JP2722560B2 - Printing device carriage control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to carriage control of a printing apparatus, and more particularly, to paper control in a state in which a print head is positioned at a collation portion where a paper stapler or the like of printing paper is applied. The present invention relates to a carriage control device of a printing apparatus which is configured to separate a print head from a sheet when receiving a feed command.

(Prior Art) Conventionally, a printing apparatus which prints on a printing paper on a platen while moving a carriage on which a wire dot type printing head is mounted along a platen has been known. Gap (distance) with wire tip surface
Is much smaller than other types of printing devices,
When the print head is positioned to print the first dot near the collation where the paper is stapled on the print paper, it is necessary to guarantee the paper feed without causing paper jams. It has been done.

As a guarantee means, for example, when the print head is at the right end of the print paper, the end of the paper is detected by the reflection type sensor, and the print head position is moved to the inside (left side) of the print paper before the line feed operation. This prevents the paper tip of the print head from being hooked on the paper stapler to prevent paper jams and line feed failure (see Japanese Utility Model Publication No. 63-23154).

On the other hand, when the print head is at the left end of the print paper, a means is provided in which a notch (recess) is provided in the platen itself to allow the paper stapler to escape.

(Problems to be Solved by the Invention) In the case of the above-described conventional wire dot type printing apparatus, for example, as shown in FIG. 4 and FIG. 5, the first dot position (the left end of the character H shown in FIG. ) And the right end face of the notch 2 at the left of the platen 1 are set with a margin of about 2 mm. Therefore, when the A dimension is set to the first dot from the center of the sprocket hole 4 formed in the paper 3, the paper stapling portion 5 applied to the collating portion of the paper 3 completely fits in the notch 2 of the platen 1. Therefore, no matter where the print head 6 is located, paper jam or line feed failure does not occur. However, when the B dimension is set to the first dot from the center of the sprocket hole 4 formed in the paper 3 as shown in FIGS. 6 and 7, the paper stapler 5 is completely formed by the notch 2 of the platen 1. Because it does not fit in
When the paper 3 is slightly floated from the platen 1 and the print head 6 is located at this portion, the distance between the leading end surface of the print head 6 and the paper 3 is not sufficiently secured, so that the paper feed is performed in this state. When the paper 3 is touched, the paper 3 and the leading end surface of the print head 6 come into contact with each other, which may cause paper jam or line feed failure. In order to solve this problem, it is conceivable that the paper is fed after the print head is moved to the inside of the print paper (position 7a in FIG. 6) even at the left end of the print paper as described in the above-mentioned publication. However, when printing the next line from the first dot position, the print head must start accelerating from outside the left end of the printing paper, so that the left end of the floating printing paper may be caught.

Therefore, according to the present invention, when the print head 6 is within a predetermined range near the collating portion of the paper and receives a paper feed command such as a line feed or a page feed, the print head 6 is separated from the platen to thereby feed the paper. It is a technical problem to be solved to prevent paper jam and line feed failure at the time.

(Means for Solving the Problems) The technical means for solving the above problems is to print on a print sheet on a platen while moving a carriage on which a wire dot type print head is mounted along the platen. The carriage control device in the printing apparatus is configured to determine whether the carriage is separated from a predetermined position with respect to the platen by a carriage separation unit and whether the print head is in a retreat necessary range near a collation portion of a sheet. Determining means for determining whether the print head is within the necessary retraction area and a paper feed command such as a line feed or a page break. And a control means for outputting a signal for causing the signal to be separated therefrom.

(Operation) According to the carriage control device of the printing apparatus having the above configuration,
When the judging means judges that the print head is in the necessary retreat area near the collating portion of the sheet and receives a paper feed command such as a line feed or a page break, the control device sends the carriage separating means to the carriage separating means. It outputs a signal for separating the carriage from the platen. As a result, the distance between the leading end surface of the print head and the printing paper is increased, so that it is possible to prevent the occurrence of paper jam or line feed failure during paper feeding.

