JPH0256223B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a platen device of an automatic form insertion device used, for example, in an inkjet printer.

[Technical background of the invention and its problems]

2. Description of the Related Art Conventionally, detection means for detecting whether a form has been inserted into an apparatus have various configurations, and one that uses a reflective sensor for extracting a photoelectric signal exists. In this type of printer, it is desirable to have the sensor facing the platen as it is close to the printing position, but in this case, the reflectance of the platen surface gradually increases due to friction, which causes There are cases where there is no large difference between the reflectance and the reflectance of the form, which may affect the reliability of detection.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a platen device for an automatic form insertion device that can always perform form detection in a constant state even if the reflectance of the platen surface changes.

[Summary of the invention]

In the present invention, a groove is provided in a part of the platen through which the form is inserted, and the reflection of light from the groove and the reflection of light from the form are detected by a clamp sensor assembly comprising a reflective sensor. Form detection is most rational because it is based on the platen position, and even if the outer peripheral surface of the platen changes to increase the reflectance due to the friction of the form, the grooves are band-shaped recesses, so the form cannot be detected. The structure is such that a constant reflectance can be maintained at all times without contact.

[Embodiments of the invention]

(Overall structure) The printing paper insertion/ejection mechanism can be roughly divided into the first
In the figure, it consists of a main body part 1, a tractor part 2, and a printing device part 3.

(Description of the main body) First, in Fig. 2, the chassis assembly 1
4 has a left frame assembly 10 and a right frame assembly 23, one on the left and one on the right, and a fan assembly 28 for ventilation etc. is attached to the front right side of the chassis assembly 14. On the right frame assembly 23 side are a stepping motor assembly 26 for driving this device, gears 2 and 27 and gears 1 and 25 for transmitting the power, and a back tension arm for applying tension to paper during continuous paper. There is an assembly 24.
On the left frame assembly 10 side, there are a home position sensor assembly 7 for determining the home position and release position of the platen assembly 17, a release position sensor assembly 8, and a clamp sensor assembly 29 for determining the clamp position of the form paper. Detection disk 4 used for the above sensor assemblies 7 and 8, change lever assembly 30 for switching modes between continuous paper and form paper, and mode changeover switch 31 for switching between modes, paper clamp for form paper. - Two solenoids, ie, solenoid 16 and solenoid 211, are attached to link mechanisms 32a and 32b that transmit the operation when releasing, and the solenoid 16 and solenoid 211 that provide the movement. Furthermore, in the case of form paper, there is a space between the left frame assembly 10 and the right frame assembly 23 for clamping and releasing the paper.
A platen assembly 1 that serves as a paper travel guide and also serves as a paper travel guide in the case of continuous paper.
7, a paper guide 113 and a paper guide 216 located before and after the platen assembly 17, which serve as paper travel guides, a back tension assembly 20 that applies tension to the paper in the case of continuous paper, and a clamp/release mechanism for the paper in the case of form paper. clamp lever assemblies 33a, 33b and release lever assemblies 19a, 19b for causing the platen assembly 17 to perform its functions; and a separator as a guide for reliably taking out the paper released from the platen assembly 17 at the release position. assembly 9, a guide stop assembly 15 for separating the tip of the paper guide 216 at the front of the platen assembly 17 from the platen surface in the case of continuous paper, and regulating the amount of separation, the left frame assembly 10, and the right frame assembly 23. It consists of a PC board assembly 22 for driving the device at the rear.
A paper end detection switch assembly 12 detects the presence or absence of continuous paper at the left end of the guide plate 21 to which this PC board assembly 22 is attached.
is attached. Note that 5 is a tension lever.

