated in the apparatus.

  The present invention has been made in view of the above points, and an object thereof is to provide a thermal transfer printing apparatus that can be easily controlled by software and can improve the degree of freedom of apparatus design. .

  In order to solve the above problems, the present invention provides the following.

  (1) A transport path for transporting a thermal transfer printing ink ribbon and a printing medium on which different color inks are applied so as to repeat a predetermined color arrangement, and pressing the ink ribbon against the printing medium And a thermal head that performs thermal transfer printing, and includes at least two or more sensors that identify the color of the ink by irradiating the ink ribbon with light, and the sensitivity of each of the sensors And the color of the ink is identified by comparing a predetermined threshold value with the output of each sensor.

  According to the present invention, at least two or more sensors for identifying the color of ink are provided in a thermal transfer printing apparatus having a transport path for transporting an ink ribbon and a printing medium and a thermal head, and the sensitivity of each sensor. Since the ink color is identified by comparing the predetermined threshold value with the output of each sensor, the comparison process is central in color identification by software.

  Therefore, timing control as described in Patent Document 1 described above is unnecessary, and control by software can be facilitated. In addition, since the present invention performs color identification of ink using the difference in sensitivity between two or more sensors, all of these sensors may be transmissive sensors, or these sensors may be All may be reflective. Therefore, since it can be a transmissive type or a reflective type according to the design specifications of the incorporated thermal transfer printing apparatus, the degree of freedom in designing the apparatus can be improved as a result.

  (2) The thermal transfer printing apparatus, wherein the sensor includes a light emitting element and a light receiving element, and the light emitting element emits infrared light.

  According to the present invention, the above-described sensor includes a light-emitting element and a light-receiving element, and infrared light is emitted from the light-emitting element, so that the sensor is not easily affected by external light and eventually malfunctions. Can be prevented.

  In particular, when the present invention is applied to the above-described thermal transfer printing apparatus, all the sensors are infrared light sensors, so that, for example, they enter from the gap of the card insertion slot, or from the heat dissipation slit or the heat dissipation hole. It is possible to prevent malfunction due to external light when performing color identification.

  (3) The thermal transfer printing apparatus, wherein the light emitting element is provided with a conductive cover that increases the directivity of infrared light.

  According to the present invention, since the light-emitting element described above is provided with a conductive cover that enhances the directivity of infrared light, it is possible to prevent interference between a plurality of sensors, thereby contributing to prevention of malfunction. be able to. Further, for example, even when two or more sensors are arranged close to each other for downsizing of the apparatus, malfunction can be prevented.

  (4) The sensor includes a light emitting element and a light receiving element, and a first sensor and a second sensor that receive, with the light receiving element, light that is transmitted through or reflected from the ink ribbon among light emitted from the light emitting element. When the output of the first sensor is V1, the output of the second sensor is V2, and the predetermined threshold is Vth, the ink color is identified by comparing them. The thermal transfer printing apparatus characterized by this.

  According to the present invention, the first sensor and the second sensor that receive the light transmitted through or reflected from the ink ribbon among the light emitted from the light emitting element by the light receiving element are considered as the above-described sensors. Since the ink color is identified by comparing the output V1 of the second sensor, the output V2 of the second sensor, and the predetermined threshold value Vth, the color can be identified using a simple comparison process. Control by software can be facilitated.

  (5) Three different colors of ink are applied to the ink ribbon, and the ink color is recognized by recognizing whether V1> V2> Vth, V1> Vth> V2, or Vth> V1> V2. A thermal transfer printing apparatus characterized by identifying

  According to the present invention, three different colors of ink are applied to the ink ribbon described above, and color identification is performed according to whether V1> V2> Vth, V1> Vth> V2, or Vth> V1> V2. Therefore, control by software can be facilitated.

  (6) The thermal transfer printing apparatus, wherein each sensitivity is made different by making a light emission amount of the light emitting element in the first sensor different from a light emission amount of the light emitting element in the second sensor.

