JP3170115B2 - Impact printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has three paper feeding routes as routes for feeding printing paper between a print head and a platen, and adjusts a gap between the print head and the platen. The present invention relates to an impact printer having three mode functions.

[0002]

2. Description of the Related Art Generally, in the construction of an impact printer, a gap between a print head and a platen (hereinafter referred to as a gap) is provided.
The print gap has a range in which good printing can be performed due to factors such as the running stability of the printing paper and the mechanical response characteristics of the printing wire in the print head. A mechanism is provided for adjusting the printing gap. Normally, the printing gap can be set to several widths, and the operator sets the number of gaps according to the thickness of the printing paper and performs printing. Although the setting of the number of gap steps was performed by a manual (manual) method by an operator operation, as the functions of the printer and the added value of the printer are increasing,
Various so-called auto-gap systems capable of automatically setting an optimum printing gap have been devised and put to practical use.
In such an automatic gap system, it is essential to detect the thickness of the printing paper fed between the printing head and the platen in order to obtain an optimum printing gap.

FIG. 6 is a schematic diagram for explaining a method of detecting the thickness of a typical print sheet. First, in the drawing, a pressure sensor 12 is provided at a position sandwiching a print sheet P fed between a platen 10 and a print head 11. The pressure sensor 12 is supported by a sensor movable mechanism (not shown) so as to be movable in the direction of the platen 10 indicated by an arrow in the figure. At the time before sheet feeding, the pressure sensor 12 moves to the platen 10 and detects the position of the platen 10,
The distance from the initial position of the pressure sensor 12 to the platen 10 is measured and stored in a memory as reference data.
Thereafter, when the printing paper P is fed, the pressure sensor 12 moves to the platen 10 again and measures the distance from the initial position to the printing paper P. By comparing the measurement data obtained here with the reference data stored in the memory, the thickness of the printing paper P is detected. The print gap is set to an optimum gap by operating a print gap automatic adjustment mechanism (not shown) based on the paper thickness detection data.
Note that the print head 1 can be used without using the pressure sensor 12.
A method of detecting the sheet thickness by bringing the leading end of the sheet 1 into contact with the platen 10 or the printing paper P has also been put to practical use.

Further, as a method for detecting the thickness of printing paper, the following method has been put to practical use. FIG.
FIG. 3 is a half sectional view of a so-called sensor print head in which a sensor is built in the print head. In the configuration of the print head 20 shown in the drawing, the armature 22 fixed to the free end side of the spring 21 has a magnetic structure including an armature yoke 23, a spring 21, a spacer 24, an upper yoke 25, a magnet 26, a lower yoke 27, a base 28, and a core 29. It is a component of the circuit. Therefore, at the time of non-printing, the armature 22 is attracted to the core 29 by the magnetic flux passing between the core 29, the spring 21 and the armature 22. On the other hand, at the time of printing, when the coil 30 is energized, the magnetic flux attracting the armature 22 is canceled, and the armature 22 is opened, whereby the spring 21 is released from a state in which the spring 21 is bent by the thickness of the spacer 24. Then, it starts moving upward together with the armature 22 in the figure. Here, since the printing wire 31 is fixed to the tip of the armature 22, it operates together with the armature 22. That is, the printing wire 31 is
While being guided by the wire guide 32, the guide nose 33
And violently protrudes from the leading end of the print paper, collides with a print sheet via an ink ribbon (not shown), and performs printing.

On the other hand, a sensor board 34 is disposed at a position facing the armature 22, and the sensor board 3
An electrode 35 is provided on 4. The electrode 35 and the armature 22 constitute a kind of capacitor.
Therefore, if a change in capacitance due to the operation of the armature 22 is detected, the time from when the armature 22 starts moving until the printing wire 31 collides with the printing paper (hereinafter, referred to as printing time) is detected. be able to.

