CN101830117A

CN101830117A - Equipment for determining position of printing head according to thickness of print record carrier

Info

Publication number: CN101830117A
Application number: CN200910037929A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-13
Filing date: 2009-03-13
Publication date: 2010-09-15

Abstract

The invention discloses equipment for determining the position of a printing head according to the thickness of a print record carrier, which comprises a reflection sensor. The reflection sensor is arranged in a protection space formed between a printing base carriage unit which carries with the printing head and an opposite printing head shell surface. When a printer is initialized or a record carrier which is thicker than the set thickness is inserted, and the printing surface of the printing head is temporarily contacted with a printing carrier which is arranged on a printing tray, slight displacement relative to the printing base carriage unit is generated. The reflection sensor detects the distance of the displacement of the printing head and generates an input signal to an evaluation circuit, and the evaluation circuit generates an output control signal to a printing head displacement control driver. Therefore, the distance between the printing head and the printing medium (or the printing tray) is automatically set.

Description

For determine the equipment of print head position according to the print record carrier thickness

● technical field

Invent relevantly, be used to set the equipment of the operating distance between printhead and the print record carrier (for example printing paper) with printer.

● background technology

During dot matrix and the initialization of ink droplet (such as ink-jet) printer; or/and insert new print record carrier (such as printing paper) afterwards, printer can locate or reorientate the predeterminable range of position to an adaptation print record carrier thickness of printhead usually.Provide accurately and the printing of optimizing for making, this predeterminable range drops in the predetermined tolerance limit extremely important for a specific printer.The varied in thickness of printing paper, such as owing to use the single-part stationery of different-thickness or the multi-ply paper of the different numbers of plies etc., the position of the relatively wild print tray of printhead must reset to obtain the optimal printing quality and prolong print head longevity.

A distance of knowing for everybody is provided with equipment (being exactly the equipment of adjusting print head position according to the thickness of the printing paper that is using) and is derived from German patent DE 42 21 265 C2.This kind equipment supposition printhead can move freely in the direction perpendicular to the print record carrier, and comprises a thickness induction roller.The signal of telecommunication of a non-direct generation (analog signal) is derived from thickness induction roller and delivers to control module and set usefulness as distance.For producing this signal, first magnetic cell is positioned on the thickness induction roller as producing first magnetic flux.Second magnetic cell produces as rightabout second magnetic flux and is positioned on the printing seat.A Hall element is arranged in the zone of second magnetic flux of printing seat.When the print record carrier is put into printer, and after printing its side locations of seat, the CD-ROM drive motor that distance arranges equipment begins action.Until default air gap has a predetermined magnitude of voltage to be added on the Hall element after reaching.This equipment work gets comparatively accurate, but should and can be more accurate.In addition, this equipment is to be positioned on the open relatively zone, so can not do safeguard protection completely to some external action, for example makes dirty.

Another the distance be provided with equipment be reveal German patent DE 196 11 772 A1.Be based on delivery roller, it can resiliently be set to the thickness of paper, be arranged to be installed on the driving shaft of a rigidity in a pair of mode, and on an axle perpendicular to the print record carrier.A measuring-signal transmitter emission light beam that is arranged on this axle, the receiver of working together is positioned to be printed on the seat.In addition, a position indicator offers and prints seat.Paper is arranged and do not have in two kinds of situations of paper at printer, follow the clock pulses of position indicator to compare by the signal that the measuring-signal receiver is accepted, according to comparative result, the printhead distance arranges device drives equipment and can adjust accordingly.This kind equipment is cost-efficient with can't deny.Because it only needs measuring-signal transmitter and measuring-signal receiver.Yet it needs an optical barrier that is made up of light-receiving and light emission, and to guarantee accurate rate and stable switching point, this switching point can not be kept when printer environment or operating temperature variation.

One of them target of the present invention is to eliminate the dither effect that is produced by stepper motor and their same mobile print seats, this vibration meeting often hinders at measurement point and prints between the printing surface and measure accurately and arrange, thereby reaches than the higher accuracy rate of the described equipment of the past document.

● summary of the invention

According to the present invention, the target of these and other will obtain by following structure.When printhead has of short duration contacting with the print record carrier of support on print tray, printhead can produce slight displacement (deformable) at the seat of supporting, this displacement stroke (distance) and/or printhead can detect with respect to the angle of record carrier, detection be by be contained in one print and the space of the printhead case surface on opposite in a reflective sensor carry out.This result can be with the form of the electric signal of a processing, from evaluation circuits output, and control driver, thereby the distance between Lookup protocol printhead and record carrier or the print tray.Of short duration period of contact in printhead and record carrier or print tray, on slight printhead with respect to printing seat " deformation " (only several microns of deformation total amounts) produce, and change signal by reflective sensor record as one, and do not exert an influence and disturb.This is measured operation and can automatically be triggered, and is independent of the location of printing seat.