  According to the present invention, since the light emission amount of the light emitting element in the first sensor described above is different from the light emission amount of the light emitting element in the second sensor described above, each sensitivity is made different. Sensitivity can be adjusted simply by adjusting the amount of current flowing through both sensors, and software control can be further facilitated. Further, even when the light emission amount decreases due to deterioration of the light emitting element over time, the sensitivity can be automatically adjusted by automatically adjusting the light emission amount. Furthermore, the variation of the sensor can be adjusted by the light emission amount.

  (7) The thermal transfer printing apparatus, wherein each sensitivity is made different by making an output voltage of the light receiving element in the first sensor different from an output voltage of the light receiving element in the second sensor.

  According to the present invention, since the output voltage of the light receiving element in the first sensor and the output voltage of the light receiving element in the second sensor are made different from each other, each sensitivity is made different. Sensitivity can be adjusted simply by adjusting the output voltage using a converter, transistor, etc., and software control can be further facilitated.

  (8) The thermal transfer printing apparatus, wherein the predetermined threshold is a variable value.

  According to the present invention, since the predetermined threshold value described above is a variable value, even if the sensitivity of each sensor cannot be adjusted by adjusting the light emission amount or the output voltage of the light emitting element (for example, over time) Appropriate color identification can be performed even when deterioration has progressed and the amount of emitted light has become extremely small.

  According to the thermal transfer printing apparatus of the present invention, it is possible to identify the color of the ink ribbon while preventing the degree of freedom in apparatus design from being lowered and preventing the software from becoming complicated.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Machine configuration]
FIG. 1 is a perspective view showing an external configuration of a thermal transfer printing apparatus (thermal printer) 1 according to an embodiment of the present invention. FIG. 2 is a side view for explaining the internal configuration of the thermal transfer printing apparatus 1 of FIG.

  1 and 2, a thermal transfer printing apparatus 1 uses an ink ribbon 3 in which ink is applied to a belt-like film, and heats the ink on the ink ribbon 3 by heating to perform printing on the card 2. Printing device. The ink ribbon 3 is for thermal transfer printing in which different color inks are applied so as to repeat a predetermined color arrangement (for example, yellow, cyan, magenta, etc.).

  The thermal transfer printing apparatus 1 includes a thermal head 4 that heats the ink ribbon 3 to print on the card 2, a cartridge 5 that supplies and winds the ink ribbon 3 (ink ribbon), and a surface of the card 2 before printing. A cleaning mechanism 6 that removes attached dust and the like, and a housing 7 in which the thermal head 4, a part of the cartridge 5, the cleaning mechanism 6, and the like are housed are provided. In addition, a transport path 8 through which the card 2 is transported is formed inside the housing 7. In the conveyance path 8, the ink ribbon 3, the card 2, and the like are conveyed. A plurality of card transport rollers 9 for transporting the card 2 are arranged in the transport path 8. Further, the thermal transfer printing apparatus 1 includes a ribbon transport roller 10 for transporting the ink ribbon 3 in the apparatus.

  In the following description, the X direction in FIG. 1 is referred to as “front-rear direction”, the Y direction as “left-right direction”, and the Z direction as “up-down direction”. Further, in FIG. 1, the X1 direction side is “front”, the X2 direction side is “back”, the Y1 direction side is “right”, the Y2 direction side is “left”, the Z1 direction side is “up”, and the Z2 direction side is “ Below. Further, the clockwise direction in FIG. 2 is “clockwise”, and the counterclockwise direction is “counterclockwise”. In the present embodiment, the left-right direction is the width direction of the card 2.

  The card 2 is a vinyl chloride card having a thickness of about 0.7 to 0.8 mm, for example. On the surface of the card 2, for example, a magnetic stripe for recording magnetic information is formed.

  The thermal head 4 is disposed approximately at the center in the front-rear direction of the thermal transfer printing apparatus 1 and above the conveyance path 8. Further, the ink ribbon 3 passes under the thermal head 4. Further, the thermal head 4 moves up and down with respect to the transport path 8 by a drive mechanism including a drive motor 12, a worm gear 13, an eccentric cam 14, and the like. The thermal head 4 performs printing on the upper surface of the card 2 by pressing the ink ribbon 3 against the card 2 and performing thermal transfer.