Therefore, when actually detecting the paper thickness, first, a reference printing time is measured. Since this measurement is performed in a state where the printing paper is not fed, the printing wire 31 collides with the platen via an ink ribbon (not shown). This operation is performed for each print wire 31, and the print time data of each print wire 31 is stored in the memory as reference data. Next, when printing paper is fed and print data is received from the host computer, any number of dots to be printed on the first line of the print data are selected, preliminary printing is performed, and printing is performed in the same manner as described above. Measure time. The difference between this printing time and the reference printing time stored in the memory is proportional to the paper thickness of the printing paper (the larger the time difference, the thicker the paper thickness.
(The smaller the time difference, the thinner the paper thickness). Therefore, the paper thickness of the printing paper can be detected by arithmetic processing from the difference between the two printing times. Therefore, the printing gap is set to the optimum gap by operating a gap adjustment mechanism (not shown) based on the detected paper thickness data.

In a conventional serial printer, a gap adjustment mode for adjusting a print gap includes an auto gap adjustment mode for adjusting a gap for each print sheet, and a gap for only the first print sheet supplied after the power is turned on. Some have three mode functions, a semi-automatic gap adjustment mode for performing adjustment and a manual gap adjustment mode for performing gap adjustment by an operator operation. Normally, when the paper thickness to be used frequently changes with cut sheets or copy paper, it is necessary to detect the thickness of each sheet and adjust the gap, so that the automatic gap adjustment mode is suitable. When using multiple sheets of the same paper thickness, such as cut sheets or copy paper, or when using continuous paper, the paper thickness is detected only for the printing paper supplied first. The semi-auto gap adjustment mode is suitable because only the gap adjustment is required.

On the other hand, in the case of the same paper, such as a copy paper or an envelope used for a voucher, which has a different thickness in some places (hereinafter referred to as special paper), an automatic gap adjustment mode or a semi-auto gap adjustment mode is used. When the mode is set, when the print gap is automatically adjusted based on the paper thickness data detected in the thin part, the gap between the print head and the print paper becomes too narrow in the thick part and the ink Problems such as contamination of the printing paper due to rubbing with the ribbon and interruption of the printing process due to paper jam occur. For this reason, when handling special paper, the manual gap adjustment mode in which the operator can set a desired number of gap steps is suitable so as not to cause the above-described problems.

Further, conventionally, as a route for feeding print paper between the print head and the platen,
Some printers have a plurality of paper feeding routes. FIG. 8 is a schematic diagram showing this type of printer configuration. In the illustrated printer configuration, the plurality of paper feeding routes include a top feed paper feeding route R1 for supplying the printing paper P1 from above the platen 10, and a printing paper P from the rear side of the platen 10.
And a bottom feed route R3 for supplying the printing paper P3 from below the platen 10. Normally, cut paper P1 such as a cut sheet is supplied through a top feed paper feed route R1 wound about half a round around the platen 10, and a continuous paper P2 provided with perforations is provided.
Are supplied through a rear feed paper feeding route R2 wound about 1/4 turn around the platen 10.

On the other hand, if the printing paper P3 has a certain thickness or more, such as thick paper, copy paper, or sticker paper, the rigidity of the entire paper increases, so that the paper cannot be wound tightly around the platen 10. . Therefore, in the case of the printing paper P3 having a certain thickness or more, the printing paper P3 is supplied through a bottom feed paper feeding route R3 which can feed paper without being wound around the platen 10. Further, even in the case of the same paper, special paper having a different thickness depending on the location is supplied through the bottom feed paper feeding route R3. In this way, the paper feed route suitable for each type of printing paper is usually determined,
The operator uses a paper feeding route according to the type of printing paper to be used.

