DE1243434B - Apparatus for controlling the display of characters on the screen of a cathode ray tube - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G 06k

German KL: 42 m6-15 / 20

Number: 1243 434

File number: D 44539IX c / 42 m6

Filing date: May 27, 1964

Open date: June 29, 1967

The present invention relates to an apparatus for controlling the display of characters in a device System that converts the characters on a cathode ray tube from electronically derived character signals represents, with the desired characters corresponding video signals from a monoscopic tube can be removed by placing the cathode ray of the monoscopic tube one after the other in the areas the screen of the monoscope tube is controlled in which one of the characters is drawn, and thereafter vertical and horizontal scanning raster signals are supplied for scanning the characters, and wherein the video signals derived thereby together with vertical and horizontal scanning raster signals be placed on the cathode ray tube. The apparatus also contains a device for generating control signals on the basis of markings in the grid field around the boundaries of the scanned area.

At least two different devices are available for er ao generation of the video signals mentioned available. One device is a point light scanner and the other a monoscope tube. Each of these devices generates signals representing characters using a Cathode ray tube along with means that cause the cathode ray selected characters scans on a screen. The point light scanner uses a scanning light spot that passes through the electron beam of the cathode ray tube is generated, which on a phosphorescent Tubular screen impacts. The point of light is directed onto a screen, which is made up of areas of transparent and opaque areas, each area representing a character. By the Point of light is directed onto a selected area and the point scans this area Conveniently located photosensitive means develop video signals that identify the character in the area represent.

The monoscope tube consists of a cathode ray tube which has a secondary electron-emitting screen, such as an aluminum screen, in the form of a smooth sheet. The screen is covered with a substance, such as carbon, that does not emit secondary electrons. The carbon is removed so as to expose the underlying aluminum to the cathode ray in a pattern which is the shape of the character for which video signals are to be generated. Several or all of the characters for which video signals are desired can be displayed on the monoscopic screen. Deflection signals are applied to the monoscope tube in order to control the apparatus for controlling the display of
Characters on the screen one
cathode ray tube

Applicant:

A. B. Dick Company, Chicago, JIl. (V. St. A.)

Representative:

Dr.-Ing. H. Ruschke and Dipl.-Ing. H. Agular,

Patent Attorneys, Munich 27, Pienzenauer Str. 2

Named as inventor:

William Evan Evans,

Los Altos Hills, Calif. (V. St. A.)

Claimed priority:

V. St. v. America dated August 30, 1963 (305 879)

Electron beam in the area of the desired character, which is represented in a subsequent apparatus should be moving. Then, scanning raster signals are supplied to the monoscopic tube so as to the beam scans the sign. Emitted from the exposed aluminum during the scan Secondary electrons are collected and form the desired video signal.

When a cathode ray tube is used to display the characters that are in the monoscopic tube were scanned, the characters are usually in the form of words or numbers in a line that extends horizontally across the screen of the cathode ray tube. Since that Scanning grid in the tube producing the character (i.e. in the monoscopic tube or the point light scanner) and the scan pattern of the prior art display cathode ray tube should occur at the same time, there will be slight deviations when advancing the character generating scanning beam shown as corresponding positional deviations in the characters that can be represented by the cathode ray tube. Switching deviations that lead to deviations in the vertical arrangement of the characters shown are very easy to recognize as the eye can very easily determine whether the lower sections of a sequence of characters are printed in a or displayed message stand on a line.

709 608/206

3 4

Although a deviation of a few percent is given to provide an output that

(less than 10) in the vertical orientation when a vertical scan generator turns on to one

Representations is permitted, which mainly for the In- generated vertical raster scanning voltage to the cable

serve to transmit information, must be created in systems with a method ray tube.

where aesthetic quality is important, the 5 In the preferred embodiment disclosed

vertical alignment will be more accurate. the invention includes a monoscope tube to one