(Description of Tractor Section) First, in FIG.
There is one tractor frame assembly 235, and on the side of the tractor frame assembly 235 there is a gear 336 coupled to the tractor shaft 248 for transmitting the movement of the stepping motor 26 and driving a tractor used for discharging continuous paper. There is a gear 437. Tractor frame assembly 134 and tractor frame assembly 23
5, there are a left tractor assembly 38 and a right tractor assembly 39 each equipped with a form paper insertion/ejection mechanism and a continuous paper ejection mechanism.
A roller 40 and a guide plate 4 are located on the rear side of the tractor frame assembly 134 and the tractor frame assembly 235 and are attached to the tractor shaft 147 to serve as a guide when inserting continuous paper.
1 and the platen assembly 17 when printing form paper, and in the case of continuous use, the pinch roller 44 is released from the platen assembly 17 so that it does not interfere with the paper travel path, and the left tractor assembly 42 A left pinch roller assembly 42 and a right pinch roller assembly 43 each have a built-in mechanism that can move left and right together with the right tractor assembly 43, and are located at the rear upper side of the tractor frame assembly 134 and the tractor frame assembly 235, and discharge continuous paper. It consists of a home guide 45 that serves as a guide when the form is ejected, and a paper support 46 that is located between the left tractor assembly 38 and the right tractor assembly 39 and serves as a guide for the leading edge of the paper when the form is ejected. In addition, 49 is the tractor shaft 3, 50 and 51 are the lift shaft assembly 1,
It is 2. Furthermore, 52 and 53 are tractor cases 1 and 2.

Although the tractor cases 1, 252, 53 are made of an insulating material, the tractor frames 34, 35 made of iron plates or the like have insulating bushes 45A.
A home guide 45 made of wire is attached to this insulating bushing 45A. Therefore, even if static electricity is generated when this continuous paper is passed through, the potential will not reach the main body 1.
Prevent electrical troubles from occurring.

(Structure of Tractor Section 2) The case of form paper will be explained with reference to FIGS. 4 and 5. Send the form to the computer 1, 262a, 62b
Insert from the rear side of the platen 91 using as a guide.

The printed paper is pressed against the surface of the platen 91 by the pinch rollers 44 incorporated in the left pinch roller assembly 42 and the right pinch roller assembly 43 with the pinch roller shaft 55 interposed by the pinch roller spring 71. Frequency feed is carried out between the two. The paper released from the platen 91 is pushed up as the platen 91 rotates using the separator 90, the rice ball-shaped portion 42c of the left pinch roller assembly 42, and the right pinch roller assembly 43 as guides, and is pushed up as the platen 91 rotates.
a, 63b toward the opening. As the platen 91 further rotates, the leading edge of the paper passes inside the front guides 1, 263a, 63b and is pushed out along the lids of the tractors 1, 265a, 65b.

In addition, in the case of a sheet with a large width such as B4, the center of the sheet tends to fall toward the tractor shaft 349, easily causing a jam, so a paper support 46 is provided to prevent this. Furthermore, when the trailing edge of the paper that has been printed separates from the pinch roller 44 and platen 91 and the platen 91 rotates, the trailing edge of the paper may slide down to the print head 92 side through the upper side of the pinch roller 44. In order to prevent this, receiving parts 42d are provided on the arm parts of the left pinch roller assembly 42 and the right pinch roller assembly 43. In addition, the front guides 1, 263a, and 63b are arranged such that the leading edge of the printed paper is located at the print head 92.
It also serves to prevent you from falling to the side.