(Example) Next, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1 and FIG. 2 showing an A-A cross section of FIG. 1, between the left and right side walls 10a and 10b of the frame 10 of the printing apparatus, a prism-shaped metal for supporting the printing paper 3 is provided. A platen 1 is constructed. Through holes 13 and 14 are respectively opened in the side walls 10a and 10b so as to face each other in front of the platen 1, and a pair of right and left having an eccentric shaft support hole 15 is formed in the through holes 13 and 14. Eccentric bodies 16 and 17 are rotatably supported, and guide shafts 18 extending in parallel with the platen 1 are fitted and fixed to both eccentric bodies 16 and 17 by small diameter support shafts 19 at both ends thereof. 17 and the guide shaft 18 are integrated.

A driven gear 20 located on a concentric circle with the eccentric body 16 is fixed to a right side surface of the right eccentric body 16 and a right wall 10
On the right side of a, a drive motor 22 composed of a step motor having a drive gear 21 meshing with the driven gear 20 is provided. Therefore, when the drive motor 22 is rotated forward and reverse,
The guide shaft 18 is moved back and forth by the eccentric action of the eccentric bodies 16 and 17 via the drive gear 21 and the driven gear 20 so as to approach or separate from the platen 1.

A reference position detection piece 23 is attached and fixed to the outer surface of the left eccentric body 17 at its end, and the left side wall 10b
A reference position detecting sensor 24 composed of a photo sensor having a light emitting element and a light receiving element is attached to the outer surface of the eccentric body 17. When the optical path passes and the optical path is interrupted, a detection signal is output from the reference position detection sensor 24. Based on the position where the detection signal is generated, a CPU 42 described later drives the drive motor 22 to move the print head 6 back and forth to a position corresponding to the thickness of the print paper.

A carriage 25 is inserted and supported on the guide shaft 18 so as to be movable along the platen 1. The carriage 25 is not shown via an endless timing belt 27 and a pair of pulleys 28 fixed on a part of the lower surface thereof. The drive motor moves along the platen 1. The timing belt 27, the pulley 28, and a driving motor (not shown) constitute a carriage moving device 41 shown in FIG. Further, in front of the carriage 25, a guide rail extending in parallel with the guide shaft 18 is provided between the side walls 10a and 10b, and a pair of upper and lower projecting pieces 26 project from the front end of the carriage 25, The projecting piece
The carriage 25 is moved left and right along the guide shaft 18 and the guide rail 29 with the 26 loosely fitted on the rear side edge of the guide rail 29. The print head 6 is mounted and fixed on the carriage 25.

Next, a control circuit of the printing apparatus will be described with reference to FIG. The input side of a CPU (central processing unit) 42 is connected to the reference position detection sensor 24 and a DIP switch 50. The dip switch 50 separates the carriage 25 from the platen 1 when the print head 6 is in a predetermined range near the left end first dot position and receives a paper feed command such as line feed or page feed from the outside. Print head 6
In the case where the control of the present invention is performed to prevent the paper jam or the line feed error by increasing the distance between the leading end surface of the printing paper 3 and the printing paper 3, and the case where printing is performed on the printing paper that does not require the control of the present invention. This is a switch for changing over the print processing capability as described above, thereby preventing a decrease in print processing capability. In the figure, a line 51 is a signal transmission line when the above control is selected by the DIP switch 50, and a line 52 is provided.
Indicates a signal transmission line when the dip switch 50 selects the release of the control.

Further, a home position sensor 53 that outputs a home position signal when the carriage 25 is located at the left end home position is connected to the input side of the CPU. Based on that home position, the leftmost first
First, the dot printing position by the print head 6 is determined.

On the other hand, the print head 6, the drive motor 22, the carriage moving device 41, and the paper feed device 54 are connected to the output side of the CPU 42. ROM4 that stores control programs
5 and a RAM 46 for storing various data are connected to the CPU 42.

Next, the operation of the embodiment will be described with reference to the flowchart of FIG.

The above flowchart shows a control procedure by the CPU 42 for preventing a paper jam or the like from occurring at the time of paper feeding. That is, when the B dimension is set to the first dot from the center of the sprocket hole 4 formed in the paper 3 as shown in FIGS.
When the print head 6 is located in this portion, the distance between the leading end surface of the print head 6 and the paper 3 is not sufficiently secured. Since the leading end surface of the print head 6 and the sheet 3 come into contact with each other and a sheet jam or a line feed failure may occur, the control is performed to prevent this.

