US3515311A

US3515311A - Control arrangement for a regenerator unit in a continuous developer

Info

Publication number: US3515311A
Application number: US743512A
Authority: US
Inventors: Hans-Dieter Frick; Walter Knapp; Victor Osegowitsch
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1967-07-11
Filing date: 1968-07-09
Publication date: 1970-06-02
Anticipated expiration: 1987-06-02
Also published as: DE1597650A1; GB1239781A; FR1573574A

Description

JEARCH ROOM" BEST AVAILABLE COPY v BEST AVAIL June 2, 1970 HANS-DIETER FRICK ETAL 9 CONTROL ARRANGEMENT FOR A REGENERATOR UNIT IN A CONTINUOUS DEVELOPER 2 Sheets-Sheet 1 Filed July 9. 1968 K m M. S m H J1 R R w 4 O P f T DIG N A I E ENS e V K m 1N. R 0 M mmm Y B S Q h .2 Q E Q BEST AVAILABLE COPY HANS-DIETER FRICK ETAL 3,515, CONTROL ARRANGEMENT FOR A REGENERATOR UNIT IN A CONTINUOUS DEVELOPER June 2, 1970 2 Sheets-Sheet 2) Filed July 9. 1968 Fig.2

Fig.3

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United States Patent ice rm. c1. Bsh 1/08 US. Cl. 22257 Claims ABSTRACT OF THE DISCLOSURE A plurality of switches connected in parallel and placed along the width of film being transported in a lengthwise direction control the current in a coil of a motor which determines the speed of the motor, in accordance with width of the film to be developed. The motor drives a diaphragm pump for a length of time depending on the duration of a timing signal which depends upon the length of film which has been processed. The timing circuit which generates the timing signal may be controlled either by a cam connected to the film transport means and a switch which starts the timing cycle when activated by the cam, or it may be started by a signal generated when a predetermined length of film has been processed.

BACKGROUND OF THE INVENTION This invention relates to a control system for controlling the amount of fresh treatment substance in a continuous film developer as a function of the width of photographic material being processed.

Known arrangements of this type comprise a plurality of switches arranged along the width of the photographic material which is being transported in a lengthwise direction through the developer. Upon closing of each of these switches, which may be microswitches, an electrical pulse is furnished to a magnetic valve which in turn permits regenerating liquid to enter into the development tank. This relatively simple arrangement has the disadvantage that exact dosages are difficult to achieve by means of a magnetic valve and that furthermore it is extremely difiicult to allow variations of the dosages as a function of various factors as for example the speed with which the film is being transported, the particular chemicals which depend on the type of material being processed etc.

SUMMARY OF THE INVENTION It is the object of this invention to furnish a control arrangement of the above-described type which permits the attainment of accurate dosages and further permits variation of these dosages as a function of various relevant factors.

This invention discloses an arrangement for varying the quantity of fresh treatment substance applied to at least one elongated strip of material being transported in a direction along the length of said strip past a determined treatment location, as a function of the total strip area to which said treatment substance is to be applied. It comprises scanning means for generating a width signal as a function of the total width of strip material being transported past said treatment location. Further provided are driving means having a speed which varies as a function of said width signal generated by said scanning means. Movable metering means are provided for supplying fresh treatment substance, the quantity of treatment substance being furnished by said metering BEST AVA|LABLS?Y3 1 l Patented June 2, 1970 means varying as a function of the speed of movement of said metering means. Finally means are provided for connecting said driving means to said metering means in such a manner that the speed of movement of said metering means varies in accordance with any variation of the speed of said driving means, whereby the amount of treatment substance applied by said metering means varies in proportion to any variation of the area of said strip being treated.

Use of a conventional metering pump, in particular a diaphragm pump, allows Variation of fresh treatment fluid in dependence on a number of parameters, since the stroke of the pump is adjustable and therefore the amount of treatment substance supplied per stroke may be varied. Also the accuracy obtainable by means of such a metering pump is considerably greater than is attainable by use of a magnetic valve.