Next, the case of continuous paper insertion will be explained with reference to FIG. The roller 40 and the guide plate 41 are used as insertion guides to pass the paper under the platen 91, and the sprocket holes of the continuous paper are hooked to the claws of the tractors 1, 265a, and 65b, and the paper is discharged to the top of the platen 91, and the home guide 45 is guided. This guides the paper to the rear side of the platen 91. In this case, in order to prevent the pinch roller 44 used for free-extraction feeding of the form paper from interfering with the running of the continuous paper, the platen 9 is
It is necessary to release it from the surface of 1. To do this, turn the change lever 93 attached to the main body 1 in the direction of the arrow. Then, the studs at the ends of the roller up arms 1, 280a, 80b are rotated by the change arms 1, 218a, 18b in the direction of the arrow in the figure, and the roller up arms 1, 2
A left pinch roller assembly 42 and a right pinch roller assembly 43 are attached to the same shaft as 80a and 80b, that is, the pinch roller shaft 55.
rotates in the direction of the arrow in the figure, and the pinch roller 44
is separated from the surface of the platen 91. Further, as the change lever 93 rotates, the paper guide 216 attached to the main body 1 is moved to the platen 91 by the same shaft as the change lever 93, that is, the wire 96 attached to the SP bracket plate 102 attached to the change shaft 101. It is separated from the surface of the continuous paper 100 and does not interfere with the running of the continuous paper 100.

Next, when the size of the paper changes, the distance between the tractors 1, 265a, and 65b must be changed depending on the size of the paper, and the mechanism will be explained below with reference to FIGS. 7 and 8. For example, when moving the right tractor 265b to change the spacing, turn the tractor stop 264b in the direction of the arrow in FIG. do. At this time, the amount of rotation of the tractor stop 264b is regulated by the bracket 95. lift lever 270b
The lift arm 272b, which is fixed to the end of the lift shaft 103 that supports the lift shaft 103 and is also used for left and right slides, and moves with the rotation thereof, similarly rotates counterclockwise, and the stud causes the roller up arm 280b to rotate clockwise. do. The roller up arm 280b is fixed to the end of the pinch roller shaft 55, and the roller up arm 280b
The pinch roller shaft 55 rotates as the right pinch roller assembly 43 rotates, and also serves as a guide when the right pinch roller assembly 43 slides. Along with this rotation, the right pinch roller assembly 43 rotates clockwise, and as a result, the pinch roller 44 is lifted off the surface of the platen 91, making it possible to slide left and right.
At this time, the right pinch roller assembly 43 is pinching one end of the shutter bracket 261b on the back side of the rice ball shape (see Figure 4), and the lift lever 270b is similarly pinched by the shutter bracket 261b (especially as shown in Figure 4). (not shown), the right tractor assembly 39 and the right pinch roller assembly 4
3 is tractor shaft 248 tractor shaft 3
49, the lift shaft 103 and the pinch roller shaft 55 are used as guides to slide left and right.

Further, the shooter brackets 1, 261a, 61b of the tractors 1, 265a, 65b are each provided with a wing 60 that projects rearward and guides the paper. This effectively prevents the paper from meandering.

(Structure of Switching Device A) First, the case of the form paper mode will be explained based on FIG. 9. What is shown in FIG. 9 is a state in which a form sheet is inserted, and the platen 91 is in the home position. That is, clamp arm 1, 2115
Clamp bar assembly 130 by a, 115b
has protruded from the surface of the platen 91 and is waiting for paper to be inserted. Furthermore, the mode changeover switch 31 is set to the form mode by the change lever 93, the pinch roller 44 is in contact with the surface of the platen 91, and the paper guide 216 is in a state where the form is free-fed. It's helping Shyonfeed.

Next, the case of continuous paper mode is shown in Figure 9 and 1.
This will be explained based on Figure 0. When the change lever 93 is rotated in the direction of the arrow in the figure, that is, counterclockwise, it is moved away from the mode changeover switch 31 and the mode is changed to the continuous paper insertion mode. Further, since the change lever 93 rotates about the change shaft 101, the link 1111 fixed to the change lever 93 is pushed downward. Therefore, the stud 1112 in the left frame assembly 10
The link 2113 rotates counterclockwise with the center of rotation acting on the link 3114, and the solenoid 16
The spindle is pushed in. At this time, the change lever 93 is attached to the left frame assembly 10 so that the stud 2119 placed thereon can rotate by a specified amount.
The mode is switched to the continuous paper insertion mode by the spring 1110 using the half-moon-shaped hole provided in the guide as a guide, and does not automatically return to the original state, that is, the form paper insertion mode. There is. Also, clamp arm 1, 2115
a and 115b are still being pulled counterclockwise by the spring 3123, and the solenoid 16 is no longer working.
Even if the clamp arms 1, 2115a, and 115b work to clamp the paper, the clamp arm 1 is attached to the ring 3114 as shown in FIG.
115a cannot be stopped. Furthermore, the clamp arm 1115a and the clamp arm 2115
b are fixed to both ends of the clamp shaft 116. Further, the paper guide 216 is attached to the SP bracket plate 102 fixed to the chain shaft 101.
The clamp shaft 116 is rotated counterclockwise by the wire 96 hung on the clamp shaft 116 as the center of rotation until it hits the guide stop shaft 117, so that its tip comes away from the surface of the platen 91 and does not interfere with the running of the continuous paper. It disappears.