The position of the printhead of determining reliably in printing seat still obtains because printhead is to be pressed in a M shape Spring Card to print on the seat, and printhead and print between be placed with a flexible intermediate layer.

The principle of reflective sensor of the present invention can be carried out or realizes in multiple different mode.For example, sensor can be contemplated to a pair of printhead shell that is placed in and go up with the printing seat and made transmitter and made receiver at a photosensitive tube on its next door by light emitting diode by one, be placed in and print on the seat, a reflecting surface is placed on the surface of the printhead shell of launching the recipient opposite.

The present invention according to other specializes equipment, and reflective sensor is to being placed on the printhead shell on opposite with magnet on the printing seat by Hall element.

In addition, ripple of wanting or bundle reflection can be by being placed in reflective sensor that the mistor printed on the seat and the magnet on the printhead shell of opposite forms to forming.

For folded light beam, if reflecting surface realizes that with a minute surface it is favourable.The metallic plate of simply polishing can be used as this minute surface and uses, and needn't to comprehend it be mirror-reflection or diffuse reflection.

So for electronics or the optical element with ripple or bundle operation, peripheral operation and the external action of ripple or bundle is harmful to its function.Therefore, according to sensor of the present invention pair, no matter be to add photosensitive tube and reflecting surface with luminous tube, or Hall element and magnet, or mistor and magnet, or other any structures, a guard space all must be arranged.For example, in part that print head surface enlarges with print seat facing to the space between the print tray.

When printhead moved towards record carrier or print tray, the signal of telecommunication of generation was very faint, so that be difficult to process.If move and touch carrier or print tray towards carrier when printhead, transformation that photosensitive tube can the tracer signal result is only and wants.

According to further characteristic of the present invention, the signal change is delivered to one with a different waveform and is equipped with the evaluation circuits that is put into wave filter, and signal will be revised.Revised control signal will obtain at the output of evaluation circuits, defines with a voltage threshold through an amplification module, and has not contained remaining interference through the signal after filtering.

Specialize equipment in other the present invention, it may be unsuitable on the printhead that reflective sensor is placed in.Make the printhead displacement not be satisfied because work as the printhead of a rigidity being connected of seat with printing, or because that is the printhead that will often change.In these cases, reflection wound sensor will be considered to separate with printhead.

Correspondingly, producing one at a reflective sensor that separates with printhead and do not have noisy test signal, thereby obtain accurate the measurement and stable print head position, also is a target of this patent.

● description of drawings:

At all accompanying drawings, wherein the note number of similar units is all the same in all figure.

Fig. 1 is that a printhead is installed in a side view on the printing seat that can move freely along the axle vertical with making plan, and is consistent with a specific equipment of the present invention.

Fig. 2 printhead is at a profile of printing on the seat, along the hatching II-II of Fig. 1

Fig. 3 is the I-d characteristic relation figure line of a reflective sensor,

Fig. 4 is the block diagram of the evaluation circuits of the concrete or equipment of one of the present invention

Fig. 5 is that a printhead is installed in a side view on the printing seat that can move freely along the axle vertical with making plan, and is consistent with another specific equipment of the present invention.

Fig. 6 is that a printhead is installed in a side view on the printing seat that can move freely along the axle vertical with making plan, and is consistent with another specific equipment of the present invention.

● the specific embodiment

With reference to figure 1,2 according to the present invention, the equipment that is set to the distance of print record carrier 7 for printhead 1 comprises that is printed a seat guide shaft 4, it is parallel to prints holder 2, the printing seat that can move along direction 3, set best distance or space for can and being used for support or carrying between the printing holder 2 of print record carrier 7 of all thickness at the end face 1a that prints holder, can on the direction 6 vertical, produce slight displacement with the printheads 1 of printing seat 5 combinations with printing moving direction 3, it is thick that the record carrier of all thickness is attributable to different paper, with or the number of plies and or the paper of different paper.Printhead end face 1a can be measured by a sensor to the distance of record carrier 7 or print tray 2.Printing seat 5 can be controlled and pass through driving (not drawing) Lookup protocol according to measurement result along the displacement of direction 6.

