JP2006338536A - Reader and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform reading while an appropriate range is irradiated with detection light by a simple structure. <P>SOLUTION: A sensor control part 51 varies an amount of energization to an LED 62, acquires voltage waveform data while adjusting an irradiation range of the detection light and calculates ratio (S/N) between a signal component valid for reading of an ID code 20 and a noise component to be an obstacle of reading about the voltage waveform data. Next, the calculated S/N value is associated with the voltage waveform data about which the value is obtained and stored in a RAM 74. Then, the ID code 20 is read by analyzing the voltage waveform data with the least ratio of the noise component by referring to the RAM 74 and detecting arrangement of bars and spaces of the ID code 20 from width and intervals of amplitude. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention uses a photoreflector that irradiates detection light from a light emitting element onto a reading target and receives reflected light reflected on the reading target with a light receiving element, and records it on the reading target based on the intensity of the reflected light. The present invention relates to a reading device that reads the recorded information, and a printer using such a reading device.

For example, a barcode is widely known in which various types of information such as character information and voice information are recorded as optically readable encoded information. In a reading apparatus that reads a barcode, a photo reflector in which a light emitting element and a light receiving element are packaged together is used.
The photo reflector irradiates the reading target with the detection light from the light emitting element, and receives the detection light reflected on the reading target with the light receiving element. The reading device reads the barcode based on the intensity of the reflected light received by the light receiving element.

  However, if the irradiation range of the detection light is not appropriate, reading becomes an obstacle, which is a problem. That is, if the illumination range of the detection light is too wide for the object to be read, the amount of light that is effective for reading out of the reflected light is reduced. Further, if the illumination range of the detection light is too narrow, it is likely to be affected by dust attached to the reading object.

Therefore, it is conceivable to adjust the irradiation range of the detection light with a lens so that the detection light is irradiated to an appropriate range. For example, Patent Document 1 below describes a lens actuator that switches an objective lens to be used according to a medium to be recorded and reproduced. If such a lens actuator is provided in a reading device, detection light is transmitted. An appropriate range can be irradiated.
JP-A-9-180218

  However, when the lens actuator as described above is used to adjust the irradiation range of the detection light, there is a problem that the number of members increases and the apparatus becomes large.

  An object of the present invention is to provide a reading device that can adjust the irradiation range of detection light with a simple configuration, and a printer using such a reading device.

  In order to achieve the above object, the reading apparatus of the present invention is characterized by including irradiation range adjusting means for changing the irradiation range of the detection light by increasing or decreasing the power supplied to the light emitting element.

  It is preferable to include a control unit that reads information recorded on the object based on the intensity of the reflected light having the least noise component among the reflected light obtained while changing the irradiation range of the detection light.

  A light emitting diode may be used as the light emitting element.

  The printer according to the present invention includes the above-described reading device, reads the recording paper information relating to the recording paper by the reading device, and determines the printing conditions based on the read recording paper information.

  According to the present invention, the irradiation range of the detection light is adjusted by increasing / decreasing the power supplied to the light source, so that the configuration is simple and the apparatus can be downsized as compared with the case where a lens actuator is provided.

  In addition, reading is performed automatically when the detection light is irradiated in the optimum range by changing the irradiation range of the detection light and performing reading based on the intensity of the reflected light with the least noise component. Because it is convenient.

  The case where the present invention is applied to a color thermal printer that thermally records an image on a thermal recording paper will be described below. In the color thermal printer 10, a long color thermal recording paper (hereinafter simply referred to as recording paper) 12 is used as a recording medium. The recording paper 12 is set in the color thermal printer 10 in the form of a recording paper roll 16 wound around the winding core 14 in a roll shape.

  As is well known, the recording paper 12 is provided with a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer in this order on a support. The yellow thermosensitive coloring layer, which is the uppermost layer, has the highest thermal sensitivity and develops yellow with a small amount of heat energy. The cyan thermosensitive coloring layer, which is the lowermost layer, has the lowest thermal sensitivity and develops cyan with large heat energy. The yellow thermosensitive coloring layer loses its coloring ability when irradiated with yellow fixing light, which is blue-violet light having a wavelength of about 420 nm. The magenta thermosensitive coloring layer develops magenta with intermediate thermal energy between the yellow thermosensitive coloring layer and the cyan thermosensitive coloring layer, and the coloring ability disappears when irradiated with magenta fixing light having a wavelength of about 365 nm. To do.

  As the recording paper 12, in addition to the standard recording paper, there are various types such as a glossy recording paper whose surface is glossy and mainly used for printing image data, and a sticker recording paper that can use the printed image as a seal. Different types are used, and the optimum printing conditions are different. For this reason, an ID code 20 indicating recording paper information relating to the recording paper is written on the side surface of the core 14. The ID code 20 is written in the form of a barcode composed of a plurality of bars and spaces arranged along the rotation direction of the core 14. The ID code 20 is read by the color thermal printer 10 and used to adjust printing conditions.

  The color thermal printer 10 includes a paper feed roller 22, a conveyance roller pair 24, a thermal head 26, an optical fixing device 28, and a cutter device 30. Each unit of the color thermal printer 10 is connected to the system controller 32 and driven and controlled by the system controller 32.

