U.S. patent number 3,786,479 [Application Number 05/154,581] was granted by the patent office on 1974-01-15 for video display system.
This patent grant is currently assigned to International Business Machines Corporation. Invention is credited to Caroll J. Brown, Donald J. Chesarek, Dale E. Fisk, Joseph T. Ma, Harold F. Martin, Zack D. Reynolds.
United States Patent |
3,786,479 |
Brown , et al. |
January 15, 1974 |
VIDEO DISPLAY SYSTEM
Abstract
A display system that uses a digital storage and processor
having stored therein a plurality of sources of binary coded
information representative of a plurality of display messages and
patterns. A graphic generator converts coded information into
analog stroke or painted display information. This stroke
information and/or asynchronous display information from other
sources is converted into television raster information which is
then cyclically stored on a magnetic disk, together with displays
from other synchronous noncoded and coded sources as well as live
television. A plurality of remote stations can select any display
information which is converted as necessary to raster video
information. These frames may be recorded on one or more tracks of
the magnetic disk. This information is then applied to the
television monitor at the station. The operator at the station can
then control the processing of the binary coded information and
request other display material while viewing the monitor and in
addition, can correlate portions of images on the CRT display with
the originating digitally controlled stroke information.
Furthermore, raster information of several selected tracks as well
as synchronized video from other sources can be compared and/or
mixed.
Inventors: |
Brown; Caroll J. (San Jose,
CA), Chesarek; Donald J. (Los Gatos, CA), Fisk; Dale
E. (San Jose, CA), Ma; Joseph T. (Los Gatos, CA),
Martin; Harold F. (Chappaqua, NY), Reynolds; Zack D.
(San Jose, CA) |
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
26851568 |
Appl.
No.: |
05/154,581 |
Filed: |
June 18, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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782154 |
Dec 9, 1968 |
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Current U.S.
Class: |
345/2.2;
345/530 |
Current CPC
Class: |
G09G
1/04 (20130101); G09G 5/393 (20130101); G06F
3/033 (20130101) |
Current International
Class: |
G09G
1/04 (20060101); G09G 5/36 (20060101); G09G
5/393 (20060101); G06F 3/033 (20060101); G06f
003/14 () |
Field of
Search: |
;178/6.6A,DIG.33,DIG.37
;340/324AD |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trafton; David L.
Attorney, Agent or Firm: Broidy; Thomas A.
Parent Case Text
PRIORITY
The present invention is a continuation of my copending application
Ser. No. 782,154 now abandoned, filed Dec. 9, 1968, and assigned to
the same assignee as this application.
Claims
We claim:
1. Display system comprising:
digital processing means including memory means having binary coded
information representative of a visual display;
converter means operative to convert said coded information into
non-coded television raster information that can be applied to a
television display device for producing a visual display
thereon;
cyclic storage means connected to said converter means for
cyclically storing said noncoded television raster information,
wherein said converter means includes generator means for
converting said coding information to non-coded display
information, and scan converter means synchronizing said non-coded
display information with said cyclic storage means;
television display means;
transducer means for manually identifying by XY coordinate signals
a portion on said display and means comparing the signals of said
generator means with the XY coordinate signals of said transducer
means; and
connecting means for selectively connecting said storage means and
said display means to regenerate said non-coded television raster
information and effect a continuous application thereof to the
visual display on said display means.
2. Display system as set forth in claim 1 wherein said portion of
said display is a rectangle determined by a pointer and preselected
coded boundary signals in said digital processing means.
3. Display apparatus as set forth in claim 1 wherein said memory
means includes a plurality of discrete binary information
representative of a plurality of visual displays,
wherein said cyclic storage means stores and cyclically regenerates
a plurality of noncoded information, and
means comparing the raster of one display with the raster of
another display.
4. A display system for digital and analog information, said system
comprising
a digital processor having a plurality of storage locations
therein, each of said storage locations having binary coded
information representative of a discrete image;
a graphic generator coupled to said digital processor for
transducing the binary coded information into X, Y, Z signals
capable of deflecting an electron beam;
scan converter means coupled to said graphic generator for
converting the X, Y, Z signals into television type raster
information of an analog or digital nature;
track selector means connected to the output of said scan converter
means;
magnetic storage means connected to the output of said track
selector means, said magnetic storage means having a plurality of
endless tracks formed thereon for storing and cyclically
regenerating raster information received from said scan converter
means;
a distribution network connected to an output of said magnetic
storage means;
and a plurality of television monitors coupled to said distribution
network for displaying the discrete image stored in said digital
processor.
