JPH09323408A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer keeping the distance between a printing head and a material to be printed perfectly constant and easy to produce. SOLUTION: This ink jet printer contains an inlet 11, a printing region 10 equipped with a printing head 15 and an outlet 12. A rotary roller 23, the backup roller 27 elastically pressed to the rotary roller 23 and the fixed lateral material 35 matched with the outer periphery of the rotary roller 23 are attached on the upstream side of the printing region. The drive roller 41 having a pointed end provided thereto and cooperating with a counter roller 46 is arranged to the outlet of the printing region and rotated in order to tightly pull a sheet to be printed within the printing region. The roller 23 and fixed lateral material 35 arranged in the vicinity of the printing region demarcate reference height forming a predetermined gap along with the front 20 of the printing head. By this constitution, the printing head is positioned at the place separated from the surface of the sheet to be printed by a definite distance regardless of the thickness of a material to be printed without providing any regulation mechanism.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a printing area designed to print on a flat material which is moved according to the feed direction from the entrance of the printer through the printing area to the exit and the printing area. And a means for adjusting the distance separating the front face of the printhead from the different materials.

[0002]

In various types of printers and in particular ink jet printers, no matter what material is used, the distance from the front face of the print head to the material to be printed is constant, for example 1.3 mm. It is important that the values are adjusted as accurately as possible. However, the thicknesses of the materials are significantly different, which means that first and foremost have a measuring means for determining this thickness and secondly to move the printhead in a direction perpendicular to the material to be printed. It is necessary, or alternatively possible, to have the support members of material move so that they have the same relative distance. These means and mechanisms add significantly to the price of the printer and are difficult and often inaccurate to make.

[0003]

SUMMARY OF THE INVENTION The present invention overcomes these disadvantages and provides a printer in which the distance between the printhead and the material to be printed is completely constant and easy to make at a reasonable cost. The purpose is to provide.

[0004]

SUMMARY OF THE INVENTION The present invention provides a means for adjusting the distance between the material to be printed and the front face of the print head such that the flat surface faces the print head to define a reference height. At least one fixed support member that cooperates with the surface of the material to form a predetermined gap with the front surface of the printhead, and for positioning the flat material in a plane through the reference height At least one mechanism intended to taut the same flat material in the printing area;
Consists of

Therefore, the support member for the material to be printed may be a thin sheet, a carbon sheet, an envelope, etc., regardless of the thickness of the material to be printed, which is arranged near the print head. Cooperates with the surface to be printed to form a constant reference height. The assembly of the printer is extremely simple, the cost price is low, the operation is reliable and the operation life is long, considering that there is no need for means for measuring the thickness and mechanism for adjusting the height. Become.

The support member comprises at least a first rotating member (ie a continuous roller, a cylinder or a segmented roller) or a fixed cross member mounted on a shaft which rotates about a fixed axis. Is advantageous. Such features provide accurate and reliable structure and operation.

The support member cooperates with a second rotating member (ie, a continuous roller, a cylinder or a partial roller) that resiliently abuts the support member, or at least a first elastic pressure pad. It is preferable to cooperate.

According to a preferred embodiment, the printer is
At least intended to cooperate with a surface of the flat material disposed downstream of the print head and rotatable about a second fixed axis and facing the print head to define a reference height with said support member. A third rotating member, the third rotating member comprising a fourth rotating member (i.e., a continuous roller, a cylinder or a partial roller) elastically pressed against the third rotating member, or at least a third rotating member. Cooperates with a second elastic pressure pad. This provides a particularly reliable operation and a simple structure.

Advantageously, the first and third rotating members are driven in rotation, the tangential speed of the outer periphery of the third rotating member being 0.1 to 1.0 higher than that of the first rotating member. % It is advantageous to be fast.

The material to be printed is thus
One of the completely taut and aligned, printed surfaces is at the reference height mentioned above, which guarantees printing with high quality and accuracy.

This printer includes a second support member consisting of a fixed cross member arranged between the first rotary member and the print head, the flat support being subjected to the printing of the second support member. The surface facing the material is aligned with the outer circumference of the first rotating member to define the reference height.

These features allow a higher print quality to be achieved and also facilitate paper entry and exit.

Other advantages will be apparent from the features set forth in the claims and a more detailed description of the invention in combination with the drawings illustrated in one illustrative embodiment.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, an ink jet printer includes a frame 14 and a print area 10 disposed between an inlet 11 and an outlet 12 for a flat material 18 to be printed. Contains.

In the print area 10, the print head 15
A carriage 16 provided with a cross member 2 slidably fitted on a shaft 17 and fixed by a protrusion 25.
I'm on top of 6. The carriage 16 is made of a flat material 18
Can be moved in a direction at right angles to the supply direction 19 of. The flat material 18 may be a paper sheet, carbon paper, envelope, etc. ranging from light weight to weight, the thickness of which may vary to a large extent.

The ink jet printer further includes a first support member 22 cooperating with the side of the flat material 18 facing the print head 15. This first support member 2
2 includes a roller 23 (which may be a continuous cylinder or a partial roller), the shaft 24 of the roller 23 of which is rotatable about a fixed axis.

A back-up counter roller (opposite roller) 27 is elastically pressed against a first support member 22 mounted on a pivot lever 28 and located adjacent to the upstream side of the print head 15 by a spring 29. Has been done.

The first fixed support member 32 is the roller 23.
And the print head 15, and the fixed support member 32 is a fixed cross member 35 in the form of a component that traverses the device.
The lower surface of the fixed cross member 35 includes the roller 23.
It is aligned with the outer circumference of.