  As shown in FIG. 2, the cartridge 5 includes a ribbon supply unit 15 that supplies the ink ribbon 3 toward the thermal head 4, and a ribbon winding unit that winds up the ink ribbon 3 after printing by the thermal head 4. 16. The ribbon supply unit 15 is disposed on the back side of the thermal head 4, and the ribbon winding unit 16 is disposed on the near side of the thermal head 4. The cartridge 5 is disposed above the conveyance path 8 and is detachable from the housing 7. The ribbon winding unit 16 is connected to a drive motor 28 that drives the ribbon transport roller 10 via a transmission unit such as a gear, and rotates together with the ribbon transport roller 10.

  The cleaning mechanism 6 is disposed at the back end of the thermal transfer printing apparatus 1. The cleaning mechanism 6 is inserted from the back side of the thermal transfer printing apparatus 1 and cleans the upper surface of the card 2 before printing by the thermal head 4.

  The housing 7 includes a first housing 17 disposed on the upper side and a second housing 18 disposed on the lower side. A shaft 19 is fixed to the back end of the first housing 17, and the first housing 17 is counterclockwise from the state shown in FIG. 2 with respect to the second housing 18 around the shaft 19. It is possible to turn to.

  When the first housing 17 is rotated counterclockwise from the state shown in FIG. 2, the cartridge 5 can be taken out from the housing 7. In the state shown in FIGS. 1 and 2, the first housing 17 is locked to the second housing 18 by the locking mechanism 20 disposed at the front end of the housing 7.

  The conveyance path 8 is formed linearly in the front-rear direction of the thermal transfer printing apparatus 1 and so as to penetrate the thermal transfer printing apparatus 1 in the front-rear direction. The card transport roller 9 is disposed so as to protrude from the lower side to the transport path 8. As shown in FIG. 1, the plurality of card transport rollers 9 are connected to the drive motor 24 via a transmission means including a pulley 22, a timing belt 23, and the like, and rotate by the power of the drive motor 24. A pad roller 25 is placed on the upper side of the card transport roller 9 excluding the card transport roller 9 disposed on the back side and the card transport roller 9 disposed substantially in the front-rear direction so as to be in pressure contact with the card transport roller 9. Is arranged.

  The ribbon transport roller 10 is disposed above the transport path 8 and on the back side of the ribbon winding unit 16. As shown in FIG. 1, the ribbon transport roller 10 is connected to a drive motor 28 via a transmission means including a pulley 26 and a timing belt 27 and is rotated by the power of the drive motor 28. A pad roller 29 is disposed on the oblique upper side of the ribbon transport roller 10 so as to be in pressure contact with the ribbon transport roller 10.

  In the present embodiment, the thermal transfer printing apparatus 1 as described above is provided with at least two or more sensors that identify the color of the ink by irradiating the ink ribbon 3 with light. More specifically, a description will be given with reference to FIG.

  FIG. 3 is a conceptual diagram for explaining the positional relationship of the sensors. FIG. 3A shows a state where two transmission infrared light sensors 51 and 52 are provided, and FIG. 3B shows that two reflection infrared light sensors 53 and 54 are provided. This shows the situation when

  The transmissive infrared light sensor 51 includes a light emitting element 51 a and a light receiving element 51 b, both of which are disposed to face each other with the ink ribbon 3 interposed therebetween. The transmissive infrared light sensor 52 is also composed of a light emitting element 52a and a light receiving element 52b, both of which are disposed to face each other with the ink ribbon 3 interposed therebetween (see FIG. 3A).

  On the other hand, the reflective infrared light sensor 53 includes a light emitting element 53 a and a light receiving element 53 b, both of which are arranged on one side of the ink ribbon 3. The reflective infrared sensor 54 also includes a light emitting element 54a and a light receiving element 54b, both of which are arranged on one side of the ink ribbon 3 (see FIG. 3B). Note that the two reflective infrared sensors 53 and 54 may be arranged on the opposite side of the ink ribbon 3 depending on the necessity in the device design.

  In the thermal transfer printing apparatus 1 according to the present embodiment, either the transmission infrared light sensors 51 and 52 or the reflection infrared light sensors 53 and 54 may be used. In order to reduce the size of the apparatus, it is preferable to shorten the distance between the sensors. However, in this case, there is a possibility that the sensors interfere with each other (for example, in the case of the transmission infrared sensor 51, from the light emitting element 51a). The irradiated infrared light may reach the light receiving element 52b, or the infrared light irradiated from the light emitting element 52a may reach the light receiving element 51b).