Furthermore, the change arms 18a and 18b fixed to the change shaft 101 are connected to the change lever 93.
It rotates counterclockwise as the roller up arm 1, 280a, 80b rotates, and its tip pushes the stud 4121 of the roller up arm 1, 280a, 80b downward. The left pinch roller assembly 42 and the right pinch roller assembly 43, which are attached to the same shaft as the roller up arms 1, 280a, and 80b, that is, the pinch roller shaft 55, are rotated clockwise to remove the pinch roller 44 from the surface of the platen 91. Leave. In this way, the mode can be changed from the form paper mode to the continuous paper mode using a single change lever 93.

Furthermore, when the mode is switched from the continuous paper mode to the form paper mode, the change shaft 101 rotates clockwise, and as a result, the link 1111 is pulled up, and the link 2113 is moved from the stud 1112.
Rotate clockwise around the center. Therefore, the link 2113 separates from the link 3114, and since the link 3114 is pulled by the spring 2118, the fixation of the spindle of the solenoid 16 is released, and the solenoid 16 becomes operative. In addition, roller up arms 1, 280a, 8
Since 0b is pulled counterclockwise by the pinch roller spring 71, the change arm 1,
When the tips of the roller up arms 1, 280a, 80b are removed from the studs 4121, the pinch roller shaft 55 rotates counterclockwise, and the pinch roller 44 is pressed against the surface of the platen 91. Further, as the chain shaft 101 rotates clockwise, the tension of the wire 96 is loosened and the paper guide 216 is pulled downward by the spring 4122, so that its tip is pressed against the surface of the platen 91. In this way, the mode can be switched from the continuous paper mode to the form paper mode using a single change lever 93.

(Structure of platen device B) Regarding the platen structure, Figures 11 to 14
As shown in the figure. First, the clamp bar assembly 130 is inserted from the outside of the platen 91, and one end of the clamp spring 134 is applied to both sides, and the other end is applied to the platen stud 138 fixed to the platen guide 137, and is pulled. Further, the release bar 131 is inserted from the inside of the platen 91 so as to fit into the groove, and the release springs 135 are hung between the ends of the release bar 131 and the platen stud 138 in the same way as the clamp bar assembly 130 and tensioned.
Further, the clamp bar assembly 130 and the release bar 131 are positioned in the radial direction by a clamp bar guide 132 fixed to a platen guide 137. The clamp bar assembly 130 has the function of clamping the inserted form paper between the platen 91 and the platen 91 at the home position of the platen 91 and transporting the paper to the print head 92 side as the platen 91 rotates. Make sure that the platen 91 does not jam as it leaves the clamp bar assembly 130 in the release position.
It has a function to separate it from the

Moreover, what is shown in FIG. 14 is a plan view of the platen 91, and at the end of the platen 91, which is made by wrapping rubber around a hollow cylindrical pipe and polishing the surface, there is a band-shaped belt having a diameter x smaller than the diameter of the platen. A groove is provided. This band-shaped groove surface is made rougher than the surface of the platen. This groove is also perpendicular to the clamp sensor assembly 29. When paper is wrapped around a normally used rubber platen with a polished surface and fed, and the surface of the platen is slightly smooth, the reflectance of the surface is approximately 90% that of white paper, according to experiments. It will be about the same level. In this state, a reflective sensor cannot be used to detect the presence or absence of form paper, and a complicated mechanism (for example, a mechanical structure) is required. Therefore, a part of the platen is made concave in a band shape to prevent the influence of wear caused by the paper and to make the surface rough, thereby increasing the S/N ratio of the clamp sensor assembly 29.