If a timing circuit is used which allows fresh treatment fluid to be supplied for a predetermined time interval cumulative errors may arise which should be eliminated. These appear particularly, if a film is used which activates a length sensor for a time period which differs considerably from an integral multiple of said predetermined time interval. These cumulative errors may be avoided by one embodiment of this invention which provides for energization of the time circuit after a predetermined length of material has been treated.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation. together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a circuit diagram of a regenerating arrangement according to the present invention;

FIG. 2 shows the construction of a metering pump; and

FIG. 2a is a horizontal sectional view of a detail in FIG. 2; and

FIG. 3 is a block diagram of an arrangement for starting the timing circuit after a predetermined film length has been treated.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 reference numeral 1 denotes a transformer having a primary connected to the main power supply and two secondary windings designated 2 and 88 respectively. A bridge rectifier arrangement 3 is connected to secondary winding 2. A smoothing condenser 4 serves to filter the pulsating direct current available at the output terminals of the rectifier arrangement, which constitute the first and second supply terminals. In parallel with capacitor 4 there is connected a capacitor 5 in series with a twoposition switch 6, also referred to as additional switching means, which when in its first position is adapted to connect the capacitor 5 to the first supply terminal via a resistance 7, thus allowing it to charge. When the switch 6 is in its second position the capacitor 5 is connected across relay 8, also referred to as additional relay means, which in turn has a diode 9 connected in parallel with its activating coil. The switch 6 can be moved from its first position to its second position in known manner by means of a cam. This cam may for example be connected to the transport arrangement for the strip-like material to be processed by means of a magnetic coupling.

A resistance 10 is also connected to the first supply terminal and has, connected to its second terminal, a

BEST AVAILABLE COPY plurality of mutually parallel switching contacts numbered 11 through 19, as well as a normally open, manually operable contact of switching means 20 and a normally open contact of a relay 21 which will be further discussed below, numbered 211:. The other terminal of each of these switches are connected via diodes 22 through 32 to resistances 33 through 43 and then to a common line 44.

Between each of these switches 11 through 19 and its corresponding diode 22 through 31 a tap is provided which connects to the anode of a corresponding one of diodes 45 through 53 respectively. The cathode of these diodes is connected via a common line 54 to first relay means namely relay 21 and a diode 55 connected in parallel to said relay. The other side of relay 21 and its parallel diode 55 are connected to the second supply terminal.

Line 44 is connected to the emitter of a transistor 56, which in turn is connected to the second supply terminal via a variable resistance 57. The base of transistor 56 is connected to the resistance via a Zener diode 58 which serves as a voltage stabilizing element. The emitter of a further transistor 59 is connected to the common point of the collector of transistor 56 and resistance 57. The base of transistor 59 is connected to the second supply terminal via a resistance 60 and a normally closed contact 61a of a relay 61 which will be described below.

Connected in parallel with the above-mentioned resistor 60 is a capacitor 62 and a tachometer winding 63. The tachometer is mounted on the same shaft as a DC motor 64. DC current for the motor is furnished by means of a rectifier arrangement 65 having a positive and a negative terminal, connected across the secondary winding 88 of transformer 1 having a filter condenser 66, via a power transistor 67. The base of transistor 67 is connected to the emitter of transistor 59 while the collector of transistor 9 is connected to the negative terminal of recitifier arrangement 65.

