JPS61248763A - Printer - Google Patents

Abstract

PURPOSE:To enable setting of a printing paper which is supplied along a platen properly at a print starting position in the paper feeding direction by mounting a printing paper head detection sensor indexing the print starting position in the paper feeding direction on a moving portion which makes reciprocating movement along the platen. CONSTITUTION:A head carriage 27 is mounted to be able to freely reciprocate on guide rods 26 and 28 that are provided in parallel to a platen 19, and it is moved in a lateral direction along the guide rods 26 and 28 by a driving device, and it is provided with a printing head 29, a paper guide 30 and a sensor 32 which detects a paper tip. Thus, under the condition that the head 29 is located in the middle of the platen 19, the sensor 32 can detect the tip of paper being supplied along the platen 19, resulting in stable holding by the head 29 and the paper tip guide 30 of the middle part of the paper tip which is detected by the sensor 32, and a sure and accurate detection of the paper tip by the sensor 32.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to printing devices such as printers and typewriters.

[Technical background of the invention]

In general, printing devices such as printers and typewriters feed paper to be printed on manually or from a paper feeder attached to the paper feed slot, hold the paper on a platen, and feed the paper along the platen. Printing is done using a head that moves back and forth.

In such a printing device, in order to align the printing start position in the conveyance direction (paper length direction, line direction) of the supplied paper, the lower half circumference of the platen is A sensor that detects the leading edge of the paper is fixed under the platen guide installed along the platen guide, and when this sensor detects the leading edge of the paper fed between the platen and the platen guide, the paper is removed from the detected position. It is fed by a predetermined amount to the print position past the head, and the print start position is kept constant.

[Problems with background technology]

In such printing devices, the detection surface of the sensor faces upward and is fixed under the platen guide, so paper dust tends to accumulate on the detection surface, causing the sensor to malfunction or not being able to detect the leading edge of the paper. A situation may arise.

Furthermore, since the distance from the sensor position to the print start position is long, the print start position may vary.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing device that can reliably set paper fed along a platen at a printing start position in the transport direction.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

The printing device 3 of this embodiment is constructed as shown in FIGS. 1 to 3.

First, as shown in FIG. 2, a frame 9 is provided inside the cover 7 of this printing device 3, and both sides 9L of this frame 9 are provided.
The platen shaft 13 is rotatably supported by the bearing 19R via a bearing 11L111R. A platen knob 15L and a gear 17 are attached to one end of the platen shaft 13, a platen 19 is attached to the center, and a gear 21 and a platen knob 15R are attached to the other end.

Further, a motor 23 for driving the platen 19 is attached to the frame 9, and the driving force of this motor 23 is transmitted through gears 24, 25.
The signal is transmitted to the gear 17 via.

Further, as shown in FIG. 1, guide rods 26, 28 are provided parallel to the platen 19. A head carriage 27 is reciprocatably attached to these guide rods 26, 28, and the head carriage 27 is driven in the wide direction along the guide rods 26, 28 by a drive device (not shown). .

The print head 2 is mounted on the head carriage 27 as shown in FIG.
9. A leading edge guide 30 and a sensor 32 for detecting the leading edge (insertion end) of the paper are attached, and a ribbon cassette 34 is detachably attached.

The sensor 32 is, for example, an optical photosensor, and the leading edge of the paper is detected by a light receiving element detecting pulsed reflected light of light irradiated from a light emitting element towards the platen 19 side in a pulsed manner. .

Also, around the platen 19 are a platen guide 31, pressure rollers 33, 35, a paper pail roller 37 that presses the paper against the platen 19, a platen cover 39, and a pair of coupling shafts for coupling the paper feed device 1 to the printing device 3. 4
1 etc. are provided.

The pressure rollers 33, 35 are moved to the shaft 45 in FIG. 1 by rotating the pressure lever 43 shown in FIG.
The guide 31 rotates around the platen 19 and is brought into or out of pressure contact with the platen 19.

Further, the paper pail roller 37 is connected to the vapor pail lever 4
By rotating the arm 51, the arm 51 is rotated about the shaft 49, and the arm 51 is brought into or out of pressure contact with the platen 19.

Note that a cover 53 can be opened and closed above the head carriage 27, and the ribbon cassette 34 can be replaced in the open state.

