JP2016120668A - Printer and ribbon color identification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ribbon color identification device which is inexpensive and excellent in durability and accuracy, and a printer having the same.SOLUTION: A printer comprises: an ink ribbon which is installed between a supply reel and a take-up reel; a printing part which performs printing processing on a medium using the ink ribbon; a sensor which has a light-emitting element and a light-receiving element and detects the ink ribbon; a sensor circuit which has a light emission circuit making the light-emitting element emit light and a light reception circuit operating the light-receiving element; and a control part which controls the sensor circuit. The control part monitors output voltage output from the light reception circuit while controlling the light emission circuit in such a manner that a current flowing in the light-emitting element gradually increases or decreases from a reference current value, and identifies the color of the ink ribbon in accordance with a length of the time t in which the output voltage becomes a set voltage value set in advance from a voltage value corresponding to the reference current value.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a printing apparatus and a ribbon color identification apparatus, and more particularly to a ribbon color identification apparatus for identifying the color of an ink ribbon and a printing apparatus including the ribbon color identification apparatus.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing processing on a medium using an ink ribbon are widely known. Such a printing apparatus uses, for example, a direct printing method in which an image is directly formed on a printing medium using a monochromatic ink ribbon, and is sometimes called a mark printer.

  The mark printer is usually equipped with an ink ribbon cassette that houses a supply reel on which an unused ink ribbon is wound and a take-up reel for winding an used ink ribbon. Various techniques for identifying the ribbon color of the ink ribbon accommodated in the ink ribbon cassette are known.

  For example, as a technique widely used at present, as shown in FIG. 13, two ribbon color detection portions A and B are formed at predetermined positions of an ink ribbon cassette, and a contact pin (push switch) on the mark printer side. The color of the ink ribbon (ribbon color) is grasped by bringing the ink into contact with the ribbon color detection portion. Ribbon colors used for a single color ink ribbon are mostly black, red, blue, and white. When the ribbon color is black, both A and B are blocked, and when the ribbon color is red, A Is closed and a hole is formed in B. When the ribbon color is blue, a hole is formed in A and B is closed. When the ribbon color is white, both A and B are formed. Has been.

  In Patent Document 1, the marker seal is divided into a plurality of sections, a non-reflective portion is formed only in one section, and a plurality of marker seals are detected by a plurality of sensors corresponding to the plurality of sections. A technique for identifying the color of an ink ribbon is disclosed.

JP 2001-71607 A

  However, since the ribbon color identification technology shown in FIG. 13 uses a contact type push switch, printing is performed even though there is no problem in the printing function due to wear of the contacts or fatigue of the spring inside the switch. There is a problem that the lifetime of the entire apparatus is shortened. Moreover, since the technique of Patent Document 1 requires a plurality of sensors, there is room for improvement in terms of cost.

  On the other hand, focusing on the change in reflectance and transmittance depending on the ribbon color of the ink ribbon, using a single sensor having a light emitting element and a light receiving element, light emitted from the light emitting element and reflected or transmitted by the ink ribbon It is conceivable to detect light with a light receiving element (measure the output voltage output from the light receiving element) and identify the ribbon color based on the voltage difference of the output voltage of the light receiving element. According to such an identification method, the above-mentioned cost and durability problems can be solved. However, since the voltage difference between the output voltages is small (particularly when the ribbon color is blue and red), sensor variations are also taken into consideration. Then, there is a difficulty in terms of accuracy (certainty of identification).

  An object of the present invention is to provide a ribbon color identification device that is low in cost and excellent in durability and accuracy, and a printing apparatus including the ribbon color identification device.

  In order to solve the above-described problem, a first aspect of the present invention is a printing apparatus, which is an ink ribbon constructed between a supply reel and a take-up reel, and a printing process on a medium using the ink ribbon. And a sensor circuit having a light emitting element and a light receiving element for detecting the ink ribbon, a light emitting circuit for emitting light from the light emitting element, and a light receiving circuit for operating the light receiving element, and the sensor. Control means for controlling the circuit, and the control means controls the light emitting circuit so that the current flowing through the light emitting element gradually increases or decreases from a reference current value, and is output from the light receiving circuit. The voltage is monitored, and the color of the ink ribbon is identified according to the length of time until the output voltage reaches a preset voltage value from a voltage value corresponding to the reference current value. To.

  In the first aspect, the control means monitors the output voltage output from the light receiving circuit by controlling the light emitting circuit so that the current flowing through the light emitting element increases or decreases by a constant value from the reference current value every predetermined time. The time until the output voltage reaches the set voltage value from the voltage value corresponding to the reference current value is timed or calculated, and the time until the output voltage reaches the set voltage value and the color of the ink ribbon The color of the ink ribbon may be identified by applying the following relationship. The set voltage value is greater than or equal to the voltage value output from the light receiving circuit when the steady current value flows through the light emitting element when the color of the ink ribbon is black, and less than the minimum voltage value or exceeds the minimum voltage value. When the ribbon color is black, it can be set to a voltage value equal to or lower than the voltage value output from the light receiving circuit when a steady current value flows through the light emitting element.

  The light emitting circuit includes a D / A converter, an operational amplifier in which the output terminal of the D / A converter is connected to the positive phase input terminal, and a transistor in which the output terminal of the operational amplifier is connected to the base via a resistor. The light emitting element is inserted between the operating power supply (Vcc) and the collector of the transistor, and the control means changes the digital voltage output to the D / A converter so that the current flowing through the light emitting element is a reference. The light emitting circuit may be controlled so as to gradually increase or decrease from the current value.

