JP2003191546A - Printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure a paper conveyance amount with high accuracy. <P>SOLUTION: A rotation detecting disc 31 mounted concentrically with the rotation shaft of a stepping motor 7 is rotated with the stepping motor 7. A CPU 11 supplies a count enabling signal to a digital counter 36 for counting the number of pulses of the pulse signal supplied to the stepping motor 7. The digital counter 36 counts the number of detection of the slit of the rotation detecting disc 31 by a magnetic sensor 32 (number of steps) by the output signal from an AND gate 35. The CPU 11 detects trouble generation by reading out the counter data (number of steps) from the digital counter 36 and comparing the number of pulses and the number of steps. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device,
In particular, the present invention relates to a printing apparatus that estimates the carry amount of a sheet based on the number of pulses of a pulse signal supplied to a stepping motor and controls the printing position, the cutting position, and the like.

[0002]

2. Description of the Related Art In a conventional label printer as a printing apparatus, the feed amount of a sheet is measured by counting the operation pulse number of a pulse motor (stepping motor) at the time of issuing a label or feeding the sheet by software. It was That is, when the motor control unit that controls the stepping motor outputs a pulse signal, it is assumed that this pulse signal is supplied to the stepping motor and rotates one step per pulse, and the pulse number of the pulse signal output by the motor control unit is The number of operation pulses of the stepping motor is counted, and the sheet feed amount is converted from the counted number. Therefore, if there is no problem, the sheet feed amount can be measured by counting the number of pulses of the pulse signal output by the motor control unit.

[0003]

As described above, according to the conventional method in which the number of pulses of the pulse signal output by the motor control unit is regarded as the number of steps at which the stepping motor actually rotates, the motor may malfunction due to a stepping motor malfunction or the like. Despite the fact that the control unit outputs a pulse signal, it is not possible to detect a mechanical or electrical failure such that the stepping motor is not actually rotating. In addition, there is a problem that the actual transport distance of the sheet cannot be accurately grasped due to the play of the gear that transmits the rotational driving force of the stepping motor to the platen roller that transports the sheet.

The present invention has been made in view of such a situation, and is to make it possible to more accurately measure the transport distance of a sheet.

[0005]

According to a first aspect of the present invention, there is provided a printing device which rotates a step for each pulse by receiving a pulse signal and a printing means for printing predetermined print data on a predetermined paper. A motor, a motor control unit that supplies a pulse signal to the motor, a counting unit that counts the number of pulses of the pulse signal that the motor control unit supplies to the motor, and a number of steps at which the motor actually rotates are detected. The step number detecting means, the conveying means that rotates by the rotational driving force of the motor, presses the paper against the printing means and conveys the sheet in the conveying direction, the number of pulses counted by the counting means, and the step number detecting means. Based on the number of steps, it is detected that at least one of the motor, the step number detecting means, and the conveying means has a defect. Characterized in that it comprises a fault detection means. Further, the defect detecting means compares the pulse number with the step number, and when the pulse number is larger than the step number,
The transport means may additionally transport the paper in the transport direction by the difference between the number of pulses and the number of steps. Further, the defect detecting means compares the number of pulses with the number of steps, and when the number of steps is greater than the number of pulses, the carrying means
The sheet can be conveyed in the direction opposite to the conveying direction by the difference between the step number and the pulse number.

[0006]

1 shows an example of the configuration of an embodiment of a label printer to which the present invention is applied. As shown in FIG. 1, the label printer 100 is driven by a control unit 10 that controls each unit, a thermal head (hereinafter, simply referred to as a head) 5 that prints on a sheet 1, and a control unit 10 A stepping motor 7
The sheet 1 is rotated by a rotational driving force of a stepping motor 7 transmitted via a timing belt (hereinafter, simply referred to as a belt) 8 to convey a sheet 1 set on a supply shaft 2 to be described later, A platen roller (hereinafter simply referred to as a platen) 6 that presses against the thermal head 5, a supply shaft 2 that rotatably supports the sheet 1, a guide roller 3 that guides the sheet 1 to the thermal head 5, And a light-receiving unit that receives the reflected light from the paper 1 of the light emitted from the light-emitting unit and outputs an electric signal corresponding to the intensity of the received light (amount of light received per unit time). And a light emitting section and a light receiving section are arranged on the back side of the sheet 1, and an eye mark (black rectangular mark) formed on the back side of the sheet 1 by printing or the like is formed based on the light receiving amount of the light receiving section. Inspection And a pitch sensor 9. Further, as will be described later with reference to FIG. 3, a rotation detection disk 31 is attached to the stepping motor 7 coaxially with a rotation shaft (not shown) of the stepping motor 7, and when the stepping motor 7 rotates, rotation detection is performed. The disk 31 for rotation also rotates.

