US3596284A - Electrographic apparatus employing plural inkers of different colors for separating signal levels or channels according to color - Google Patents

Abstract

An electrographic recorder is described which lays down a line of electrostatic charge on a charge retentive surface of a strip of electrographic recording paper. In one embodiment, the transverse position of the line charge image on the recording strip is representative of the amplitude of the signal being recorded. Plural inkers each dispensing a different color of charged pigment are arranged to ink charge images within separate strip-shaped zones of the recording strip. Thus, the inked electrostatic image will have a color dependent upon the amplitude range it happens to correspond to at any position taken longitudinally along the strip. The transverse position of the boundary between different colors is adjustable by sliding or pivoting the inkers, whereby the different colored amplitude ranges are made adjustable. In a second and third embodiment a multichannel recorder or printer is described wherein the signals corresponding to the different channels are each recorded in their own separate strip-shaped zone of the recording paper. Each separate recording zone has its own separate inker with pigment of a different color than that of its neighbors.

Description

United States Patent [72] Inventor Renn Zapbiropoulos Los Altos, Calif. 21 AppLNo. 871,706 [22] Filed Nov. 20, 1969 [45] Patented July 27, 1971 [73] Assignee Varian Associates Palo Alto, Calif. Continuation of application Ser. No. 612,540, Jan. 30, 1967, now abandoned.

[54] ELECTROGRAPHIC APPARATUS EMPLOYING PLURAL INKERS OF DIFFERENT COLORS FOR SEPARATING SIGNAL LEVELS 0R CHANNELS ACCORDING TO COLOR 4 Claims, 6 Drawing Figs.

[52] U.S. Cl 346/74, 101/1, 1l7/17.5, 118/637, 346/46 [51] Int. Cl Q01d 15/06, G01d 9/10, 603g 13/10 [56] References Cited UNlT ED STATES PATENTS 2,044,586 6/1936 Marcellus 346/46 2,143,376 H1939 Hansell..... 346/74X 3,270,349 8/1966 Murphy.... 346/46 3,277,493 10/1966 Fyler 346/74 3,383,699 5/1968 Lapinskia. 3,434,878 3/1969 Reis Primary Examiner Bernard Konick Assistant Examiner-Gary M. Hoffman Attorney-Leon F. Herbert ABSTRACT: An electrographic recorder is described which lays down a line of electrostatic charge on a charge retentive surface of a strip of electrographic recording paper. In one embodiment, the transverse position of the line charge image on the recording strip is representative of the amplitude of the signal being recorded. Plural inkers each dispensing a different color of charged pigment are arranged to ink charge images within separate strip-shaped zones of the recording strip. Thus, the inked electrostatic image will have a color dependent upon the amplitude range it happens to correspond to at any position taken longitudinally along the strip. The transverse position of the boundary between different colors is adjustable by sliding or pivoting the inkers, whereby the different colored amplitude ranges are made adjustable. In a second and third embodiment a multichannel recorder or printer is described wherein the signals corresponding to the different channels are each recorded in their own separate strip-shaped zone of the recording paper. Each separate recording zone has its own separate inker with pigment of a different color than that of its neighbors.

PATENTED JULZHQT: 3.596 284 FIG. 3

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INVENTOR.

REhN ZAPHIROPOULOS BY (ah ATTORNEY ELECTROGRAPIIIC APPARATUS EMPLOYING PLURAL INKERS OF DIFFERENT COLORS FOR SEPARATING SIGNAL LEVELS OF. CHANNELS ACCORDING TO COLOR This application is a continuation of application Ser. N 0. 612,540 filed Jan. 30, 1967, now abandoned.

DESCRIPTION OF THE PRIOR ART Heretofore, electrographic recorders have inked the charge image with one color of pigment regardless of its transverse position on the recording paper. It is desired to have an electrographic recorder that will change the color of the recorded trace when the signal falls below or exceeds a certain predetermined amplitude. For example, if the recorder is recording the temperature of some device it is desirable to have the trace appear one color such as green when it is within a normal operating range of temperature and to appear another color such as red when the temperature is outside the normal operating range.

Also, in multichannel recorders, where each recording channel is assigned a certain strip-shaped zone of the recording paper, it is desirable to have the recorded signals for the different channels recorded with a different color trace such that the different channels are more easily distinguished by an observer.

SUMMARY OF THE INVENTION The principal object of the present invention is the provision of 'an improved electrographic recorder or printer apparatus.

One feature of the present invention is the provision of an electrographic recorder or printer having two or more inkers dispensing charged pigment particles of difi'erent colors onto separate strip-shaped zones of the recording medium, whereby the charge images recorded within the separate strip zones of the recording medium are recorded in different colors. In one embodiment of the present invention, the color of a recorded signal can be made to change as the signal amplitude changes from one range of amplitudes to another range of amplitudes. In another embodiment of the present invention, separate signal channels can be allocated to separate strip-shaped zones of the recording medium for recording the signals of the separate. channels in different colors.