  Further, the ink ribbon may be housed in an ink ribbon cassette having an exposed portion where the ink ribbon is exposed, and the sensor may be a reflective sensor disposed in the vicinity of the exposed portion. The control unit may change the printing condition on the medium by the printing unit according to the color of the identified ink ribbon.

  In order to solve the above-mentioned problem, a second aspect of the present invention is a ribbon color identification device for identifying the color of an ink ribbon, the sensor having a light emitting element and a light receiving element and detecting the ink ribbon. A sensor circuit having a light emitting circuit that emits light from the light emitting element and a light receiving circuit that operates the light receiving element, and a control unit that controls the sensor circuit, wherein the control unit includes a current flowing through the light emitting element. The light emitting circuit is controlled so as to gradually increase or decrease from a reference current value to monitor the output voltage output from the light receiving circuit, and the output voltage is preset from a voltage value corresponding to the reference current value. The color of the ink ribbon is identified according to the length of time until the set voltage value is reached.

  According to the present invention, since the color of the ink ribbon can be identified using a single sensor, the cost can be reduced, and since the color of the ink ribbon can be identified without contact, it has excellent durability and control. The means controls the light emitting circuit so that the current flowing through the light emitting element gradually increases or decreases from the reference current value and monitors the output voltage output from the light receiving circuit, and the output voltage corresponds to the reference current value. Since the color of the ink ribbon is identified according to the length of time from the value to the preset voltage value, it is possible to obtain an effect that the color of the ink ribbon can be accurately identified.

1 is an external view of a printer according to an embodiment to which the present invention is applicable. The top view of the attachment which can be mounted | worn with the attachment part of the printer of embodiment is shown, (A) shows a label cassette, (B) shows the attachment for tubes. It is a perspective view of a cassette mounting portion and an ink ribbon cassette of the printer of the embodiment. FIG. 2 is a block diagram illustrating a control unit and a connection system of the printer according to the embodiment. It is a circuit diagram which shows a sensor circuit among sensor control parts. 6 is a flowchart of a ribbon color identification routine executed by the CPU of the control unit of the printer according to the embodiment. It is a graph which shows the relationship between the output voltage output from a light receiving circuit, and time when the ribbon color of an ink ribbon is black. It is a graph which shows the relationship between the output voltage and time which are output from a light receiving circuit when the ribbon color of an ink ribbon is blue. It is a graph which shows the relationship between the output voltage and time which are output from a light receiving circuit when the ribbon color of an ink ribbon is red. It is a graph which shows the relationship between the output voltage and time which are output from a light receiving circuit when the ribbon color of an ink ribbon is white. It is explanatory drawing which shows typically the relationship between the length of time until the output voltage output from a light receiving circuit turns into a setting voltage value from a maximum voltage value, and the ribbon color of an ink ribbon. It is a graph which shows the relationship between the output voltage and time which are output from a light receiving circuit when an ink ribbon runs out. It is explanatory drawing which shows the conventional ribbon color identification principle typically. It is explanatory drawing which shows typically the relationship between the length of time from the voltage value when an output voltage output from a light receiving circuit flows through a reference current value to a set voltage value, and the ribbon color of the ink ribbon.

  In the following, an embodiment in which the present invention is applied to a mark printer capable of printing arbitrary characters on a long print medium such as a label or a tube will be described with reference to the drawings.

(Constitution)
<Overall configuration>
As shown in FIG. 1, the printer 1 according to the present embodiment is configured to be portable like a notebook computer, and roughly includes an input unit 13 having a keyboard and an input control unit, an LCD, and a display control unit. The printing unit 20 that prints on the print medium via the ink ribbon R by selectively generating heat from the heating elements arranged in the main scanning direction that constitute the display unit 14 and the thermal head 6, and the medium of the printing unit 20 A cutting unit 7 provided on the downstream side in the transport direction for cutting the print medium and a control unit 15 (see FIG. 4) for controlling these units are provided. Further, the printer 1 has a cassette mounting portion 30 in which the ink ribbon cassette 8 is mounted (see FIG. 3).

<Input section>
The input unit 13 has function keys, letters / numbers / symbol keys, a space key, a conversion key, a cross direction key, a return key, and the like, as in a notebook type computer, and an operator operates these keys. Thus, it is possible to input the type, size, setting condition, and the like of the print medium.

<Display section>
The LCD of the display unit 14 includes various information display areas for displaying input modes and the like, character information display areas for displaying characters, numbers, and symbols (hereinafter abbreviated as characters) input from the input unit 13, character sizes, and the like. The parameter display area is divided into three display areas, and various information display areas and parameter display areas are respectively arranged above and below the character information display area.

<Printing section>
The printing unit 20 includes transport rollers 2 a and 2 b for transporting a print medium, a platen roller 3 disposed opposite to the thermal head 6 on the downstream side of the transport rollers 2 a and 2 b, and a platen roller on the downstream side of the platen roller 3. 3 and a pinch roller 4 disposed so as to be opposed to each other.

  An ink ribbon R is interposed between the platen roller 3 and the thermal head 6. As will be described later, the ink ribbon R is accommodated in the ink ribbon cassette 8, supplied from the supply reel 8c of the ink ribbon cassette 8, and taken up by the take-up reel 8d.

  On the upstream side of the transport rollers 2a and 2b, a stepping motor 5 for rotating the transport roller 2a, the platen roller 3 and the take-up reel 8d of the ink ribbon cassette 8 via a gear (not shown) is disposed. On one side (left side in FIG. 1) and on one side (lower side in FIG. 1) of the cutting portion 7, the retreat position where the thermal head 6 is retracted from the medium conveyance path and the platen roller 3 via a gear and a cam (not shown). A stepping motor 9 is disposed to move between the printing position and the printing position that is in pressure contact therewith.