FIG. 2 is a block diagram showing an electrical configuration example of the embodiment shown in FIG. As shown in the figure, the control unit 10 stores a predetermined control program in a ROM (re
CPU (central processing), which operates according to a control program stored in the ROM 12 and controls each unit.
unit) 11 and a RAM (random ac) for storing various data necessary for the CPU 11 to operate.
and an EEPROM for storing various data that should be retained even when the power is turned off.
(Electrically erasable an
d programmable read only
memory) 21, a motor control unit 14 that supplies a pulse signal to the stepping motor 7 to rotate the stepping motor 7, and control corresponding to print data such as characters, graphics, and bar codes to be printed, which are supplied from the CPU 11. A head controller 15 that generates a signal and supplies the signal to the thermal head 5 to perform a printing operation and a light emitting unit of the pitch sensor 9 under the control of the CPU 11 emits light and is output from the light receiving unit. Receives an electrical signal,
A sensor control unit 16 that converts the digital data to supply it to the CPU 11 as pitch detection data, an external interface 17, and an interface 20 are provided.
Further, the control unit 10 includes an input unit 18 for inputting various data and commands, and a display unit 19 for displaying input data and various information input from the input unit 18 via an interface 20. It is connected. Input unit 18
The input data input from the CPU 11 is supplied to the CPU 11 via the interface 20, and the display data corresponding to various information displayed on the display unit 19 is supplied from the CPU 11 via the interface 20. Further, various data and commands can be transmitted / received to / from various devices such as a personal computer (PC) 200 externally connected via the external interface 17.

FIG. 3 is a block diagram showing an example of the construction of the paper transport measuring mechanism and the paper transport measuring circuit. As shown in the figure, the rotation shaft (not shown) of the rotation detecting disk 31 is coaxially connected to the rotation shaft (not shown) of the stepping motor 7, and when the stepping motor 7 rotates by one step, the rotation is rotated. The detection disk 31 is also designed to rotate by one step. The rotation detecting disk 31 is made of iron material, and in FIG. 3, there is only one notch (slit) on the circumference.
However, in practice, this slit is so arranged as to output a detection signal indicating that the magnetic sensor 32 has detected the slit each time the stepping motor 7 rotates by one step. Disk for rotation detection 31
Is formed for each step angle that rotates.

The magnetic sensor 32 is arranged on the outer circumference of the rotation detecting disk 31, and the rotation detecting disk 31 is detected from the change in magnetism.
The notch is detected and a detection signal is output. When the detection signal from the magnetic sensor 32 is input, the amplifier 33 amplifies the voltage of this detection signal and outputs it. The comparator 34 outputs the amplified detection signal output from the amplifier 33 as a pulse waveform signal and outputs it. The output pulse waveform signal is supplied to the AND gate 35.

On the other hand, the CPU 11 supplies a high level count enable signal (count pulse gate signal) to the AND gate 35 at the timing when the motor controller 14 supplies a pulse signal to the stepping motor 7. The AND gate 35 determines that the pulse waveform signal supplied from the comparator 34 is at a high level and that the CPU
When the count enable signal is supplied from 11, the voltage level of the output signal is set to the high level.

The digital counter 36 includes an AND gate 3
When the level of the output signal from 5 changes to high level, the count value is incremented by 1. Therefore, when the motor control unit 14 supplies the pulse signal to the stepping motor 7 and the stepping motor 7 actually rotates by one step, the count value is incremented. That is, the count value of the digital counter 36 is
It accurately represents the number of steps that the stepping motor 7 has rotated.

The count value (counter data) of the digital counter 36 is supplied to the CPU 11 when a counter data read signal is supplied from the CPU 11.
Further, when the counter reset signal is supplied from the CPU 11, the digital counter 36 sets the count value to 0 (reset). For example, the digital counter 36 is 1
A 6-bit counter can count up to 65536 (= 2 ¹⁶ ). When the paper 1 is transported by 0.125 mm (mm) per step,
The transport distance of the sheet 1 can be detected up to 8192 (= 65536 × 0.125) mm.

Next, the operations of the sheet transport measuring mechanism and the sheet transport measuring circuit will be described with reference to the flow chart shown in FIG. First of all, in step S1,
The CPU 11 receives, via the interface 20, the paper conveyance command input by the operator operating the input unit 18.

Next, in step S2, the paper conveyance amount (the number of pulses of the pulse signal to be supplied to the stepping motor 7) is calculated. For example, when the transport distance of the sheet 1 per pulse is 0.125 mm, the sheet 1 is 30 m
When carrying only m, the number of pulses of the pulse signal to be supplied to the stepping motor 7 is 240 (= 30 / 0.12).
5). Here, the sheet 1 is composed of a backing sheet and labels that are peelably attached to the backing sheet at equal intervals, and the label pitch (the distance from the head of the label to the head of the next label) is 30 mm.