[0011]

However, in the above-described conventional serial printer, the gap adjustment mode can be freely set by an operator's operation. Since the same applies to the case where paper is supplied, for example, while printing is performed in the semi-auto gap adjustment mode on continuous paper supplied from the rear feed paper feed route R2, only one sheet is cut from the top feed paper feed route R1. If you want to print the cut paper, switch the gap adjustment mode setting from semi-auto gap adjustment mode to auto gap adjustment mode or manual gap adjustment mode before using cut paper. , Again the gap adjustment mode to the original semi-auto gap adjustment mode Etc. it is necessary to reset, there is a troublesome that must be re-set the gap adjustment mode by the operator operation every time the printing paper handling changes and paper feed route changes.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and an impact printer capable of automatically setting an optimum gap adjustment mode corresponding to a paper feeding route to which printing paper is actually supplied. The purpose is to provide.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and a printing paper is provided from above a platen as a paper feeding route for feeding printing paper between a printing head and a platen. The printer has three feed routes: a top feed route that feeds paper, a rear feed route that feeds printing paper from the back side of the platen, and a bottom feed route that feeds printing paper from below the platen. Auto gap adjustment mode that adjusts the gap for each printing paper as the gap adjustment mode that adjusts the gap between the head and platen, semi-auto gap adjustment that adjusts the gap only for the first printing paper supplied after turning on the power 3 of manual gap adjustment mode in which gap adjustment is performed by mode and operator operation In the impact printer equipped with the mode function, the paper feed route detection sensor that detects which of the three paper feed routes the print paper is supplied to and the detection signal from the paper feed route detection sensor. And a selection means for selecting a preset gap adjustment mode for each of the three paper feed routes based on the paper feed route. Further, printing conditions corresponding to the thickness of the printing paper are different for each of the three paper feeding routes.

[0014]

In the impact printer according to the present invention, the paper feed route detecting sensor detects which of the three paper feed routes the printing paper is supplied from, and the selecting means based on the detection signal. In order to select a preset gap adjustment mode for each paper feed route, the optimal gap adjustment mode is automatically set according to the paper feed route to which the printing paper was actually supplied during the printing process. Become. In addition, since the setting step of the printing gap corresponding to the paper thickness of the printing paper and the setting condition of the corresponding printing speed are different for each printing route, even when handling special printing paper as well as plain paper, Good printing can be performed.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of an embodiment of a serial printer according to the present invention. First, as a configuration of the printer, as shown in FIG. 2, as a paper feed route for feeding print paper between the print head 11 and the platen 10, a top feed paper feed for supplying print paper P1 from above the platen 10 is provided. Route R1, a rear feed paper feed route R2 for supplying the print paper P2 from the back side of the platen 10, and a bottom feed paper feed route R3 for supplying the print paper P3 from below the platen 10.
It has two paper feeding routes. The gap adjustment mode for adjusting the printing gap includes an auto gap adjustment mode for adjusting the gap for each printing sheet, a semi-auto gap adjustment mode for adjusting the gap only for the first printing sheet supplied after the power is turned on, and an operator. It has three mode functions of a manual gap adjustment mode in which a gap is adjusted by operation.

In the configuration of the present embodiment, as shown in FIG. 1, the paper feeding route for detecting which of the three paper feeding routes R1, R2, and R3 the printing paper is supplied to is detected. A route detecting sensor 1 and a selecting means 2 for selecting a gap adjustment mode preset for each of the three paper feeding routes R1, R2, R3 based on a detection signal from the paper feeding route detecting sensor 1 are provided. Have been. As shown in FIG. 2, for example, the paper feed route detection sensor 1 includes three optical sensors 1a, 1b, 1 arranged for each paper feed route.
c, each of the optical sensors 1a, 1b, 1
c, the on / off state is switched by the printing paper supplied to each paper feeding route intercepting the sensor beam, and this is a detection signal (on / off signal) from the paper feeding route detection sensor 1 and is transmitted to the selecting means 2. Sent out. Therefore, the selection unit 2 can determine from which paper feed route paper has been supplied, based on which of the three optical sensors 1a, 1b, and 1c has transmitted the detection signal.

