JP2009095991A - Recording apparatus and method for controlling recording apparatus - Google Patents

Abstract

In a recording apparatus that uses an optical sensor to determine the presence or absence of a recording medium on a conveyance path, it is possible to accurately determine the presence or absence of a recording medium without increasing costs or making a significant change in configuration.
A printer is mounted on a carriage that can move back and forth, and a recording head that records an image on a recording medium, a transport unit that transports the recording medium, and a carriage that is mounted on the carriage toward a transport path of the recording medium. The recording medium is conveyed by the paper width sensor 43 that detects the reflected light by irradiating the light, and the presence or absence of the recording medium at the position of the paper width sensor 43 is determined based on the detection value of the paper width sensor 43 being conveyed. A controller 60 that determines whether there is a recording medium, and when it is determined that there is no recording medium based on the detection value of the paper width sensor 43, the carriage is moved, and the paper width during or after movement The presence or absence of a recording medium is determined based on the detection value of the sensor 43.
[Selection] Figure 8

Description

  The present invention relates to a recording apparatus provided with an optical sensor, and a control method for the recording apparatus.

Generally, in a recording apparatus such as a printer, the presence or absence of a recording medium is detected by using an optical sensor that emits light toward the conveyance path of the recording medium (recording paper), and the width, leading edge, and trailing edge of the recording medium are detected. Detected. The optical sensor has the advantage of being able to detect without touching the recording medium, but if the reflected light from the recording medium is significantly different from the usual, such as when the surface of the recording medium is printed with a solid black color, an error will occur. There is a risk of detection. In view of this, a printer has been proposed in which a plurality of optical sensors are provided on the conveyance path of the recording medium, and the detection values of the plurality of optical sensors are combined to determine the presence or absence of a paper edge (for example, Patent Document 1). reference).
JP-A-2002-137847

If the number of sensors is increased as in the printer described in Patent Document 1 to prevent erroneous detection, there is a problem in that the cost increases in accordance with the increase in sensors. In addition, it is necessary to satisfy the conditions such as ensuring an appropriate distance between the sensors, but the space where the sensors can be arranged around the recording head is limited. It was difficult.
Therefore, the present invention accurately determines the presence / absence of a recording medium in a recording apparatus that uses an optical sensor to determine the presence / absence of a recording medium on a conveyance path, using a technique that can be realized without increasing costs or drastically changing the configuration. The purpose is to enable judgment.

In order to solve the above-described problems, the present invention is mounted on a carriage that can reciprocate and records an image on a recording medium, a transport unit that transports the recording medium, and mounted on the carriage. An optical sensor for irradiating the light toward the transport path and detecting reflected light, and the transport unit transports the recording medium, while the optical sensor is based on the detection value of the optical sensor during transport. A control unit that determines the presence or absence of the recording medium at a sensor position, and the control unit does not have the recording medium based on a detection value of the optical sensor from a state where it is determined that the recording medium is present. And determining whether or not the recording medium is present based on a detection value of the optical sensor during or after the movement. To.
According to this configuration, the presence or absence of the recording medium is determined based on the detection value of the optical sensor mounted on the carriage, and when it is determined that there is no recording medium from the state where the recording medium is determined, The optical sensor is moved, and the presence or absence of the recording medium is determined based on the detection value of the optical sensor during or after the movement. Thereby, for example, the reflected light detection value detected by the optical sensor in the case where the reflected light is reduced despite the presence of the recording medium due to the fact that there is a region having a low surface reflectance on the recording medium. Even if the situation does not match the presence or absence of the recording medium, it is possible to accurately determine the presence or absence of the recording medium by moving the optical sensor and making a determination again without relying on a configuration that increases costs. Can be judged.

In the above configuration, when the detection value of the optical sensor becomes a value indicating the presence of the recording medium during the movement of the carriage, it is determined that the recording medium is present, and the carriage reaches the end of the movable range. In the meantime, if the detection value of the optical sensor does not become a value indicating the presence of the recording medium, it may be determined that there is no recording medium.
In this case, when it is determined that there is no recording medium based on the detection value of the optical sensor, the determination is made based on the detection value of the optical sensor during the movement of the carriage, and the detection value of the optical sensor is the presence of the recording medium. Since it is determined that there is a recording medium when the value indicates, the presence / absence of the recording medium can be determined accurately and promptly. Further, it is possible to more accurately determine that there is no recording medium based on the detection value of the optical sensor from the start of the carriage movement to the end of the movable range.

In the above configuration, when the control unit determines that there is no recording medium based on a detection value of the optical sensor during the discharging operation of discharging the recording medium on which an image is recorded by the recording head. The carriage may be moved, and it may be determined whether or not the discharge of the recording medium is completed based on a detection value of the moving optical sensor.
In this case, in the operation of discharging the recording medium after recording the image, it is possible to accurately determine the progress of discharging the recording medium by determining the presence or absence of the recording medium in the conveyance path. Thereby, for example, the discharge operation can be continued even after the discharge of the recording medium has been completed, or the discharge operation can be terminated even when the recording medium is not discharged.