A blade 36 made of a plastic material, for example, a Mylar (registered trademark) having a thickness of 0.12 mm is provided on the top of the pivot lever 28. The blade 36 is attached to the pivot lever 28,
At the end portion, the surface of the flat member 18 opposite to the surface to be printed is pressed to press the flat member 18 against the fixed cross member 35. In this way, the fixed cross member 35 and the blade 36
Work together to ensure a correct alignment during the introduction of the flat member 18 and to be held in place at the bottom of the page when the flat member 18 is no longer held by the roller 23 and the counter roller 27. Make sure that

The printer comprises downstream of the print head 15 a mechanism 40 intended to tension the material 18 to be printed in the printing zone 10. The mechanism 40 has a roller 41 arranged on a shaft 42 rotatable around a fixed axis. The rollers 41 are imbedded with fine tips 43 intended to cooperate with the flat member 18. Counter roller 46
Are elastically pressed against the roller 41 by the spring 47. The roller 41 and the roller 23 are rotated by a motor (not shown). Roller 4
The tangential displacement speed of 1 is slightly faster than the roller 23,
As a result, the material 18 is taut in the printed area. A tangential velocity difference of 0.1 to 1.0% is particularly advantageous.

The flat material 18 is introduced through the inlet 11,
The roller 23 and the counter roller 27 are slid on the surface 50 of the frame 14 and guided by the guide member 51.
Is gripped between. The upper surface of the flat member 18 to be printed is then printed regardless of the thickness of the material 18 to define a reference height that forms a predetermined gap h with the front surface 20 of the print head 15. The head 15 is always maintained at the same position and height. Eventually, the position of the counter roller 27 changes as a function of the thickness of the flat member 18.

The flat member 18 is then pressed against the stationary cross member 35 by the plastic blade 36 to bring it into perfect alignment with the outer circumference of the roller 23. The flat member 18 is thus fixed to the first support member 22 and the first fixing member 22 until it reaches between the roller 41 and the counter roller 46 in order to be pulled taut in the printing area 10 when it is introduced. It is guided by the support member 32.

The gap distance h between the surface of the flat member 18 to be printed and the front surface of the print head 15 is also
Constant for all materials to be printed,
This fully adjusted gap is defined by the support members 22, 32.
And the roller 41 and in the printing area 10 by the action of a pulling force on the flat member 18.

It will be clear that the embodiment described above has no limiting features and that any desired modifications may be made to the interior of the frame as claimed in claim 1. In particular, the rotary members 23, 27, 41 and 46 can be constituted by continuous rollers or cylinders or discontinuous rollers arranged on a common shaft. Roller 23
Can be replaced by a fixed support member in the form of a cross member. The rollers 23 and 41 do not necessarily have to be driven, and the printer in this case may include additional drive members.

The rollers 27 and 46 can be replaced by elastic support pads. The print head 15 and the fixed support member can be arranged below the material 18 to be printed, in which case the printing is done upwards. Instead of being horizontal, the reference height can be tilted or even vertical.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of an embodiment of the present invention.

[Explanation of symbols]

10 print areas, 14 frames, 15 print heads, 16 carriages, 17, 24, 42 shafts, 22 first support members, 23, 41 rollers, 27, 46 counter rollers, 28 pivot levers, 29, 47 springs, 32 1st fixed support member, 35 fixed cross members, 40 pulling mechanism,
51 guide member,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Alan Tabasso Swiss Ferment Seaash-1417 Esseltan, En Froudville (no address) (72) Inventor George Zogana Swiss Federated Search-1018 Lausanne, Schmann De Bosson 45

Claims (10)

[Claims] 1. A printing area adapted to allow a print head to print on a flat material which is moved in accordance with a feed direction from an inlet of a printer through its interior to an outlet, said flat material and said print head. An adjusting means for adjusting a separation distance from the front surface of the print head, the adjusting means defining a reference height forming a predetermined gap with the front surface of the print head. A first support member cooperating with a surface of the flat material facing the print head, and in the printing area for positioning the flat material in a plane passing through the reference height. An inkjet printer, comprising: a mechanism adapted to pull a flat material. 2. The inkjet printer according to claim 1, wherein the first supporting member includes a first rotating member fixed on a shaft rotatable about a fixed axis. 3. The ink jet printer according to claim 1, wherein the first support member includes a fixed cross member. 4. The ink jet printer according to claim 3, further comprising an elastic blade disposed opposite to the fixed cross member for pressing the flat material against the fixed cross member. 5. The second supporting member cooperates with the second rotating member elastically pressed against the first supporting member.
An inkjet printer according to item 1. 6. The ink jet printer according to claim 2, wherein the first support member cooperates with an elastic support pad. 7. A third rotating member fitted on a shaft rotatable about a fixed axis and arranged downstream of the print head, the third rotating member being configured to adjust the reference height together with the first supporting member. A third rotating member adapted to cooperate with the surface of the flat material facing the print head for defining, the third rotating member being resilient to the third rotating member. The inkjet printer of claim 1, wherein the inkjet printer cooperates with a positively pressed fourth rotating member. 8. A third rotating member fitted on a shaft rotatable about a fixed axis and arranged downstream of the print head, the third rotating member being configured to adjust the reference height together with the first supporting member. A third rotating member adapted to cooperate with the surface of the flat material opposite the print head for defining, the third rotating member cooperating with an elastic support pad, The inkjet printer according to claim 1. 9. The third rotating member comprises a flattened material for forming a mechanism designed to be rotated by a drive mechanism to pull the flattened material within the printing area. The inkjet printer according to claim 7 or 8, wherein cooperating fine tips are provided on the outer circumference. 10. The first and third rotating members are rotated, and the tangential speed of the outer periphery of the third rotating member is faster than the tangential speed of the outer periphery of the first rotating member. The inkjet printer according to claim 7, which is 0.1 to 1.0% faster.