In step S3, the number of pulses of the pulse signal calculated in step S2 (C1) is set to RA.
It is set in the transport calculation value storage area of M13. Next, in step S4, the CPU 11 supplies a counter reset signal to the digital counter 36 and sets the count value of the digital counter 36 to zero.

Next, in step S5, the CPU 11
Reads the pulse number C1 of the pulse signal stored in the conveyance calculation value storage area of the RAM 13 and instructs the motor control unit 14 to supply the pulse signal to the stepping motor 7 by the number of pulses. The motor control unit 14 that has received the command from the CPU 11 supplies the pulse signal to the stepping motor 7. Next, in step S6, the CP
U11 sets the voltage level of the count enable signal to the high level and opens the counter gate (counter start).
That is, a signal having a high voltage value is supplied to one input terminal of the AND gate 35.

As a result, when the magnetic sensor 32 detects the cutout of the rotation detecting disk 31, the AND gate 35.
The voltage value of the output signal of changes to the high level. When the voltage value of the output signal of the AND gate 35 changes to the high level, the digital counter 36 increments the count value by 1.

Next, in step S7, the paper conveyance control is started, and the motor controller 14 supplies the stepping motor 7 with pulse signals for the remaining number of pulses and the digital counter 36 performs counting. . In step S8, the paper transport control for the pulse number C1 is completed.

Next, in step S9, the CPU 11
Closes the counter gate (stops the counter) by setting the voltage value of the count enable signal to the low level. That is, since a signal whose voltage value is low level is input to one input terminal of the AND gate 35,
The voltage value of the output signal of the gate 35 is always low level.

Next, in step S10, the CPU 1
1 supplies a counter data read signal to the digital counter 36. The digital counter 36 is a CPU
When the counter data read signal is supplied from 11, the counter data (count value) is supplied to the CPU 11.
The CPU 11 receives the counter data (denoted as C2) sent from the digital counter 36.

Next, in step S11, the CPU 1
1 detects a defect when the paper is conveyed. As a defect,
For example, cases A to C are possible. Case A
Is when there is no pulse input from the AND gate 35 to the digital counter 36, or when the count value of the digital counter 36 after conveyance is 0. In this case, it is considered that a so-called paper jam error occurs in which the paper 1 is not conveyed due to jamming of the paper 1.

In case B, the digital counter 3 after transportation is used.
This is the case where the count value of 6 is significantly smaller than the count value (C1) calculated in step S2. In this case, it is considered that a paper jam error or a conveyance slip has occurred.

In case C, the digital counter 3 after transportation is used.
This is the case where the count value of 6 is significantly larger than the count value (C1) calculated in step S2. In this case, it is considered that the conveyance control failure or the conveyance mechanism failure occurred.

Next, in step S12, the count value calculated in step S2 (C1: calculated value)
And the counter data (C2: corresponding to the actual carry amount) of the digital counter 36 read in step S10 are compared, and the correction process according to the comparison result is executed.

When the comparison result is C2 <C1, it indicates that the actual carry amount is smaller than the calculated value, and as the correction process, the differential additional carry (the paper 1 is carried in the carry direction (forward direction) by the number of steps of the difference). The process of carrying) is performed.
Here, the difference is a value obtained by subtracting the counter data C2 corresponding to the actual carry amount from the calculated value C1.

If the comparison result is C2 = C1, it indicates that the calculated value and the actual carry amount are equal, and no correction processing is performed.

Further, when the comparison result is C2> C1, it indicates that the actual carry amount is larger than the calculated value, and as the correction process, the differential back carry (the process of carrying the paper 1 in the back direction by the difference step number). ) Is done. Here, the difference is a value obtained by subtracting the calculated value C1 from the counter data C2 corresponding to the actual carry amount.

In this way, after the correction processing is performed according to the comparison result of the calculated value C1 and the counter data C2 corresponding to the actual carry amount, this processing is ended.

As described above, according to this embodiment, the following effects can be obtained. The first effect is to directly connect to the rotation shaft of the stepping motor 7 that drives the platen roller 6 and to mount the rotation detection disk 31 coaxially.
By detecting the slit of the rotation detecting disk 31 with the magnetic sensor 32, it is possible to detect the number of steps in which the stepping motor 7 rotates with high accuracy, and thus it is possible to measure the transport distance of the paper 1 with high accuracy. Is to be.

The second effect is that since the number of steps by which the stepping motor 7 rotates is measured by hardware, the load on the CPU 11 during printing is reduced, and the processing of the CPU 11 can be allocated to other processing correspondingly. It is possible.