  FIG. 1 shows a state where a tube is mounted as the print medium M. To explain with this example, at the time of printing, the thermal head 6 is pressed against the printing medium M with the ink ribbon R of the ink ribbon cassette 8 interposed therebetween, and the heating elements constituting the thermal head 6 are selectively heated. The ink ribbon R is melted and a character string is printed on the print medium M line by line. In the following description, it is assumed that a tube is used for the print medium M according to the example of FIG. 1 except when necessary.

<Cutting part>
On the downstream side of the pinch roller 4, a cutting part 7 for cutting the print medium M is arranged. The cutting part 7 has a cutter blade 7a and a cutter blade cradle 7b. The cutter blade pedestal 7b includes a full cut surface constituted by a flat surface and a half cut surface having protrusions at both ends, and the full cut surface or the half cut surface is set substantially perpendicular to the cutter blade 7a. By doing so, it is possible to perform full cut processing and half cut processing of the print medium M. Here, the half-cut means that the print medium M is cut partially, and the cutting ratio is not limited. Further, the half-cutting method may be changed depending on the type of the print medium M. For example, when the print medium M is a label with a release paper, the label may be cut without cutting the release paper, or a roll paper or a ribbon. In the case of a tape, a perforation may be inserted.

  When printing by the thermal head 6 is completed and transported downstream by a predetermined length, the cutter blade 7a is operated (moved from the retracted position to the advanced position) to obtain the print medium M having a desired length by the operator. it can. In this embodiment, the rotational driving force of the stepping motor 9 is used for the operation of the cutter blade 7a via a cam (not shown), and the stepping of the cutter blade receiving base 7b is also performed via another cam or the like. The rotational driving force of the motor 9 is used.

<Attachment part>
The printer 1 is configured to be able to perform printing and cutting processing on various print media M by changing the attachment attached to the attachment unit 10. FIG. 2 shows an example of the configuration of the label cassette and the tube attachment. For example, when the label cassette 11 shown in FIG. 2A is attached to the attachment unit 10, the label with release paper is pulled out from the inside of the cassette, and printing and cutting processing can be performed on the label. In addition, when the tube attachment 12 shown in FIG. 2B is mounted on the attachment unit 10, printing and cutting processing can be performed on the tube by inserting the tube from the tube insertion opening 12 a.

<Ink ribbon cassette>
As shown in FIG. 3, the ink ribbon cassette 8 accommodates a supply reel 8c around which the ink ribbon R is wound and a take-up reel 8d for winding the ink ribbon R in a cassette case 8a. The ink ribbon R is installed between the supply reel 8c and the take-up reel 8d, and the ink ribbon R is exposed to the ink ribbon cassette 8 so as to be compatible with the printing process by the thermal head 6 in the printing unit 20. An exposed portion 8b is formed.

<Cassette mounting part>
As shown in FIG. 3, the printer 1 includes a cassette mounting portion 30 on which the ink ribbon cassette 8 is mounted. The cassette mounting unit 30 has a cassette mounting table 31 having a rectangular plane on which the ink ribbon cassette 8 can be mounted. The cassette mounting table 31 has three rod-shaped engagement protrusions 36 to 38 that engage with the ink ribbon cassette 8 and two claw faces that have a fitting claw at the tip and are opposed to the upper side and the side surface. Plate-shaped cassette holders 34 and 35 that are pressed from the side are provided upright. On the other hand, the cassette case 8a of the ink ribbon cassette 8 is formed with engagement holes and engagement side surfaces for engaging with or engaging with the engagement protrusions 36 to 38 and the cassette pressers 34 and 35.

  Further, on the cassette mounting table 31, a supply reel rotation shaft 32 that engages with the supply reel 8c of the ink ribbon cassette 8 and a take-up reel rotation shaft 33 that engages with the take-up reel 8d are erected in a rotatable manner. Note that the rotational driving force of the stepping motor 5 is transmitted to the take-up reel rotating shaft 33 through a gear or the like (not shown).

<Sensor>
A support member (not shown) for supporting the reflective sensor Se is fixed to the cassette mounting table 31. The sensor Se has a light emitting element (LED) Le and a light receiving element (phototransistor) Lr, and in order to detect the ink ribbon R, the exposed portion 8b of the ink ribbon cassette 8 placed on the cassette placing table 31. (See FIGS. 3 and 5). The sensor Se is supported by the above-described support member at a position facing one side surface of the exposed portion 8b, and does not interfere with the mounting of the ink ribbon cassette 8 on the cassette mounting portion 30 from above. Is arranged.

<Control unit>
As shown in FIG. 4, the control unit 15 includes a microprocessor having a CPU, a ROM, and a RAM. An external bus is connected to the control unit 15. Connected to the external bus are an input unit 13, a display unit 14, a printing unit 20, a driver 18 that controls the operation of the stepping motors 5 and 9, and a sensor control unit 19 that controls information from various sensors including the sensor Se. Yes. The stepping motors 5 and 9 described above are connected to the driver 18, and various sensors are connected to the sensor control unit 19.

  The control unit 15 has an interface (not shown), and can be connected to a host device such as a personal computer via an external bus. For this reason, the operator can input from the host device in place of the input from the input unit 13, and further, by installing an external storage device such as a RAM card or USB, the data stored in the external storage device can be stored. Use is also possible.

