JP2820172B2 - Printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device connected to an electronic computer and used, for example, to a dot impact serial printer.

[0002]

2. Description of the Related Art FIG. 10 is a cross-sectional view showing a conventional printing apparatus of this type. In the drawing, reference numeral 1 denotes a print head which moves perpendicularly to the paper surface and prints, 2 denotes a platen facing the print head 1, and 3 denotes a platen. A continuous form wound and transported around the platen 2, a tractor 4 for transporting the continuous form 3, a pinch roller 5 for pressing against the platen 2 via the continuous form 3 and transporting the continuous form 3, a single form 7, Is a drive roller for conveying the cut sheet 6, 8 is a pinch roller for pressing the drive roller 7 through the cut sheet 6 and conveying the cut sheet 6, and 9, 10 are 7, 8
Drive roller and pinch roller similar to the above, 11 is an arrow indicating the forward direction of the continuous form 3, and 12 is an arrow indicating the forward direction of the single form 6.

FIG. 10 shows a continuous form transport mechanism including a platen 2, a tractor 4, and a pinch roller 5 for transporting a continuous form 3 as described above, and a drive system (not shown) including a drive motor for driving the continuous form transport mechanism. , And drive rollers 7, 9, 9
1 shows a printing apparatus having a second transport unit including a cut-sheet transport mechanism including pinch rollers 8 and 10 and a drive system (not shown) including a drive motor and the like for driving the single-sheet transport mechanism.

Next, a description will be given of a continuous form transport operation and a single form transport operation of this type of printing apparatus. FIG. 11 is a view showing a continuous form transport state. The continuous form 3 is forwardly transported in the direction of arrow 11 by the rotation of the platen 2 and the tractor 4. Here, it is necessary that the platen 2 be made of a material that withstands the impact of the print head 1 and has an appropriate coefficient of friction for transporting the paper. Generally, hard rubber or the like is used. Also, during the continuous form transport, the single form transport mechanism is stopped. FIG. 12 is a diagram showing a cut-sheet conveyance state, and cut-sheet 6 is composed of drive rollers 7 and 9 and pinch rollers 8.
By the rotation drive of 10, the normal conveyance is performed in the direction of arrow 12.
During the single-sheet transfer, the continuous form transfer mechanism is stopped.

As described above, in a printing apparatus having a continuous form transport mechanism and a single form transport mechanism, each of which can be driven independently, a continuous form 3 is loaded on a platen 2 and a tractor 4 as shown in FIG. One of the features is that the printing / transporting process of the cut sheet 6 can be performed even in the state. At this time, the continuous form transport mechanism including the platen 2 is stopped.

[0006]

Since this type of conventional printing apparatus is configured as described above, the platen 2 is stopped during single-sheet printing conveyance, so that the print head 1 is the same as the platen 2. The portion is hit a plurality of times, and the abrasion on the platen 2 and dents such as a concave portion due to the hitting cause a decrease in paper transport performance, a decrease in print quality, and the like, thereby shortening the life of the printing apparatus.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to obtain a printing apparatus having a longer life. It is another object of the present invention to obtain a power-saving and low-noise printing device.

[0008]

A printing apparatus according to a first aspect of the invention has the following elements. (A) a first transport means for transporting a continuous form while rotating a platen; (b) a second transport means for transporting a single form on a transport path different from the first transport means; A print head for performing printing, (d) first detecting means for detecting the state of loading of the form into the first transport means, and (e) second detecting the thickness of the form transported by the second transport means. (F) the form is not loaded by the first detecting means during the printing and carrying of the form by the print head and the second carrying means.
In a case where the Most sensed, and, when the thickness of the document detected by the second detecting means is less than a predetermined thickness, up
Platen driving means for rotating the Latin .

[0009]

[Action] second sensing means in the first aspect of the present invention detects the thickness of the single-cut sheet conveyed by the second conveying means, it prohibits the rotation of wasteful platen during printing on the cut sheet. That is,
The printing apparatus according to the first aspect of the invention reduces noise and saves power by rotating the platen only under predetermined conditions.

[0010]

[Embodiment 1] Hereinafter will be described with reference to FIG an embodiment of this invention. FIG. 1 is a diagram showing an embodiment of the present invention, in which 1 to 10 are the same as those described in the conventional example. In the figure, reference numeral 13 denotes a detector for detecting whether or not the continuous form 3 is loaded, and reference numeral 14 denotes a platen 2 by a platen driving means 18.
, A drive motor for driving the drive rollers 7 and 9, 16 a drive motor for driving the platen, 17 a drive control unit for controlling the drive motor, and 18 a platen in the drive control unit 17. Drive means.