In the above configuration, the control unit moves the carriage to a predetermined position while discharging the recording medium by the transport unit, determines the presence or absence of the recording medium, and determines that the recording medium is not present and then moves the carriage. If the recording medium is determined to be present based on the detection value of the moving optical sensor, the carriage is returned to the predetermined position, and then the recording medium is ejected by the transport unit. May be.
In this case, when it is determined that there is a recording medium, the carriage is returned to a predetermined position, and then the recording medium is discharged by the transport unit. Therefore, it is determined again that there is no recording medium based on the detection value of the optical sensor. In this case, the same operation is promptly performed to determine the presence or absence of the recording medium. Accordingly, there is an advantage that the presence / absence of the recording medium can always be accurately determined by the same method.

In the above configuration, the control unit moves the carriage to a predetermined position while discharging the recording medium by the transport unit, determines the presence or absence of the recording medium, and determines that the recording medium is not present and then moves the carriage. When the recording medium is determined to be present based on the detection value of the moving optical sensor, the recording medium is ejected by the transport unit while the carriage is stopped at the position. You may let them.
In this case, if it is determined that there is a recording medium, the recording medium is discharged by the transport unit while the carriage is stopped at the position, so that the amount of movement of the carriage in the operation of discharging the recording medium can be suppressed, Throughput can be improved.

The said structure WHEREIN: It is good also as a structure which provided the guide plate comprised so that the reflectance of light might become low in the position where light is irradiated from the said optical sensor.
In this case, when there is no recording medium at the position of the optical sensor, the amount of reflected light detected by the optical sensor becomes very low, and the difference in the detection value of the optical sensor due to the presence or absence of the recording medium increases. For this reason, based on the detection value of the optical sensor, the presence / absence of the recording medium can be easily and accurately determined.

In order to solve the above problems, the present invention is mounted on a carriage that can reciprocate, and is mounted on a recording head that records an image on a recording medium, a transport unit that transports the recording medium, and the carriage. An optical sensor for detecting reflected light by irradiating light toward a recording medium conveyance path, and controlling the recording apparatus to convey the recording medium by the conveyance unit, while the optical being conveyed The presence or absence of the recording medium at the position of the optical sensor is determined based on the detection value of the optical sensor, and when it is determined that there is no recording medium from the state where the recording medium is determined, the carriage is There is provided a control method for a recording apparatus, characterized by determining whether or not the recording medium is present based on a detection value of the optical sensor during or after movement.
According to this control method, the presence / absence of the recording medium is determined based on the detection value of the optical sensor mounted on the carriage, and when it is determined that there is no recording medium from the state where the recording medium is determined, the carriage At the same time, the optical sensor is moved, and the presence or absence of the recording medium is determined based on the detected value of the optical sensor during or after the movement. Thereby, for example, the reflected light detection value detected by the optical sensor in the case where the reflected light is reduced despite the presence of the recording medium due to the fact that there is a region having a low surface reflectance on the recording medium. Even if the situation does not match the presence or absence of the recording medium, it is possible to accurately determine the presence or absence of the recording medium by moving the optical sensor and making a determination again without relying on a configuration that increases costs. Can be judged.

  In addition, a computer program for realizing the above method is stored in a magnetic recording medium such as a flexible disk or a hard disk device, a magneto-optical recording medium such as an MO, a CD-R, a CD-RW, a DVD ± R, a DVD ± RW, or a DVD. -It is good also as a form recorded on various recording media, such as optical recording media, such as RAM, and the memory | storage device using a semiconductor storage device, in the format which can be read by a computer. If this program is executed by a computer, the same effect as the above control method can be obtained.

  According to the present invention, it is possible to accurately convey even in a situation where the detected value of the reflected light detected by the optical sensor and the presence or absence of the recording medium do not match without relying on a configuration that causes an increase in cost. The presence or absence of a recording medium on the road can be determined.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a perspective view showing an external appearance of a printer 10 according to a first embodiment to which the present invention is applied. FIG. 2 is a side sectional view of the printer 10. FIG. 3 is a perspective view showing the frame configuration with the ink ribbon cartridge 29 removed, and FIG. 4 is a perspective view showing the frame configuration of FIG. 3 as viewed from the tractor unit 13 side. FIG. 5 is a perspective view showing the frame configuration with the ink ribbon cartridge 29 attached.

The printer 10 includes a recording head 20 that selectively ejects a plurality of recording wires, and a carriage 21 on which the recording head 20 is mounted. The recording wires ejected from the recording head 20 are recorded on a recording medium (the sheet shown in FIG. 8). P) is a serial dot impact printer that records an image including characters by striking on P).
As the sheet P, a cut sheet cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected can be used. The material of the cut sheet and continuous sheet is not limited to paper, and may be a synthetic resin, and the surface may be coated with an inorganic material or an organic material. Examples of the cut sheet include a cut sheet, a copy paper, a passbook, and a cut film, and the continuous sheet includes a continuous sheet.

  As shown in FIGS. 1 and 2, the printer 10 is roughly divided into a printer main body 12 constituting a recording unit, a tractor unit 13 for supplying a sheet P from the rear (rear side) of the printer main body 12, and a printer main body. 12 and a sheet guide 14 for manually feeding the sheet P from the front (front side). This recording unit is configured to be covered with an exterior composed of an upper case 15 and a lower case 16. The printer main body 12 includes a controller 60 (FIG. 8) as a control unit including an MPU and the like, and a recording mechanism unit that conveys the sheet P and records an image according to the control of the controller 60.