On the other hand, the gap adjustment mode setting unit 3 includes:
A gap adjustment mode is set in advance for each of the paper feeding routes R1, R2, and R3. The mode setting information in the gap adjustment mode setting section 3 is read by the selecting means 2 as necessary. The mode setting conditions in the gap adjustment mode setting unit 3 can be set by the operator through various menu settings, mechanical lever operation, or a function code from the host computer via the mode setting input unit 4, for example. It can be changed to the condition of.

The selection means 2 selects a gap adjustment mode corresponding to the paper feed route detected by the paper feed route detection sensor 1 based on a mode setting condition preset in the gap adjustment mode setting section 3. Then, the selected chap adjustment mode is transferred to the gap adjusting means 5. Thereby, the gap adjusting unit 5 operates according to the gap adjusting mode selected by the selecting unit 2.

FIG. 3 is a diagram showing an example of mode setting conditions in the gap adjustment mode setting section. First, in the case of Example 1, when the printing paper is supplied through the top feed paper feeding route R1, a semi-auto gap adjustment mode is performed. When the printing paper is supplied through the rear feeding paper feeding route R2, the automatic gap adjustment mode is performed. When printing paper is supplied through the bottom feed paper feeding route R3, the manual gap adjustment mode is set. The mode setting conditions of Example 1 are as follows: cut paper having the same thickness is used in the top feed paper feed route R1, continuous paper of which thickness is not particularly determined is used in the rear feed paper feed route R2, and bottom feed paper feed route R2 is used. The route R3 is suitable when special paper is used.

On the other hand, in the case of Example 2, when printing paper is supplied along the top feed paper feeding route R1, a manual gap adjustment mode is set, and when printing paper is supplied along the rear feed paper feeding route R2, semi-auto gap adjustment is performed. The mode is set to the semi-auto gap adjustment mode when the printing paper is supplied in the bottom feed paper feeding route R3. The mode setting conditions of Example 2 are as follows:
The top feed route R1 uses a cut sheet feeder to use a large amount of envelopes, for example, with an optimum number of gaps corresponding to four, and the rear feed route R2 and the bottom feed route R3 use a particularly large amount of printing paper. Suitable when the type is not determined.

Further, since the printing paper supplied through the bottom feed paper feeding route R3 is often a special paper, when the operator sets the number of gaps in the manual gap adjustment mode, it is necessary to ensure the running stability of the printing paper and the prevention of dirt. Considering this, the print gap is set slightly wider than when the paper is fed along the top feed paper feed route R1 or the rear feed paper feed route R2. Similarly, even when the gap adjustment mode corresponding to the bottom feed paper feed route R3 is set to the auto gap adjustment mode or the semi-auto gap adjustment mode, the top feed paper feed route R1 and the rear feed paper feed route R2 are used. The print gap is set wider than when paper is fed.

FIG. 4 is a diagram showing the setting conditions of the number of gaps according to the paper thickness of each paper feeding route. FIG. 5 is a diagram showing the setting conditions of the printing speed according to the number of gaps of each paper feeding route. FIG. As can be understood from the drawing, the paper thickness corresponding to each gap number is set to be 0.5 mm thinner in the bottom feed route R3 than in the top feed route R1 and the rear feed route R2. ing. Therefore, for example, even when the paper thickness is the same of 0.23 mm, the number of gaps is set to four in the top feed paper feed route R1 and the rear feed paper feed route R2, and five in the bottom feed paper feed route R3. Is set to

Regarding the relationship between the number of gap stages and the printing speed, the top feed route R1 and the rear feed route R2 are 100% for the first to third stages, 80% for the fourth to sixth stages, and seven stages for the six stages. In the bottom feed route R3, the first and second stages are 100%, the third to fifth stages are 80%, and the sixth and subsequent stages are 50%.
%. Therefore, for example, even when the number of gap stages is set to the same three, the printing speed is 1 in the top feed route R1 and the rear feed route R2.
In the bottom feed paper feeding route R3, the speed is set to 80%, which is later than that.
Similarly, although not shown, the coil feed time of the print head is set to be slightly longer in the bottom feed route R3 than in the top feed route R1 and the rear feed route R2. It has become.