A paper feed device 101 as shown in FIGS. 4 to 7, for example, is attached to the paper feed/discharge port 5 of the printing device 3 configured as described above.

This paper feeding device 101 has arc-shaped support portions 105 on side frames 103 on both sides (only one side frame is shown in the figure), which engages with the coupling shaft 41. .

Further, a lock lever 10 is provided on the outside of the side frame 103.
7 is pivotally supported at its intermediate portion by a shaft 109. This lock lever 107 fixes the paper feeder 101 to the coupling shaft 41 and includes an engaging portion 111 that engages with the coupling shaft 41.

Shafts 113 and 115 are attached to the rear of the side frame 103, and a guide 117 bent in an N-shape is attached. A paper feed frame 119 is detachably attached to the back of the guide 117. In addition, a paper feed tray 121 is attached to the shaft 115, and rotates via a crank 125 when a set lever 123 is rotated, and a side plate 127 is slidable, so that paper of different sizes can be handled. It has become.

A separation lever 131 having separation claws 129 for separating the stacked sheets P one by one during feeding is rotatably attached to the outside of the side plate 127 by a shaft 133.

A paper feed roller 137 is attached to a shaft 135 supported by the side frame 103 above and in front of the paper feed table 121 .

A manual feed guide 139 and a guide 141 are provided in front of the paper feed tray 121 and a guide 141 is provided opposite to the guide 139 to guide the paper P fed by the paper feed roller 137 to the guide 117.
and 139, and also pass the manual paper through the guide 139.
and 141 to lead between the platen 19 and the platen guide 31.

Note that a paper ejection frame 143 is detachably attached to the manual feed guide 139.

A paper discharge roller 147 is attached to a shaft 145 on the guide 141, and a gear 149 is attached to one end and a fifth roller is attached to the other end.
A gear 151 is attached as shown in the figure. gear 149
A gear 153 connecting the two is rotatably supported by a shaft 155 between the gear 21 and the gear 21.

Further, a paper ejection guide 157 is rotatable about a shaft 159 facing the paper ejection roller 147 .

As shown in FIG. 5, a gear 161 that meshes with a gear 151 and a gear 165 that meshes with a gear 163 are attached to the shaft 109.

Gear 163 is supported by shaft 167 and meshes with gear 169.

This gear 169 has a protrusion 171 inside and is supported by a shaft 175 together with a gear 173 as shown in FIG. A pipe 177 into which a shaft 175 is inserted is attached to the gear 173, and a coil spring 179 is fitted into the circumferential surface of the vibrator 177. Note that this coil spring 179 is wound clockwise from the inside to the outside.

As shown in FIG. 7, a stop cam 183 having two protrusions 181 is fitted into the circumferential surface of the coil spring 179, and one end of the coil spring 179 is fixed.

A pipe 185 is attached to the gear 169, a shaft 175 is inserted into the vibrator 185, and the vibrator 185 is inserted into the coil spring 179.

That is, a spring clutch is interposed between the X cars 169 and 173, and a stop cam 183 is attached to this spring clutch.

A gear 187 is attached to the shaft 135, and this gear 187
is meshed with gear 173.

On the other hand, a stop lever 189 that engages with a projection 181 of a stop cam 183 is rotatably supported by a shaft 191.
It is urged downward by a spring 193.

Next, in the above configuration, the operation of the printing device 3 will be explained together with the operation of the paper feeding device 101.

As shown in FIG. 4, set the paper P on the paper feed tray 121,
The set lever 123 is rotated to rotate the paper feed table 121 and press the paper P against the paper feed roller 137.

In such a state, when a print command is issued, the head carriage 27 moves from the home position at the left end to the center side and waits for paper to be supplied.

Further, the motor 23 shown in FIG. 2 is rotationally driven, and the platen shaft 13 shown in FIG. 4 is rotated clockwise.

Therefore, the gear 149 also rotates clockwise via the gear 21.153. Therefore, the gear 151 shown in FIG. 5 attached to the other end of the shaft 145 of this gear 149 rotates counterclockwise (the gear 14
9).