Connected between the Zener diode 58 and the second supply terminal are two further Zener

diodes

68 and 69 which also serve as voltage stabilizers. Connected in parallel to Zener

diodes

68 and 69 is the timing circuit which consists of a variable resistance 70 connected to the positive supply terminal of rectifier arrangement 65, a resistance 71 connected to resistance 70, and a capacitor 72 connected to resistance 71 and the second supply terminal. In parallel with capacitor 72, the timing capacitor, is a resistance 73 and a normally open contact pair 61b of relay 61. The common point of resistance 71 and capacitor 72 is also connected to the control electrode of a double-base diode 74, having one base connected to the second supply terminal via resistance 75 and a second base connected to the positive supply terminal via a resistance 76. The combination of

resistor

70 and 71 serves as timing resistor, while discharge of capacitor 72 is effected by closing of contacts 61b via resistance 73. The common point of diode 74 and resistance 75 is connected to the gate of a thyristor 78 via a resistance 77. The thyristor 78 is connected in series with relay 61 and a diode parallel thereto namely diode 79 between the first and second supply terminal. In parallel with thyristor 78 is a pair of normally open contacts 8a operated by relay 8. Components 70 through 79 thus constitute a timing circuit for controlling relay 61.

A conventional metering pump is shown in FIG. 2. This may be driven by motor 64. A motor 64 drives a cam shaft 81 by means of a gearing arrangement 80. Cam shaft 81, as shown in FIG. 2a has a cross section with, for example, three control cams evenly distributed around its circumference. The

control cams

82a, 82b and 82c have a conical shape, so that an axial displacement of earns 82 relative to the conventional diaphragm pumps 83 and 84 permits a control of the amount of fluid pumped per stroke. The relative axial displacement between the diaphragm pumps 83 and 84 relative to the 4 cam 82 is accomplished by

screws

85 and 86. Thus adjustment of the particular amount of chemical per unit surface of the material to be treated may for example be adjusted in dependence on the intensity of illumination. The operation of the above-described arrangement is the following:

When the arrangement developer is first activated, activator switch 87 in the circuit of the secondary winding 2 of transmormer 1 is closed. This causes voltage to be applied to the circuitry. However no current is supplied to the motor 64 since

transistors

56, 59, 60 are blocked.

If a strip of material to be processed, for example, a film, now enters the tank developer, at least one of the switches 11 through 19 depending on the width of the material will be closed. This causes curent to flow through transistor 56, causing a voltage drop to appear across resistor 57. This has no immediate effect on motor 64, since contact 61a is open. It is the function of transistor 56 to produce a voltage drop across resistor 57 which is proportional to the number of closed switches 11 through 19. The two sets of diodes 22 through .30 and 45 through 53 prevent a back coupling between open switches and the voltage generated across resistance 57. Relay 21 is now also activated which causes a closing of contact 21a. This causes resistance 42 to be connected in parallel with the resistors corresponding to the already closed switches, thus furnishing a basic operating current independent of the width of the material to be processed to the motor 64. In a preferred embodiment of this invention, a contact controlled by relay 21 may serve to energize a magnetic coupling connecting activating means for switch 6 to the transport arrangement for the film passing through the developer. These activating means may comprise a cam which switches switch 6 from the first position to the second position once per revolution for a short time. This short switching of the switch 6 causes the capacitor 5 to be decoupled from the first supply terminal and to discharge over relay 8. Relay 8 is thus activated and closes contacts 8a shorting thyristor 78 for a short time. After discharge of capacitor 5 these contacts again open. This causes relay 61 to be deactivated closing contact 61a and opening contact 61b. Contact 61b starts the timing cycle so that relay 61 remains deenergized for a predetermined time period determined by capacitor 72 and

resistors

71 and 70.

Closing of contact 61a results in connection of the base of transistor 59 to the second supply terminal. This causes transistor 59 to become conductive and in turn causes activation of power transistor 67. The motor 64 now operates with a speed determined by its control voltage which is determined by the voltage drop across resistor 57. The speed is stabilized by tachometer 63 and resistance 60 in the known fashion. The pump thus furnishes more or less regenerating fluid, or treatment substance, depending on the speed of the motor which in turn depends upon how many of the switches 11 through 19 are closed.

