DE3446531A1 - MEASURING HEAD - Google Patents

Description

Koenig & Bauer AG 'I'. I "\

Measuring head

pie invention relates to a measuring head for determining a Position of a body, in particular paper, preferably in a sheet-fed rotary printing press according to the preamble of claim 1.

Such measuring heads have become known, for example, from Dß-AS 2ü 46 602. With the measuring head described there, the machine speeds required today (15 - 20,000 sheets / hour) do not achieve the required measuring accuracy and measuring speed.

DE-PS 30 32 950 discloses a device for the metrological evaluation of video camera images for web edge control known. Such a device has too coarse a resolution and is too sluggish, so that it cannot be used to solve the problem at hand.

The invention is based on the object of a measuring head

to determine a position of an edge of a body

create, which gets by with a measuring time of approx. 10 msec

and with which a measuring accuracy of at least - / 100 mm can be achieved.

Particular advantages of the invention are in particular that this fast and sufficiently accurate measuring head in sheet-fed rotary printing machines can be used to determine the position of sheet edges. He can pull in side pull tags

Koenig & Bauer AG. "·.". ♦! .ΊΘ84-Ί · 2? -19

loose sheet infeeds from sheet-fed rotary printing machines as Measuring element-for actuators that move cylinders with gripping devices (known e.g. from DE-AS 20 46 602) or from on slides of sheet rotation _ gripping devices mounted on printing press cylinders can be used (known e.g. from DE-PS 28 08 528). The short measuring time of the measuring head according to the invention allows Maintaining a high degree of overlap (70%) when increasing the production speed from currently 15,000 sheets / hour to 20,000 sheets / hour or an increase in the degree of overlap significantly beyond 70%, and thus a further slowing down of the shingling speed and thus an even smoother run-up of the leading edge of the sheet the front lays and / or a longer calming phase of the sheet at the front lays.

The measuring device can advantageously also without optical system and can therefore be built in a very space-saving manner and therefore conveniently e.g. in a sheet metal sheet a sheet-fed rotary printing press.

In addition, the measuring device can be equipped with an electronic zero point shift, so that mechanical Saving adjusting and adjusting devices.

An embodiment of the invention is shown in the drawing and is described in more detail below. Show it:

Fig. 1 is a block diagram of the measuring head according to the invention,

2 shows a block diagram of a display unit according to the invention to display the measured values of the rfeßkopf,

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Koenig & Bauer AG. "..". - '.' 1584-12-19

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3 shows a representation of a generated by means of the CCD sensor Video signal when the sensor is partially covered,

Fig. 4 shows a measuring head (without light source) in plan view and in an enlarged view.

Fig. 5 Arrangement of the measuring device according to the invention, e.g. in a sheet-fed rotary printing press (in side view).

In FIG. 5, a measuring head 1 is installed, for example, in a feed table 2 of a sheet-fed rotary printing press. An infrared light source 3 is arranged above it, which emits an IR light with, for example, 750 nm and illuminates the measuring head 1. The measuring head 1 is covered by means of a scratch-resistant glass plate 6 towards the body to be measured, for example a piece of paper 4. Underneath is an infrared filter 5, which prevents the influence of external light in the daylight wave range spectrum. According to the invention, a CCD line sensor (charged coupled device) 11 is provided as the measuring element. CCD line sensors consist, for example, of 1728 picture elements arranged in a line. These picture elements are, for example, 10 µm 13 pm: a center-to-center distance between two picture elements is 10 ^ m. The CCD sensor 11 is, for example, 17.28 mm long and thus has 1728 picture elements, ie there are 100 measuring cells per millimeter.

The CCD line sensor 11 consists in a known manner of four interacting functional groups.

1. -Photosensitive area-

This area takes care of the light distribution

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available information. Br consists of 1728 photosensitive Image elements that are isolated from one another with the aid of a suitable stop diffusion. The picture elements do not need any control electrodes that would obstruct the incidence of light. The photons can reach the picture elements directly. Each picture element has an encompassing potential threshold from the other separated so that the charges cannot run into one another. The photosensitive area is on At the beginning and at the end through isolation areas, the length of which corresponds to 8 picture elements, as well as through 8 subsequent covered picture elements added. These deliver a black level current that is present in this Arrangement, however, is not evaluated.

2. -Integration area-

An integration element (memory) is assigned to each photosensitive element, which stores the photons generated electrons collects. At the end of the integration time, an applied pulse causes the charges passed to a shift register.

3. -shift register-

The charge packets are transported to the output circuit via two shift registers. Either of the two ... shift register has 879 elements. At the end of the shift register there is an output gate, which is the transition which enables charge packages to the following output levels.

