DE2007608A1 - Improved thermographic apparatus - Google Patents

Description

DIPL-INC. HANS MEISSNER 2β BREMEN. February 18, 1970

D1PL.-INÄ ERICH BOLTE ZSÜStSn » ⁶³²¹

“ATINTANWALTI

Ofrex Group Limited 2007608

London, England

Improved thermographic apparatus

The invention relates to an improved thermographic Copier with one pass, at the »usaaaenlaen. Sheets by means of transport be moved past a heating point with a heat source powered by electrical energy.

Such copiers produce facsimile copies of printed or otherwise applied Things on an original. The copy is made from the original to the one merged with it heat-sensitive sheet.

Various types of folded sheets can be used in the above device, which depends on the type of facsimile copy desired. υ.B. can put together a simple copy sheet for coproduction of things contained on the original, it can be in a different compilation but also maternal break Z / U compilations are used to produce the mother breaks for later use in hectographic apparatus of duplicates. In this case, the Hutterpause gives the mirror image of the original again. Another type of compilation is for the creation of print or duplicate templates Istencil sheet) and another sheet composition is used for the production of 'transparencies, in which the things of the original in one for Projection into a projector suitable iform appear.

Di · ^ development or transmission of things that

00M37 / 1930

Makes the facsimile copy appear on a copy sheet, a master copy, an original or a transparency sheet is for making copies greatest possible sharpness at a certain temperature or a certain temperature range of the Jirhitsungsetelle Torzüge. This temperature or this temperature range can be different for the various sheets put together, in practice However, the problem arises to keep the specific temperature or the specific temperature range at the heating parts constant over a period of time in which a number of collated sheets of paper pass through the copier.

When a number of collated sheets of paper run through in rapid succession, the general tendency is Temperature level of the heating point to rise and appear on the copy difficult to transfer Things such as thin lines or other markings of a similar character, only imperfectly or not at all.

JSs has been tried to solve this problem by increasing the number of times per unit of time by the Heating point led sheet compilations was changed in such a way that with the later ! Pieces of the series the number of throughputs has been increased.

However, this solution presents difficulties, in particular since it is necessary that different amounts of micrometers of a predetermined size or in predetermined Areas of size to achieve a flawless Ethiopia adjusted to all of the aforementioned types of rapier Need to become.

The object of the invention is therefore to provide an improved thermographic copier of the initially introduced

001137/1930

ITS
S?

to create the type mentioned, dtr no longer has the aforementioned disadvantages and solves the problem of increasing temperature in a particularly advantageous manner.

According to the invention, this object is achieved by that the aforesaid apparatus has a temperature sensor which is exposed to a temperature which corresponds to that which every set of sheets of paper passes through the heating station assumes that the temperature sensor emits a signal that changes with the temperature and that control devices are present which respond to this signal in order to increase or decrease the heat emitted by the heat source and so on at least partially the exact temperature change counteract.

The invention is preferably, but not exclusively, applied to a thermographic machine related to the aforementioned type, in which the heating point consists of a pair of rollers, one of which is hollow and a heat source supplied with electrical energy, E.B. . Contains an infrared lamp and the a material, e.g. glass, which allows the heat to pass through the roll wall, and wherein the roller is a counter-pressure roller which forms a bottleneck with the first-mentioned roller through which the put together leaves run hinduoh. In this case, the control device contains one Voltage regulator, 4-way is set by the signal from the heat sensor.

The gradual rise in temperature at the heating point depends on the

009837/1930

SAO ORIGINAL

-The roller to be kept in any case a certain amount of heat absorbs (just as it allows thermal radiation to pass through the wall). By conduction thus, heat is applied to each sheet assembly from the roller surface during sheet passage is transmitted through the ± .heating table and thereby the base or starting temperature of the heat-sensitive material daa at or in one or more the sheets of the compilation is attached, increased. If now the material is an additional Exposure to heat patterns depending on the things present on the original leaves the compilation the r-hot spot with one again increased temperature, but the temperature favorable for a good reproduction of the original on the copy, the Hutterpause eUc. can go out.