  Therefore, in order to prevent such interference between sensors, a conductive cover that increases the directivity of infrared light may be provided. Specifically, as shown in FIG. 3C, a conductive cover 60 is provided around the light emitting element 51a and the light emitting element 52a (here, the light emitting element 51a and the light emitting element 52a are integrally molded. ) Thereby, the directivity of the light emitting element is increased, and malfunction can be prevented even when the sensors are arranged close to each other.

  Here, the thermal transfer printing apparatus 1 according to the present embodiment is characterized in that the sensitivities of the two sensors are different. Hereinafter, the circuit configuration of the thermal transfer printing apparatus 1 will be described in detail by taking as an example the case where the transmissive infrared light sensors 51 and 52 are employed.

[Circuit configuration]
FIG. 4 is a circuit diagram showing an electrical circuit configuration of the thermal transfer printing apparatus 1 according to the embodiment of the present invention.

  4, the thermal transfer printing apparatus 1 has a CPU 100, a memory 101, an A / D converter 102, transmissive infrared light sensors 51 and 52, and power supplies VCC1 and VCC2. In FIG. 4, only main electrical elements are illustrated, and the thermal transfer printing apparatus 1 may include other electrical elements.

  The CPU 100 is responsible for integrated control of the thermal transfer printing apparatus 1 and sends a memory read signal and a memory write signal to the memory 101. Then, data stored in the memory 101 is read or data is written to the memory 101 via the data bus. The CPU 100 also sends an A / D read signal to the A / D converter 102. Then, digital data is acquired from the A / D converter 102 via the data bus.

  The A / D converter 102 is connected to the transmission infrared light sensors 51 and 52, and converts analog signals input from these sensors into digital signals. As described above, the transmission infrared light sensor 51 includes the light emitting element 51a and the light receiving element 51b. In FIG. 4, the infrared LED 1 is used as the light emitting element 51a, and the phototransistor 1 (PT1) is used as the light receiving element 51b. ) Is adopted. The transmission infrared light sensor 52 includes the light emitting element 52a and the light receiving element 52b as described above. In FIG. 4, the infrared LED 2 is used as the light emitting element 52a, and the phototransistor 2 is used as the light receiving element 52b. (PT2) is adopted.

  The anode terminals of the infrared LED 1 and the infrared LED 2 are connected to the LED power supply VCC1 via a resistor R11 and a resistor R21, respectively. The cathode terminals of the infrared LED 1 and the infrared LED 2 are both grounded. Therefore, as a technique for making the sensitivity of each of the transmission infrared light sensors 51 and 52 different, the resistance value of the resistor R11 and the resistance value of the resistor R21 can be made different. That is, the amount of current flowing through the infrared LED 1 and the amount of current flowing through the infrared LED 2 can be made different, and thus the amount of light emitted from the infrared LED 1 and the amount of light emitted from the infrared LED 2 can be made different.

  In the present embodiment, VCC1 is used as the power source of the infrared LED and is shared by the transmission infrared light sensors 51 and 52, but separate power sources may be used. This also makes it possible to vary the sensitivities of the transmissive infrared light sensors 51 and 52.

  On the other hand, the collector terminals of the phototransistor 1 (PT1) and the phototransistor 2 (PT2) are both connected to the phototransistor power supply VCC2. The emitter terminals of the phototransistor 1 (PT1) and the phototransistor 2 (PT2) are both grounded through a resistor R12 and a resistor R22, respectively. Therefore, as a technique for making the sensitivity of each of the transmission infrared light sensors 51 and 52 different, the resistance value of the resistor R12 and the resistance value of the resistor R22 can be made different. That is, the collector current of the phototransistor 1 (PT1) is different from the collector current of the phototransistor 2 (PT2), and consequently the output voltage of the phototransistor 1 (PT1) and the phototransistor 2 (PT2) The output voltage can be made different.