5. The display system of claim 4 wherein at least one source of
beam directing and intensification or video information is coupled
to the input of the scan converter means; and
a selection of alternate video sources including a video tape
recorder, television camera, and film scanner are also provided,
said sources being coupled directly to the distribution network.
Description
BACKGROUND OF THE INVENTION
1. FIELD OF INVENTION
A display system wherein the displays originate from a digital
processor storage unit and other sources.
2. DESCRIPTION OF THE PRIOR ART
In computer display systems, binary-coded information is stored
which represents a particular message or pattern to be displayed on
a cathode ray tube. This binary information is decoded into a form
suitable to be applied to the display device such as an analog
signal to deflect an electron beam in a stroke type movement of an
electron beam. In order to regenerate the display, the
predetermined information is cyclically accessed and repeatedly
applied to the display. A plurality of displays are frequently
employed which have access by some remote means to the
processor.
The prior art display signals normally only emanate from one
source, that is, a computer or photographic slides or a tape
recorder, etc., since normally it is not feasible to accommodate
other sources.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a new and
improved display system having a central processing unit which can
originate and modify displayed information.
A further object of the invention is the provision of a new display
system for selectively applying image forming signals to a display
device wherein the digital display information in the computer or
files can be processed and changed without affecting the visual
image.
A still further object of the invention is to provide a new and
improved display system that has a high degree of flexibility, and
can accommodate various sources of displayable information.
Still another object of this invention is the provision of a new
and improved display system that can utilize various sources of
visual displays with a minimum of complexity at the display
station(s).
Still a further object of the invention is to provide a display
system that can identify a point or area on the display with a
minimum of interruption and/or computer processing time.
The above objects of the present invention are realized in one form
thereof by employing a computer based system which contains a
plurality of storage locations having binary information
representative of a plurality of displayable frames of messages or
patterns. This coded data is selectively converted to television
raster information which is then buffered and regenerated in this
noncoded form. This noncoded information is cyclically regenerated
to thereby provide a visually continuous display on a monitor. By
cyclically regenerating the noncoded information, the binary coded
information in the computer representing this display can be
processed, modified, compared, etc., without affecting the visual
display at the remote station.
As a further feature of the invention, a means is provided at the
remote station to generate XY information of a particular point on
the display. This information is compared with signals
corresponding to spatial coordinates which are provided at the
output of a graphic generator prior to scan conversion into raster
video form. In so doing, process time of the computer processor is
saved, and display signal regeneration is not interrupted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 contains a schematic diagram partially in block form of a
display system embodying the invention,
FIG. 2 illustrates a graphic generator together witha scan
converter suitable for use in the embodiment in FIG. 1,
FIG. 3 illustrates an electron beam deflection path, and
FIG. 4 illustrates a block diagram of a system suitable as a
coordinate compare.
GENERAL DESCRIPTION
The above objects of the present invention are accomplished by a
system connected to a digital storage and processor 10 that has a
plurality of storage locations containing binary coded information,
representing a plurality of separate images. Control means 20 can
be actuated by keyboard 100 or other suitable means to effect
movement of the data for an image to a graphic generator 30 which
transduces the binary coded information into X, Y and Z signals
which are capable of deflecting an electron beam to thereby provide
a stroke type display or pattern. This X, Y, Z information is
selectively applied to an electron beam type scan converter 40 or
50 which converts the X, Y, Z display information into television
type full frame formatted raster video information which can be a
time sequence of analog or digital signals. The output of the scan
converter is applied to a track selector 60 which then switches
this video information to a magnetic disk storage 70 having a
plurality of endless tracks thereon. Tracks of the magnetic storage
unit 70 are read out through a distribution network 80 to provide
raster displays by a plurality of remote television monitors such
as 90. Also, at the remote station and positioned adjacent to the
television monitor 90 is a coordinate identification means 110
which identifies XY locations of selected portions of the displayed
image provided by monitor 90. Other sources of images such as from
films or real scenes come from a scanner or television camera 150,
a video file or tape recorder 160, or a television camera 170.