Another feature of the present invention is the same as that of the preceding feature wherein the boundary between adjacent inking strips is adjustable by adjusting the positions of the different inkers relative to the recording medium. In one embodiment of the present invention, this permits changing the range of amplitudes of the recorded signal or signals corresponding to each of the separate colors. Inthe multichannel recorder, it permits changing the width of the recording strip corresponding to each of the separate channels.

Other features and advantages of the present invention will become apparent upon a perusal of the following specification taken in connection with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. I is a schematic diagram of: an electrographic recorder employing features of the present invention,

FIG. 2 is a schematic diagram of an adjustable inker of the present invention,

FIG. 3 is a schematic diagram of an alternative embodiment of an adjustable inker,

FIG. 4 is a schematic diagram of another alternative embodiment of an adjustable inker,

FIG. 5 is a schematic diagram of an alternative recorder embodiment employing features of the present invention, and

FIG. 6 is a schematic diagram of a portion of a color image reproduction device employing features of the present invention.

. 2 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, there is shown an electrographic recorder 1 incorporating features of the present invention. An electrical input signal to be recorded is applied across a pair of input terminals 2 and 3. The input signal is fed to an error detector 4 wherein the input signal is compared with a reference voltage derived from a potentiometer 5 to produce an error or difference signal which is fed to an amplifier 6. The output of the amplifier 6 is fed to a reversible motor 7. The output shaft of the motor 7 drives the pickoff 8 of the potentiometer 5 via a mechanical linkage 9. A recording stylus 11 is coupled to the mechanical linkage 9 to move across a moving recording web 12 in variable accordance with the position of the pickoff electrode 8.

A writing electrical potential as of 800 volts relative to ground is applied to the writing stylus II. An isolating capacitor 13 separates the reference voltage from the writing voltage. The recording web 12 is, for example, an electrographic recording paper having a charge retentive dielectric film surface disposed adjacent the stylus 11 and a conductive paper backing in contact with a conductive plate 14 operating at ground potential.

The stylus 11 is, thus, caused to assume a transverse position (ordinate position along the 0 axis) on the recording web 12 corresponding to that reference voltage as picked otf the potentiometer 5 which just balances out the input signal to be recorded. Therefore, the ordinate position of the stylus 11 corresponds to the amplitude of the input signal. The web 12 is caused to move in the abscissa direction A in accordance with a function against which the input signal is to be measured. For example, if the input signal is to be measured against time, the web 12 may be pulled past the stylus in the A direction at some predetermined rate.

The Writing stylus ll deposits a line-type change image I5 upon the charge retentive surface of the web 12. A pair of inkers (pigment applicators) l6 and 17 are positioned over the web 12 to apply charged pigment particles to the charge images for development (inking) thereof. The inkers 16 and 17 may be of any one of a number of different types. For example, they may comprise hollow channel members having an open side adjacent the web 12 with powdered pigment being carried as a colloidal suspension in an air stream. The particles are attracted out of the suspension by electrostatic attraction to the charge images. In a preferred embodiment, the pigment particles are applied by an open sided channel containing a flow of charged pigment particles colloidally suspended in a liquid vehicle. The liquid is under less than atmospheric pressure such that the web is pressed up against the open side of the inking channel, sealing same. A suitable liquid inking channel is described and claimed in copending U.S-. Pat. application No. 577,443 filed Sept. 6, 1966, now U.S. Pat. No. 3,392,706 and assigned to the same assignee as that of the present invention.

The inking channels 16 and 17 contain different colored pigment particles and are arranged across the web 12 to ink separate strip shaped zones 18 and 19 of the web 12. Thus, that portion of the charge image which falls within zone 18 is inked in a first color such as, for example, red, whereas that portion of the charge image which falls within zone 19 is inked in a second color such as, for example, green. Since the zones 18 and 19 correspond to different amplitude ranges of the signal being recorded, the recording is in red when the amplitude of the signal being recorded exceeds some predetermined value corresponding to a line of demarcation 21 between the red and green zones 18 and 19, respectively. This is especially desirable for observation since it serves as a warning to the operator that the signal is above some predetermined range of value and this is readily apparent with only the most cursory observation of the recording.

17 across the web 12 to a new location which offsets the line of demarcation 21 relative to its original position.

FIG. 2 shows an inking system wherein the inkers 16 and 17 are movable as a unit transversely of the web 12 to change the position of the line of demarcation 21 between the red and green zones 18 and 19, respectively.

FIG. 3 shows an alternative arrangement for adjusting the line of demarcation 21. In this case, a partition member 22 which separates the inking chamber portions of the inking channels 16 and 17 is movable transversely of the web 12 to move the line of demarcation 21.

Referring now to FIG. 4, there is shown another alternative arrangement for adjusting the position of the line of demarcation 21 between the inking zones 18 and 19. In this case, the inking channels 16 and 17 are pivotable about points 23 and 24, respectively. The inkers 16 and 17 are each pivoted to positions which will cause them to sweep adjacent stripshaped zones 18 and 19 of the web 12. The line of demarcation 21 is defined by the boundary between the two zones 18 and 19.