<Sensor circuit>
The sensor control unit 19 has a sensor circuit that controls the sensor Se. As shown in FIG. 5, the sensor circuit includes a light emitting circuit 19A that emits light from the light emitting element Le and a light receiving circuit 19B that operates the light receiving element Lr.

  The light emitting circuit 19A includes a D / A converter DA, an operational amplifier OP in which the output terminal of the D / A converter is connected to the positive phase input terminal, and a transistor Tr1 in which the output terminal of the operational amplifier OP is connected to the base via the resistor R1. The light emitting element Le is inserted between the operating power supply (Vcc) and the collector of the transistor Tr.

  That is, the anode side of the light emitting element Le is connected to Vcc (for example, +3.3 V), and the cathode side is connected to the collector of the transistor Tr1. The base of the transistor Tr1 is connected to the output terminal of the operational amplifier OP via the resistor R1, and the positive phase input terminal of the operational amplifier OP is connected to the DA output port of the control unit 15 via the D / A converter DA. The emitter of the transistor Tr1 is connected to the opposite phase input terminal of the operational amplifier OP and one end of a resistor R2 whose other end is connected to the ground (hereinafter abbreviated as GND). For this reason, the light emitting element Le can emit light by outputting a digital voltage from the control unit 15.

  On the other hand, the light receiving circuit 19B is configured such that the output voltage changes according to the amount of light received by the light receiving element Lr and received by the light emitting element Le and reflected by the ink ribbon 8. That is, the collector of the phototransistor constituting the light receiving element Lr is connected to Vcc via the resistor R3, and the emitter is connected to GND. The collector of the phototransistor is connected to the AD input port of the control unit 15 incorporating the A / D converter. For this reason, the control part 15 can take in the output voltage of the collector of a phototransistor, ie, the output voltage output from a sensor circuit (light receiving circuit 19B).

(Ribbon color identification principle)
Next, the principle of identifying the ribbon color of the ink ribbon 8 by the printer 1 of this embodiment will be described.

  Generally, since a sensor has variations in light emitting elements and light receiving elements, brightness adjustment (calibration) is performed in order to correct the variations. In the brightness adjustment, for example, a reference reflector (hereinafter referred to as “reference plate”) is used instead of the ink ribbon 8 shown in FIG. 5, and the output voltage from the light receiving circuit 19B is set to a reference voltage value (for example, preset). , 1.8V), a current value that flows through the light emitting element Le in a steady state is set (hereinafter, this current value is referred to as a “steady current value”, for example, 15 mA). As such a reference plate, for example, a plate having a higher reflectance than a black ink ribbon can be used. Specifically, by changing the digital voltage value output from the control unit 15 to the D / A converter DA so that the current flowing through the light emitting element Le gradually increases from a reference current value (for example, 0 [mA]), A digital voltage value when the output voltage output from the light receiving circuit 19B becomes the above-described reference voltage value is acquired, and the acquired digital voltage value is stored in, for example, a nonvolatile memory. When the light emitting element Le emits light in a steady state, the digital voltage value is read from the nonvolatile memory, and the read digital voltage value is output from the control unit 15 to the D / A converter DA. Flow a steady current value.

  By the way, utilizing the fact that the reflectance varies depending on the ribbon color of the ink ribbon 8, the voltage of the output voltage output from the light receiving circuit 19B when the light emitting element Le emits light with the digital voltage value stored in the nonvolatile memory 21. It can be considered that the ribbon color of the ink ribbon 8 is identified by the difference. Table 1 below shows an example of an output voltage output from the light receiving circuit 19B according to such an identification method. A transparent tape is wound around the end portion of the ink ribbon 8, and when the ribbon is cut, the transparent tape is exposed at the exposed portion 8.

  As shown in Table 1, the voltage difference between the output voltages output from the light receiving circuit 19B is small. In particular, the voltage difference between the blue and red ribbon colors is small, and taking into account sensor variations, there are difficulties in terms of accuracy (certainty of identification), and there is a problem to be improved.

  In order to solve this problem, the printer 1 does not identify the ribbon color according to the output voltage of the light receiving circuit 19B, but the output voltage of the light receiving circuit 19B is determined in advance from the voltage value corresponding to the reference current value. The ribbon color is identified according to the length of time until the set voltage value is reached. The details are as follows.

  By changing the digital voltage value output to the D / A converter DA, the light emitting circuit 19A is controlled and output from the light receiving circuit 19B so that the current flowing through the light emitting element Le gradually increases or decreases from the reference current value. Monitor the output voltage. For example, by changing the digital voltage value output to the D / A converter DA, the current flowing through the light emitting element Le becomes a constant value (for example, 50 ms) from the reference current value (for example, 0 [mA]) every predetermined time (for example, 50 ms). For example, the light emitting circuit 19A is controlled so as to increase or decrease by 0.15 mA) and the output voltage output from the light receiving circuit 19B is monitored.

  7 to 10 show the above-described steady current value (15 [mA]) from the reference current value (0 [mA]) to the light emitting element Le when the ribbon color of the ink ribbon is black, blue, red, and white, respectively. This shows the relationship between the output voltage output from the light receiving circuit 19B and time when the flow rate is increased by 0.15 mA every 50 ms.