A particularly simple and effective measure to at least partially cancel this effect is according to the invention in that the temperature sensor bo is attached that it is once from the surface temperature the roller in which the heat source is attached is influenced and, on the other hand, also the Radiant heat is exposed to the heat source itself. üby this measure the temperature sensor is one Exposed to temperature influence that corresponds or comes close to that which each sheet compilation exposed to the heating station.

Another feature of the invention is that the voltage regulator is responsive to a switch set in the beginning of the flow path to the heating point is built in and of every continuous oil compilation is operated and the power supply is closed

009837/1930

the heat source guaranteed over a period of time, the passage of a sheet compilation the .heating point corresponds.

In the following an embodiment of the invention is explained in more detail with reference to the drawings. Show it:

Fig. 1 is a side view and partial vertical section of a copier according to the invention, FIG. 2 shows a section of the schematic

View of the device for setting the various throughput speeds, -Fig. 3 a circuit diagram of the power supply

for the heat source and

Fig. ^L · the graphical representation of various waveforms s of the circle, the t. or; its mode of action.

according to jrig. 1 the copier consists of one ! {imitate 10 with entrance and exit passages 11 and 12, the one pass-through path for those who are resolved together Form leaves through the heating point.

The & rhitzunstelle consists of a pair of rollers 14 · and 15 »with the latter roller in a swivel arm 16 is mounted, which is pushed up by spring force *.

The roller 15 consists of elastic material such as rubber, which, however, has to be heat-resistant, and the roller 14 consists of material which is transparent to infrared radiation , for example glass with a low coefficient of thermal expansion such as orcilicate glass.

009837/1930

BATH ORIGINAL

The roller 14 is driven via the intermediate stage of a continuously variable transmission 13, which Shaft 19 »the worm 20 and the gear 21 through the electric motor 17»

The gear wheel 21 is mounted on a shaft on which a drive roller 22 runs. The roller 22 serves in conjunction with a support roller 25 and the opposite roller 15 to support and Positioning the glass roller 14 while this around their horizontal axis revolves.

Inside the roller 14 there is a heat source operated by electrical energy v / io, for example an infrared lamp 24, which is surrounded by a reflector 25, which radiates the infrared radiation through a longitudinal slot 27 in it bundled. The exit slit has a uniform cross-section over the largest part of its length and can be widened at its bindings.

The copier also has a temperature sensor on, which is placed opposite the Erhifczungsstelle in such a way that he the temperature changes perceives that occur in each zone of the collated leaves when these the J pass through heat dissipation.

One of the factors responsible for the temperature of any sheet composition in its performance is the surface temperature of the roller 15 · This determines the basic or initial temperature of the entire surface of the special sheet of each composition, the one with the heat-sensitive Material is uncovered or contains it

009837/1930

- ^r ? -

The heat distribution or the tint caused by the printed letters or other things attached to the original is mainly used caused by the thermal radiation through the wall of the roller 15. According to Fig. 1 measures the Temperature sensor the surface temperature of the roller 14 with a resistance sensor Ph. The sensor Ph is held by a clamp 28, it has a small radial distance from the roller 14 of normal 1.6 mm and is preferably but not necessarily arranged between the rollers 22 and 23 The heat sensor also receives heat from the infrared lamp, whereby the heat radiation passes through the wall of the roller 14 and a bore 25a in the eeflector runs.

The temperature state in which the heat sensor itself is located, therefore corresponds to that to which each Compilation of sheets as they pass through the heating station, being subjected in the transverse direction.

Depending on the measured temperature, the temperature sensor gives an output signal that for this purpose, the power supply to the lamp 24 is used via a control circuit according to Pig. 3 to be regulated in such a way that the current access for the lamp decreases as the surface temperature of the roller 14 increases.

The electric drive rotor 17 is on a guide rail 29 attached, on which it can be moved in the direction of arrow 30. Through this movement are different axial points of the soffit cone 31 in contact with the rubber-edged Driving wheel 32 of the continuously variable transmission brought i'ür the change and determination of the setting of the motor 40 and thus the change

Q09837 / 1930

the speed of rotation of the roller 14- is indicated by the copier on the front a hand lever 4-2, which is in a slot in the front wall 33 of the housing is movable. The hand lever 32 is with an angle lever 34 and a pivot lever 35 'on itself upwardly extending pulling member 36 acts, operatively connected. The pulling part 36 acts on the motor 40 or its holder.