  In the present embodiment, VCC2 is used as the power source of the phototransistor and is shared by the transmission infrared light sensors 51 and 52, but separate power sources may be used. This also makes it possible to vary the sensitivities of the transmissive infrared light sensors 51 and 52.

  As described above, when the sensitivities of the transmission infrared light sensors 51 and 52 are made different, the CPU 100 can identify the color of the ink applied to the ink ribbon. A specific operation will be described. First, the CPU 100 turns on a memory write signal and stores a threshold for ribbon identification in the memory 101 in advance. Next, the A / D converter 102 takes in the output signals (output voltages) V1 and V2 of the transmissive infrared light sensors 51 and 52 and converts them into digital values. Next, the CPU 100 reads the data converted into the digital value via the data bus with the A / D read signal turned ON. Then, the CPU 100 reads the threshold value Vth stored in advance in the memory 101 by turning on the memory read signal and compares it with the data read from the A / D converter 102. Specific comparison processing will be described in detail with reference to FIG.

  FIG. 5 is an explanatory diagram for explaining a comparison process for identifying the color of the ink ribbon 3. 5A to 5C, the horizontal axis indicates the passage of time, and the vertical axis indicates the voltage recognized by the CPU 100. V1 represents the output voltage from the (high sensitivity) transmissive infrared light sensor 51, V2 represents the output voltage from the (low sensitivity) transmissive infrared light sensor 52, and Vth represents the ribbon color identification. Indicates the threshold for.

  When a graph such as that shown in FIG. 5A is obtained, both V1 and V2 are higher than Vth, so that the transmissive infrared light sensors 51 and 52 receive a large amount of LED light. . Therefore, it can be determined that a portion of the ink ribbon 3 having a high infrared light transmittance (for example, a transparent portion) is detected. Further, when a graph as shown in FIG. 5C is obtained, V1 and V2 are both lower than Vth. Therefore, in the transmissive infrared light sensors 51 and 52, the LED ribbon is blocked by the ink ribbon 3. Therefore, it can be determined that the black portion of the ink ribbon 3 is detected. When a graph as shown in FIG. 5B is obtained, it can be determined that the color is between FIG. 5A and FIG.

  The threshold value Vth is set so that a predetermined color can be identified. In this embodiment, by recognizing whether V1> V2> Vth (pattern (i)), V1> Vth> V2 (pattern (ii)), or Vth> V1> V2 (pattern (iii)). Although the ink color is identified, for example, the ink color may be identified by recognizing any two (for example, the case of FIG. 5B may be omitted).

  In the present embodiment, the transmissive infrared light sensors 51 and 52 are used, but the same applies to the case where the reflective infrared light sensors 53 and 54 are used. When the reflective infrared light sensors 53 and 54 are used, for example, when a graph as shown in FIG. 5A is obtained, the output of both V1 and V2 is high because the reflected light is large. As a result, it can be determined that a bright portion (for example, a yellow portion) of the ink ribbon 3 is detected. Further, when a graph as shown in FIG. 5C is obtained, it can be determined that a portion with a low reflectance (for example, a black portion) of the ink ribbon 3 is detected because the reflected light is small. When a graph as shown in FIG. 5B is obtained, it can be determined that the color is between FIG. 5A and FIG. As in the case of using the transmission infrared light sensors 51 and 52, the threshold value Vth is set so that a predetermined color can be identified.

  Furthermore, in the present embodiment, two transmission infrared light sensors 51 and 52 are used. However, for example, three sensors may be used. This will be described in detail with reference to FIG.

  FIG. 6 is an explanatory diagram for explaining a comparison process for identifying the color of the ink ribbon 3. 6A to 6D, the horizontal axis indicates the passage of time, and the vertical axis indicates the voltage recognized by the CPU 100. FIG. V1 indicates the output voltage from the (high sensitivity) sensor, V2 indicates the output voltage from the (medium sensitivity) sensor, V3 indicates the output voltage from the (low sensitivity) sensor, and Vth is , Shows a threshold for ribbon color identification.