  7 to 10 correspond to the case where the current flowing through the light emitting element Le is 0 [mA], and when the operating voltage (Vcc) of the light receiving element Lr is 3.3 V, the maximum voltage value shown in FIGS. 2V (a value obtained by subtracting 0.1 V corresponding to the voltage drop Vce (sat) of the light receiving element Lr). On the other hand, the voltage value when the voltage waveform of the output voltage output from the light receiving element Lr in FIGS. 7 to 10 is horizontal corresponds to when the steady current value flows through the light emitting element Le. 7 to 10 represent the output of the oscilloscope, the voltage value of the horizontal waveform portion is expressed as a state in which the output voltage of the light receiving element Lr is held (latched). The reflectance of each of the black, blue, red, and white ink ribbons described above has a relationship of black ink ribbon <blue ink ribbon <red ink ribbon <white ink ribbon. Are in the relationship of black ink ribbon> blue ink ribbon> red ink ribbon> white ink ribbon.

  FIG. 11A schematically shows the relationship between the length of time t until the output voltage of the light receiving circuit 19B reaches the voltage value of the horizontal waveform portion described above from the maximum voltage value and the black, blue, red, and white ink ribbons. The voltage waveform is a superposition of FIGS. 7 to 10. Note that the voltage value of the horizontal waveform portion is slightly exaggerated in order to clarify the voltage difference between the ink ribbons of the respective colors.

  As is clear from FIG. 11A, the length of time t from when the output voltage of the light receiving circuit 19B becomes the voltage value of the horizontal waveform portion described above to the maximum voltage value is white ink ribbon, red ink ribbon, blue Ink ribbon and black ink ribbon become longer in this order. Therefore, it can be seen that the ribbon color of the ink ribbon R can be identified according to the length of the time t.

  FIG. 11A shows an example in which 1.0 [s], 1.8 [s], and 2.5 [s] are set as the threshold values of time t. That is, when the time t <1.0 [s], the white ink ribbon, when 1.0 [s] ≦ time t <1.8, the red ink ribbon, and 1.8 [s] ≦ time t <2. When it is 5, it can be determined as a blue ink ribbon, and when time t ≧ 2.5, it can be determined as a white ink ribbon.

  In the above embodiment, the current flowing through the light emitting element Le increases from a reference current value (for example, 0 mA) to a steady current value (for example, 15 mA) by a constant value (for example, 0.15 mA) every predetermined time (for example, 50 ms). Thus, the light emitting circuit 19A is controlled to monitor the output voltage output from the light receiving circuit 19B. However, the present invention does not necessarily require the current flowing through the light emitting element Le to flow to a steady current value. That is, the light receiving circuit 19A is controlled by controlling the light emitting circuit 19A so that the current flowing through the light emitting element Le increases from a reference current value (for example, 0 mA) by a constant value (for example, 0.15 mA) every predetermined time (for example, 50 ms). You may make it monitor until the output voltage output from 19B becomes a preset voltage value.

  In this case, the set voltage value is theoretically a voltage value (for example, 1.62 V) output from the light receiving circuit 19B when the steady current value flows through the light emitting element Le when the ribbon color of the ink ribbon R is black. ) Above and below the maximum voltage value. Therefore, for example, as shown by a chain line in FIG. 11A, the reference voltage value can be set to a voltage close to the maximum voltage value. In this case, the output voltage output from the light receiving circuit 19B is the set voltage. Although the time until the value is shortened (processing time can be shortened), the margin of time t for identifying each color is reduced. For this reason, in consideration of accuracy (identification certainty), it is preferable that the margin is as wide as possible (the wider the margin, the more accurate the ribbon color can be prevented). The reference current value does not need to be 0 mA, and may be different from the steady current value to such an extent that a margin capable of discriminating the color of the ink ribbon is obtained. For example, when the reference current value is 5 mA, the time until the steady current value (15 mA) is reached is shortened. However, when the number of ink ribbon colors to be determined is small, the threshold value can be reduced and the margin is widened. Since it can be taken, it can be determined.

  Therefore, in FIG. 11A, as the set voltage value, the voltage value output from the light receiving circuit 19B when the steady current value (15 mA) flows through the light emitting element Le when the ribbon color of the ink ribbon R is black. An example in which is set is shown. The advantage of setting the set voltage value in this way is that it is not necessary to adjust the brightness when the printer 1 is manufactured for the sensor Se. That is, in this mode, the output voltage output from the light receiving circuit 19B by controlling the light emitting circuit 19A so that the current flowing through the light emitting element Le increases by a constant value from the reference current value every predetermined time is the set voltage value. (The steady-state current value is not used), the set voltage value that has been set may be stored in the ROM. Aside from the inspection for the sensor Se, the brightness adjustment of the sensor Se using the reference plate for each printer 1 It is not necessary to store the digital voltage value corresponding to the steady current value of the light emitting element Le in the nonvolatile memory.

  On the other hand, FIG. 11B is an example in which the above-described reference voltage value (for example, 1.8 V) is set as the set voltage value. Also in this example, since the margin of time t can be widened, accuracy (certainty of identification) can be ensured, and luminance adjustment at the time of manufacturing the printer 1 with respect to the sensor Se is unnecessary. Therefore, the set voltage value is equal to or higher than the voltage value output from the light receiving circuit 19B when the steady current value flows through the light emitting element Le when the ribbon color of the ink ribbon R is black, and lower than the reference voltage value. Although it is preferable to set, the present invention is not limited to this range because it can be set within the theoretical range described above. In the following, for the sake of simplicity, as shown in FIG. 11A, the received light when the set voltage value is a steady current value flows through the light emitting element Le when the ribbon color of the ink ribbon R is black. Description will be made assuming that the voltage value output from the circuit 19B is set.