In addition to the exact vertical alignment of the display system. Of course, however represented characters, the aesthetic quality of the teachings of the invention may not apply to this type of a can be further improved by restricting the various symbol-generating tubes and the Sy symbol be arranged at a proportional distance io system to which it belongs does not need a representation, d. i.e., when different spaces are to be pro system, but can e.g. B. a printing system portional to be different to the width of the character. In the preferred embodiment Characters can be added along a line, as the objects of the invention are achieved by using a horizones is common in conventional printing. So taler guide bar as a reference mark below should z. B. along a line for the character "r" 15 pre-marked each character on a monoscope screen Space as will be seen for the character "i" and on similar ones. The apparatus arranges each character in the Wise more space for the character "R" than for the representation in vertical terms according to the character "R" should be provided. For a representation exact spacing (which is the same for all characters) high quality must be characterized by the width between the sign and its changes allowed, even if all associated guide bars are on the monoscope screen The characters to be served are of the same type. In addition, the device carries an entire are. If different types of writing are required, horizontal space for each character are turned, larger changes are made in proportion to the length of the guide bellows. In addition to differences in the overall kens that corresponds to the character on the monoscope width, which is ascribed to each drawing space, belongs to the screen, and adds left and right protection must For the best possible aesthetic quality, additional spaces are created that are altered by the relative arrangement Clear the sign and the guide bar in the left and right protective guards (Spacing) if the times are not symmetrical. The screen is available in a variety of Chen be admitted to split the focus of the areas, with each area first and Character with the focus of the character space 30 has second surfaces, which from the characters and to match. So should z. B. consist of the guide bar and a first second sign »L« have more protective space on the left than on the emission characteristic. A third have the right side. Area that covers the remainder of the screen area owns

From the USA patent specification 3,017,625 a Sy is a second secondary emission characteristic and around _:

stem for generating the video signals known at 35 gives the character and extends between the

however, the alignment and the proportional drawing area and the guide bar area. That

Arrangement of characters are not dealt with. Character scanning raster of the monoscope tube, which from

Furthermore, from U.S. Patent 2,624,798, a series of vertical scan lines is made up System known, which a marking sufficiently large, so that each scan of the monoscope shows with the help of which one of the character widths per tube beam is triggered in the third area and Portional arrangement can be achieved, but any scan line in the area of the guide bar is included character alignment is not given. kens extends. The grid of the performing Catho-

As a result, an object of this invention is a ray tube that is inconsistent with the mono price raster Arrangement that synchronizes the alignment of the telescope tube, but becomes instead chen improved, which by a cathode ray 45 a time signal, which de-tube from the monoscope tube displayed or printed and wrapped by one when the beam is from a face with Character generating cathode ray tube derived a first secondary emission characteristic on a are. Area with a second secondary emission character-

Another object of the present invention is to use ristics to turn each vertical sawtooth Means for scanning the scanning raster for the display of the to add different characters to trigger from a time cathode ray tube just before one The generating cathode ray tube recorded a series of video signals to control the beam and displayed by a cathode ray tube, the intensity of the reproduction from the monoscopic tube represents or can be printed. is produced. The time signal is taken from the video

Another object of the invention is to separate signals in a line by gate circuits that only

surface generating cathode ray device means, rend an initial portion of each vertical segment

which are assigned to each character, width and keying are switched on. The time signal appears

To save protection space information that this is not in the display, because the display grid is in

Signs concern. Answer to and therefore after its appearance

The stated objectives of the present invention 60 is triggered. This same time signal is applied to a

are achieved by an apparatus which is thereby given horizontal scanning raster generator to the

is characterized in that, in order to display the characters beam of the cathode ray tube horizontally

to be shown in an aligned arrangement, each to be moved in parts. As a result, the

of the character with an adjacent reference marking beam of the display tube moved by a distance,

tion is provided, which together with the line 65 is proportional to the length of the guide bar,

is scanned by the beam passing through and each displayed character is displayed vertically.

the scanning device is controlled to be time-based as the vertical alignment is controlled by the

pulse to generate the exact distance between the lower section on a gate circuit

of a character and the associated guide bar instead of through. Switching circuits is determined.