As shown in FIGS. 3 and 4, the printer main body 12 has a back frame 27, a platen 22, a carriage shaft 28, a plurality of roller shafts 23 a, a tractor unit 13, etc. spanned between a pair of side frames 25 and 26. The carriage shaft 28 is provided with a carriage 21, and each roller shaft 23 a is provided with a conveyance roller 23.
The recording mechanism section includes a recording head 20, a carriage 21, a platen 22, and a plurality of conveyance rollers 23. A plurality of conveying rollers 23 including those shown in the drawings are provided. The conveyance rollers 23 are arranged above and below the conveyance path of the sheet P and convey the sheet P with the sheet P interposed therebetween. A pair of conveyance rollers 23 are arranged in front of and behind the printer main body 12 with respect to the platen 22. The transport roller 23 is connected to a PF (Paper Feed) motor 56 (FIG. 8) via a drive wheel train 41 arranged outside the right side frame 26, and is driven by the driving force of the PF motor 56 in FIG. , And is driven to rotate clockwise or counterclockwise. By the rotation of the transport roller 23, the sheet P is transported from the front (sheet guide 14 side) to the rear and from the rear to the front of the printer body 12.
The PF motor 56 is configured as a stepping motor that rotates in a predetermined direction by an input pulse, and the conveyance amount of the sheet P by the conveyance roller 23 substantially corresponds to the number of operation steps of the PF motor 56. Here, the conveyance direction of the sheet P is a sub-scanning direction orthogonal to a main scanning direction of a carriage 21 described later. The plurality of transport rollers 23 provided in the printer 10 constitute a transport unit together with the PF motor 56 and the driving wheel train unit 41 that transmits the driving force of the PF motor 56 to the transport roller 23.

The carriage 21 is slidably inserted into the carriage shaft 28 and connected to an endless timing belt 48 (FIG. 3) arranged side by side on the carriage shaft 28. The timing belt 48 is reciprocated by forward and reverse operations of a carriage drive motor 57 (FIG. 8). Accordingly, the carriage 21 is driven together with the timing belt 48 by the forward and reverse operations of the carriage drive motor 57 and is guided by the carriage shaft 28 to reciprocate. The moving direction of the carriage 21 is a main scanning direction.
The carriage 21 carries the recording head 20. The recording head 20 includes a number of recording wires (not shown), and these recording wires are ejected toward the platen 22. The platen 22 is a platen extending along the movement range of the recording head 20 that moves in the main scanning direction together with the carriage 21, that is, in the main scanning direction.

As shown in FIG. 5, a stationery type ink ribbon cartridge 29 is detachably mounted on the printer main body 12, and the ink ribbon of the ink ribbon cartridge 29 is fed between the recording head 20 and the platen 22. The recording head 20 projects an image by causing a recording wire to protrude and strike the ink ribbon while traveling along with the carriage 21 in the main scanning direction, and attach the ink of the ink ribbon to the recording surface of the sheet P.
A ribbon mask holder 51 that protects the sheet P from the ink ribbon is attached to the carriage 21 between the ink ribbon fed out from the ink ribbon cartridge 29 and the sheet P.

  A paper guide 45 serving as a guide plate is disposed on the sheet conveyance downstream side of the platen 22 (the right side in FIG. 2 and the back side of the platen 22 in FIG. 3). It is guided by being placed on a guide surface 45a which is a surface. The paper guide 45 is stretched over the left side frame 25 and the right side frame 26, extends in the main scanning direction of the recording head 20, and receives the entire paper width of the conveyed sheet P from below. . The guide surface 45a of the paper guide 45 is formed with an inclined surface 45b and a paper powder discharge hole 46, which will be described later, in a manner extending in the main scanning direction.

  The tractor unit 13 supplies a continuous sheet to the recording head 20 side, and has a pair of left and right tractors 30 as shown in FIG. As shown in FIG. 2, each tractor 30 includes a tractor driving pulley 30a, a tractor driven pulley 30b, and a tractor belt 31 wound around these pulleys 30a and 30b, and the driving force of the PF motor 56 is a driving mechanism. By being transmitted via (not shown), the tractor driving pulley 30a is rotationally driven, and the tractor belt 31 is driven to convey the continuous sheet. This continuous sheet is, for example, sprocket paper in which sprocket holes that engage with pins of the tractor belt 31 are formed. The tractor unit 13 supplies a continuous sheet to the conveyance roller 23 in order to record an image by the recording head 20, and further, during the recording operation by the recording head 20 and the discharging operation after the recording operation, the conveyance roller 23. Operates with and sends continuous sheets.

FIG. 6 is a perspective view showing the configuration of the carriage 21.
The carriage 21 is integrally formed with a boss portion 19a through which the carriage shaft 28 is slidably inserted, and the carriage 21 is movable only in the main scanning direction via the boss portion 19a. Moored at. The ink ribbon in the ink ribbon cartridge 29 is fed out between the main body 51a of the ribbon mask holder 51 attached to the tip of the carriage 21 and the guide pin 52 as described above.

Further, a paper width sensor 43 as an optical sensor for detecting the presence or absence of the sheet P below the main body 51a of the ribbon mask holder 51 is disposed. The paper width sensor 43 is configured as a reflection type optical sensor, and includes a light emitting unit (not shown) including an LED and the like, and a light receiving unit (not shown) including a phototransistor and a photodiode. The light receiving unit is arranged in a manner to face the paper guide 45 in the vertical direction.
The paper width sensor 43 irradiates detection light toward the inclined surface 45b or the recording surface of the sheet P conveyed on the inclined surface 45b while the carriage 21 is scanned in the main scanning direction.