  The paper feed roller 22 is disposed so as to be in contact with the outer peripheral surface of the recording paper roll 16, and feeds the leading end side of the recording paper 12 from the recording paper roll 16 onto the conveyance path. The conveyance roller pair 24 nips the fed recording paper 12 and reciprocates it in the A direction and the B direction. The paper feed roller 22 and the transport roller pair 24 are driven by a transport motor 34. As the transport motor 34, a stepping motor that rotates a predetermined amount according to the number of supplied drive pulses is used. The system controller 32 controls the conveyance amount of the recording paper 12 by adjusting the number of drive pulses supplied to the conveyance motor 34.

  During this conveyance, thermal recording by the thermal head 26 and optical fixing by the optical fixing device 28 are performed on the recording paper 12. The thermal head 26 presses the recording paper 12 and heats each thermosensitive coloring layer to thermally record an image of each color of yellow, magenta, and cyan. A platen roller 36 that supports the recording paper 12 that receives pressure from the thermal head 26 from the back side is provided at a position facing the thermal head 26. The recording paper 12 is thermally recorded while being sandwiched between the thermal head 26 and the platen roller 36.

  The optical fixing unit 28 includes a yellow fixing lamp 38 that emits yellow fixing light, a magenta fixing lamp 40 that emits magenta fixing light, and a reflector 42. The yellow fixing lamp 38 irradiates the yellow thermosensitive coloring layer on which the yellow image has been thermally recorded with the yellow fixing light to fix the yellow image. The magenta fixing lamp 40 irradiates the magenta thermosensitive coloring layer on which a magenta image has been recorded with a magenta fixing light to fix the light. The reflector 42 reflects the light emitted from the fixing lamps 38 and 40 for yellow and magenta toward the recording paper 12.

  The cutter device 30 includes a fixed blade 44 that extends in the width direction of the recording paper 12 and a rotary blade 46 that moves along the fixed blade 44. The rotary blade 46 is driven by a cutter motor 48. The system controller 32 controls the cutter motor 48 to drive the rotary blade 46 to cut the recording paper 12. The cut recording paper 12 is discharged from a paper discharge port (not shown).

  The color thermal printer 10 is provided with a photo reflector 50 as a sensor for reading the ID code 20 described above. The photo reflector 50 is disposed so as to face the side surface of the core 14, and is driven and controlled by a drive signal transmitted from a sensor control unit 51 provided in the system controller 32.

  In FIG. 2 showing the reading mechanism of the ID code 20, the photo reflector 50 includes a light emitting circuit 52 and a light receiving circuit 54. The light emitting circuit 52 is provided with a D / A converter 56, an amplifier 58, an FET 60, and a light emitting diode (LED) 62. The D / A converter 56 converts the digital drive signal input from the sensor control unit 51 into an analog drive signal and outputs the analog drive signal to the amplifier 58. The amplifier 58 is connected to the gate electrode of the FET 60, and amplifies the drive signal sufficient for driving the FET 60.

  The FET 60 is composed of a well-known field effect transistor, and includes a source electrode and a drain electrode in addition to the gate electrode described above. The FET 60 allows a current corresponding to the magnitude of the voltage applied to the gate electrode to flow between the source electrode and the drain electrode. The LED 62 is connected to the FET 60, emits light by a current flowing between the source electrode and the drain electrode, and irradiates detection light toward the core 14 on which the ID code 20 is written.

  On the other hand, the light receiving circuit 54 is provided with a phototransistor 64, an amplifier 66, and an A / D converter 68. Detection light from the LED 62 is reflected by the core 14 and enters the phototransistor 64. As a result, a voltage having a magnitude corresponding to the reflection intensity of the detection light is generated at the electrodes at both ends of the phototransistor 64. This voltage is amplified by the amplifier 66 and then digitally converted by the A / D converter 68 and is output to the sensor control unit 51 as voltage waveform data representing a temporal change in the voltage value.

  The sensor control unit 51 drives the photo reflector 50 while rotating the recording paper roll 16 to acquire voltage waveform data. The ID code 20 written on the core 14 has different reflectivity of detection light between the bar portion and the space portion. Therefore, the ID code 20 is analyzed by analyzing the voltage waveform data obtained while rotating the recording paper roll 16. 20 can be read.

  However, when the irradiation range of the detection light is wider than the width of the core 14, the amount of light effective for reading out of the light incident on the phototransistor 64 is reduced, and the irradiation range of the detection light is the core 14. If it is narrower than the width, the influence of dust or the like adhering to the core 14 will increase. As described above, when the irradiation range of the detection light is not appropriate, the ratio of the noise component included in the voltage waveform data is increased, and there is a problem that reliable reading cannot be performed. For this reason, the sensor control unit 51 adjusts the irradiation range of the detection light, and performs reading in a state where the detection light is irradiated to the optimal irradiation range.