  FIG. 12 is a graph showing the relationship between the output voltage output from the light receiving circuit and the time when the ink ribbon runs out (transparent tape). As described above, the transparent tape is wound around the end portion of the ink ribbon 8, and when the ribbon is cut, the transparent tape is exposed at the exposed portion 8. Therefore, the printer 1 can detect ribbon breakage as in the case of identifying the ribbon color of the ink ribbon R. In this case, for example, 5 [s] can be set as the threshold value of time t. That is, it can be determined that the black ink ribbon is 2.5 [s] ≦ time t <5, and the ribbon is broken when time t ≧ 5.

  The control unit 15 monitors the output voltage output from the light receiving circuit 19B, and identifies the ribbon color of the ink ribbon R according to the length of time t until the output voltage reaches the set voltage value from the maximum voltage value. For example, the time t until the output voltage reaches the set voltage value from the maximum voltage value is measured or calculated, and the time t is a predetermined relationship between the length of time until the set voltage value is reached and the ink ribbon R ( 11 (A)), the ribbon color of the ink ribbon R is identified.

  Even if the control unit 15 (the CPU) counts the time t directly with an internal clock or the sampling rate of the A / D converter built in the control unit 15 is known, (the number of sampling data) × ( The time t may be calculated from the sampling rate. In the latter mode, the sampling data is temporarily stored in a RAM that functions as a buffer.

(Operation)
Next, the operation of the printer 1 of the present embodiment will be described with a CPU of the control unit 15 (hereinafter abbreviated as “CPU”) as a subject.

  When the printer 1 is turned on, the program and program data stored in the ROM are expanded in the RAM, and the CPU performs an initial setting process for moving each unit described above to a predetermined home position. In the initial setting process, a ribbon color identification routine for identifying the ribbon color of the ink ribbon R is also executed.

  As shown in FIG. 6, in this ribbon color identification routine, in step 102, time t is measured (timed or calculated), and in step 104, it is determined whether or not time t is less than 1.0 [s]. If the determination in step 104 is affirmative, the ribbon color of the ink ribbon R is determined to be white in step 106 and the ribbon color identification routine is terminated. If the determination in step 104 is negative, the time t is 1.0 [ s] or more and less than 1.8 [s].

  If an affirmative determination is made in step 108, the ribbon color of the ink ribbon R is determined to be red in step 110 and the ribbon color identification routine is terminated. If a negative determination is made in step 108, the time t is 1.8 [ s] or more and less than 2.5 [s]. If the determination in step 112 is affirmative, the ribbon color of the ink ribbon R is determined to be blue in step 114 and the ribbon color identification routine is terminated. If the determination in step 112 is negative, the time t is 2.5 [ s] or more and less than 5 [s].

  If an affirmative determination is made in step 116, the ribbon color of the ink ribbon R is determined to be black in step 118 and the ribbon color identification routine is terminated. If a negative determination is made in step 120, it is determined that the ribbon is out and the ink ribbon cassette is displayed on the display unit 14. 8 is displayed and the ribbon color identification routine is terminated.

  After completion of the initial setting, the CPU waits for input of print command information and cutting command information from the input unit 13 by the operator. When these pieces of information are input, the CPU generates print data according to the input print command information and waits for a print start instruction from the operator.

  When the operator presses a predetermined button (for example, enter button) of the input unit 13 to give a print start instruction, the print medium M is referred to the output from the sensor arranged on the upstream side of the transport rollers 2a and 2b. It is determined whether or not it is set at a predetermined position. If a negative determination is made, the fact is displayed on the display unit 14 and waits. If an affirmative determination is made, the stepping motors 5 and 9 are driven to print on the print medium M. Apply processing.

  That is, the thermal head 6 is moved to a printing position where the thermal head 6 is pressed against the platen roller 3, and is output to the thermal head 6 line by line according to the generated print data. At this time, the CPU changes the amount of heat generated by the thermal head 6 (printing condition on the printing medium M) according to the ribbon color of the ink ribbon R identified by the ribbon color identification routine. For example, assuming that the heat generation when the ribbon color of the ink ribbon R is black is 100%, about 80% to 90% when the ribbon color is blue, and about 70% to 80% when the ribbon color is red. When the ribbon color is white, the calorific value is set to 60% to 70%, but the present invention is not limited to this. Considering the specific heat of the print medium M, the amount of heat generated by the thermal head 6 may be changed according to the type of the print medium M and the ribbon color of the ink ribbon R.

  The print medium M is conveyed downstream on the medium conveyance path by the rotational driving force of the conveyance rollers 2 a and 2 b, the platen roller 3, and the pinch roller 4, and a desired character is printed in the printing unit 20. In the present embodiment, since the stepping motors 5 and 9 are used for transporting the print medium M, the CPU counts the number of output pulses, whereby the front end of the print medium M with respect to the position of the heating element of the thermal head 6. The position relationship, that is, the printing position can be grasped.

  When the printing process on the printing medium M by the printing unit 20 (thermal head 6) is completed, the CPU moves the thermal head 6 to the retracted position where the thermal head 6 is retracted from the medium conveyance path, and the sensor from the sensor arranged on the downstream side of the pinch roller 4 With reference to the output, it is determined whether or not the leading edge of the print medium M is located downstream of the sensor position. If the determination is affirmative, the transport rollers 2a and 2b, the platen roller 3 and the pinch roller 4 are reversed. Then, the print medium M is reversely fed by a predetermined distance so that the front end of the print medium M is located upstream from the position of the sensor, and then the transport rollers 2a, 2b, the platen roller 3, and the pinch roller 4 are rotated forward to cut the print medium M. When the determination is negative, the transport rollers 2a and 2b, the platen roller 3 and the pinch roller 4 are rotated in the normal direction to transport the print medium M to the cutting unit 30 side.