  The colors that can be identified from the graphs shown in FIGS. 6A to 6D are summarized in FIG. According to FIG. 6 (e), in the case of FIG. 6 (a) (pattern (i)), it can be identified as “transparent” in the case of the transmission infrared light sensor, and in the case of the reflection infrared light sensor. Can be identified as "bright (yellow)". In the case of FIG. 6B (pattern (ii)), it can be identified as “intermediate color 1” in the case of the transmission infrared light sensor, and “intermediate color 1” in the case of the reflection infrared light sensor. Can be identified. In the case of FIG. 6C (pattern (iii)), it can be identified as “intermediate color 2” in the case of the transmission infrared light sensor, and “intermediate color 2” in the case of the reflection infrared light sensor. Can be identified. In the case of FIG. 6D (pattern (iv)), in the case of a transmission infrared light sensor, it can be identified as “dark (black)”, and in the case of a reflection infrared light sensor, “dark ( Black) ".

  In this way, color identification is possible regardless of whether the number of sensors is two or three. The greater the number of sensors, the greater the number of colors that can be identified. The setting criteria for the threshold value Vth will be described. If the sensor power supply is Vcc, the sensor output is 0 to Vcc [V]. If Vth is too close to Vcc, there is no margin of Vth with respect to fluctuations in Vcc, and there is a risk of false detection (possibly Vth> Vcc). On the other hand, if Vth is too close to 0 [V], the margin of Vth with respect to ground fluctuations disappears, and there is a risk of erroneous detection (Vth <ground may occur). Therefore, the threshold value Vth is preferably set to a value having a certain margin with respect to the power supply and the ground. For example, when Vcc is 5 [V], it is appropriate to set Vth to 2 to 3 [V]. When the appropriate threshold value Vth can be set, the sensor outputs V1, V2, etc. are set according to the type of ink to be identified (considering the characteristics of light such as color) (for example, experimental data is statistically calculated). Process or set by experience). In the present embodiment, the threshold value Vth is an invariable value, but it may be a variable value in consideration of deterioration of the LED over time.

[Identification processing]
FIG. 7 is a flowchart for explaining a ribbon position detection flow in the thermal transfer printing apparatus 1 according to the present embodiment. 8 and 9 are flowcharts for explaining a ribbon color identification flow in the thermal transfer printing apparatus 1 according to this embodiment. 8 shows a flowchart when there are two sensors (see FIG. 5), and FIG. 9 shows a flowchart when there are three sensors (see FIG. 6).

  In FIG. 7, first, the printing medium (card 2) is taken in (step S1). More specifically, the CPU 100 transmits a drive signal to the drive motor 24 (generally via a motor drive control circuit), and rotates the drive motor 24. If it does so, the card | curd conveyance roller 9 will rotate via the transmission means comprised from the pulley 22, timing belt 23, etc., and taking in of the card | curd 2 will be performed. When the card 2 is taken to the standby position, the card 2 is held at that position (step S2).

  Next, the ribbon take-up motor (drive motor 28) is rotated (step S3). More specifically, the CPU 100 transmits a drive signal to the drive motor 28 (generally via a motor drive control circuit), and rotates the drive motor 28. If it does so, the ribbon winding part 16 will rotate with the ribbon conveyance roller 10 via transmission means, such as a gearwheel. The ribbon has a length of + α for each medium for each color.

  Next, it is determined whether or not the ribbon leading color has been detected (step S4). More specifically, identification processing as shown in FIGS. 8 and 9 is performed. As shown in FIG. 8, in the case of two transmissive infrared light sensors (see FIG. 5), the CPU 100 determines whether or not V1> Vth (step S21). If V1> Vth is not satisfied, Vth> V1> V2 is determined, and a black ribbon is detected (see step S22, pattern (iii) in FIG. 5C). On the other hand, if V1> Vth, the CPU 100 determines whether or not V2> Vth (step S23). If V2> Vth is not satisfied, it is determined that V1> Vth> V2 and is detected as an intermediate color ribbon. (See step S24, pattern (ii) in FIG. 5B). If V2> Vth, it is determined that V1> V2> Vth, and a transparent color ribbon is detected (see step S25, pattern (i) in FIG. 5A). In this way, the CPU 100 can identify what color the ribbon leading color is.