The novel features which are believed to be characteristic of the invention are particularly noted presented in the claims. The invention itself, both in its structure and in its Operation is best understood from the following description when taken in conjunction with the drawings be, where

F i g. Figure 1 shows, as an example, a monoscope screen and the scan path used to generate the word »THE« is required,

F i g. FIG. 2 shows a monoscope screen to which guide lines according to the first embodiment of FIG Invention added,

F i g. 3 is a schematic block diagram showing the manner in which the first embodiment the invention can be used in a system for producing and displaying characters,

F i g. 4 is a waveform diagram to aid in understanding the invention;

F i g. Figure 5 shows a monoscope screen in the guide bar according to a second embodiment are added to the invention, and

F i g. Fig. 6 is a schematic block diagram showing the manner in which the system apparatus the F i g. 3 can be modified to be used with the second embodiment of the invention to become.

F i g. Fig. 1 shows a monoscope screen and, as an example, the scanning of the characters used to form the Word "THE" are required for representation. The monoscope screen 10 has a number of Character areas, each area having character identity information in the form of an area, whose shape corresponds to the shape of the sign that is to be represented. It is believed, that the cathode ray of the monoscope tube is deflected over a path to select the characters "THE" which is represented by the line 14 drawn on the screen. Of the Cathode ray starts from some "rest" position and moves to a position to the left of the letter "T". There the beam is deflected to provide a small raster scan pattern. This consists of a fast linear saw tooth that moves the beam from the bottom to the top of the Character moves, and from a slow linear slope that moves the beam over the selected character moved from left to right. In current practice, the vertical deflection is the performing Cathode ray tube in exact synchronism with the vertical deflection in the monoscope tube. In this way, the scan on the monoscope screen 10 provides a representation as it does on the screen of the display cathode ray tube 16 in FIG. 1 is shown.

After the letter "T" has been scanned, the cathode ray is then deflected to scan the letter "H" and then the letter "E". Because according to the state of the art the scanning raster of both the monoscope and the display tube are in exact synchronism, any deviation in the arrangement or in the indexing of the monoscopic scanning raster in the Appearance. The most common difficulty lies in the vertical indexing of the scanning grid the monoscope tube, through which the orientation of the characters shown in the displaying tube becomes imprecise.

The exact alignment of the characters shown in the displaying tube is achieved by using the The scanning raster of the display tube is only triggered when the scanning raster of the monoscope tube is down is in a predetermined position relative to the scanned character, thereby compensating any switching deviations in the

ίο monoscope tube is brought about. So is according to a first embodiment as shown in FIG. 2, character position information is shown in the form relatively narrow lead lines 20, 22, 24 on the monoscope screen between the rows of characters intended. The vertical amplitude of the scanning raster is increased so that it is 20% larger than the largest vertical dimension of the characters, and the scanning grid is established by conventional indexing circuits arranged so that the lower

ao section of the grid always use the horizontal guide line crossed.

F i g. 3 is a schematic block diagram of a system using the first embodiment. There is only so much of the complete monoscope system for character generation and reproduction shown as is necessary for the skilled person. The input information for the system becomes a Data pulse source 30 removed.

The data pulse source includes a source of digital signals converted into analog deflection voltages can be converted, which are required to the electron beam of the monoscope tube to switch to a desired character position. The output of the data pulse source becomes given to switching circuits 32, which do the necessary conversion of the pulse signals into horizontal and make vertical deflection voltages for the electron beam of the monoscope tube. the Output signals of the switching circuits 32, which consist of the horizontal and vertical deflection signals exist are given to two adding circuits 34 and 36, respectively. On these adding circuits are also for a combination with the deflection signals the small raster signals from a small raster generator 38 given. This generator generates the necessary horizontal ones at the right time and vertical raster signals, whereby the raster scanning the character for the selected character is achieved. Thus, the horizontal and vertical raster signals in the respective adding circuits 34 and 36 are added to the corresponding horizontal and vertical deflection signals. the Output signals of the two adding circuits 34, 36 are applied to the corresponding deflection electrodes a monoscope tube 39 given. The required operating voltages for the monoscope tube are removed from high-voltage circuits 40, which are symbolically connected to the monoscope tube 39 are shown.