As shown in Figure 1, printhead has an anterior 1b and a bigger rear portion 1c (as be used for loading solenoid and printing arm in dot-matrix printer).When printhead 1 contacts with record carrier 7, the shell 1f of printhead has a displacement with respect to printing seat 5.Linear displacement stroke (distance) 9a and the angular shift 9b sensor 8 that can be reflected detects.Reflective sensor 8 is placed on a free space 18, and this space is on the surface 19 of the printing seat 5 on the opposite of surperficial 1d of the bottom of print head surface 1f 1e, between the lower surface 1h of the anterior 1b of printhead 1.Space 20 is defined as the distance of surperficial 1d to 19; Under two kinds of operator schemes, when printhead 1 contacts with record carrier 7, sensor 8 can measure linear displacement 9a and angular shift 9b.Measurement result is delivered to an evaluation circuits 11 (Fig. 4) as input signal and is operated the displacement that is controlled on the direction 6 and drives (not drawing), thereby printhead 1 is set with respect to the distance of record carrier 7 or print tray 2.Therefore, linear displacement 9a and angular shift 9b derive from input signal, and this signal has formed the foundation of a definite print unit (print needle or ink gun) position corresponding to the thickness of record carrier.

Expectancy model according to an operation, when powering on or reset, printer carries out initialization, print seat 5 and be with that printhead 1 is at once controllable 6 to advance towards record carrier 7 along direction, print in the holder so that cause printhead 1 initially to be connected in the same manner, and produce displacement to the rear portion with respect to printing seat 5.In the second pattern of operation, print tray 1 initially has segment distance with print tray 2, and this distance is set by factory preset or user oneself.Make it a standard or default value can be held individual layer record carrier 7, on printer, have one than standard or default thick record carrier, printhead will contact or linkage record carrier 7, therefore produce with respect to printing seat 5 and produce backward displacement, the printhead 1 of measuring is processed with respect to the translocation distance 9a and the angular shift 9b that print seat, as the purposes of automatic adjustment printhead 1 with respect to record carrier 7 or print tray position 2.

Printhead 1 can vertically be installed and use a M shape spring 13 to be fastened on and print on the seat 5.Between printhead and the printing seat a flexible pad 12 (Fig. 2) is arranged.Printhead 1 comprises two pin 1g, and pin passes elastomeric pad, is engaged in the pinhole 5a that prints seat 5.This pad allows printhead 1 that the displacement of linear and angle is arranged with printing seat 5 relatively.

Reflective sensor 8 is being printed formation a pair of 14 between seat 5 and the printhead shell 1f.Should there be 15 and photosensitive tubes 16 of light emitting diode (LED) to be positioned at the opposite side of LED15 to 14 first side or part, and in same plane.For example all be arranged on the surface 19 of printing seat 5 at the specific equipment LED15 of illustrated invention and photosensitive tube 16.Second side to 14 comprises that a reflecting surface 17 is arranged on the surperficial 1d of opposite printer casing 1f of LED15 and photosensitive tube 16.And can there be a minute surface 17a to realize (Fig. 1).During operation, LED15 transmitting optics signal is reflected by minute surface 17 then, is received by photosensitive tube 16 again.Signal of telecommunication of photosensitive tube 16 outputs is responded the reflected signal of the reception that originates from the distance between surperficial 1d and the surface 19.

Specialize in the equipment in another invention, sensor 8 can form 14 by being contained in the Hall element 30 of printing on the seat 5 and the magnet 32 that is fixed on the printhead shell 1f of opposite.(Fig. 5) 30 pairs of Hall elements have the magnetic-field-sensitive that magnet 32 produces.Response as the change of distance that produces coming from record carrier thickness produces a corresponding output signal.

Equipment is specialized in another invention to be provided 14, is to realize (Fig. 6) by being installed in the magnetosensitive electrification resistance 34 of printing on the seat 5 and the permanent magnet 36 on printhead shell 1f on opposite.The magnetic field that resistance 34 inductions are produced by opposite magnet 36.Export one and follow carrier thickness relevant, and the output signal that the change of distance that produces causes.

Specialize equipment for any one invention to 14, one comprises space 18 and is provided by a printhead shell 1f who suitably designs.This space is by the face 1d of printhead shell 1f, and the face 1h of the bottom of the face 19 of printing seat 5 and the previous section 1b of printhead 1 constitutes.

Specialize equipment according to an invention, measuring method uses reflective sensor 8 to decide because signal change 23 (Fig. 3) that the displacement that printhead 1 air exercise block 5 takes place causes.When printhead 1, together with printing seat 5, on direction 6, move when being still on the print tray 2 towards record carrier 7, at printhead 1 with print seat 5 deformation (being exactly displacement) generation between the two.Printhead 1 can be shifted with respect to printing seat 5.Cause actual range or sensor to the distance in the space 20 between two elements of 14 change (being exactly to become big).

