JPH04246566A - printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device for printing and recording image information such as characters and numbers on print recording media such as bankbooks and forms.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 8, this type of printing device has a print head 1 and a platen 2 provided opposite to the print head 1. It is mounted on a carriage (not shown) that moves vertically. On the other hand, the platen 2 is movable forward and backward relative to the print head 1, and is moved in the vertical direction by a cam mechanism (not shown).

[0003] Near the platen 2, a first conveyance mechanism 3 and a second conveyance mechanism 4 are provided before and after the print head 1. These conveyance mechanisms 3 and 4 include a pair of upper and lower rollers 5.
, 6, 7, and 8, and the print recording medium P is held between these rollers 5 to 8 and conveyed between the print head 1 and the platen 2. It is configured to convey the print recording medium P to a discharge port (not shown).

[0004] Also, a stopper 9 is provided near the print head 1.
is provided facing the platen 2, and is configured to maintain a constant distance (print gap) between the print head 1 and the print recording medium P with this stopper 9.

By the way, in the printing apparatus configured as described above, when the print recording medium P is conveyed between the print head 1 and the platen 2 by the first conveyance mechanism 3, the print recording medium P is transferred as shown in FIG. is in a relaxed state between rollers 5, 6 and rollers 7, 8. For this reason, conventionally the platen 2
When pressed against the stopper 9, the printing position on the print recording medium P shifts, causing a problem in that printing misalignment occurs.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and its purpose is to eliminate slack that occurs in a print recording medium conveyed between a print head and a platen. It is an object of the present invention to provide a printing device that can print at a predetermined position on a print recording medium conveyed between a print head and a platen.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a print head, a platen that is provided to move forward and backward with respect to the print head, and a print between the print head and the platen. a first conveying means for conveying a recording medium while sandwiching it between a pair of rollers; a distance maintaining means provided opposite to the platen for keeping a constant distance between the print head and the print recording medium; a second conveying means for conveying the print recording medium passed between the platen and sandwiched between a pair of rollers that can freely approach and separate; and detecting the print recording medium conveyed between the print head and the platen. and means for pressing the platen against the spacing holding means based on a signal from the detecting means, and changing the state of the roller of the second conveying means from an open state to a closed state after the pressing. It is equipped with

[0008]

[Operation] In the present invention, the print recording medium conveyed between the print head and the platen is detected by the detection means, and the platen is pressed against the interval holding means based on the signal from the detection means. By changing the state of the rollers of the conveying means from the open state to the closed state, it is possible to remove slack that occurs in the print recording medium conveyed between the print head and the platen.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of a printing apparatus showing an embodiment of the present invention. In the figure, 1 is a print head, 2 is a platen, 3 is a first transport mechanism, 4 is a second transport mechanism,
5 to 8 are rollers, and 9 is a stopper, which are the same as those shown in FIG. Further, 10 is a contact/separation mechanism for bringing the roller 8 into contact with/separating from the roller 7, and this contact/separation mechanism 10 includes a solenoid 11 and a solenoid 1.
A plunger 12 held at 1 and this plunger 12
A swing lever 14 is connected to the swing lever 14 via a connecting member 13.

The swing lever 14 is able to swing freely around a shaft 15, and when the plunger 12 is attracted by the solenoid 11, it swings clockwise around the shaft 15, thereby causing the roller 8 to move toward the roller. It is designed to be separated from 7. Note that the swing lever 14 has a plunger 12.
A tension spring 16 is connected to pull the solenoid back from the solenoid 11.

Further, a third transport mechanism 17 is provided between the platen 2 and the first transport mechanism 5. This third
The conveyance mechanism 17 includes a pair of upper and lower rollers 18, 1 that can freely approach and separate.
9, and is configured so that the print recording medium P is conveyed between the print head 1 and the platen 2 by these rollers 18 and 19.

The roller 19 is rotatably held at one end of an L-shaped swing lever 20. A plunger 22 is connected to the other end of the swing lever 20 via a connecting member 21.
When the plunger 22 is attracted by the solenoid 23, the swinging lever 20 swings counterclockwise in the figure about the shaft 24, thereby separating the roller 19 from the roller 18. Note that a tension spring 25 for pulling the plunger 22 back from the solenoid 23 is connected to the swing lever 20 .

Further, 26 is a medium sensor that optically detects the print recording medium P conveyed between the print head 1 and the platen 2, and the detection signal output from this medium sensor 26 is sent to the control device 27. It is now entered.

The control device 27 includes solenoids 11 and 2.
Drive circuits 28 and 29 for driving the solenoids 11 and 24 are connected to each other, and the solenoids 11 and 24 are driven and controlled by control signals from a control device 27.

As shown in FIGS. 2 and 3, the platen 2 is divided into three divided platens 2a, 2b, and 2 in order to absorb the difference in thickness between the left and right sides of the print recording medium P and the thickness of the binding margin.
It is formed from c. These divided platens 2a, 2
b, 2c are guide plates 3 provided movably in the vertical direction;
1, 32, 33, and is held at the upper end of the guide plate 3.
Swing levers 37, 38, and 39 are swingably supported on the shafts 1, 32, and 33 via support shafts 34, 35, and 36, respectively. One end of these swing levers 37, 38, 39 is fixed to the guide plates 31, 32, 33, and the other end has a connecting pin 40 connected via a connecting rod 46 and coil springs 43, 44, 45. , 41, 42 are provided.