Next, the operation will be described with reference to the flowchart of FIG. At the time of single-sheet printing conveyance, when the detector 13 detects that the continuous form 3 is not loaded, the platen driving means 18 sends a signal to the drive motor 16 to drive the platen 2. Thus, the platen 2 rotates forward in the direction of the arrow 14. As a result, the impact points of the print head 1 are dispersed on the circumference of the platen 2.

As described above, in the printing apparatus according to the present invention, when performing the single-sheet printing conveyance in the state shown in FIG. 12, that is, in a state where the continuous form is not loaded, the driving motor 15 of the single-sheet conveyance mechanism is being driven. The drive motor 16 of the continuous form transport mechanism is also driven simultaneously.

On the other hand, as shown in FIG. 3, that is, when a continuous form 3 is loaded, simultaneous driving is
Are not shifted at this time.

As described above, the first embodiment includes the continuous form transport mechanism (first transport means) configured to rotationally drive the platen and the single-sheet transport mechanism (second transport means). In a printing device that has a drive motor that is independently compatible with the above, the drive motor of the single-sheet transport mechanism and the drive motor of the continuous form transport mechanism are used simultaneously when the continuous form is not loaded in the continuous form transport mechanism during single-sheet transport. A printing apparatus characterized by being driven has been described.

Embodiment 2 FIG. It will now be discussed other printer according to this invention. Since the printing apparatus according to the first embodiment is configured as described above, driving the two paper transport drive motors at the same time increases drive noise, reduces noise, and reduces power consumption. There is an improvement that it becomes larger and it is difficult to save power. The second embodiment has been made in order to improve the above points, and has as its object to obtain an apparatus capable of reducing noise and power consumption and extending the life of the platen.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view of this type of printing apparatus, in which the same reference numerals are given to the same and corresponding parts as those described in the first embodiment. 19 is the pinch roller 8 for the thickness of the cut sheet.
Is a second detector that detects from the position of. In addition, the detector 13 shown in the first embodiment is hereinafter referred to as a first detector to distinguish it from the second detector.

FIGS. 5, 6 and 7 are flow charts relating to paper transport of the printing apparatus according to the second embodiment. FIG. 5 shows a configuration in which the platen is rotated when the sheet has a thickness equal to or less than a predetermined thickness. FIG. 6 shows a configuration in which the platen is rotated by one line feed during paper feeding. FIG. 7 shows a configuration in which the platen is rotated only at the time of a line feed immediately after printing.

Next, the operation will be described. As described in the first embodiment, the life of the platen is extended by simultaneously rotating the platen at the time of single-sheet printing. However, the strength of the impact at the time of printing on the platen varies depending on the thickness of the paper. When the sheet is thicker than a predetermined thickness, the impact strength on the platen is reduced to a level that does not affect the life of the platen. That is, when the sheet thickness detected by the second detector 19 is equal to or larger than a predetermined value, the simultaneous rotation of the platen is unnecessary. Therefore, as shown in the flowchart of FIG. 5, by determining the sheet thickness, unnecessary rotation of the platen can be omitted, and noise reduction and power saving can be achieved.

In the example shown in FIG. 4, an example of the second detector for detecting the thickness of the cut sheet from the position of the pinch roller 8 is shown, but a paper thickness detector as shown in FIG. The second detector may be used. 8, 20 is a motor,
Reference numeral 21 denotes a pinion gear, and reference numeral 22 denotes a rack. The print head 1 is hit against the platen 2 by a stepping motor 20, and then the print head is moved up and down by returning a predetermined pulse. Thereby, the thickness of the paper can be detected.

Further, the damage caused by the impact of the platen is not so bad as to print one cut sheet at the same place. If the platen is simultaneously rotated for one line feed at the time of feeding the cut sheet, the expected result is obtained. The purpose of the above is fully achieved. When the number of sheets corresponding to the number of line feeds per platen rotation has been printed, the platen may be rotated. Therefore, as shown in the flow chart of FIG. 6, when the paper feed is detected by the second detector 19 and the platen feeds one line at the time of feeding the cut sheet, the same simultaneous driving as in the first embodiment can be performed with minimum simultaneous driving. Is obtained, and
Low noise and power saving can be achieved.