Referring now to FIG. there is shown an alternative multichannel recorder embodiment of the present invention. In this case, two separate recorder channels 25 and 26, each similar to the recorder 1 of FIG. 1, are arranged within one recorder 27 to record their separate input signals upon separate strip-shaped zones 18 and 19 on a common recording web 12. Two inkers 16 and 17 are arranged to ink the charge images within the separate strip zones 18 and 19, respectively. Different colored pigments are employed in the separate inkers 16 and 17 such that each channel is recorded in a differentcolor, thereby facilitating separation of the recordings of the two separate channels.

Referring now to FIG. 6, there is shown another embodi ment of the present invention. More specifically, there is shown a portion of an electrostatic printing and inking structure of a color image reproduction apparatus employing electrographic techniques. The color reproduction apparatus is v described and claimed in copending U.S. Pat. application No.

612,471 filed Jan. 30, I967 now US. Pat. No. 3,523,l58 and assigned to the same assignee as the present invention. The color image reproducing device employs the separate channel inking feature of the present invention.

An array of fixed writing electrodes 31, only partially shown and greatly enlarged in scale, are arranged across the electrographic recording web 12 with the electrodes 31 having their ends disposed adjacent the charge retentive surface of the web 12. The electrodes 31 are insulated from each other and arranged in groups 32 of three (triads). The first electrode R in each triad 32 is connected to a red color sensing and print circuit, not shown. The second electrode G in each triad 32 is connected to a green color sensing and printing circuit, not shown. The third electrode B in each triad 32 is connected to a blue color sensing and printing circuit, not shown.

The sensing and printing circuits scan the color image to be reproduced line by line. Each circuit scans for its primary color content as the line is scanned. The respective color content signals are fed to the respective color printing electrodes R, G, or B. The electrodes 31 of the triads are selectively energized in accordance with the outputs of the three primary color circuits and cause line charge images to be deposited upon the moving web 12. The electrodes are scanned at a vary rapid rate compared to the re at which the web 12 moves past the electrodes 31. The line charge images are very narrow, i.e., or: the order of 0.001 inches wide and very closely spaced to each other, i.e., on the order of a 0.001 inches.

Three primary color inkers 33, 34 and 35 (red, green and blue) are spaced apart along the 'web 12 and each extends across the web 12. The inkers 33, 34 and 35 each include an array of inking slots 36, 37 and 38 cut through the sidewall of the inking channels 33-35 with each slot array being positioned in registration with the respective color printing electrode 31 and charge image 15 to be inked. The slots 36-38 have widths e ual to the widths of the charge ima es 15. Thus, the red inker 3 inks an array of narrow strip-s aped zones corresponding to all the red" charge images and no other, while the green inker 34 inks an array of narrow strip-shaped zones corresponding to only the green" charge images and the blue inker 35 inks an array of \narrow strip-shaped zones corresponding to only the blue" charge images. The result is that the color image to be reproduced is printed on the web 12. The resolution of the printed color image depends upon how narrow the charge image lines 15 can be made and how narrow the separate strip-shaped inking zones can be made. The inking channels 33,34 and 35 are preferably adjustable in position across the web 12 in order to bring the slots 36-38 into precise registration with the electrodes 31 and line charge images 15.

Since many changes could be made in the above construc tion and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in he accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

lclaim:

1. In an electrographic apparatus for providing a multicolored visible image on the charge retentive surface of a recording medium, the combination comprising:

electrode means for forming an electric charge image upon the charge retentive surface of the recording medium; means for moving the recording medium relative to the electrode means along a path of travel;

developing means including a first applicator portion and a second applicator portion spaced from the electrode means along the path of travel for exposing the charge image to pigment particles of a first and second color respectively to provide a multicolored visible image, each of the applicator portions being pivotally adjustable with respect to the recording medium to define adjustable developing widths for the first and second colors.

2. The apparatus of claim 1, wherein the electrode means is an array of metallic electrodes extending across the recording medium.

3. The apparatus of claim 1, wherein the first applicator portion is pivotal about a first axis proximate one edge of the recording medium and the second applicator portion is pivotal about a second axis proximate the other edge of the recording medium.

4. The apparatus of claim 3, wherein the applicator portions are pivotally secured together at a movable pivot point between the first and second axis.

Claims (4)

1. In an electrographic apparatus for providing a multicolored visible image on the charge retentive surface of a recording medium, the combination comprising: electrode means for forming an electric charge image upon the charge retentive surface of the recording medium; means for moving the recording medium relative to the electrode means along a path of travel; developing means including a first applicator portion and a second applicator portion spaced from the electrode means along the path of travel for exposing the charge image to pigment particles of a first and second color respectively to provide a multicolored visible image, each of the applicator portions being pivotally adjustable with respect to the recording medium to define adjustable developing widths for the first and second colors.

2. The apparatus of claim 1, wherein the electrode means is an array of metallic electrodes extending across the recording medium.

3. The apparatus of Claim 1, wherein the first applicator portion is pivotal about a first axis proximate one edge of the recording medium and the second applicator portion is pivotal about a second axis proximate the other edge of the recording medium.

4. The apparatus of claim 3, wherein the applicator portions are pivotally secured together at a movable pivot point between the first and second axis.

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