JP2551782B2 - Method of transporting printing paper in printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transporting printing paper in a printer, which is partially thick like an envelope (described as "special paper" in the drawings). The present invention relates to a sheet conveying method in a printer in which sheets having different sizes are used.

-Prior Art-In a printer capable of printing both ordinary office paper and envelopes, as shown in FIG. 3, two sensors 1 and 2 for detecting the edge of the paper are provided in the paper feed path. By arranging one of them so as to be hooked on the flap portion 3 of the envelope, and utilizing the fact that the timings of paper detection by the sensors 1 and 2 differ between normal paper and envelope, whether the supplied paper is normal paper or not A method for automatically detecting whether it is an envelope is known.

On the other hand, it is well known that the print head or the platen is moved back and forth in order to set the print gap according to the thickness of the inserted paper. For example, as shown in FIG. A device is known in which the platen 5 is supported by a cam 6 and the pulse motor 7 rotates the cam 6 to adjust the print gap 8. In this structure, the platen 5 is moved upward, and the head support 11 is pushed while the paper 10 is once sandwiched between the platen 5 and the ribbon mask 9,
The platen 5 is lowered by a certain amount from the reference position detected by the sensor 12 to set the print gap according to the sheet thickness. In the figure, 13 is a print head, 14 is a carrier, 15 is a pin that pivotally supports the head support 11 on the carrier 14, 16 is the head support 11 in the clockwise direction in the figure,
That is, a spring urges the print head 13 in the downward direction, and 17 is a stopper that engages with the head support 11 and defines the lower end position of the print head 13.

-Problems to be solved by the invention-The print gap set by the above device is 3/100.
Although it is about millimeters, the raw material paper such as envelopes is usually 7/10
It has a thickness of about 0 mm. Therefore, the glued part of the envelope is about 7/100 mm thicker than other parts. On the other hand, the printing process on the envelope is performed on a portion other than the normal pasting portion, and the setting of the print gap is also performed on the basis of the thickness of the printing portion. Therefore, a large load resistance is applied when the pasting portion passes through the tip of the print head 13 or when the carrier 14 is moved to the head (or the tail) of the print line, and paper skew occurs.

Particularly, in a printer in which the print gap is set with the structure as shown in FIG. 4, the ribbon mask 9 cannot be made flexible, so that the load resistance also becomes large and the occurrence of paper skew increases accordingly.

-Means for Solving Problems- Therefore, in the present invention, the detection means 1 and 2 for detecting the difference between the normal paper and the envelope are provided, and the print gap 8 is provided.
When the printing paper is conveyed in the printer having the structures 6 and 7 for automatically setting the print thickness according to the paper thickness, when the supplied paper is the normal paper, the print gap 8 is left as the size for printing, that is, the printing is performed. When the supplied paper is an envelope, etc., the paper feeding operation and the position setting of the carrier 14 are repeated when the printing operation and the paper feeding operation are repeated without expanding or narrowing the print gap between the operations and the paper feeding operation. The above problem is solved by expanding the print gap 8 by a predetermined amount before performing the operation, and by performing the print operation after narrowing the print gap 8 by the predetermined amount after the completion of the paper conveying operation and the position setting operation of the carrier 14. ing.

-Operation-According to the above method, when the supplied paper is an envelope or the like, the paper is conveyed and the position of the carrier is set with the print gap 8 being expanded, so that the pasting portion is attached to the ribbon mask 9 and the platen. An increase in the load resistance when passing between 5 and 5 can be avoided, while vivid printing is guaranteed because the printing operation is performed under the set print gap 8. When the supplied paper is a normal paper, the print gap 8 is not expanded / contracted, so that the throughput does not decrease due to the operation time of the expansion / contraction operation.

-Embodiment- An embodiment of the method of the present invention in a printer having the envelope detecting means shown in FIG. 3 and the print gap setting means shown in FIG. 4 will be described below.

FIG. 1 shows a first embodiment of the method of the present invention. Based on the detection result of the sheet type by the sensors 1 and 2, a control program is set to a normal sheet processing routine 20 and an envelope processing routine 21.
It is distributed to and. In the normal paper processing routine 20, the print gap 8 set in step 22 is set.
While maintaining the above, the paper feed, the movement of the carrier and the printing operation are performed. On the other hand, in the envelope processing routine 21, after the print gap is set in step 23, if it is necessary to feed the paper or move the carrier before printing, the pulse motor 7 shown in FIG. Then, as shown by an imaginary line in the figure, the platen 5 is lowered approximately twice the thickness of the raw material paper of the envelope (14/100 mm in this embodiment), and then the paper is fed and / or the carrier is moved. The same 20-pulse forward rotation command is given to the pulse motor 7 to raise the platen 5 to the normal print gap setting position, and then the printing operation is performed.

The printing operation that does not involve paper feeding or carrier movement is executed, for example, when color printing is performed by overprinting using ink ribbons of a plurality of colors.

In the second embodiment shown in FIG. 2, the sensor 1 of FIG.
1 in the paper flag when it is detected as an envelope in 2
When the paper feed or the carrier movement is executed, the flag is referred to, and if the flag is set to 1, the platen lowering and platen returning operations are performed before and after the paper feed or the carrier movement. .

-Effects of the Invention-According to the method of the present invention described above, when a sheet having a partially different thickness such as an envelope is used, when the sheet thickness portion passes between the ribbon mask and the platen. It is possible to avoid an increase in load resistance caused by the above, and to avoid a paper jam or a paper skew resulting from this.
Even in the case of envelopes, the print gap can be set to a normal value without considering the thickness of the paper thickness portion, so clear printing can be performed and throughput during normal paper processing is reduced. Nothing.

[Brief description of drawings]

FIG. 1 is a control flow chart showing a first embodiment of the present invention, FIG. 2 is a control flow chart showing a second embodiment, and FIG. 3 is a schematic view showing an example of a means for detecting the distinction between envelopes and normal paper. FIG. 4 is a side view schematically showing an example of print gap setting means. In the figure, 1,2: Sensor, 5: Platen 6: Cam, 7: Pulse motor 8: Print gap, 9: Ribbon mask 10: Printing paper, 13: Print head 14: Carrier 20: Normal paper processing routine 21: Envelope Processing routine

Claims (1)

(57) [Claims] 1. A detection means (1), (2) for detecting the distinction between a normal paper and an envelope, a platen (5) and a print head (1).
In a method of transporting a printing paper in a printer having an advancing / retreating drive source (7) for advancing / retreating at least one of (3) to set a print gap (8), the detection means (1) and (2) detect the normal paper. When the paper is fed or the carrier is moved prior to printing in the detected state, the paper is fed or the carrier is moved without giving a drive signal to the advancing / retreating drive source (7), and the detecting means (1), (2) is operated by the envelope. When the paper feed or the carrier movement is performed prior to the printing in the state of detecting the above, the operation of giving a predetermined amount of drive signal in the print gap expanding direction to the advancing / retreating drive source (7), the operation of feeding the paper or the carrier and the advancing / retreating operation. The paper feed or the carrier movement is performed by the operation of supplying the drive source (7) with the predetermined amount of the reverse drive signal. The method of conveying the printing paper in the printer.