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Koenig & Bauer AG. · *. ♦ ". - *. .'1904 * 12: -19

4. -Output levels-

Behind the output gates, at the end of two shift registers, there are two impedance converters combined with charge ad management provided - The incoming charge packets are converted into voltage pulses at the output in these output stages of the line sensor, which are proportional to the amount of charge of the charge packets.

The task of the block diagrams (Fig. 1, 2) shown The circuit according to the invention is:

- to supply the sensor with the necessary clock phases and voltages,

- to regulate the lighting source in order to ensure long-term stability,

- process the video signal,

- recognize the transition from dark to light,

- to create a measure for the position of the dark / light transition,

- digitally forward the position of the paper edge to a display device,

- to keep the zero point variable via a preselection switch and subtransfer,

- to display the measured value in decimal format with the aid of a numerical display,

- to ensure synchronization with the machine via external electronic or mechanical switches.

- all components with a power supply sufficient to supply.

- to forward the measured values to an external computer or actuators via an interface.

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Koenig & Bauer AG __ · * ".. **. · Ί."% 984-Ί »3-19

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If, for example, a sheet-fed rotary printing press is now supposed to be 20,000 Sheets per hour are fed, results from the fact that with one cylinder revolution per sheet 180 msec, available stand, which corresponds to a time of 0.5 msec / degree. If, for example, a sheet shifter is to be used instead of the well-known sideload, so stand at a sheet speed of 20,000 sheets / hour. only measurement times in the order of 10 msec available.

During a measuring time of 10 msec, in the invention Embodiment run through 2.5 series of measurements for safety reasons, i.e. within 4 msec, 1728 Run through readout, 32 reference and 288 spaces. This means a frequency of 512 kHz. One clock frequency 0T of an oscillator 9 is 1.024 MHz. Other specifications are possible.

The complex measuring process of the measuring device according to the invention is described in principle on the basis of the block diagram (FIG. 1). A CCD sensor 11 of the measuring head 1 (entire FIG. 1) is operated continuously at a measuring rate of 250 Hz. (= 4 msec.). The oscillator 9, a clock processor 12, a driver module 13 and a CCD supply 14 supply the CCD sensor 11 with all the necessary clocks 0T, 0X _t 0R and voltages Vpg, Vei, Vt. For example, a machine sync pulse 0EX reaches a linkage logic module 18 via a light barrier. Via the linkage logic module 18, a count of an 11-bit counter 19 is then obtained at the moment of a light / dark transition (see FIG. 3)

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CCD sensor 11 with partial coverage, e.g. by the sheet 4, which by means of a video amplifier 21 and a Precision Koinparator 26 is generated, transferred to a memory and by means of a multiplexer 23, which is from a Binary counter 24 is controlled, transmitted to a display device 32 (Fig. 2). A transmission rate is e.g. 3. 6500 bit / s.

The clock signals 0T, 0X, 0R required for the CCD sensor 11 are, as already mentioned, continuously generated in the clock processor 12 and transmitted to a CCD driver 13 and converted there to a desired level, for example CMOS level. 01, 0X, 0R are clock signals (Rechteckirapulse) of different frequency, they are out of phase with one another, being denoted by the transport 0T clock signal with 0X, the transfer clock signal and with 0R the reset clock signal.

The 0X signal is sent to the transfer gate of the CCD sensor 11 to move the accumulated charge from the image sensor elements to the transport shift register.

If the signal 0T is applied to the corresponding gate of the CCD sensor 11, transport shift registers for moving the charge packs from the individual image sensor elements to the charge detector / amplifier (= charge-voltage sumse tzer) are activated in it.

The reset signal 0R is required to switch the counters 10, 19 and CCD sensor 11 to zero.

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Koenig & Bauer AG

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Clock signals 0Ύ and 0R are fed to a forward counter 10, for example a 4-bit counter. After a certain number of lead pulses, this switches the clock pulses 0T through as switched pulses 0TH to a main counter 19 (= 11-bit counter). After 2048 0TH pulses, the main counter 19 emits a set pulse 0S to the clock processing stage 12, in which it is used for. Reset pulse 0R is converted. This reset pulse 0R therefore cyclically sets the _{forward counter 10 and the main counter 19 to zero f} as well as the CCD sensor 11. The main counter 19 continuously transmits its counter reading ZS to a digital memory 22. 0T pulses are also sent from the clock processing stage 12 to the synchronization stage 18. The combination logic stage 18, designed as a synchronization stage, has the task of generating a memory transfer pulse 0h from the pulses 0T, 0Z and 0EX and delivering it to the memory 22.