The video signal output from the monoscope tube is fed to a video amplifier 42. These signals are then applied to the cathode ray control electrode of a display cathode ray tube 44. As has been the practice up to now, the cathode ray of the tube 44 is passed through the horizontal and vertical deflection signals received by display format circuits 46 and also by the Generator 38 of the small grid can be generated. In

7 8

In the first embodiment, the horizontal deflection signals to be selected for a scan will be the letter "S" from the display format circuitry. As indicated above, the vertical amplitude gene 46 is added to the horizontal signals from the generator of the output voltage of the small raster generator 38 of the small raster in an adder circuit by about 20% greater than the largest vertical dimension 48. According to the prior art, there are 5 solution of the characters, whereby the lower portion of the vertical deflection signals, which are always given to the display grid, the horizontal guide line 20 crosses the cathode ray tube. The resulting video signal waveform output voltages of the adder circuit 50, which is shown in FIG. 4 at 64. Since the guide vertical deflection signals from the display line is relatively narrow, the signal mating circuits 46 and the vertical signals from io appear as a positive peak 64 A added directly in front of the drawing generator 38 of the small raster. The information. In a correctly working character output voltage of the corresponding adder generator, this peak will always occur in an initial circuitry 48 and 50 corresponding to the section (about the first 10%) of the vertical horizontal and vertical deflection electrodes of the scanning and can therefore be affected by the full- Display cathode ray tube 44 given. 15 continuous video signal through a correctly timed

The system shown so far in FIG. 3 described gate circuit can be separated. The timing

was, is the one that is currently used to represent the gate circuit z. B. from the verti-

derived from characters on the screen of a cathode ray return blanking pulse derived from the

tube is used. According to a first execution raster generator 38 is supplied. When the rear

Rungsform the development of this well-known Sy- 20 edge of this tip, which by the AND gate53

stems, the output signal of the video amplifier passes through it, is used to generate

except that it applies to the display cathode ray tube of each sawtooth of the vertical sawtooth scan signal,

for controlling the cathode ray supplied from the vertical scanning generator 54

also given to a gate circuit 53, which, as it is going to trigger, will then be a sequence of characters

also a signal from the generator of the small 25 on the screen of the display cathode ray tube

Raster, a synchronization or time display that is always precisely aligned, independent

signal 68 provides (Fig. 4). depending on the presence of small switching deviations

The gates can have all suitable positions in the monoscope.

lungs to perform the required function. 4 becomes the gate signal, which respectively. For example, a vertical return 30 is provided by the multivibrator 52 in FIG Blanking signal from generator 38 for dark waveform 66 is shown. The separated synchronism control of the scanning beam in its return sationssignal, which is used to trigger the generator obtained and differentiated by a network 51. 54 is used is shown in waveform 68 The output of the network 51 is set to mono. The output voltage of generator 54, stable multivibrator 52 connected to that of the 35 which is the vertical component of the small Dardifferentiated Reverse blanking signal energized, gate position grid includes, which respond to the display circuit signals supplies. This gate signal is given by the cathode ray tube are displayed on one input of an AND gate 53 waveform 70. Since there is no vertical deflection given two entrances. The other entrance to the display cathode ray tube in front of the signal of this AND gate consists of the output 40 occurrence of the synchronization signal 68 occurs, signal of the video amplifier 42. The output voltage does not become the component 64 ^ 4 in the video signal When using the multivibrator circuit, the switch-on is shown on the screen of the cathode ray tube, voltage for the AND gate 53, whereby the output only the video input voltage of the AND gate, which is derived from the characters themselves, only the synchronizing signals and no signals from the guide lines cation signals which by waveform 45 will therefore actually effect the display. 68 in FIG. 4 are shown. According to another, according to a second embodiment, a Possibility can be provided in place of a monostable multi-monoscope screen of the type shown in FIG. 5 vibrators is shown using a blocking oscillator circuit. The monoscope screen of FIG. 5 subordinate, separates from the screen of FIG. 2 basically there-

Triggered by such a synchronization 50 that the information stored on the screen

signal, a vertical scanning generator 54 generates a version not only for vertical alignment

tical scanning raster signal, which uses characters on the adding, but in addition to it

circuit 50 is given, in which it is used to the vertical, characters proportionally spaced

len deflection signal from the presentation format switch so that the signal for each character in a

services 46 is added. The output voltage of the 55 provided line of characters provided space one

Vertical scan generator 54 is used instead of the function of the width of the character. With others

tical output voltage of the generator 38 of the small- words means that, while the space that is created

used in a grid. long according to a line of displayed characters

For a better understanding of the operation of the first embodiment was available,

first embodiment is shown in FIG. 4 referenced, 60 was the same for each character, according to the second

the waveform represents which characters different from those in Fig. 3 embodiment

system shown have been removed. The sawtooth spaces along a displayed line of characters

60 represents the vertical scan signals occupying the generator.