After expiration of the time cycle, the relay 61 again becomes active, opening contact 61a and closing contact 61b. Opening of contact 61a again causes a blocking of power transistor 67 and thus a stopping of the motor. This operates independently of whether or not any of the switches 11 through 19 are closed at this moment. Closing of contact 61b causes capacitor 72 to discharge via resistance 73 and thus return to initial conditions.

However, as long as one of the switches 11 through 19 remains closed, the cam switching switch 6 from the first to the second position continues to operate and switch 6 is thus again switched for a short time. Thus a new regeneration cycle begins. In order to achieve the best use of the available time, it is desirable to cause the operation of the timing cycle to be only slightly shorter than the time between two sequential activations of the switch 6.

The manually operated switch 20 with resistor 43 may be used for a fine manual adjustment if for any reason BEST AVAILABLE COPY such adjustment is required. The motor 64 then continues to operate as long as switch is closed resulting in the highest possible speed and thus in the highest possible amount of fresh treatment substance supplied for a number of cycles of the timing circuit.

Another possible arrangement for operating switch 6 or an equivalent thereof is shown in FIG. 3. As shown here in block diagram form, a length sensor 90 generates a length signal proportional to the length of strip material which has been processed. This signal is cumulatively stored in a storage 91. When the signal stored in the storage 91 exceeds a predetermined threshold value comparator 92 causes switch 6 or its equivalent, possibly an electrically operated switch, to be switched from the first to the second position causing the operating described in relationship to FIGS 1. and 2 above.

The storage means are conventional elements as for example an electromechanical signal storing unit described and illustrated in FIGS. 2 and 3 of our copending US. application 460,758 filed Feb. 6, 1965. The switch 32 of that unit corresponds to switch 6 of the present arrangement. The length sensor may for example be a simple switch, controlled by a spring biased lever extending into the path of the film.

While the invention has been illustrated and described as embodiment in a circuit using relays as switching elements, it is not intended to be limited to the details shown, since various modifications and circuit changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essenial characteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Arrangement for varying the quantity of fresh treatment substance applied to at least one elongated strip of material being transported in a direction along the length of said strip past a determined treatment location, as a function of the total strip surface area to which said treatment substance is to be applied, comprising in combination, scanning means for generating a width signal as a function of the total width of strip material being transported past said treatment location; driving means having a speed which varies as a function of said width signal generated by said scanning means; movable metering means for supplying fresh treatment substance for application to said elongated strip material, the quantity of treatment substance being furnished by said metering means varying as a function of the speed of movement of said metering means; and means for connecting said driving means to said metering means in such a manner that the speed of movement of said metering means varies in accordance with any variation of the driving speed of the driving means, whereby the amount of treatment substance applied by said metering means varies in proportion to any variation of the area of said strip being treated.

2. An arrangement as set forth in claim 1, wherein said metering means comprise a metering pump.

3. An arrangement as set forth in claim 1, wherein said driving means comprise a motor having a coil; and wherein the speed of said motor varies as a function of the current in said coil.

4. An arrangement as set forth in claim 3, wherein said motor is a direct current motor with permanent magnet excitation.

5, An arrangement as set forth in claim 4 also comprising a tachometer mounted on the shaft of said motor for regulating the speed of said motor.

6. An arrangement as set forth in claim 3 also comprising a voltage source having a first and second supply terminal; wherein said scanning means comprise a plurality of switching means arranged along the width of said strip of material being transported in a direction along the length of said strip in such a manner that the number of said switching means operated varies with the width of material being transported; wherein said switching means each have a first and second switching terminal; also comprising connecting means for connecting all of said first switching terminals to said first supply terminal; and further comprising additional connecting means for connecting all of said second switching terminals to said coil of said motor in such a manner that the current through said coil varies as a function of the number of said switching means which are operated.

7. An arrangement as set forth in claim 6 also comprising at least one resistor connected in series with each of said switching means.

8. An arrangement as set forth in claim 6 also comprising amplifier means connected between said switching means and said coil of said motor.