In step S1, the CUP 42 receives a signal from the dip switch 50, and executes a control according to the present invention based on the signal from the switch 50 to determine whether or not the print head 6 is in the retreat mode for avoiding the paper stapler from the paper stapler. It is determined whether or not. As a result of the determination, when it is determined that the control is to be performed, the process proceeds to step S2, and when it is determined that the control is not performed, the process directly proceeds to step S4.

If the decision result in the step S1 is YES, in a step S2, is the current position of the print head 6 starting from the home position based on the home position signal from the home position sensor 53 located to the left of the first print position? Determine whether or not. That is, as shown in FIG. 6, the print head 6 is located in a range where the print wire can be hooked on the paper stapler of the print paper 3 in which the print paper 3 is lifted from the platen 1 by a paper stapler or the like. 6
Is determined to be required to be separated (evacuated) from the platen 1. If the decision result in the step S2 is NO, the process shifts to the step S4, while the decision result in the step S2 is YES.
In step S3, the process proceeds to step S3, in which the drive motor 22 is driven to rotate the guide shaft 18 by a predetermined amount, and the print head 6 is retracted to the position 7b in FIG. . Thereafter, the process proceeds to step S4, in which the paper feeding device 54 is driven to perform a paper feeding operation.

In the above embodiment, it is determined whether or not the print dot position is in the retreat required range based on the first dot position at the left end. However, as described in the above-mentioned publication, a sensor for detecting the sheet edge is used. You may. The print head 6 can also be separated from the platen 1 by using a sensor at the right end of the sheet.

As described above, the printing paper 3 is lifted from the platen 1 by a paper stapler or the like, and the leading end surface of the printing head 6 comes into contact with the printing paper 3 at the time of paper feeding, so that paper jam, line feed failure, etc. may occur. If the print head 6 is provided, the print head 6 is separated from the platen 1 immediately before the paper feed, thereby avoiding the occurrence of an abnormal state such as a paper jam or a line feed failure at the time of paper feed. it can.

In the above-described embodiment, a special mechanism is used because a mechanism for appropriately adjusting the distance between the print head 6 and the printing paper 3 according to the thickness of the printing paper 3 to avoid paper hooking is employed. It can be manufactured at low cost without adding.

(Effect of the Invention) As described above, according to the present invention, the print head is located at the left end
The distance between the leading end surface of the print head and the printing paper is set by separating the carriage with the print head from the platen when a paper feed command such as a line feed or page break is issued from the outside, which is within the necessary refuge area near the dot position. Therefore, it is possible to prevent paper jam and line feed failure during paper feeding.

[Brief description of the drawings]

FIG. 1 is a plan view showing a part of a printing apparatus embodying the present invention in a cutaway view, FIG. 2 is an enlarged sectional view taken along line AA of FIG.
3 is a control block diagram of the printing apparatus, FIG. 4 is a schematic plan view showing the relative positions of the platen, the printing paper, and the print head, FIG. 5 is a front view of FIG. 4, and FIG. FIG. 7 is a schematic plan view showing a relative position where an abnormal state between the printing paper and the print head is likely to occur, FIG. 7 is a front view of FIG. 6, and FIG. 8 is a control flowchart. In the figure, 1 is a platen, 3 is a printing paper, 6 is a print head, 16 and 17 are eccentrics, 18 is a guide shaft, 22 is a drive motor, 25 is a carriage, and 42 is a CPU.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-111176 (JP, A) JP-A-2-92671 (JP, A) JP-A-2-92672 (JP, A) JP-A-53-21 115321 (JP, A) JP-A-59-136268 (JP, A) JP-A-52-134740 (JP, A) JP-A-1-146964 (JP, U) JP-A-58-42060 (JP, U)

Claims (1)

(57) [Claims] 1. A printing apparatus for printing on printing paper on a platen while moving a carriage on which a wire dot type printing head is mounted along a platen, wherein the carriage is moved from a predetermined position with respect to the platen. A carriage separation unit for separating the print head; a determination unit for determining whether the print head is in a retreat necessary range near a collating portion of the sheet; and the determination unit determines that the print head is in a retreat required range. Control means for outputting a signal for separating the carriage from the platen to the carriage separating means based on the determined result and a paper feed command such as line feed or page break. Carriage control device of the printing device.