(Structure of Form Clamp/Release Device C) The structure of this mechanism will be explained based on FIGS. 15 to 20. First, at the home position of the platen 91, the clamp bar assembly 130 is in a state protruding from the platen 91, and in this state, the form paper 147 is inserted using the shooters 1, 262a, and 62b as guides. Shooter 1, 262a,
Form paper 147 inserted using 62b as a guide
The paper falls along the paper guide 113 and is stopped by the clamp 144 on the clamp bar assembly 130. In addition, since the center of the clamp sensor 143 is attached above the abdomen of the clamp 144, it has a function of checking the presence or absence of the form paper 147 in the form paper mode, and this clamp sensor 143 detects whether the form paper 147 is present. Once this is confirmed, the solenoid 16 is activated and the link 3114 is pulled and rotated counterclockwise about the stud 5145 attached to the left frame assembly 10. Since the clamp arm 1115a is tensioned by the spring 3123 between it and the stud 5145,
When the link 3114 rotates counterclockwise, the distal end of the link 3114 and the clamp arm 1115a disengage, and as a result, the clamp arms 1, 2115a, and 115b rotate counterclockwise about the clamp shaft 116. Since the clamp bar assembly 130 is pulled toward the inside of the platen 91 by the clamp spring 134, the clamp arm 1, 2115a, 115
b rotates counterclockwise, the clamp bar assembly 130 also retracts into the platen 91 and the clamp 1
The leading edge of the form sheet 147 is sandwiched between the sheet 44 and the platen 91. The state is shown in FIG.

Next, when the platen 91 rotates, the form paper 147 also moves toward the printing unit side, and printing starts on the form paper 147, and then the platen 91
1 rotates and reaches the release position, the solenoid 211 is activated and the leading edge of the form 147 is released from the platen 91. When the solenoid 211 operates, the release levers 1, 2140a, 140b rotate clockwise around the release shaft 146, and the release lever tip 141 attached to the tip lifts the clamp bar assembly 130 and the release bar 131 and releases the form 147.
away from the platen 91. In order to prevent the form paper 147 from being pulled by the release bar 131 when releasing the form paper 147 from the platen 91,
The structure is such that the clamp bar assembly 130 is first lifted, and then the release bar 131 is lifted.

When the release levers 1, 2140a, 140b rotate clockwise around the release shaft 146, the link 414 attached to the tip thereof
2 is lifted upward, and as a result, the clamp arms 1, 2115a, 115b rotate clockwise about the clamp shaft 116. When the clamp arms 1, 2115a, 115b rotate clockwise around the clamp shaft 116, their tips engage with the link 3114, keeping the clamp bar assembly 130 and release bar 131 protruding from the platen 91. When the platen 91 further rotates, the clamp bar assembly 130 is disengaged from the release lever tip 141 and the clamp spring 134 is released as shown in FIG.
into the platen 91. In this state, the release bar 131 is still on the release lever tip 141, and the form sheet 147 is placed on the platen 9.
1, the leading edge of the form sheet 147 is discharged upward as the platen 91 rotates using the separator 90 as a guide. When the platen 91 rotates a little further, the clamp bar assembly 130
Similarly, the release bar 131 is also detached from the release lever tip 141 and pulled into the platen 91.
The clamp bar assembly 130 and release bar 131 that have been retracted into the platen 91 are supported by a clamp bar guide 132. Further, when the platen 91 is further rotated by the detection disk 4 and the release position sensor assembly 8, the solenoid 16 is activated and the clamp arm 1115a and the link 3114 are disengaged, and the clamp arm 1, 211
5a, 115b and release lever 1, 2140
Even if the tips of a and 140b escape toward the center of the platen 91 and the platen 91 continues to rotate, the clamp bar assembly 130 and release bar 1
31 and clamp arm 1, 2115a, 115b
It is designed so that it does not lock.