  As shown in FIG. 3, the irradiation range of the detection light from the LED 62 varies depending on the energization amount to the LED 62, and the irradiation range is widened when the energization amount is large, and the irradiation range is narrowed when the energization amount is small. Have Using this property, the sensor control unit 51 adjusts the voltage value applied to the gate electrode of the FET 60 via the D / A converter 56 and the amplifier 58, thereby changing the energization amount to the LED 62 and irradiating the detection light. Adjust the range.

  Hereinafter, the reading procedure performed while adjusting the irradiation range of the detection light will be described based on the flowchart shown in FIG. The sensor control unit 51 includes a ROM 70, a noise analysis unit 72, a RAM 74, and an ID code analysis unit 76 (see FIG. 3). The ROM 70 stores a value from the minimum value A (1) to the maximum value A (n) as a value representing the energization amount to the LED 62. The sensor control unit 51 changes the energization amount to the LED 62 from the minimum value A (1) to the maximum value A (n), and acquires n pieces of voltage waveform data.

  Each time new voltage waveform data is acquired, the noise analysis unit 72 calculates a ratio (S / N) between a signal component effective for reading the ID code 20 and a noise component that obstructs reading. In the calculation of S / N, for example, of the amplitude of the voltage waveform data, an amplitude equal to or larger than a preset threshold is regarded as an effective signal, and an amplitude smaller than the threshold is regarded as noise. Then, the minimum amplitude of the effective signals is Vs, the minimum amplitude of the noise components is Vn, and the ratio Vs / Vn is acquired as S / N. The obtained S / N value is stored in the RAM 74 in association with the acquired voltage waveform data.

  The ID code analysis unit 76 refers to the RAM 74 and extracts voltage waveform data with the smallest noise component ratio. Then, the ID code analyzing unit 76 analyzes the voltage waveform data, and reads the ID code 20 by detecting the bar and space arrangement of the ID code 20 from the amplitude width and interval.

  As described above, if the detection light is not irradiated in an appropriate range, the noise component included in the voltage waveform data increases. For this reason, the voltage waveform data with the least noise component is obtained in a state where the detection light is irradiated in the optimum irradiation range, and the ID code 20 is read based on this voltage waveform data, so that reliable reading is possible. It can be carried out.

  The operation of the present invention having the above configuration will be described below. On the winding core 14 of the recording paper roll 16, an ID code 20 on which information relating to the recording paper 12 is recorded is recorded. The color thermal printer 10 reads the ID code 20 when, for example, the recording paper roll is replaced or when the power is turned on. Then, the printing conditions are adjusted based on the recording paper information recorded in the ID code 20.

  The ID code 20 is read by analyzing voltage waveform data representing the reflection intensity of the detection light emitted from the LED 62 to the core 14 of the recording paper roll 16. At this time, by changing the energization amount to the LED 62, the irradiation range of the detection light is adjusted, and a plurality of voltage waveform data is acquired. And reading is performed based on what was acquired in the state where the noise component was the smallest among these several voltage waveform data, and the detection light was irradiated to the appropriate range. Thereby, reliable reading can be performed. Further, since the irradiation range of the detection light is adjusted by changing the energization amount to the LED 62, an increase in the number of members can be suppressed.

  In the present invention, it is only necessary to adjust the irradiation range of the detection light by increasing / decreasing the power supplied to the light source. Therefore, the detailed configuration is not limited to the above embodiment and can be changed as appropriate. For example, in the above-described embodiment, the example in which the ID code is read by one phototransistor has been described. However, the ID code may be read by using a line sensor in which a plurality of phototransistors are arranged, an area sensor, or the like. .

  Moreover, although the said embodiment demonstrated the example which controls the electricity supply amount to LED using FET, you may control the electricity supply amount to LED using a variable resistance, for example. Further, although an example in which one LED is provided has been described, a plurality of LEDs may be provided. Further, although an example in which the present invention is applied to a color thermal printer has been described, the present invention may be applied to other devices.

It is a block diagram of a color thermal printer. It is a block diagram of the reading mechanism which reads ID code. It is explanatory drawing showing the relationship between the energization amount to LED, and the irradiation range of detection light. It is a flowchart showing the reading procedure of ID code.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Color thermal printer 12 Recording paper 14 Core 16 Recording paper roll 20 ID code 26 Thermal head 28 Optical fixing device 32 System controller 50 Photo reflector 51 Sensor control part 60 FET
62 LED
64 Phototransistor 70 ROM
72 Noise analysis unit 74 RAM
76 ID code analyzer

Claims (4)

Using a photoreflector that irradiates the detection light from the light emitting element to the reading object and receives the reflected light reflected by the reading object by the light receiving element, information recorded on the reading object based on the intensity of the reflected light In the reading device to read
A reading apparatus comprising: an irradiation range adjusting unit that changes the irradiation range of the detection light by increasing or decreasing the power supplied to the light emitting element.   Control means for reading information recorded on the object based on the intensity of the reflected light with the least noise component among the reflected light obtained while changing the irradiation range of the detection light, Reading device.   The reading device according to claim 1, wherein a light emitting diode is used as the light emitting element. A printer comprising the reading device according to claim 1, wherein the reading device reads recording paper information relating to the recording paper, and determines a printing condition based on the read recording paper information.

Images