This rotation of gear 151 causes gears 161 and 165 to rotate clockwise, and gear 163 meshing with gear 165 to rotate counterclockwise. This causes gear 169 to rotate clockwise. Therefore, the vibrator 177 rotates. At that time, as shown in Figure 7, the spring 17
The protrusion 18 of the stop cam 183 holding one end of 9
1 is locked by the stop lever 189, the vibrator 185 idles inside the spring 179. When the rotation of the gear 169 further progresses and the protrusion 171 pushes up the stop lever 189, the stop cam 183 is unlocked and the vibrator 185 and the spring 179 are connected.
A vibrator 177 connected to this spring 179 rotates.

For this reason, the gear 173 fixed to this vibrator 177
rotates clockwise.

As a result, the gear 187 rotates to the left, so that the paper feed roller 137 shown in FIG. 4, which is attached to the shaft 135, rotates to the right. For this reason, the paper P is sent out, the paper P gets caught on the separation claw 129 and bends, and when it exceeds the elastic limit, it bounces and becomes 1
The paper is separated into sheets and enters between the platen 19 and the pressure roller 33 along guides 117 and 139.

When the paper P is held between the platen 19 and the pressure rollers 33 and 35, the paper P is pulled by the rotation of the platen 19. Therefore, a force is applied to the paper feed roller 137 to rotate it clockwise. This force is transferred to the gear 18 via the shaft 135.
7, and further to the gear 173 in FIG. 7, causing the gear 173 to rotate clockwise.

The gear 173, which rotates when the paper P is pulled by the platen 19 and the pressure roller 33, and the gear 169, which drives the rotation of the platen shaft 13 via the gear 21, rotate in the same direction, but may have different speeds. Therefore, unless a roller equipped with a one-way clutch is used for the paper feed roller 137, the connection between the gears 169 and 173 will be damaged.

However, since the gear 173 is rotating in the direction in which the spring 179 opens, the force from the gear 169 is transmitted to the gear 173, but the force from the gear 173 is not transmitted to the gear 169.

When the leading edge of the paper P held between the platen 19 and the pressure rollers 33 and 35 is guided by the leading edge guide 30 shown in FIG. The light is reflected and received by a light receiving element. For this reason, the leading edge of the cut paper P is rendered.

Therefore, a predetermined amount of paper P is fed from the leading edge detection position, paper feeding is temporarily stopped at the printing start position, and the print head 29, which was located in the center, returns to the home position on the left side by the movement of the carriage 27, and prints. Start.

-The platen rotates by one line each time printing of each line is completed.

The printed paper P is passed through the paper ejection roller 35 and the paper ejection guide 157.
It is discharged through the gap between the

The leading edge of the paper P to be discharged rises along the manual feed guide 139 and the paper discharge frame 143, and when the trailing edge of the paper P is discharged, the trailing edge of the paper is supported by the recessed part of the guide 141 and is moved to the paper discharge stacker. be accommodated in.

By the way, while the protrusion 171 comes off the stop lever 189 and the tip of the lever 189 falls onto the surface of the stop cam 183 and continues to rotate, the paper feed roller 137 feeds out the paper P. When the tip of the stop lever 189 engages with the protrusion 181 of the stop cam 183, the vibrator 185 idles within the spring 179, and the gear 173 stops rotating.

When the projection 171 pushes up the lever 189 again, the paper is fed. This cycle is repeated, and the paper P is automatically sent out at regular intervals.

Note that even if the paper size is changed, the time (feeding distance) from the leading edge of one sheet to the leading edge of the next sheet remains the same.

Therefore, there will be a gap between the short paper and the trailing edge of the paper.

On the other hand, when the platen 19 is reversed to shift the printing position on the paper, the gear 169 is also reversed. As a result, the vibrator 185 is also reversed, but since the spring 179 is rotating in the opening direction, the rotational force of the vibrator 185 is transferred to the vibrator 177.
is not transmitted. Therefore, even if the platen 19 is reversed, the gear 173 does not rotate and the paper feed roller 137 also does not rotate.

According to this embodiment described above, the following effects can be obtained.

(1) A paper leading edge detection sensor 32 that determines the printing start position in the transport direction of the paper is attached to the head carriage 27, and the paper is fed along the platen 19 with the head 29 positioned at the center of the platen 19. Since the leading edge of the paper is detected by the sensor 32, the leading edge of the paper detected by the sensor 32 is the head 29, ? 5 and tip guide 30
This allows the central portion to be held stably, and the sensor 32 can accurately and reliably detect the leading edge of the paper.