FIG. 7 is a cross-sectional view of the main part showing a state in which the sheet P is conveyed onto the paper guide 45.
As described above, in the paper guide 45, a part of the guide surface 45a as a plane constituting the conveyance path of the sheet P is recessed to form the inclined surface 45b extending in the main scanning direction, and the lower end of the inclined surface 45b is opened. This is a paper dust discharge hole 46. For this reason, when paper dust accumulates on the guide surface 45 a on which the sheet P is conveyed, the paper dust falls from the inclined surface 45 b to the paper dust discharge hole 46 due to vibration during operation of the printer 10. The sheet P is conveyed so as to pass over the paper dust discharge hole 46 and the inclined surface 45b, and the inclined surface 45b guides the front end of the sheet P so as not to be caught by the paper powder discharge hole 46 when the sheet P is conveyed. Playing a role.

As shown in FIG. 7, the light emitted from the light emitting portion (not shown) of the paper width sensor 43 is emitted substantially perpendicularly to the sheet P toward the paper dust discharge hole 46 as indicated by a symbol L in the drawing. . Here, when the sheet P exists immediately below the paper width sensor 43, the reflected light reflected by the recording surface of the sheet P reaches the paper width sensor 43 as indicated by a reference symbol R in the drawing, and a light receiving unit (illustrated) provided in the paper width sensor 43. (Abbreviated).
On the other hand, when the sheet P is not directly below the paper width sensor 43, the light emitted from the paper width sensor 43 enters the paper powder discharge hole 46 or is reflected by the inclined surface 45b.
The reflected light of the light incident inside the paper dust discharge hole 46 hardly returns to the paper width sensor 43, and the surface of the paper guide 45 including the guide surface 45a is dark (for example, black) so that the reflectance is low. Is colored (painted). On the other hand, many of the sheets P are brighter than the guide surface 45a (for example, whiteness is about 80% to 50% for white paper). Therefore, the reflected light R reflected by the sheet P from the light L emitted from the paper width sensor 43 is much stronger than the reflected light reflected from the guide surface 45a, the inclined surface 45b, the paper dust discharge hole 46, and the like. Since it is light, the presence or absence of the sheet P immediately below the paper width sensor 43 can be determined based on whether or not the amount of light received (detected value) detected by the paper width sensor 43 exceeds a predetermined threshold.

For example, the printer 10 acquires the detection value of the paper width sensor 43 while moving the carriage 21 in the main scanning direction, and specifies the position of the paper width sensor 43 in the main scanning direction when the detection value of the paper width sensor 43 exceeds a threshold value. By doing so, the positions of both ends of the sheet P can be determined, and the width of the sheet P can be obtained.
Further, for example, based on the detection value of the paper width sensor 43 during the conveyance of the sheet P by the operation of the PF motor 56, it can be detected whether the leading end or the trailing end of the sheet P has passed under the carriage 21. That is, based on whether or not the detection value of the paper width sensor 43 is equal to or less than the threshold value, it can be determined whether or not the sheet P has moved away from the lower side of the paper width sensor 43 and the discharge has been completed.

In the printer 10, manual feeding for manually supplying a cut sheet from the front side and rear feeding for supplying a continuous sheet by the tractor unit 13 from the rear side can be performed.
At the time of manual feeding, the operator places the sheet P on the sheet guide 14 and pushes it toward the inside of the printer main body 12. The sheet guide 14 includes a wall portion that abuts against the left end of the sheet P when the sheet P is inserted at the left end when viewed from the front side (FIG. 1). The sheet P is in contact with the wall portion, that is, the sheet guide. 14 is pushed into the left end (FIG. 1). At the time of manual feeding, the left end is the 0-digit position of the carriage 21 and the right end is the 80-digit position when viewed from the front side where the sheet P is supplied.

When the leading edge of the sheet P is detected by the paper end sensor 44 (FIG. 8) disposed between the sheet guide 14 and the front side conveyance roller 23, the conveyance roller 23 is driven by the PF motor 56 (FIG. 8). Then, the sheet P is conveyed toward the recording head 20. When the sheet P is conveyed and reaches just below the carriage 21, the paper width sensor 43 receives the reflected light from the sheet P, and the detected value exceeds the threshold value. In response to the change in the detected value of the paper width sensor 43, the printer 10 starts recording by the recording head 20. Recording by the recording head 20 is performed for each line, and during the recording, the sheet P is conveyed to the rear side by the conveyance roller 23 line by line. When the recording by the recording head 20 is completed, the sheet P is discharged to the sheet guide 14 by the PF motor 56 and the conveyance roller 23.
During this manual feeding operation, a series of operation steps for conveying the sheet P from the front side to the rear side of the printer main body 12 is a feeding sequence, and a series of operations for conveying the sheet P from the rear side of the printer main body 12 to the front side. The operation process is a discharge sequence.