9. An arrangement as set forth in claim 8 wherein said amplifier means comprise a transistor stage.

10. An arrangement as set forth in claim 8 wherein said amplifier means comprise thyristors.

11. An arrangement as set forth in claim 6 also comprising means for generating a signal in proportion to the length of material which has been treated; also comprising first relay means connected to said switching means and said length signal generating means in such a manner that said length signal generating means is activated upon operation of any of said switching means.

12. An arrangement as set forth in claim 11 also comprising additional switching means having a stable first position and adapted to be switched to a second position upon activation; activating means for activating said additional switching means; and means coupling said activating means to the means transporting said strip of material upon activation of said first relay means.

13 An arrangement as set forth in claim 12 wherein said activating means comprise a cam; and wherein said coupling means comprise magnetic coupling means.

14. An arrangement as set forth in claim'12 also comprising a timing circuit for generating a timing signal for a specified time duration after receipt of a start signal; means for applying said timing signal to the coil of said motor in such a manner that said motor operates for the duration of said timing signal only; and wherein movement of said additional switching means from said second position to said first position generates said start signal.

15. An arrangement as set forth in claim 14 wherein said timing circuit comprises a timing capacitor; timing resistance means series connected to said timing capacitor; and means connecting the series connection of timing capacitor and timing resistance to said voltage source.

16. An arrangement as set forth in claim 15 also comprising means for discharging said timing capacitor upon termination of said specified time duration.

17. An arrangement as set forth in claim 16 also comrising timing relay means having a first and second pair of timing contacts; wherein said first pair of timing contacts is connected to the coil of said motor, thus constituting said means for applying said timing signal to said coil; wherein said second pair of timing contacts is connected to said timing capacitor in such a manner that closing of said pair of contacts causes discharge of said capacitor, said second pair of timing contacts thus constituting said means for discharging said timing capacitor; and wherein said first pair of timing contacts is adapted to open upon energization of said timing relay means and said second pair of timing contacts are adapted to close upon energization of said timing relay means.

18. An arrangement as set forth in claim 16 also com prising a capacitor connected to said voltage source when said additional switching means are in said first position;

BEST AVAILABLE COPY 7 additional relay means connected across said capacitor in such a manner that said relay becomes energized during discharge of said capacitor when said additional switching means are in said second position, said additional relay means having a first pair of additional relay contacts connected to said timing relay means in such a manner that said timing relay means are energized when said first pair of additional relay contacts is closed.

19. An arrangement as set forth in claim 17 also comprising a double base diode having an emitter connected to said timing capacitor, a first base connected to said first supply terminal; a second base, a resistance connected to said second base and to said second supply terminal; and thyristor means connected in series with said timing relay means, said thyristor having a control electrode connected to the second base of said double base diode and a main conducting path connected in parallel to said additional relay contact pair.

20. An arrangement as set forth in claim 18 also comprising a series connection of manually operated switching means and a further resistor, connected in parallel to said scanning means and associated resistors, operation of said manually operated switching means thus causing additional current to flow through the coil of said motor.

21. An arrangement as set forth in claim 19 also comprising means for furnishing snfiicient basic current to said coil of said motor to assure a minimum motor speed independent of said scanning means.

22. An arrangement as set forth in claim 20 also comprising means for stabilizing the voltage supplied by said voltage source.

23. An arrangement as set forth in claim 22 wherein said stabilizing means comprise Zener diodes.

24. An arrangement as set forth in claim 1 also comprising timing means for activating said driving means for a predetermined time period upon receipt of a drive signal; means for generating a length signal as a function of the length of material having been treated by said treatment substance; means for cumulatively storing said length signal thus furnishing a stored length signal; and means for generating said drive signal when said stored length signal attains a predetermined value.

25. An arrangement as set forth in claim 1 wherein said metering means comprise a diaphragm pump.

References Cited UNITED STATES PATENTS 4/1968 Zawiski ll8-8 X 4/1968 Clement 118-8 X US. Cl. X.R. 22276