38. Waveform 62 represents the horizontal The screen of FIG. 5 contains a number of

Scanning signals of the generator 38 of the small raster 65 character areas, which for the sake of simplicity in a

Now, when looking at FIG. 2, an assumed right-angled "4 * 4" matrix is arranged. so

men that the switching circuits have the horizontal, each line of characters no longer has a single one

len and vertical deflection signals have been supplied to guide line that goes under all characters in a

Line extends, but the screen of the F i g. 5 used a single guide bar for each character. Have the guide bars so used a length which is proportional to the space that should be added to the assigned character, when this is displayed, and the guide bars are arranged relative to the characters that they precisely define the left and right protective spaces. Each guide bar is at the exact distance below placed on the lower portion of its associated character, thereby aligning the characters is enabled according to the teachings of the first embodiment.

In particular, each drawing area consists of three different areas, so to speak. A first Area 80, shaped to identify a particular character, belongs to each area. the first surface has a first secondary emission characteristic. It should z. B. be assumed that the first surface consists of exposed aluminum. Under the information area that identifies the symbol 80 there is a second surface 82, which forms the aforementioned guide beam, which represents positional information for the character. The top edge of the guide bar surface 82 is located from the lower portion of the drawing surface 80 at a precise distance that the is the same for all drawing areas on the screen. The second surface 82 has the same secondary emission characteristics like the first surface 80. A third surface 84 encompasses the remainder of the screen surface, surrounds the drawing surface 80 and extends between the drawing surface 80 and the guide bar surface 82. The third surface can be regarded as a protective surface and has a secondary emission characteristic, which is different from that of surfaces 80 and 82. If z. For example, it is assumed that surfaces 80 and 82 are made of exposed aluminum exist, then the surface 84 can be formed by aluminum coated with carbon.

It should be noted that although the distance between face 82 and the lower edge of the drawing face 80 is identical in each drawing area, the lengths of areas 82 vary considerably by area to change area. So is the difference in length between the area 82 under the sign Pay attention to “k” and the “r” character. Also, the difference is in the length of the face 82 to be observed under the "r" and "R" characters. The lengths of the surfaces 82 are equal to that horizontal space along a displayed line of characters representing each guide bar face 82 assigned characters. The proportional arrangement is achieved by effecting becomes that the electron beam of the monoscope tube every scan of a character immediately to the left of the guide bar surface 82 triggers. It should be noted that the left end of the guide bar surface 82 is similarly arranged in each of the character areas. This is how the monoscope tube becomes provide no output as long as the beam is deflected vertically in the area 84 and not the guide bar surface 82 intersects. Only when the beam from the guide bar surface 82 into the Protective surface 84 passes over, the monoscope tube will provide an output signal. When using this Output signal to control the horizontal scanning generator connected to the display cathode ray tube is coupled, the imaging electron beam will only move in the horizontal direction for so long move as the guide bar surface 82 is scanned. When the right end of the guide beam face 82 is reached, the horizontal scan generator associated with the display cathode ray tube is paired, stop and wait for the next character to be scanned. To the characteristic of proportional Arrangement in the system of character generation and representation of FIG. 3 to be installed, the system device is modified by using the method shown in FIG. 3 part of the device outlined by dashed lines through the apparatus of FIG. 6 is replaced. In particular, instead of connecting the output of the video amplifier 42 directly to the AND gate 53 a polarized differentiating circuit 88 provided in between to give a signal to the AND gate 53, which the leaving of the upper Edge of the beam 82 through the beam. In addition, instead of the horizontal output of the To connect the small raster generator 38 to the adder circuit 48, a horizontal scanning generator 90 is provided. The horizontal scan generator 90 is triggered by the same synchronization signal, which comes from AND gate 53 and is used to trigger vertical scan generator 54. As a result, according to the second embodiment, the presentation format circuits 46 accordingly arrange the beam in the display cathode ray tube, which is then in the position is held until the vertical or horizontal scan generators 54 and 90 have been triggered. It it should be noted that, since the monoscopic tube beam scans each character area, it initially alone does the Surface 84 scans and then the guide bar surface 82 intersects. The beam becomes multiple scan lines in the protective surface 84 before crossing the drawing surface 80. During this period the display cathode ray tube is deflected, but nothing from the display cathode ray tube is displayed as the video amplifier 42 is no video signal on the CRT control electrode. The sign is from the Display tube displayed during those intervals in which the scan lines the drawing area 80 cut. Subsequent to these intervals, the monoscope electron beam is in turn over several Scan lines in the protective area 84 run without scanning the drawing area 80, and thereby the display electron beam move horizontally without applying a video signal to the display tube 44.