  As shown in FIG. 9, in the case of three transmissive infrared light sensors (see FIG. 6), the CPU 100 determines whether or not V1> Vth (step S31). It is determined that Vth> V1> V2> V3, and a black ribbon is detected (see step S32, pattern (iv) in FIG. 6D). On the other hand, if V1> Vth, the CPU 100 determines whether or not V2> Vth (step S33). If V2> Vth is not satisfied, it is determined that V1> Vth> V2 and the intermediate color 2 ribbon is detected. (See step S34, pattern (iii) in FIG. 6C). On the other hand, if V2> Vth, the CPU 100 determines whether or not V3> Vth (step S35). If V3> Vth is not satisfied, it is determined that V2> Vth> V3, and the intermediate color 1 ribbon is detected. (See step S36, pattern (ii) in FIG. 6B). If V3> Vth, it is determined that V1> V2> V3> Vth, and a transparent color ribbon is detected (see step S37, pattern (i) in FIG. 6A). In this way, the CPU 100 can identify the color of the ribbon head color even when there are three sensors.

  If the ribbon leading color cannot be detected in the process of step S4 in FIG. 7, the process returns to step S3, and the ribbon take-up motor is further rotated. On the other hand, when the ribbon head color is detected, the rotation of the ribbon take-up motor is stopped (step S5), the medium (card 2) is set at the print start position (step S6), and the head color is printed. , Medium conveyance and ribbon winding are performed (step S7).

  Next, ribbon feeding for detecting the next color is performed (step S8), and it is determined whether or not the next color is detected (step S9). Since the processes in steps S8 and S9 are the same as the processes in steps S3 and S4 described above, the description thereof is omitted.

  If the next color is detected in step S9, the ribbon take-up motor is stopped (step S10) and the medium is set at the print start position (step S10) as in steps S5 to S7 (step S10). S11), next color printing, medium conveyance, and ribbon winding are performed (step S12). For the third and subsequent colors, it is determined whether or not the end color has been printed after the process of step S12 (step S13). If the end color printing has not been completed, the process returns to step S8, and the steps from step S8 to step S12 are repeated until the end color printing is completed. When the printing of the end color is completed, the ribbon take-up motor stops (step S14). Finally, the medium (card 2) is ejected (step S15), and a series of processing ends.

[Effect of the embodiment]
As described above, according to the thermal transfer printing apparatus 1 according to the present embodiment, a plurality of sensors having different sensitivities are used, and ink color identification is performed by a processing flow (see FIGS. 8 and 9) centering on comparison processing. Since it can be performed, control by software can be facilitated.

  The sensor used may be a transmissive type or a reflective type (see FIG. 3), and can be freely selected according to the design specifications of the thermal transfer printing apparatus 1 to be incorporated. Therefore, the degree of freedom in device design can be improved.

  Moreover, in this embodiment, since the thing which irradiates infrared light is used as a light emitting element, it becomes difficult to receive the influence by external light, and it can prevent a malfunctioning by extension. And as mentioned above, by providing a conducting cover, the directivity of infrared light can be increased (see FIG. 3C), interference between sensors can be prevented, and malfunction can be prevented.

  Moreover, since sensitivity adjustment can be performed only by adjusting the light emission amount and output voltage of a plurality of sensors, control by software can be further facilitated. Note that by making the threshold variable, for example, even when the deterioration of the sensor with time progresses and the amount of emitted light becomes extremely small, appropriate color identification can be performed.

[Modification]
FIG. 10 is a circuit diagram showing an electrical circuit configuration of a thermal transfer printing apparatus 1 ′ according to another embodiment of the present invention.

  As shown in FIG. 10, the collector terminals of the phototransistor 1 (PT1) and the phototransistor 2 (PT2) are connected to the power supply VCC2 through the resistors R12 and R22, respectively, and the emitter terminals are grounded. Good. In such a circuit configuration, when the sensitivity is high, a large amount of LED current flows, so that the voltage drop at the resistor increases and the sensor voltage decreases. That is, the output voltage V1 from the high-sensitivity transmission infrared light sensor 51 is lower than the output voltage V2 from the low-sensitivity transmission infrared light sensor 52.