When the signals are provided in noncoded video form (such as
analog) from the storage disk 70, they are regenerated and produce
a continuous visual display on the monitor such as 90. The
computer-derived display source is also simultaneously present in
coded form in the digital storage and processor 10. Thus, while the
image is being regenerated and viewed in noncoded form, the image
in coded form can be scanned and utilized or processed in the
digital processor 10. The coded image can be analyzed, compared,
modified, etc., while the displayed noncoded image is being viewed
without interruption. In addition, without interrupting this
viewing, the image in noncoded video form can also be compared
and/or coordinated with other images on the disk.
The magnetic disk storage 70 includes a clock track having clock
pulses thereon which develop horizontal and vertical raster sync.
Since the binary coded information is not being regenerated to
provide a regenerative display and since the readout of the scan
converter is synchronized with the sync signals from the storage
disk, the scan converters 40 and 50 can then be used, without
interrupting the display, to convert exterior asynchronous display
information to synchronous display information. Synchronous
exterior video sources can also be applied to the monitors or
records on the disk in response to the synchronizing pulses
developed from the clock pulses on the disk. The clock track can
have conventional vertical and horizontal television sync pulses
applied thereto for two video fields so that when using a
conventional monitor synchronization for 525 lines is provided. The
read out of the scan converters 40 and 50 is synchronized with the
clock pulses or sync pulses on the clock track.
DETAILED DESCRIPTION
The digital storage and processor 10 includes a plurality of frame
storage locations 11, 12 and 13, each of which contains binary
coded information representing a message and/or patterns for an
individual image shown as number 1, number 2 and number N,
respectively. As illustrated, the binary coded information is a
series of binary words with each word representing a letter or
numeral by way of an alphanumeric code. In these codes, such as
used with the IBM 2250 display, normally the words consist of six
to eight binary bits. When this information is applied to a
conventional graphic generator 30, the output thereof will be
analog X and Y signals (horizontal and vertical electron beam
deflection signals) as well as a Z signal (analog or digital beam
gating signal).
In addition, the storage locations 11, 12 and 13 could contain
images other than alphanumeric. In such a case, binary coded words
may represent end points of lines. These end points would then be
converted to X and Y (horizontal and vertical) analog deflection
signals that would deflect the electron beams from one end point to
another as well as Z or beam gating signals to enable proper
intensification of the beam. Other suitable generators that convert
binary coded information (of images) to displays are shown in U.S.
Pat. Nos. 3,334,304 and 3,205,488. Also see January 1961
Proceedings of IRE, pp. 185-195.
The operator at station S can effect, by way of keyboard 100,
commands from the subsystem control 20 to selectively transmit the
binary information for one image from location 11, 12, etc. to a
graphic generator 30.
The graphic generator 30 converts the binary-coded information to
analog X and Y deflection and Z gating or intensification
information that is suitable to deflect an electron beam in a
stroke type form such as is common in graphic displays and, as
illustrated in FIG. 3, (which provides an electron beam path of the
number seven by moving the beam from A to B). This stroke type
deflection is converted to television raster type information by
applying it to either a scan converter 40 or a scan converter
50.
FIG. 2, for purposes of clarity, sets forth in more detail a
conventional type graphic generator such as is employed to convert
binary coded display information into alphanumeric stroke
information. THe graphic generator 30, so illustrated, continuously
has digital X position information which is applied to a coarse D
to A converter 31 and Y position information which applies to a
coarse D to A converter 32. The output of converter 31 is applied
to an amplifier or yoke driver 33 and the output of converter 32 is
applied to an amplifier or yoke driver 34. Conventionally, the
coarse X information provides a signal representing the distance
from the sides of the display at which a character starts to be
written and the Y information indicates how far from the bottom or
the top of the display (which line) the start of the character
writing begins. Fine information is provided to a character
generator 35 which converts this binary coded information into fine
X and Y information analog and Z information which could be digital
or analog. Thus, if the binary fine information from the processor
indicates an A to be written, the character generator provides the
analog deflection signal for the X and Y deflection yokes,
necessary to write an A at or from the point determined by the X
and Y coarse information. The X fine analog signal is amplified by
amplifier 37 and combined with the coarse analog signal at point C.