Claims (10)

Patent claims: 1. Apparatus for controlling the display of characters in a system which uses the characters a cathode ray tube of electronically derived character signals representing the desired Video signals corresponding to characters can be picked up from a monoscopic tube by the cathode ray of the monoscopic tube is steered successively into the areas of the screen of the monoscope tube in which one of the characters is predetermined, and then vertical and horizontal scanning raster signals for scanning of the characters are supplied, and the video signals derived thereby together with vertical and horizontal scanning raster 709 608/206 Signals are given to the cathode ray tube, with a device for generating Control signals based on markings in the grid to the boundaries of the scanned Range, characterized in that, to the characters shown in an aligned order, each character with an adjacent fiducial mark which is scanned together with the character by the beam, whichever is controlled by the scanning device (38) to generate a timing pulse (68) which to a gate circuit (53) to provide an output signal to a vertical scan generator (54) turns on to apply a generated vertical raster scanning voltage to the cathode ray tube (44) to be created. 2. Apparatus according to claim 1, characterized in that the reference mark has the shape of a has horizontal line (20) appearing on the screen ao of the monoscope tube (10) under each character is mapped out, in which they correct deviations when switching the monoscope tube target. 3. Apparatus according to claim 1 or 2, characterized in that the gate circuit (53) from an AND gate with a first input to which the time signals and the video signals are applied and a switch-on input to which a differentiating circuit (51) and this in turn a monostable flip-flop (52) are connected upstream from the vertical scanning raster signals to give derived switch-on signals to the switch-on input of the AND gate. 4. Apparatus according to claim 3, characterized in that the switch-on signals from the vertical retrace blanking pulses the scanning device (38) can be derived. 5. Apparatus according to claim 1, characterized in that the generating monoscope tube (10) a screen having a plurality of discrete areas thereon, in each of the areas a character and a reference mark are pre-drawn as character position information are. 6. Apparatus according to claim 5, characterized in that the scanning device (38) has a first vertical scanning raster generator, a first horizontal scanning raster generator and devices (34, 36) comprising the first vertical and horizontal scanning raster generators with the Coupling the character-producing monoscopic tube (39) so that the electron beam can scan lines tracked over one of the areas, and the cathode ray tube controller one a second vertical scan raster generator (54), a second horizontal scan raster generator (90), and Means (48, 50) comprising the second vertical and horizontal scan raster generators with the display cathode ray tube (44) so that the electron beam of the display Cathode ray tube crosses the selected position after each of the timing pulses. 7. Apparatus according to claims 5 and 6, characterized in that the characters and character position information are represented in each of the areas of the monoscope tube by areas (80, 82) which have a first secondary emission characteristic wherein the area (84) therebetween in each of the regions has a second secondary emission characteristic. 8. Apparatus according to claim 7, characterized in that the time pulse due to the transition of the scanning electron beam of the monoscope tube from a surface (82) with the first secondary emission characteristic to a surface (84) with the second secondary emission characteristic is developed during an initial portion of each successive crossing of that one of the areas. 9. Apparatus according to claim 7, characterized in that the first and second surfaces are separated by equal distances in each of the plurality of areas. 10. Apparatus according to any one of the preceding claims, characterized in that each Character has its own reference mark in the form of a line, the length of which depends on the width of the character depends. Considered publications:
German Auslegeschrift No. 1067 627;
U.S. Patent Nos. 2,624,798, 3,017,625. 1 sheet of drawings 709 608/206 6.67 © Bundesdruckerei Berlin