When all printing is completed and the platen 91 reaches the home position, the detection disc 4 and the home position sensor assembly 7 activate the solenoid 211.
is activated, and the machine enters a waiting state for the insertion of form paper.

Next, in FIG. 20, the state immediately after the form sheet 147 is fed out after printing is completed is shown by dotted lines. That is, as the platen 91 rotates, the form sheet 147 pinched by the pinch roller 44 is guided by the rice ball-shaped portions 42c of the pinch roller assemblies 42 and 43, and is moved between the front guides 1, 263a, 63b and the tractors 1, 265.
The paper is ejected through the gap between the upper surface of the lid 65a and the upper surface of the lid 65b. When the rear end is separated from the pinch roller 44 and becomes free, it rises slightly due to the inertia of the form 147 and then falls due to its own weight. During this descent, the form sheet 147 is aligned with the inclination of the front guides 1, 263a, 63b as shown by the dotted lines, so that it is received by the receiving portions 42d of the pinch roller assemblies 42, 43. Therefore, the rear end of the form sheet 147 will not fall toward the pinch roller 44 side.

Next, FIG. 21 is a timing chart showing an operating state at L level. The part that was not mentioned in the above explanation is that there is a form/continuous paper switching switch and the selection is made before the start. Other operations are as described above.

〔Effect of the invention〕

The present invention provides a hollow cylindrical platen with a clamp bar assembly and a release bar to clamp a form and send it out by rotating in one direction. Since the groove is set to a predetermined state, the reflectance of the groove part will not come into contact with the surface of the groove, so the reflectance will not change and the document will be read reliably. It is something that can be detected.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is a perspective view of the tractor section separated from the main body section, Fig. 2 is an exploded perspective view of the main body side, and Fig. 3 is an exploded view of the tractor section. 4 is a front view of the tractor unit, FIG. 5 is a side view of a portion thereof, FIG. 6 is a vertical side view when continuous paper is inserted, and FIG. 7 is a partially enlarged vertical side view. FIG. 8 is a vertical side view of the released state, FIG. 9 is a vertical side view of the home position in the form paper mode, FIG. 10 is a vertical side view of the home position in the continuous paper mode, and FIG. 11 is a vertical side view of the home position in the continuous paper mode.
The figures are an exploded perspective view of the platen, Fig. 12 is a side view thereof, Fig. 13 is a partially cutaway front view, Fig. 14 is a plan view, Fig. 15 is a vertical side view just before clamping the form, and Fig. 15 is a side view of the platen. Figure 16 is a vertical side view in the clamped state, Figure 17 is a vertical side view when the clamp is released and the form is fed out, Figure 18 is a vertical side view when it is ejected, and Figure 19 is a vertical side view when printing or continuously feeding paper. A side view, FIG. 20 is a partially enlarged longitudinal sectional side view when a form is ejected, and FIG. 21 is a timing chart. 20... Clamp sensor assembly, 91...
Platen, 130... Clamp bar assembly, 1
31...Release bar.

Claims (1)

[Claims] 1 Two parallel grooves are formed in a hollow cylindrical platen, one groove is equipped with a clamp bar assembly for clamping the form, the other groove is provided with a release bar for releasing the clamped form, and a reflection type sensor is installed. A platen device for an automatic form insertion device, characterized in that a groove is formed in the outer circumferential surface of the platen facing the clamp sensor assembly comprising a band-shaped recess and whose light reflectance is set to a predetermined state.