On the other hand, when rear feeding is performed by the tractor unit 13, the tractor unit 13 and the conveyance roller 23 are driven by the operation of the PF motor 56, and the sheet P composed of continuous sheets is conveyed toward the recording head 20. Then, recording by the recording head 20 is started. After the start of recording, every time the recording head 20 performs one line of recording by the tractor unit 13 and the conveying roller 23, the sheet P is conveyed by a predetermined length and sequentially discharged from the front side.
In both cases of manual feeding and rear feeding, the conveying path of the sheet P is between the conveying rollers 23 and 23 provided facing each other as shown in FIG. This is a substantially horizontal path passing between the platen 22 and the platen 22.
The manual feeding and the rear feeding can be switched by switching the mechanism for transmitting the driving force of the PF motor 56 to the tractor unit 13 by an operator switching a lever (not shown), or described later. It may be switched automatically by the controller 60. At the time of rear feeding, the left end is the 0 digit position when viewed from the tractor unit 13 side to which the sheet P is supplied.

FIG. 8 is a block diagram illustrating the configuration of the control system of the printer 10.
The printer 10 includes a controller 60 that controls each part of the printer 10, a motor driver circuit 55 that drives each part including a motor according to the control of the controller 60, and a gate array 58 that outputs the detection state of each sensor to the controller 60. ing.
The controller 60 includes an MPU 61, a flash ROM 62 that stores a control program executed by the MPU 61 and data processed by the control program, and a memory that temporarily stores a program executed by the MPU 61 and processed data. 63. The MPU 61 reads out and executes the control program stored in the flash ROM 62, references the detection state of each sensor input from the gate array 58, outputs control information to the motor driver circuit 55, and outputs the PF motor 56. Then, the carriage drive motor 57 and the recording head 20 are operated.
The flash ROM 62 is configured by a rewritable nonvolatile memory and stores a control program and data in advance, and stores various data related to the operation of the printer 10 as necessary.
A job including control information for instructing image recording and image data to be recorded on the sheet P is input to the MPU 61 from the host computer 100 outside the printer 10.

  The motor driver circuit 55 is connected to the MPU 61, and outputs a drive current and a control signal to the PF motor 56, the carriage drive motor 57 and the recording head 20 in accordance with control information input from the MPU 61. The motor driver circuit 55 outputs a drive pulse together with a drive current to the PF motor 56 configured as a stepping motor, and the PF motor 56 rotates by the number of steps corresponding to the drive pulse. The motor driver circuit 55 outputs a driving current to a carriage driving motor 57 configured as a servo motor, thereby operating the carriage driving motor 57 to reciprocate the carriage 21 in the main scanning direction. Further, the motor driver circuit 55 controls the recording head 20 in accordance with the control information input from the MPU 61 and causes a wire (not shown) provided in the recording head 20 to protrude.

The gate array 58 converts the detection value output as an analog signal from the paper width sensor 43 and the paper edge sensor 44 into a digital signal indicating the detection value, and outputs the digital signal to the MPU 61.
As described above, the paper width sensor 43 is a sensor that is mounted on the ribbon mask holder 51 included in the carriage 21 and detects the presence or absence of the sheet P in the vicinity of the recording head 20, and irradiates light toward the guide surface 45a. The amount of the reflected light received is output as a detection value. Since the paper width sensor 43 and the guide surface 45a are close to each other, the paper width sensor 43 functions as a sensor having higher sensitivity than the paper edge sensor 44 described below.
The paper end sensor 44 is disposed at the base end portion of the sheet guide 14 and detects the front end of the sheet P that is about to enter the printer main body 12 from the sheet guide 14. The paper edge sensor 44 includes, for example, a reflection type optical sensor having a light emitting unit and a light receiving unit facing the conveyance path of the sheet P, or a light emitting unit and a light receiving unit facing each other across the conveyance path of the sheet P. It is a transmissive optical sensor.

The printer 10 configured as described above conveys the sheet P inserted from the sheet guide 14 by driving the PF motor 56 by the motor driver circuit 55 under the control of the controller 60 in the feeding sequence. . When the sheet P reaches the recording position, the carriage driving motor 57 is driven by the motor driver circuit 55, the carriage 21 is moved in the main scanning direction, and an image is recorded by the recording head 20.
After the image is recorded on the sheet P, the printer 10 executes a discharge sequence and discharges the sheet P from the sheet guide 14. In the discharge sequence, it is determined whether or not the discharge of the sheet P is completed based on the detection value of the paper width sensor 43 while performing the operation of driving the PF motor 56 and rotating the transport roller 23 to transport the sheet P. To do.

As described above, the printer 10 causes the paper width sensor 43 to detect reflected light, and determines whether or not the sheet P is directly below the paper width sensor 43 based on whether or not the detected value exceeds a preset threshold value. judge. However, in the case where the sheet P on which the black solid printing is applied is used, the reflectance of light on the surface of the sheet P is very low, and in a state where the low reflectance portion is located immediately below the paper width sensor 43, The amount of light received by the paper width sensor 43 is significantly lower than when the reflected light of the light color portion of the sheet P is received. In this case, there is a possibility that the detection value of the paper width sensor 43 is equal to or less than the threshold value even though the sheet P is directly below the paper width sensor 43, and it is erroneously determined that there is no sheet P.
Therefore, if the printer 10 determines that the detection value by the paper width sensor 43 is low and the sheet P does not exist (“no sheet”), the printer 10 scans the carriage 21 to monitor the detection value of the paper width sensor 43, and really Checking for the presence of P prevents erroneous determination. Hereinafter, this operation will be described in detail.