Further, in the case where the line feed is continued for N lines after printing, simultaneous rotation of the platen is required only for one line feed immediately after printing. Therefore, as shown in the flowchart of FIG. 7, when the second detector (not shown in FIG. 4) inside the drive control unit 17 detects that the line feed amount is a plurality of lines, By making the rotation only one line feed immediately after printing, further noise reduction and power saving can be achieved.

As described above, in the second embodiment, the platen is simultaneously rotated when it is detected that the continuous form is not loaded in the first transport means when transporting the cut sheet by the second transport means. In the printing apparatus, the thickness of the cut sheet is detected, and the platen is rotated simultaneously only when the thickness is below a predetermined thickness. Further, when it is detected that the cut sheet is fed to the second conveying means and it is detected that the continuous form is not loaded in the first conveying means, the cut sheet is supplied to the first conveying means. The printing apparatus has been described in which the platen is rotated by one line feed at the time of insertion. In addition, the printing apparatus has been described in which the platen is simultaneously rotated by one line at the time of a plurality of line feeds after printing on the cut sheet being processed by the second transport means. As described above, the sheet thickness, sheet supply, and multiple line feeds are performed by the second detector 19 that detects the sheet conveyance state.

As described above, in the second embodiment, the continuous form transport mechanism (first transport means) and the single-sheet transport mechanism (second transport means) which are configured to rotate the platen are provided. In a printing apparatus having a mechanism drive motor independently corresponding to a mechanism, when the slip transport mechanism is in a predetermined transport state, the drive of the slip transport mechanism is performed based on the loading state of the continuous form into the continuous slip transport mechanism. The printing apparatus has been described in which the drive of the motor and the drive motor of the continuous form transport mechanism is controlled. By limiting the conditions for simultaneous driving, noise reduction and power saving can be achieved.

Embodiment 3 FIG. In the above-described embodiment, the case where each of the first and second transport means has a drive motor is shown. However, as shown in FIG. 9, one drive motor 16 and a power transmission destination switching mechanism are provided for both transport means. 23, the connection may be switched in the middle of the drive transmission to drive one of the first and second transporting means and simultaneously drive the second transporting means and the platen driving means.

Embodiment 4 FIG. The line feed immediately after printing shown in the second embodiment is not limited to one line feed, but may be a predetermined N line feed. Further, one line feed at the time of sheet feeding shown in the second embodiment may be at the time of sheet discharge, and the line feed amount may be N line feeds.

Embodiment 5 FIG. Further, in the above-described embodiment, the case of the continuous form and the single form has been described. However, the present invention is not limited to this, and any form or sheet may be used. Here, the form or paper may be any printing object printed by the print head. Also,
What is printed is not limited to characters, but may be other data such as figures, images, and symbols.

[0027]

According to the first aspect of the invention, the rotation of the platen is limited to a predetermined condition, so that noise reduction and power saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart diagram according to an embodiment of the invention of this.

FIG. 3 is a sectional view showing this type of printing apparatus.

4 is a cross-sectional view showing a printing apparatus of the invention of this.

FIG. 5 is a flowchart diagram according to an embodiment of the invention of this.

FIG. 6 is a flowchart according to an embodiment.

FIG. 7 is a flowchart according to an embodiment.

8 shows a by the printing apparatus to another embodiment of the invention of this.

FIG. 9 is a diagram showing a power transmission destination switching mechanism.

FIG. 10 is a sectional view showing a conventional printing apparatus.

FIG. 11 is a sectional view showing a conventional printing apparatus.

FIG. 12 is a sectional view showing a conventional printing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Platen 3 Continuous report 4 Tractor 5 Pinch roller 6 Cut sheet 7 Drive roller 8 Pinch roller 9 Drive roller 10 Pinch roller 13 Detector / first detector 15, 16 Drive motor 17 Drive control unit 18 Platen drive means 19 Second detector

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 11/48 B41J 11/42

Claims (1)

(57) [Claims] 1. A printing apparatus having the following elements: (a) a first transport means for transporting a form while rotating a platen; and (b) a second transport means for transporting a form along a transport path different from that of the first transport means. (C) a print head for performing printing on a form, (d) a first detecting means for detecting the state of loading of the form into the first carrying means, and (e) a form being carried by the second carrying means. (F) a form is not loaded by the first detecting means during printing and transport of the form by the print head and the second transport means.
In a case where the Most sensed, and, when the thickness of the document detected by the second detecting means is less than a predetermined thickness, up
Platen driving means for rotating the Latin .