  Further, the CPU instructs the cutting command information to a position facing the cutter blade 7a through the medium conveyance path in accordance with the cutting command information from the time when the print command information and the cutting command information are input by the operator to this time. The receiving surface of the cutter blade cradle 7b is positioned so that the surface (full cut surface, half cut surface) commanded in step 1 faces.

  When the leading edge of the print medium M passes the position of the cutter blade 7a and the cutting position with respect to the print medium M is conveyed to the position of the cutter blade 7a, the CPU drives the rollers 2a and 2b, the platen roller 3, and the pinch roller 4. Is stopped, the conveyance of the printing medium M is stopped, and the cutting blade 7a is advanced toward the cutting blade receiving base 7b to cut the printing medium M. The CPU monitors whether or not the leading edge of the print medium M has reached the position of the sensor with reference to the output from the sensor arranged on the downstream side of the pinch roller 4, and performs stepping based on the position of the sensor. By counting the number of output pulses to the motor 9, the relationship of the position of the front end of the printing medium M with respect to the position of the cutter blade 7a, that is, the cutting position can be grasped.

  Next, the CPU restarts driving of the rollers 2 a and 2 b, the platen roller 3, and the pinch roller 4, conveys the print medium M further downstream by a predetermined distance, and discharges it from the printer 1. Then, after a predetermined time has elapsed, the driving of the rollers 2a, 2b, the platen roller 3, and the pinch roller 4 is stopped, and the operation based on the input print / cut command information is ended. Note that the CPU further prevents rollers 2a and 2b, the platen roller 3, and the pinch roller from preventing the print medium M from being positioned on the curved portion on the medium conveyance path and bending the print medium M after a predetermined time has elapsed. 4 is driven to rewind the print medium M toward the transport rollers 2a and 2b.

(Effects etc.)
Next, effects and the like of the printer 1 of this embodiment will be described.

  In the printer 1 of this embodiment, since the ribbon color of the ink ribbon R can be identified using a single sensor Se, the cost can be reduced, and the ribbon color of the ink ribbon R can be identified without contact. Durability can be increased. Further, the CPU controls the light emitting circuit 19A to monitor the output voltage output from the light receiving circuit 19B so that the current flowing through the light emitting element Le gradually increases from the reference current value, and the output voltage is the maximum voltage value (reference value). Since the color of the ink ribbon is identified according to the length of the time t from when the current value is passed to the set voltage value (see FIGS. 11A and 6), the light receiving circuit Compared to identifying the ribbon color according to the output voltage of 19B, the color of the ink ribbon can be identified with high accuracy.

  Further, in the printer 1 of the present embodiment, the light emitting circuit 19A is controlled so as to gradually increase the current flowing through the light emitting element Le from the reference current value (without using the steady current value) and output from the light receiving circuit 19B. Monitor the output voltage. For this reason, it is not necessary to adjust the brightness of the sensor Se using the reference plate for each printer 1.

  Further, in the printer 1 of the present embodiment, the printing condition (heat generation amount) of the printing unit 20 (thermal head 6) is changed according to the identified ribbon color of the ink ribbon R. For this reason, the print quality of characters and the like printed on the print medium M can be improved.

  In the above-described embodiment, an example in which the present invention is applied to the printing apparatus (printer 1) has been described. However, the present invention is not limited thereto, and is applicable to a ribbon color identification apparatus that identifies the color of an ink ribbon. . In the above embodiment, an example in which a single color ribbon is used as the ink ribbon R has been described. However, the present invention is not limited to this, and for example, a plurality of colors such as Y (yellow), M (magenta), and C (cyan) are used. The present invention can also be applied to the case of identifying the ribbon color of an ink ribbon that has been repeated in the frame order, or to detect the position of a specific ribbon color. In such an aspect, the identification processing time and the like can be shortened by setting the exemplified predetermined time short. Further, in the above embodiment, specific numerical values are shown for the reference current value, the set voltage value, the predetermined time, the constant amount, the threshold value for time t, and the like, but it goes without saying that the present invention is not limited to this. .

  Further, in the above-described embodiment, the direct printing type printer 1 that directly forms an image on the print medium M using the ink ribbon R is illustrated, but the present invention is not limited to this. For example, the present invention is also applicable to an indirect printing system printing apparatus that forms an image on an intermediate transfer medium using an ink ribbon and transfers the image formed on the intermediate transfer medium to a print medium.

  Furthermore, in the above embodiment, the ink ribbon cassette 8 in which the supply reel 8c and the take-up reel 8d are accommodated in the cassette case 8a is illustrated, but the present invention is not limited to this and without using the cassette case 8a. The present invention can also be applied to a printing apparatus in which the supply reel 8c and the take-up reel 8d can be mounted on the supply reel rotation shaft and the take-up reel rotation shaft, respectively.

  In the above embodiment, as shown in FIG. 5, the example in which the collector side of the phototransistor is used as the output voltage of the light receiving circuit 19B is shown. However, the present invention is not limited to this, and for example, the emitter side of the phototransistor May be the output voltage of the light receiving circuit 19B. In this case, the waveforms of the output voltages shown in FIGS. 7 to 12 are reversed in the vertical direction. In such an aspect, the set voltage value described above is equal to or less than the voltage value output from the light receiving circuit Lr when the steady current value flows through the light emitting element Le when the ribbon voltage of the ink ribbon R exceeds the minimum voltage value and is black. Is set to the voltage value. At this time, a preferable set voltage value is not less than the reference voltage value and not more than the voltage value output from the light receiving circuit 19B when the steady current value flows through the light emitting element Le when the ribbon color of the ink ribbon R is black. You may make it set to a voltage value. At this time, when the emitter side of the phototransistor is used as the output voltage of the reflection type sensor, the resistor R3 in FIG. 5 is inserted between the emitter side of the phototransistor and the ground (GND), and the operating power supply (Vcc) is directly supplied to the photosensor. You may make it connect to the collector side of a transistor.