Fig. 3 has shown the electric current I p of photosensitive tube and the relation between the translocation distance d.After the foregoing displacement that detects printhead 1, an operating point 21 is selected, drops on the decline zone of the I-d curve of reflective sensor 8.From putting 21, the slope of curve is by suitable known technology decision.Little signal landing 22 signals with a typical number microvolt size have just obtained.

Fig. 4 has shown evaluation circuits 11 according to of the present invention specializing.Fig. 1 is seen in the description of emission sensor 8.The side that LED15 and photosensitive tube 16 form 14.The surface of emission 17 forms opposite side.Measure in the signal of photosensitive tube 16 and change 23, be imported into module 24, signal is amplified to the level that can further operate, filter 25 receives from the signal after 24 the amplification, filter out any interference and skew that appears on the signal, one second amplifier module 26 is by setting a voltage threshold, the interference of removing all remnants, the output signal of amplifier 25 is clean signals, the displacement that on behalf of printhead, it produce because of 1 contact history carrier.In order to remove the interference of the generation of mechanical oscillation in any printer, the further software of output signal 27 is processed and can be carried out.

Because original output signal 27 when printing, is not the dynamics that printhead moves that places one's entire reliance upon, thereby evaluation circuits 11 and unique wave filter 25 can optimisedly further improve the processing of measuring-signal transformation 23.

Claims

1. a printing holder that the support record carrier is arranged, one as the printhead that prints to record carrier, and one printed seat and be used to carry printhead and main can moving up and can be with printing holder and the recording medium vertical second party distance between the print surface that is used to regulate printhead and the record carrier that moves up substantially in the first party that is parallel to the record carrier of printing holder and will being printed, the present invention forms a mechanism as by printing seat this distance of controlled mobile adjustment in response to the different-thickness of the record carrier that is printed along second direction, thereby make print quality more optimize, said mechanism forms:

1) referring to install printhead makes it on the seat and can provide a printhead with respect to the displacement along said second direction of printing seat with record carrier is of short duration when contacting at the printing surface of printhead to printing;

2) the second surface on printhead away from printing surface, with the opposite location that is placed in the printing seat, with be arranged on space therebetween, said printhead prints face with record carrier is of short duration contact after, produce when printing the displacement of seat along said second direction, this space is along said second direction and the city is set for being variable on the second direction third direction at angle.With

3) reflective sensor refers to be to detect the said variable in said space, and prints seat and move to reach with the correct adjustment printhead prints face of said detection variable and the distance between the record carrier along said second direction for one of output is used for realizing control.

2. as the 1st described device, said here reflective sensor is that device is in said space.

3. such as the 1st described device, further consist of an evaluation circuits as receiving the said signal of telecommunication as a differential signal that is caused in the variation that printhead is of short duration when touching record carrier by said space, process this differential signal with being used as by filtering and amplification, be used for realizing the said seat of printing along the controlled movement of said second direction to produce an output signal, thus the distance between correct adjustment printhead and the record carrier.

4. as the 1st described device, said installation method is by a spring here, and resiliently the fastening printhead is to printing on the seat as a downward direction, and elastomeric pad is placed on printhead and prints between the seat.

5. as the 1st described device, here said emission sensor comprises a light emitting diode, and as the transmitting optics signal, a reflecting surface is as receiving optical signal, and reflection is received from the optical signalling of light emitting diode and photosensitive tube as the optical signalling that receives from reflecting surface.Said light emitting diode, reflecting surface and photosensitive tube are to be arranged in a space, so the travel distance of optical signalling from the luminous tube to the photosensitive tube can be different because of the difference in said space.

6. as the 5th described device, wherein said reflecting surface comprises a mirror.

7. as the 1st described device, wherein said emission sensor comprises one of them a magnet that is placed in the printhead second surface and prints seat, as the usefulness that produces a magnetic field.With a Hall element, be placed among the other side of printhead second surface and printing seat, as the intensity that detects the magnetic field produced, said Hall element and magnet are to be placed in different that said space so the travel distance of optical signalling from the luminous tube to the photosensitive tube can be because of said space.

8. as the 1st described device, wherein said emission sensor comprises one of them a magnet that is placed in the printhead second surface and prints seat, as the usefulness that produces a magnetic field.With a mistor, be placed among the other side of printhead second surface and printing seat, as the intensity that detects the magnetic field produced, said mistor and magnet are to be placed in different that said space so the travel distance of optical signalling from the luminous tube to the photosensitive tube can be because of said space.