The current-amplified pulses 0T, 0X and 0R in the driver stage 13 reach the CCD sensor 11. The supply voltages Vpg, Vei and Vt are generated by a CCD supply 14 and fed to the CCD sensor 11.

As shown in FIG. 3, the position of a body edge, for example a sheet edge 29, on the CCD sensor 11 is measured between two transfer signals OX. As can be seen from the figure, the CCD sensor 11 emits an analog video signal V when illuminated by an IR radiator. The length and amplitude of this video signal V is a measure for

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Koenig & Bauer AG '":: **: .Jia6U-12« lS

3A46531

the position of a body edge to be measured e.g. sheet edge The video signal V becomes a signal in the amplifier 21 (Fig. 1) VA reinforced. This is then the comparator 26 and a control module 34 for controlling the illuminance of the IR emitter 3 supplied.

The comparator 26 is equipped with at least one upper and lower adjustable switching threshold for the video signal VA and delivers a digital pulse 07, which is fed to the synchronization module 18, when the set lower video signal level is exceeded during the light / dark transition, i.e. when the CCD sensor 11 is partially covered will. In the synchronization module 18, the pulses 0Z, 0Ί and 0EX are processed into a transfer pulse 0L. This pulse 0h activates the memory 22, so that when there is an edge of the takeover pulse 0L, it takes over the current count at the main counter 19 at that point in time into the memory 22. The counter reading is output from the memory 22 to a display unit 32 by means of the multiplexer 23, which is controlled via a 4-bit binary counter 24 (entire FIG. 2).

The CCD sensor 11 is, as already mentioned, from an infrared light source 3 irradiated. It is arranged above the sensor 11 at a small distance. Since the sensor 11 A control module 34 is sensitive to changes in illuminance and temperature fluctuations provided for regulating the illuminance of the light source 3. The voltage level is used as the actual value of the video signal V taken with an adjustable,

Koenig & Bauer AG ■ *** :: "*: * · Ί98 * 4— 12H * §

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a setpoint corresponding to a certain illuminance is compared. According to the rule deviation the illuminance is regulated by means of a control module 34.

The display device 32 (FIG. 2) has a preselection switch on. The zero point of the measuring system can be shifted by means of subtraction by means of the preselection switch 36. The setting value BCD value B corresponding to the preselection switch 36 is fed to a BCD / binary code converter 37. The from BCD value B converted into a binary value A is inverted and fed to a full adder 38.

The clock frequency 00 required for the data transmission is generated in an oscillator 39. The corresponding pulses 00 are fed to a demultiplexer 41 and a buffer store 42. The demultiplexer 41 generates a sync pulse 0Sy in order to achieve a phase equality of multiplexer 23 (in measuring head 1) and demultiplexer 41 in display unit 32. The data OM arriving serially from the multiplexer 23 (measuring head 1) at the demultiplexer 41 are separated into 16-bit in the demultiplexer 41 and sent as 0DE pulses to the buffer memory 42 and temporarily stored there. New data overwrite the old one.

In addition, the clock signals are generated in the demultiplexer 41 and fed to the 4-bit counter 24 of the measuring head 1. From the buffer memory 42 are pulses »jZfZW to the Full adder 38 delivered and added to the inverted binary value A of the preselection switch 36. Next, the Full adder 38 has a connection (interface) for one

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Calculator 40 on. The outgoing ones added in the full adder 38 · Binary pulses 0VO are converted into a binary / BCD code converter 43 and delivered by this as a 0BCD pulse to a multiplexer 45, which is controlled by an oscillator is driven. From the multiplexer 45 pulses 0MU reach a digital display device 46, on which the measured value corresponding value can be read.

Should a measurement via the measuring head 1 to a certain Point in time, an external synchronization pulse 0EX must be supplied to the measuring head from outside. as Pulse generator is suitable e.g. a forked IR light barrier, or a mechanical button.

Any zero point can be selected via the preselection switch 36 set or, for example, for sheet displacement processes in rotary rotary printing machines, any desired value for the location can be entered.

For the sake of simplicity, it has not been described that every signal or value V, VA or every pulse A, B, 0BCD, 0DE, 0EX, 0L, 0M, 0MU, 00, 0OS, 0R, 0S, 0Sy, 0SP, 0T, 0TA, 0TH, 0VO, 0ZW is each transported over a signal line of the same name.

The multiplexer 23 has an output 0M to which the signal line 0M is connected, the counter 24 has the Inputs 0Sy and 0TA, to which the signal lines 0Sy and 0TA are connected, the demultiplexer 41 has the Outputs'0TA, 0Sy and the input 0M to which the Signal lines 0TA, 0Sy and 0M are connected.