(2) The paper leading edge detection sensor 32 is not fixed around the platen guide 31 located in the lower half of the platen 19, but is attached to the head carriage 27 that constantly moves back and forth, so the sensor 32 is an optical type. Even if paper dust is present, it is difficult for paper dust to accumulate, eliminating errors in paper detection.

(3) Since the sensor 32 is attached to the head carriage 27, which is easy to work with, maintenance is easier than when the sensor 32 is attached around the guide 31, which is difficult to work with.

(4) Since the sensor 32 is attached to the carriage 27, the distance from when the sensor 32 detects the leading edge of the paper to the printing start position can be reduced. Therefore, the printing start position can be set with high precision.

[Modified example]

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and for example, the following modifications are possible.

(1) In the embodiment described above, the paper leading edge detection sensor 32 was attached to the upper surface of the carriage 27, but it may be attached to the side surface of the carriage 27 on the platen 19 side or the lower surface of the carriage 27.

(2) In the above embodiment, the sensor 32 is a sensor that irradiates the platen 19 with pulsed light that is less affected by outside light and receives the reflected light. In the case where a light beam (light beam, light bar, etc.) is applied, it may be possible to simply emit continuous light and detect it. Furthermore, the sensor is not limited to an optical sensor, and may be a mechanical sensor.

(3) Although the sensor 32 is attached to the carriage 27 in the above embodiment, it may be attached to the print head 29 or the ribbon cassette 34.

(4) The paper leading edge detection sensor 32 is connected to the guide rod 26
．． It may be mounted on a separate carriage from the head carriage 27 that moves along 28.

(5) The mounting position of the leading edge detection sensor 32 may be movable in the paper conveyance direction. This allows you to adjust the launch position.

〔Effect of the invention〕

As explained above, according to the present invention, a paper leading edge detection sensor that determines the printing start position in the paper transport direction is attached to a movable part that reciprocates along the platen, and is attached to a carriage that reciprocates along the platen. The printing start position in the conveying direction of the paper is controlled by detecting the leading edge of the paper fed along the platen with the leading edge detection sensor in a state where the loaded head is located at the center of the platen. Therefore, it is possible to obtain a printing device that can reliably set the paper fed along the platen at the printing start position in the transport direction.

[Brief explanation of the drawing]

1 to 3 are diagrams showing the configuration of a printing device according to an embodiment of the present invention, in which FIG. 1 is a vertical sectional view of the printing device, and FIG.
The figure is a cross-sectional view of the printing device, and FIG. 3 is a diagram showing the structure around the print head. 4 to 7 are diagrams showing the configuration of a paper feeding device in an embodiment of the present invention, in which FIG. 4 is a sectional view of the paper feeding device, and FIG. 5 is a drive provided on the left side frame. The diagram showing the transmission mechanism, and FIGS. 6 and 7 are cross-sectional views showing the structure around the spring clutch. l eases paper feed device 3111111116 Printing device 5 ----- Paper feed/discharge port 19 --- Axis platen 23 --- Motor 27 --- Head carriage 29 --- Print head 31 --- -Platen guide 32---Sensor 34...
・Ribbon cassette 33.35--Pressure roller 37--Paper bail roller Patent applicant Nippon Seimitsu Kogyo Co., Ltd. Procedural amendment dated 1985, Patent Application No. 090098 2, Title of the Invention -rI') Sochi Printing Device 3, Relationship to the Amended Person's Case Patent Applicant Koufu Shamamyamachi

Claims (3)

[Claims] (1) A head attached to a carriage that reciprocates along the platen is positioned at the center of the platen, and the paper is held on the platen, and when printing, the head is moved to the printing position to print. A printing device characterized in that a paper leading edge detection sensor for determining a printing start position in a paper conveyance direction is attached to a movable part that reciprocates along the platen. (2) In the printing device according to claim 1,
A printing device characterized in that the leading edge detection sensor is attached to the carriage. (3) In the printing device according to claim 1,
A printing device characterized in that the leading edge detection sensor is attached to the head.