  Furthermore, in the above embodiment, the reflective sensor is exemplified as the sensor Se. However, the present invention is not limited to this, and a transmissive sensor may be used. Further, the sensor Se is not limited to the 3.3V system, and other voltage systems such as a 1.8V, 5V, and 12V system may be used. In the above-described embodiment, an example in which the operating voltage is the same for the light emitting element Le and the light receiving element Lr has been described. However, the present invention is not limited to this. Furthermore, in the said embodiment, although LED was illustrated in the light emitting element Le and the phototransistor was shown in the light receiving element Lr, this invention is not restrict | limited to this.

  In the present embodiment, the light emitting circuit 19A is controlled such that the current flowing through the light emitting element Le gradually increases from the reference current value. However, the reference current value is set to 15 mA, for example, and the CPU The light emitting circuit 19A is controlled to monitor the output voltage output from the light receiving circuit 19B so that the current flowing through Le gradually decreases from the reference current value, and the output voltage is set from the voltage value when the reference current value flows. You may make it identify the color of an ink ribbon according to the length of time t until it becomes voltage value (for example, 2.8V). In this case, an example is shown in which 0.65 [s], 0.9 [s], and 1.1 [s] are set as the threshold values for time t. That is, when the time t <0.65 [s], the white ink ribbon, when 0.65 [s] ≦ time t <0.9, the red ink ribbon, 0.9 [s] ≦ time t <1. When it is 1, it can be determined as a blue ink ribbon, and when time t ≧ 1.1, it can be determined as a white ink ribbon (FIG. 14).

  As described above, the present invention provides a ribbon color identification device that is low in cost and excellent in durability and accuracy, and a printing apparatus including the ribbon color identification device. Since it contributes to manufacturing and sales, it has industrial applicability.

1 Printer (printing device)
8 Ink ribbon cassette 8b Exposed part 8c Supply reel 8d Take-up reel 15 Control part (control means)
19A Light emitting circuit 19B Light receiving circuit 20 Printing unit (printing means)
Le light emitting element Lr light receiving element M Print medium (medium)
R Ink ribbon Se sensor

Claims (7)

An ink ribbon constructed between the supply reel and the take-up reel;
Printing means for performing a printing process on the medium using the ink ribbon;
A sensor having a light emitting element and a light receiving element to detect the ink ribbon;
A sensor circuit having a light emitting circuit for emitting the light emitting element and a light receiving circuit for operating the light receiving element;
Control means for controlling the sensor circuit;
With
The control means monitors the output voltage output from the light receiving circuit by controlling the light emitting circuit so that a current flowing through the light emitting element gradually increases or decreases from a reference current value, and the output voltage is the reference voltage A printing apparatus that identifies a color of the ink ribbon according to a length of time from a voltage value corresponding to a current value to a preset voltage value set in advance. The control means includes
The output voltage output from the light receiving circuit is monitored by controlling the light emitting circuit so that a current flowing through the light emitting element increases or decreases by a constant value from a reference current value every predetermined time, and the output voltage is the reference voltage The time from the voltage value corresponding to the current value to the set voltage value is measured or calculated,
The color of the ink ribbon is identified by applying the timed or calculated time to a predetermined relationship between the length of time until the set voltage value is reached and the color of the ink ribbon.
The printing apparatus according to claim 1.   The set voltage value is a voltage value greater than or equal to a voltage value output from the light receiving circuit when a steady current value flows through the light emitting element when the color of the ink ribbon is black, and less than the maximum voltage value, or 2. A voltage value equal to or lower than a voltage value output from the light receiving circuit when the steady current value flows through the light emitting element when the ink ribbon color is black when the minimum voltage value is exceeded. Or the printing apparatus of Claim 2. The light emitting circuit includes a D / A converter, an operational amplifier in which an output terminal of the D / A converter is connected to a positive phase input terminal, and a transistor in which an output terminal of the operational amplifier is connected to a base via a resistor. The light emitting element is inserted between the operating power supply (Vcc) and the collector of the transistor,
The control means controls the light emitting circuit so that a current flowing through the light emitting element gradually increases or decreases from a reference current value by changing a digital voltage output to the D / A converter. The printing apparatus according to any one of claims 1 to 3.   The ink ribbon is accommodated in an ink ribbon cassette having an exposed portion through which the ink ribbon is exposed, and the sensor is a reflective sensor disposed in the vicinity of the exposed portion. 5. The printing apparatus according to any one of 4 above.   6. The printing according to claim 1, wherein the control unit changes a printing condition on the medium by the printing unit in accordance with the color of the identified ink ribbon. apparatus. In a ribbon color identification device for identifying the color of an ink ribbon,
A sensor having a light emitting element and a light receiving element to detect the ink ribbon;
A sensor circuit having a light emitting circuit for emitting the light emitting element and a light receiving circuit for operating the light receiving element;
Control means for controlling the sensor circuit;
With
The control means monitors the output voltage output from the light receiving circuit by controlling the light emitting circuit so that a current flowing through the light emitting element gradually increases or decreases from a reference current value, and the output voltage is the reference voltage A ribbon color identification device for identifying a color of the ink ribbon according to a length of time from a voltage value corresponding to a current value to a preset voltage value set in advance.

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