FIG. 9 is a flowchart showing the operation of the printer 10, and particularly shows the operation in the discharge sequence.
When starting the discharge sequence for discharging the sheet P, the controller 60 drives the carriage drive motor 57 to move the carriage 21 to the basic position at the time of discharge (step S11), and drives the PF motor 56 to convey the sheet P. Is started (step S12).
Here, the basic position is a position away from the end (0 digit position) of the movable range of the carriage 21 by a predetermined distance (a preset distance). When the carriage 21 is in this basic position, the printer 10 is a position where the range in which the smallest usable sheet P is conveyed and the paper width sensor 43 overlap. That is, when the carriage 21 is moved to the basic position, the conveyed sheet P always passes directly below the paper width sensor 43 regardless of the size of the sheet P. For this reason, by moving the carriage 21 to the basic position, the reflected light from the sheet P conveyed in the discharge sequence can be reliably detected by the paper width sensor 43.

  The controller 60 monitors the detection value of the paper width sensor 43 while conveying the sheet P (step S13), and conveys the sheet P until the detection value of the paper width sensor 43 is equal to or less than the threshold value and it is determined that “no sheet”. Continue (step S13; No). When the detection value of the paper width sensor 43 changes and it is determined that there is no sheet from the state where it is determined that there is a sheet (step S13; Yes), the controller 60 starts to move the carriage 21 (step S14). ). The movement of the carriage 21 is a movement toward the end position (80-digit position) of the movable range, and the paper width sensor 43 straddles the side edge of the sheet P during this movement.

During the movement of the carriage 21 to the end position, the controller 60 monitors the detection value of the paper width sensor 43 (step S15). If the detection value of the paper width sensor 43 does not change to “with sheet”, the carriage 21 reaches the end position. It is discriminated whether or not (step S16), and if the end position has not been reached, the process returns to step S15. Thereby, the detection value of the paper width sensor 43 exceeds the threshold value and changes to “with sheet” (step S15; Yes) or until the carriage 21 reaches the end position of the movable range (step S16; Yes). The carriage 21 is moved.
When the carriage 21 reaches the end position, the controller 60 determines that the sheet P is not directly under the paper width sensor 43 and the discharge of the sheet P is completed (step S17), and the discharge sequence is ended (step S18). At the end of the discharge sequence, the carriage 21 may be returned to the original end position (0 digit position) under the control of the controller 60.

  On the other hand, when the detection value of the paper width sensor 43 exceeds the threshold value and changes to “with sheet” while moving the carriage 21 to the end position (80 digit position) (step S15; Yes), the controller 60 It is determined that the discharge of P has not ended yet, and the carriage 21 is moved to the basic position (step S19). Further, the controller 60 causes the PF motor 56 to convey the sheet P by a predetermined amount (step S20), and returns to step S13.

  As described above, according to the printer 10 according to the first embodiment to which the present invention is applied, the presence or absence of the sheet P is determined based on the detection value of the paper width sensor 43 mounted on the carriage 21, and the paper width sensor 43. When the sheet width sensor 43 is moved together with the carriage 21 from the state where it is determined that “sheet is present” and “sheet is not present”, the detected value of the sheet width sensor 43 during the movement is changed. Based on this, the presence or absence of the sheet P is determined. Thus, even in a situation where the detection value of the paper width sensor 43 and the presence / absence of the sheet P do not match, the determination is made again by moving the paper width sensor 43 without depending on a configuration that causes an increase in cost. Thus, the presence or absence of the sheet P can be accurately determined.

There is a possibility that the sheet P has a region with a very low light reflectance, such as a portion where dark solid color printing has been performed in advance or a portion where dark color solid printing is performed by the printer 10. However, since a marginal part (for example, a width of 3 millimeters) usually exists at the side edge of the sheet P, if the sheet P is directly under the sheet width sensor 43, the sheet width sensor 43 is almost always accompanied by the movement of the carriage 21. Detects the reflected light from the white or light-colored portion, and determines that “there is a sheet”. On the other hand, when the sheet P does not exist immediately below the paper width sensor 43, even if the carriage 21 is moved, the paper width sensor 43 does not receive the reflected light from the sheet P. Therefore, the detected value of the paper width sensor 43 is Stays low.
As described above, when the printer 10 determines “no sheet”, the carriage 21 moves in the main scanning direction and determines the presence / absence of the sheet P based on the detection value of the paper width sensor 43 being moved. In addition, there is an extraordinary effect that the presence or absence of the sheet P whose light reflectance is not uniform can be accurately determined by using the reflection type paper width sensor 43.

The controller 60 determines that there is a sheet when the detection value of the paper width sensor 43 becomes a value indicating the presence of the sheet P while the carriage 21 is moving, so the presence or absence of the sheet P is accurately and promptly determined. Can be judged. If the detected value of the paper width sensor 43 does not indicate the presence of the sheet P before the carriage 21 reaches the end of the movable range, it is determined that there is no sheet P, so the carriage 21 is moved. By moving until reaching the end of the possible range and using the detection value of the paper width sensor 43 during that time, the presence or absence of the sheet P can be made more accurate.
Further, in the discharge sequence for discharging the sheet P on which the image is recorded by the recording head 20, the progress of the discharge of the sheet P can be accurately determined. For example, the discharge operation is continued even though the discharge of the sheet P has already been completed. Alternatively, it is possible to prevent problems such as the end of the discharge operation when the sheet P is not discharged.