  Therefore, in the thermal transfer printing apparatus 1 ′ having the circuit configuration shown in FIG. 10, the ink color is identified by recognizing whether V1 <V2 <Vth, V1 <Vth <V2, or Vth <V1 <V2. Can do. In FIG. 10, the two transmissive infrared light sensors 51 and 52 are used, but the same applies when three sensors are used. That is, in a thermal transfer printing apparatus using three sensors, V1 (high sensitivity) <V2 (medium sensitivity) <V3 (low sensitivity) <Vth, V1 <V2 <Vth <V3, or V1 <Vth <V2 <. By recognizing whether V3 or Vth <V1 <V2 <V3, the ink color can be identified.

  Further, one of the two sensors may be a transmissive sensor and the other may be a reflective sensor depending on the device design. In the case of three, one or two sensors may be transmissive and the rest may be reflective. In any case, the ink colors can be identified by setting the thresholds according to the characteristics of the ribbon to be detected by changing the sensitivity of each sensor.

  The thermal transfer printing apparatus according to the present invention is useful as an apparatus capable of identifying the color of an ink ribbon while preventing a reduction in the degree of freedom in apparatus design and complication of software.

It is a perspective view which shows the external appearance structure of the thermal transfer printing apparatus which concerns on embodiment of this invention. It is a side view for demonstrating the internal structure of the thermal transfer printing apparatus of FIG. It is a conceptual diagram for demonstrating the arrangement | positioning relationship of a sensor. It is a circuit diagram which shows the electrical circuit structure of the thermal transfer printing apparatus which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the comparison process for performing the color identification of an ink ribbon. It is explanatory drawing for demonstrating the comparison process for performing the color identification of an ink ribbon. It is a flowchart for demonstrating the ribbon position detection flow in the thermal transfer printing apparatus which concerns on this embodiment. It is a flowchart for demonstrating the ribbon color identification flow in the thermal transfer printing apparatus which concerns on this embodiment. It is a flowchart for demonstrating the ribbon color identification flow in the thermal transfer printing apparatus which concerns on this embodiment. It is a circuit diagram which shows the electrical circuit structure of the thermal transfer printing apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal transfer printing apparatus 2 Card 3 Ink ribbon 4 Thermal head 51,52 Transmission type infrared light sensor 53,54 Reflection type infrared light sensor 100 CPU
101 memory 102 A / D converter

Claims (8)

A transport path for transporting a thermal transfer printing ink ribbon and a printing medium on which different color inks are applied so as to repeat a predetermined color arrangement;
In a thermal transfer printing apparatus having a thermal head that performs thermal transfer printing by pressing the ink ribbon against the printing medium,
Comprising at least two sensors for identifying the color of the ink by irradiating the ink ribbon with light;
A thermal transfer printing apparatus, wherein the sensitivity of each sensor is made different, and the color of the ink is identified by comparing a predetermined threshold value with the output of each sensor.   The thermal transfer printing apparatus according to claim 1, wherein the sensor includes a light emitting element and a light receiving element, and the light emitting element emits infrared light.   The thermal transfer printing apparatus according to claim 2, wherein the light emitting element is provided with a conductive cover that increases the directivity of infrared light. The sensor includes a light emitting element and a light receiving element, and includes a first sensor and a second sensor that receive light transmitted through or reflected by the ink ribbon out of light emitted from the light emitting element. ,
When the output of the first sensor is V1, the output of the second sensor is V2, and the predetermined threshold is Vth, the ink color is identified by comparing them. The thermal transfer printing apparatus according to claim 1.   Three different colors of ink are applied to the ink ribbon, and the color of the ink is identified by recognizing whether V1> V2> Vth, V1> Vth> V2, or Vth> V1> V2. The thermal transfer printing apparatus according to claim 4.   6. The thermal transfer according to claim 4, wherein each of the sensitivities is made different by making a light emission amount of the light emitting element in the first sensor different from a light emission amount of the light emitting element in the second sensor. Printing device.   6. The thermal transfer according to claim 4, wherein each of the sensitivities is made different by making the output voltage of the light receiving element in the first sensor different from the output voltage of the light receiving element in the second sensor. Printing device.   The thermal transfer printing apparatus according to claim 1, wherein the predetermined threshold value is a variable value.

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