The front wall 33 of the housing carries a scale with markings 56a, 36b, 36c, 36d, to indicate various Positions of the hand lever 32 or of position ranges which, in their extension correspond to the upper and lower limits for certain types of sheet compositions. The mark For example, 36a gives the highest throughput speed of the sheet compilations required for the production of hectographic mother pauses, 36b the speed for making copies on copy sheets and 36c relates to sheet assemblies for the production of duplicate or print templates. Of course, the machine according to the invention also for other purposes. can be used, for example, for joining sheet compilations, with two or more sheets by means of heat-sensitive adhesive contained on or in one of the sheets, be connected to each other.

The conical circle according to the invention is described below with reference to FIG. The conical circle becomes by any power supply, e.g. from the light pipe with the connections Ti and T2 with electrical energy supplied. It gets AC from 5u to 60 Hz and usually 11U or 220-240 Volts voltage used. The input current is in

009837/1930

a diode bridge W1 to W4 rectified and between the anode and cathode of a thyristor SCR1 Applied across the filament R1 of the infrared lamp 24 and noise suppressing induction coils L1 and L2. The trigger electrode of the thyristor is connected to the Moving contact of the moving relay A1 connected and holds in the position shown Thyristor the circuit open (high impedance at the load R1) and the coil R1 is not current.

When passing through a sheet compilation the input 11 moves the front edge of the compilation a sensor 37 in the form of an upright Tastere, the one on a horizontally mounted spindle is attached and actuates a normally open micro switch 81. When this switch is closed is, the working turn of the relay A1 is etromdurcfloesen through the diode D2 and at the same time the Capacitor C2 is charged through resistor R11 to a voltage that is generated by resistor chain R2, R8 and R9 is determined and is normally 24 volts, stabilized by the Zener diode ZD1.

The passage of current through the relay 11 moves the movable contact up and closes the relay.

The temperature sensor resistor is in the base circuit of the transistor T1 in a base circuit via the Control resistance R1O switched «The · resistance value of the temperature sensor Th and the resistor R1O determined the emitter current and thereby the voltage across the resistors R6 and R7 and the charge current of the capacitor C1 via the diode D1. Sin another charge

009837/1930

BAD ORiSlNAL

- ίο -

current flows to the capacitor C1 through the resistor R5.

If the voltage in the capacitor C1 rises above a predetermined value, the control electrode of the release pulse (trigger) generator UJT1 , a device semiconductor, a short circuit between the bases B1 and B2 to and at the upper end of the resistor R4, connected to the base B2, is a Generates a positive surge of current applied to the trigger electrode of SCR1.

The specific point in time when this pulse occurs in each half cycle of the rectified current is generated, depends on the size of the adjustable portion of the charge current that flows through the diode D1 flows to the capacitor C1.

As shown in Fig.4, in the two rectified half-periods of the supply voltage in the part A, trigger pulses (trigger coil) are generated in accordance with Bdi at the early beginning of each half cycle. The * occurs when the surface temperature of the roller 14 is relatively low and the Resistance value of the temperature sensor Th as well is low. The early arrival of the trigger pulse creates flow through the üelaAing R1 for a high proportion Every period,

In part C of FIG. 4, trigger pulses are shown which have been generated later in the half cycle, since the roller has a higher surface temperature and the lamp has a stronger radiation and the temperature level is generally higher. Both circumstances give the temperature sensor a higher resistance value.

009837/1930

BATH ORIGINAL

It is therefore obvious that the swelling of the Trigger pulse the size / distance ratio of the current pulses in the pulse generating sub-circle of the Thyristor SCR1 and thus the average current determined by the load H1.

If the feeler 37 goes back after the trailing edge of the sheet assembly has been moved past, the switch 1 opens without the relay A1 opening immediately. The opening takes place only after a time delay which is given by the time constant of the combination of R11 and 02. This delay is built in to keep the contact of relay A1 in the upper position long enough to ensure the correct .heating of the rear areas of the sheet compilations, thus to ensure the Be ·· - ^ before marriage, which are between it and the heating point when the heater 37 goes back.