A third effect is that it is possible to provide a service for accurately informing cleaning and maintenance time in accordance with the set sheet conveyance distance.

A fourth effect is that by comparing the amount of paper transport estimated by the transport control with the amount of paper actually transported, it is possible to determine the mechanical or electrical malfunction of the transport system. It is something that can be discovered.

The fifth effect is that the sheet position can be calculated more accurately by grasping the actual sheet conveyance amount with high accuracy.

In the above-described embodiment, the rotation shaft of the rotation detection disc 31 is mounted coaxially with the rotation shaft (not shown) of the stepping motor 7, but the slit of the rotation detection disc 31 is rotated. Alternatively, the teeth of the drive transmission gear may be substituted, and the teeth of the gear may be detected by a magnetic sensor or an optical sensor and the number thereof may be counted.

Further, two or more slits may be formed on the circumference of the rotation detecting disk 31. Further, the rotation detection disk 31 may be attached to the rotation shaft of the platen roller 6.

Further, it is possible to detect whether or not the rotation detecting disk 31 is rotating by irradiating the slit of the rotation detecting disk 31 with light and detecting the light transmitted through the slit using an optical sensor. You can also

Further, the rotational driving force of the stepping motor 7 may be transmitted to the platen roller 6 by a gear, and the tooth portion of the gear may be detected by an optical sensor or a magnetic sensor.

In the above embodiment, the case where the present invention is applied to the label printer has been described.
The present invention is not limited to this, and the present invention can be applied to other printing devices.

Further, it goes without saying that the configurations and operations of the above-described embodiments are examples, and can be modified as appropriate without departing from the spirit of the present invention.

[0040]

As described above, according to the printing apparatus of the present invention, the printing means prints the predetermined print data on the predetermined paper, and the motor receives the pulse signal, and then, every one pulse. The motor control means supplies a pulse signal to the motor, the counting means counts the number of pulses of the pulse signal supplied to the motor by the motor control section, and the step number detection means The motor detects the number of steps actually rotated, the conveying means is rotated by the rotational driving force of the motor, presses the paper against the printing means and conveys it in the conveying direction, and the defect detecting means is counted by the counting means. Based on the number of pulses and the number of steps detected by the step number detecting means, at least one of the motor, the step number detecting means, and the conveying means is defective. Since so as to detect that the can grasp the conveyed amount of the sheet with high accuracy, it is possible to detect the occurrence of problems.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of an embodiment of a label printer to which a printing device of the present invention is applied.

FIG. 2 is a block diagram showing a configuration example of a control unit in FIG.

FIG. 3 is a block diagram showing a configuration example of a sheet transport measuring mechanism and a sheet transport measuring circuit.

FIG. 4 is a flowchart for explaining the operation of the paper transport measuring mechanism and the paper transport measuring circuit of FIG.

[Explanation of symbols]

1 sheet 2 supply axis 3 guide rollers 5 thermal head 6 Platen roller 7 Stepping motor 8 belts 9 Pitch sensor 10 Control unit 11 CPU 12 ROM 13 RAM 14 Motor control unit 15 Head controller 16 Sensor control unit 17 External interface 18 Input section 19 Display 20 interfaces 21 EEPROM 31 Rotation detection disk 32 Magnetic sensor 33 amplifier 34 Comparator 35 AND gate 36 digital counter 100 label printer 200 Personal Computer (PC)

Claims (3)

[Claims] 1. A printing unit that prints predetermined print data on a predetermined sheet, a motor that receives a pulse signal and that rotates one step for each pulse, and supplies the pulse signal to the motor. A motor control unit; a counting unit that counts the number of pulses of a pulse signal that the motor control unit supplies to the motor; a step number detection unit that detects the number of steps in which the motor actually rotates; Conveying means that is rotated by a rotational driving force and presses the paper against the printing means to convey it in the conveying direction, the number of pulses counted by the counting means, and the number of steps detected by the step number detecting means. Based on the above, there is a problem in at least one of the motor, the step number detecting means, and the conveying means. A printing apparatus comprising: a failure detection unit that detects the occurrence of an occurrence. 2. The defect detecting means compares the number of pulses with the number of steps, and when the number of pulses is greater than the number of steps, the conveying means removes the paper from the number of pulses and the number of steps. The printing apparatus according to claim 1, wherein the printing apparatus is additionally fed in the feeding direction by a difference of (1). 3. The malfunction detecting means compares the number of pulses with the number of steps, and when the number of steps is greater than the number of pulses, the conveying means removes the paper from the number of steps and the number of pulses. The printing apparatus according to claim 1, wherein the printing apparatus is carried in a direction opposite to the carrying direction by a difference of (1).