One end of a swing lever 48 is connected to one end of the connecting rod 46 via a connecting pin 47. The swing lever 48 is swingably held by a support shaft 49, and a cam 50 for moving the platen 2 in the vertical direction is engaged with the other end thereof. In addition, the connecting pin 40,
41, 42 are long holes 51, 52, 5 formed in the continuous rod 46.
3 is loosely fitted.

FIG. 4 shows the platen 2, the first transport mechanism 3, the second transport mechanism 4, the third transport mechanism 17, and the medium sensor 26.
and the operation timing of the solenoids 11 and 23. As shown in the figure, when the print recording medium P is detected by the medium sensor 26, the solenoid 11 is turned on, and after a predetermined time T, the first conveyance is started. The motor (not shown) that drives the mechanism 3 stops rotating. As a result, the leading end of the print recording medium P passes between the print head 1 and the platen 2, and is located between the rollers 7 and 8, as shown in FIG.

When the leading end of the print recording medium P is positioned between the rollers 7 and 8 in this way, the solenoid 2
3 is switched from on to off, and the platen 2 further moves from the lowered position to the raised position. As a result, the print recording medium P is pressed against the stopper 9 as shown in FIG. 6, and is in a linearly extended state. Thereafter, the solenoid 11 is switched from on to off, and the print recording medium P is sandwiched between the rollers 7 and 8 as shown in FIG.

Note that when the print recording medium P is sandwiched between the rollers 7 and 8, after the platen 2 moves from the raised position to the lowered position, the first to third transport mechanisms 3, 4, 1
7 is driven by a motor (not shown), and the print recording medium P
transport to the position where you want to print. When the print recording medium P is conveyed to a predetermined position, the platen 2 moves from the lowered position to the raised position, and the print head 1 performs printing.

In this way, in the above embodiment, the print head 1
A pair of conveyance rollers 7 that can freely approach and separate the second conveyance mechanism 4 that conveys the print recording medium P that has passed between the platen 2 and the platen 2;
After the print recording medium P conveyed between the print head 1 and the platen 2 is pressed against the stopper 9 by the platen 2, the conveyance roller 8 is pressed against the conveyance roller 7 by the solenoid 11, and the print head 1 is Since the print recording medium P that has passed between the platen 2 and the platen 2 is sandwiched between the conveyance roller 7 and the conveyance roller 8, slack in the print recording medium P can be removed. Therefore, when the platen 2 is pressed against the stopper 9, the printing position on the print recording medium P does not shift, and it is possible to prevent printing misalignment due to loosening of the print recording medium P.

It should be noted that the present invention is not limited to the above embodiments. For example, in the above embodiment, a pair of rollers 18 and 19 that can freely approach and separate between the first conveyance mechanism 3 and the platen 2 is provided.
Although the third transport mechanism 17 consisting of
It is not necessary to provide the transport mechanism 17.

[0022]

As explained above, the present invention includes a print head, a platen that is provided to move forward and backward with respect to the print head, and a pair of rollers that hold a print recording medium between the print head and the platen. a first conveying means for conveying the print head while holding it therein; a distance maintaining means provided opposite to the platen for maintaining a constant distance between the print head and the print recording medium; a second conveyance means for conveying the passed print recording medium by sandwiching it between a pair of rollers that can freely approach and separate; a detection means for detecting the print recording medium conveyed between the print head and the platen; The apparatus further includes means for pressing the platen against the distance holding means based on a signal from the detection means, and changing the state of the rollers of the second conveying means from an open state to a closed state after the pressing. Therefore, it is possible to remove slack that occurs in the print recording medium conveyed between the print head and the platen, and it is possible to print at a predetermined position on the print recording medium conveyed between the print head and the platen. We can provide a printing device that can.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a printing device showing an embodiment of the present invention.

FIG. 2 is a plan view of the platen in the same embodiment.

FIG. 3 is a front view of the platen in the same embodiment.

FIG. 4 is a diagram showing the operation timing of each part in the same embodiment.

FIG. 5 is a diagram for explaining the operation of the same embodiment.

FIG. 6 is a diagram for explaining the operation of the embodiment.

FIG. 7 is a diagram for explaining the operation of the embodiment.

FIG. 8 is a diagram showing a conventional example.

FIG. 9 is a diagram showing the state of a print recording medium in a conventional example.

[Explanation of symbols]

1... Print head, 2... Platen, 3... First conveyance mechanism,
4...Second conveyance mechanism, 5-8...Roller, 9...Stopper,
DESCRIPTION OF SYMBOLS 10... Contact/separation mechanism, 11... Solenoid, 12... Plunger, 14... Rocking lever, 26... Medium sensor, 27... Control device.

Claims (1)

[Claims] Claims: 1. A print head, a platen provided to be movable forward and backward with respect to the print head, and a first print recording medium that is conveyed while being sandwiched between the print head and the platen by a pair of rollers. A conveying means, a distance holding means provided opposite to the platen and maintaining a constant distance between the print head and the print recording medium, and a print recording medium that has passed between the print head and the platen can be freely moved toward and away from the conveyance means. a second conveyance means that conveys the print medium while being held between a pair of rollers; a detection means that detects the print recording medium conveyed between the print head and the platen; and a second conveyance means that detects the print recording medium conveyed between the print head and the platen; A printing device characterized by comprising means for pressing the rollers of the second conveying means against the spacing holding means and changing the state of the rollers of the second conveying means from an open state to a closed state after the pressing.