Obviously, the control loop allows a very flexible adaptation of the requirements for processing a variety of different sheet compositions. The resistor RTO is preferably a variable resistor which can be adjusted to compensate for the effect of the heat sensor 3 Th (through guide angle reduction of SCR1 with the increase in the temperature of the surface of the Roller 14) the needs of the various sheet compartments, that are used in the device must be set accordingly.

The mode of operation of the control circuit depends on the setting device for setting the throughput speed the compilations independently and accordingly a simple adjustment mechanism

0Q9837 / 1930

BATH

according to Pig. 2] mm »can be used without the Copying machine becomes complicated and expensive.

Even if the arrangement of the temperature sensor according to J? Ig. 1 seems particularly appropriate, since it does not interfere with the work of moving parts of the apparatus there, it is easily accessible there and also the correct proportions of heat from the roller surface (Z. ¹ ! '. By radiation and partly by convection) and from the lamp (by radiation; it is guided to it, the temperature changes take place according to those which the transverse areas of the sheet assemblies experience when passing through the heating points, but a different arrangement can also be made.

The heat sensor can, for example, be inside the roller 14 and is then applied by heat from the inner surface of the roller and also from the lamp applied, with shields may still be attached. Alternatively, the temperature sensor also near the heating point above or below the outlet path 12 of the pass with a possible contact to the compilations.

Instead of the cone of the energy supply too The infrared lamp can also have a movable shield placed between the lamp and the heating point be. The sign can then either be de sen directly through the pouring means, e.g. through the mechanical movement (Bimetal strip), or another by heat moved means or indirectly by a motor that

is moved by the signal from the temperature sensor, will be verbdbben.

009837/1930

Claims (1)

P_a_t_e_n_t_a_n_s_p__r_ü_c_h .__ e_ MT) Thermographic copier with one pass, in the folded sheets by means of transport at a heating point with a with electrical energy powered heat source are moved over, characterized by that the apparatus has a temperature sensor (Th) which corresponds to a temperature which corresponds to that which each assembly is exposed to when passing through the heating point (13) assumes that the temperature sensor is on emits a signal that changes with the temperature and that control devices are present that respond to this dignal and that emitted by the heat source (24) to increase or decrease heat and thus at least partially counteract temperature changes. 2. copier according to claim 1, characterized in that the heating point (13) consists of one There is a pair of rollers (14 »15), one of which (Η) is hollow is made of a material which is transparent to radiation from the heat source to the sheet assemblies and the source of goods powered by electricity and that the Hegel circuit contains a voltage regulator (SCR1) includes, which is dependent on the output of the Temperature sensor (Th) is adjustable. 009837/1930 5. copier according to claim 1 and 2, characterized in that that the temperature sensor (Th) is arranged so that it once through the the heat source contained roller (14) and on the other hand by the heat source (24) "is influenced. 4. copier according to claim 1 Ms 3, characterized in that that the current control device has a pulse-forming sub-circuit (SGRI, R1, L1 and L2) which serve to feed the heat source (24) and a size / distance ratio depending on the Have the output signal of the heat sensor (th). 5. copier according to "nspruch 1 to 4, characterized in that that the voltage regulator is dependent A switch (S1) works in the input section (11) of the passageway to the heating point of the sheet compilations running through the input section is operated and the power supply of the heat source is guaranteed as long as the run corresponds to a compilation by the heating station. 6. copier according to claim 5 »characterized in that the control circuit has a ^ eitverzögeruncsunterkreis (D2, A1 / 1, R11,02) for maintaining the supply of energy to the heat source (24) after the rear edge of the respective flat arrangement has the switch (S1 ) happened, namely liu \ · 009837/1930 enough, iuii an unambiguous representation also of the ^ inge to ensure the rear part of the original. 7.. Copier according to Claims 1 "to 6, characterized in that that the 'means of transport (15,15,22,21,20, 19,1 ^, 17) for the movement of the jilatt groupings Passage (11, 12) through a hand lever (32) for adjustment have the throughput speed, and that Display means (36a - J56d) in connection with the hand lever are available which have a plurality of different speeds or their ranges for processing different copies. For the applicant: Meissner & Bolte Patent anwält e Bremen, February 18, 1970 Applicant: Ofrex Group! Limited
London / England 009837/1930 j Le e rs e11 e