  Further, the controller 60 moves the carriage 21 when determining that “no sheet” while discharging the sheet P by the transport unit, and determines that “sheet is present” based on the detection value of the paper width sensor 43 being moved. In this case, the carriage 21 is returned to a predetermined position, and then the sheet P is discharged by the conveyance unit. Therefore, when it is determined again that there is no sheet based on the detection value of the paper width sensor 43, the same operation is promptly performed. The presence or absence of the sheet P can be determined. Accordingly, there is an advantage that the presence / absence of the sheet P can always be accurately determined by the same method.

  Further, in the paper guide 45, an inclined surface 45b and a paper dust discharge hole 46 are disposed at a position where light is emitted from the paper width sensor 43 so that the reflectance of the light is lowered. The inclined surface 45b is colored dark. For this reason, the difference in the detection value of the paper width sensor 43 due to the presence or absence of the sheet P becomes large, and the presence or absence of the sheet P can be easily and more accurately determined based on the detection value of the paper width sensor 43.

[Second Embodiment]
FIG. 10 is a flowchart showing the operation of the printer 10 according to the second embodiment to which the present invention is applied, and particularly shows the operation in the discharge sequence.
In the second embodiment, parts that are configured in the same manner as in the first embodiment are given the same reference numerals, and illustration and description thereof are omitted. Further, in the flowchart of FIG. 10 according to the second embodiment, the same reference numerals are given to the steps for performing the same processes as those of the flowchart of FIG. 9 according to the first embodiment, and the description thereof will be omitted.

  In the operation illustrated in FIG. 10, the controller 60 performs the processes of steps S11 to S18 (FIG. 9). When the detection value of the paper width sensor 43 increases and the determination changes to “sheet present” (step S15; Yes), the controller 60 drives the PF motor 56 while the carriage 21 is stopped at that position. Then, the conveyance is resumed (step S25). That is, the state where the light color portion of the sheet P is directly under the paper width sensor 43 is maintained, and the conveyance of the sheet P is resumed. After resuming the conveyance of the sheet P, the controller 60 monitors the detection value of the paper width sensor 43 (step S26), and conveys the sheet P until the detection value of the paper width sensor 43 decreases to determine “no sheet”. If “No sheet” is determined (step S26; Yes), the process proceeds to step S17.

According to the second embodiment, the detection value of the paper width sensor 43 decreases from the state determined as “sheet present” based on the detection value of the paper width sensor 43 to determine “no sheet”, and the carriage 21 When the detected value of the paper width sensor 43 increases again by moving the carriage, the carriage 21 is stopped at that position and the conveyance of the sheet P is resumed.
As a result, as in the first embodiment, the presence or absence of the sheet P can be accurately determined even if there is an influence of, for example, a black solid area of the sheet P. Further, when the carriage 21 is moved and the paper width sensor 43 detects the reflected light from the bright color portion of the sheet P, the paper width sensor 43 is stopped at this position and the conveyance of the sheet P is resumed. The amount of movement of the carriage 21 after determining “None” can be suppressed, and the throughput can be improved.

In the first and second embodiments described above, when the detection value of the paper width sensor 43 is equal to or less than a preset threshold value after determining “with sheet”, and “without sheet” is determined. While the carriage 21 is moved, the presence / absence of the sheet P is determined based on the detection value of the paper width sensor 43 during the movement. However, the present invention is not limited to this. The sheet P may be moved by a predetermined distance to be stopped, and the presence or absence of the sheet P may be determined based on the detection value of the paper width sensor 43 in the stopped state. In this case, every time it is determined that there is no sheet, the carriage 21 is moved by a predetermined distance, and the detection value of the paper width sensor 43 is acquired to make a determination. The carriage 21 reaches the end position of the movable range. Then, it may be determined that the discharge of the sheet P is completed.
Furthermore, when the size in the width direction of the sheet P or the position of the side edge of the sheet P that is detected or set in advance is stored and it is determined that there is no sheet based on the detection value of the paper width sensor 43, the paper width The carriage 21 may be moved until the sensor 43 overlaps the position of the side edge of the sheet P, and the presence or absence of the sheet P may be determined based on the detection value of the paper width sensor 43 at this position. In this case, when the detection value of the paper width sensor 43 decreases and it is determined that there is no sheet, the paper width sensor 43 is moved to a blank area existing in almost all sheets P, and the presence / absence of the sheet P is determined. As a result, the presence or absence of the sheet P can be reliably determined, and the number of movements of the carriage 21 can be greatly reduced, thereby significantly improving the throughput.

  In the first and second embodiments, the case where the presence or absence of the sheet P is determined based on the detection value of the paper width sensor 43 in the operation of the discharge sequence for discharging the sheet P has been described. The present invention is not limited to this, and in the case of determining whether or not there is a sheet P in a feeding sequence in which the sheet P inserted from the sheet guide 14 is conveyed directly below the recording head 20 in the case of manual sheet feeding, the present invention is used. You may apply. In this case, if the detection value of the paper width sensor 43 decreases during the conveyance of the sheet P, it may be due to the influence of the black solid area of the sheet P or due to an abnormality such as a tear of the sheet P or a deviation from the conveyance path. There is an advantage that it can be accurately determined.