As described above, the reason for changing the setting number of printing gaps and the setting conditions of printing speed according to the paper thickness for each paper feeding route is called special paper. Most of the paper is fed through the bottom feed paper feed route R3. In other words, for special paper, the printing gap is set wider in consideration of the running stability of the printing paper and the prevention of dirt. Impact force is weakened. Therefore, when the paper is fed by the bottom feed paper feeding route R3, as described above, the printing speed is reduced or the energizing time to the coil is increased so that a sufficient impact force can be obtained over the entire area of the paper.

[0025]

As described above, according to the impact printer of the present invention, the paper feed route detecting sensor detects the paper feed route of the print paper fed from an arbitrary paper feed route. On the basis of this detection signal, the selection means selects a preset gap adjustment mode for each paper feed route. Accordingly, it is possible to automatically set a gap adjustment mode suitable for that. As a result, the operator does not need to switch the gap adjustment mode each time the paper feed route is changed or the type of print paper to be handled is changed, thereby eliminating the troublesome setting of the conventional gap adjustment mode. In addition, the setting number of print gaps corresponding to the paper thickness of the printing paper and the setting conditions of the corresponding printing speed are different for each paper feeding route, so even when handling special paper as well as plain paper, Good printing can be performed on various printing papers without the need for complicated setting work.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a functional configuration of a printer according to an embodiment.

FIG. 2 is a schematic diagram illustrating a printer configuration according to an embodiment.

FIG. 3 is a diagram illustrating an example of a mode setting condition in a gap adjustment mode setting unit.

FIG. 4 is a diagram illustrating setting conditions of the number of gap stages according to the sheet thickness of each sheet feeding route.

FIG. 5 is a diagram showing print speed setting conditions according to the number of gap stages for each paper feed route.

FIG. 6 is a view for explaining a method of detecting a representative print paper thickness.

FIG. 7 is a half sectional view of a sensor print head.

FIG. 8 is a schematic diagram showing a printer configuration in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed route detection sensor 1a-1c Optical sensor 2 Selection means 10 Platen 11 Print head R1 Top feed paper feed route R2 Rear feed paper feed route R3 Bottom feed paper feed route P1-P3 Print paper

Continued on the front page (72) Inventor Takanori Mimura 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Yuhiko Shimosugi 1-7-112 Toranomon, Minato-ku, Tokyo (56) References JP-A-2-147249 (JP, A) JP-A-5-69632 (JP, A) JP-A-3-118175 (JP, A) JP-A-4-197760 (JP, A) JP-A-63-265649 (JP, A)

Claims (2)

(57) [Claims] 1. A paper feed route for feeding printing paper between a print head and a platen, a top feed paper feeding route for feeding printing paper from above the platen, and a printing paper feeding from the back side of the platen. A gap adjustment mode for adjusting a gap between the print head and the platen while having three feed routes, a rear feed route and a bottom feed route for supplying print paper from below the platen. , Auto gap adjustment mode to adjust the gap for each printing paper,
An impact printer having three mode functions, a semi-automatic gap adjustment mode for adjusting the gap only for the first print sheet supplied after the power is turned on and a manual gap adjustment mode for adjusting the gap by an operator's operation. A paper feed route detection sensor for detecting which paper feed route the printing paper is supplied to in the paper route, and a detection signal from the paper feed route detection sensor,
Selecting means for selecting a preset gap adjustment mode for each of the three paper feed routes. 2. The printing paper according to claim 1, wherein a set number of printing gaps corresponding to the thickness of printing paper and a setting condition of a printing speed corresponding to the set number of printing gaps are different for each of the three paper feeding routes. The impact printer according to claim 1, wherein