With a sheet transfer cylinder 47 is designated.

/ Parts list

Koenig & Bauer AG

Parts list ■ Measuring head ^ 26 Comparator • Curved edge 1 Feed table 27 2 Infrared light source 28 "3 arc 29 Display unit 4th Infrared filter 30th Infrared light source 5 Glass plate 31 Rule module 6th Curved edge 32 7th _ 33 Preselection switch δ oscillator 34 BCD / binary code converter 9 Flow counter 35 Impulse full adder 10 CCD sensor element 36 oscillator 11th Clock processing stage 37 computer 12th Driver stage 38 Demultiplexer 13th Power supply stage 39 Cache 14th 40 Binary / BCD code converter 15th 41 oscillator 16 42 multiplexer 17th Linkage logic level 43 Display device 18th Main counter 44 Sheet transfer cylinder 19th 45 20th Video amplifier stage 46 21 Storage level 47 22nd multiplexer 48 23 counter 49 24 50 25th

/ Claims

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Claims (1)

Koenig & Bauer ~ AG - **;: **; . ^ Expectations Electrical measuring head for detecting a position of a body, preferably an edge of a print carrier in a rotary printing machine, the measuring head cooperating with an evaluation unit, characterized in that that a CCD sensor element (11) is provided as the measuring element. Device for detecting the position of an edge of a body, preferably an edge of a print carrier in a rotary printing press, characterized in that a first oscillator (9) is in operative connection with a clock processing stage (12) via a data line (0T), that clock processing stage (12) via signal lines (0T, 0X, 0R) with a driver stage (13) via data lines (0T, 0R) with an advance counter (10) via a signal line (JZiT) "with a linkage logic stage (18) that the advance counter (10 ) via signal lines (0TH, 0R) with a main counter (19) and the clock processing stage (12) are operatively connected via a signal line (0S) that the main counter (19) and a memory stage (22) via a signal line (ZS) and the memory stage (22) via a signal line (0SP) with a multiplexer stage (23) is in operative connection that the driver stage (13) via signal lines (0T, 0X, 0R) with a CCD sensor (11) and this via signal lines (Vpg, Vei, COPY Koenig & Bauer AG **%. ", .Ziaeu-I?. ·"! & Vt) with a voltage supply stage (14) and via a signal line (V) with a video amplifier stage (21) is in operative connection that the video amplifier stage (21) via signal lines (VA) with a control module (34) and a comparator (26) and these via a signal line (0Z) to the logic logic stage (18) are in operative connection that the linkage logic level (18) via a signal line (0L) with the memory stage (22) is in operative connection that a third counter (24) is provided, which is in operative connection with the multiplexer (23) via signal lines (0Sy, 0TA) indicates that the logic stage (18) has an input (0EX) for an external switching pulse (0EX) has that the multiplexer (23) has a pulse output (0M) that the third counter (24) each has an input (0Sy and 0TA) for receiving synchronization (0Sy) and clock pulses (0TA). 3. L 'measuring head circuit according to claim 2, characterized in that that a display unit (32) is provided for evaluating the measured values (0M) of the measuring head (1). 4. measuring head circuit according to claim 2 and 3, characterized in that that the cooperating with her display unit (32) has a demultiplexer (41) which over a signal line (0DE) with a buffer stage (42) and with an oscillator (39) via a further signal line (00) is connected that the oscillator (39) via a signal line (00) with the COPY Koenig & Bauer AG .-. ·· .. "..:.". Intermediate storage stage (42) is operatively connected that a full adder (38) is provided that this full adder (38) over signal lines (0ZW; 0VO; A) with the intermediate storage stage (42), a binary y / BCD code converter (43) and a BCD-ZBinary code converter (37) is in operative connection that the binary-ZBCD code converter (43) via a signal line (0BCD) with a multiplexer (45) is in operative connection that the multiplexer (45) via signal lines (0OS, 0MU) in operative connection with an oscillator (44) and a display device (46) stands that an adjustable preselection switch (36) is provided, which is via a signal line (B) with the BCD-binary code converter (37) is in operative connection that the demultiplexer (41) has two outputs (0TA, 0Sy) and an input (0M) to the signal lines (0TA, 0Sy, 0M) as a connection can be connected to the measuring head (1). Measuring head according to the above claims, characterized in that an infrared radiator (3) is connected as the light source is used with an infrared filter (5) of the same wavelength. Rfeßkopf according to the above claims, characterized by a closed control circuit (34) for maintaining a uniform radiation intensity of the infrared radiator (3) by evaluating the voltage level of the video signal (V) of the CCD element (11).