  In the first and second embodiments, the example in which the present invention is applied to the printer 10 as a dot impact printer has been described. However, the present invention is not limited to this, and the sheet P is fed and Any printer can be applied as long as it is a printer that performs a discharging operation and detects the sheet P by irradiating a part of the sheet P with light. Specifically, the present invention can be applied to an ink jet printer that records an image by ejecting ink onto a recording surface of a recording medium, and an image is recorded on thermal paper by a recording head including a heating element. The present invention can also be applied to a thermal printer, a thermal sublimation printer, or a recording apparatus that records an image by an electrophotographic method such as a copying machine or a facsimile. Furthermore, the present invention can also be applied to an electronic device incorporating the various printers described above.

FIG. 2 is a perspective view illustrating an appearance of the front of the printer according to the first embodiment. It is a sectional side view of a printer. FIG. 4 is a perspective view showing a frame configuration with an ink ribbon cartridge removed. It is a perspective view which shows the frame structure of FIG. 3 seeing from the tractor unit side. It is a perspective view which shows the state which mounted | wore the ink ribbon cartridge. It is a perspective view of a carriage. It is principal part sectional drawing which shows the state which conveyed the sheet | seat on paper guidance. FIG. 3 is a block diagram illustrating a configuration of a printer control system. 3 is a flowchart illustrating an operation of a printer. 6 is a flowchart illustrating an operation of a printer according to a second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer (recording device), 11 ... Recording head, 12 ... Printer main body, 13 ... Tractor unit, 14 ... Sheet guide, 15 ... Upper case, 16 ... Lower case, 20 ... Recording head, 21 ... Carriage, 22 ... Platen , 23 ... Conveying roller (conveying unit), 23a ... Roller shaft, 25 ... Left side frame, 26 ... Right side frame, 27 ... Back frame, 28 ... Carriage shaft, 29 ... Ink ribbon cartridge, 30 ... Tractor, 31 ... Tractor Belt 41, driving wheel train section (conveyance section) 43 paper width sensor (optical sensor) 45 paper guide (guide plate) 45 a guide surface 45 b inclined surface 46 paper paper discharge hole 48 ... Timing belt 51 ... Ribbon mask holder 55 ... Motor driver circuit 56 ... PF motor (conveying unit) 58 ... Gate array 6 ... controller (control unit), P ... sheet.

Claims (7)

A recording head mounted on a reciprocating carriage and recording an image on a recording medium;
A transport unit for transporting the recording medium;
An optical sensor that is mounted on the carriage and detects reflected light by irradiating light toward a conveyance path of the recording medium;
A control unit for determining the presence or absence of the recording medium at the position of the optical sensor based on a detection value of the optical sensor being conveyed while the recording medium is conveyed by the conveyance unit;
The control unit moves the carriage when determining that there is no recording medium based on the detection value of the optical sensor from the state where it is determined that the recording medium is present, and moves the carriage during or after the movement. Determining the presence or absence of the recording medium based on a detection value of an optical sensor;
A recording apparatus. The recording apparatus according to claim 1,
The controller is
When the detection value of the optical sensor becomes a value indicating the presence of the recording medium during the movement of the carriage, it is determined that there is the recording medium,
Determining that there is no recording medium if the detection value of the optical sensor does not indicate the presence of the recording medium before the carriage reaches the end of the movable range;
A recording apparatus. The recording apparatus according to claim 1 or 2,
When the control unit determines that there is no recording medium based on the detection value of the optical sensor during the discharging operation of discharging the recording medium on which an image is recorded by the recording head, the control unit moves the carriage. Determining whether or not the discharge of the recording medium is completed based on a detection value of the moving optical sensor,
A recording apparatus. The recording apparatus according to claim 3, wherein
The control unit determines the presence or absence of the recording medium by moving the carriage to a predetermined position while discharging the recording medium by the transport unit;
After determining that there is no recording medium, the carriage is moved, and when it is determined that there is the recording medium based on the detection value of the moving optical sensor, the carriage is returned to the predetermined position. Discharging the recording medium by the transport unit;
A recording apparatus. The recording apparatus according to claim 3, wherein
The control unit determines the presence or absence of the recording medium by moving the carriage to a predetermined position while discharging the recording medium by the transport unit;
The carriage is moved after it is determined that there is no recording medium, and the carriage is stopped at the position when it is determined that there is the recording medium based on the detection value of the moving optical sensor And discharging the recording medium by the transport unit,
A recording apparatus. The recording apparatus according to any one of claims 1 to 5,
A guide plate configured to reduce the reflectance of light at a position irradiated with light from the optical sensor;
A recording apparatus. A recording head that is mounted on a carriage that can be reciprocated and records an image on a recording medium, a transport unit that transports the recording medium, and a light that is mounted on the carriage and irradiates the transport path of the recording medium. Controlling a recording apparatus including an optical sensor for detecting reflected light;
While transporting the recording medium by the transport unit, based on the detection value of the optical sensor during transport, determine the presence or absence of the recording medium at the position of the optical sensor,
When it is determined that there is no recording medium from the state where it is determined that there is the recording medium, the carriage is moved, and the presence or absence of the recording medium is determined based on the detection value of the optical sensor during or after the movement. Judging,
A control method for a recording apparatus.

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