The Y fine analog deflection signal is combined with the coarse
analog deflection signal at point D. Character generator 35
furthermore generates an intensity signal which passes through the
intensity amplifier 36 to vary the current of the electron beam by
varying the bias on a grid 41. If the display is to be digital this
signal will merely turn the electron beam on and off as is known
conventionally.
The typical scan converters 40 and 50 which are illustrated herein
may be a type of electron beam storage tube such as a television
camera or vidicon tube described in more detail in co-pending
application, Ser. No. 775,861, filed Nov. 14, 1968 in the name of
John W. Brookman, Johm B. Murphy, Zack D. Reynolds and entitled
"Photo Erasable Scan Converter" and assigned to the same assignee
as the present invention. This co-pending application describes a
television camera tube in which an electron beam is applied to the
target in a stroke fashion and then the target is read out in
raster form by the electron beam. Any suitable scan converter, such
as a storage tube, could be employed for the function defined
herein. For the purposes of illustration, the storage tube 40
includes a cathode 47, a grid 41 which could gate on or off the
electron beam or vary the intensity of the beam by the output of
the Z intensity amplifier 36. The coarse and fine X deflection
signal combined at point C is applied to the X deflection yoke 42.
The fine and coarse Y deflection signal combined at point D is
applied to the Y deflection yoke 43. During write, switches 46a and
46b are up.
Thus, the binary coded information defining one image is converted
by generator 30 to electron beam analog stroke information to
provide an image on target 44. During readout, switches 46a and 46b
are down and the yokes 42 and 43 are deflected in the conventional
raster mode by deflection circuits 46 so that the target 44
develops at the output 45 a typical raster or television type
signal. The output of the scan converter 40 or 50 is selectively
applied to a cyclic storage means such as a magnetic disk 70 by way
of a channel selector 60.
The track selector 60 selectively applies the raster information
from either scan converter 40 or 50 to one of the plurality of
magnetic tracks TR1 through TRN by way of magnetic heads 71 through
71N. The magnetic disk 72 is rotated at 1,800 rpm so that each
rotation of the disk takes the time normally used or elapsed for
the recording or playing back of one video frame (two interlaced
video fields). The disk can be rotated at 3,600 rpm so that the
time for one rotation of the disk is equal to the time required for
one video field. In such a case, two tracks would have to be
utilized to provide one video frame by alternately switching
between these tracks.
A separate track TRC is employed on the disk 72 with this track
containing vertical and horizontal synchronizing pulses required
for one video frame. In a conventional television system, this
would require 525 horizontal sync pulses and two vertical sync
pulses. The signal on the track TRC is either the required number
of the sync pulses, horizontal and vertical (for one frame) or
conventionally a multiple of pulses are recorded with the frequency
divided down by a sync generator 74 to provide the required number
of vertical and horizontal sync pulses.
When the actual horizontal and vertical sync pulses are recorded,
the sync generator 74 is not needed but rather the output of head
73 is connected directly to the circuits 46 of scan converters 40
and 50 so as to provide proper synchronization of the horizontal
and vertical raster circuits 46 shown in FIG. 2. In addition, the
head 73 would also be directly connected to the distribution
network 80 where the sync signals will be added to the video
information from any of the tracks TR1 through TRN. Alternatively,
two tracks may be employed for the synchronization function of TRC,
one with horizontal sync pulses and one with vertical sync pulses.
Sync pulses are made available for other sources 150, 160 and 170
to provide a synchronous input directly into the track selector 60.
Alternatively, the clock track TRC could contain a multiple number
of clock pulses which, when divided down, will produce 525
horizontal sync pulses and two vertical sync pulses. This division
occurs in the sync generator 74 and operates in the same fashion as
is done for developing sync pulses for a conventional television
camera. An example would be that the clock track contained 6,300
pulses with this output being divided by 12 to produce 525
horizontal pulses and divided by 3,150 to produce two vertical sync
pulses. The magnetic head 73 is employed to record these pulses and
thereafter reads these pulses out (when appropriate) to a sync
generator 74 which divides the frequency of the pulses down to
provide both the horizontal and vertical synchronization
pulses.
Recording a different number of pulses on TRC and dividing by
different numbers in the sync generator 74 will allow television
displays having other than 525 lines to be generated. This could be
down to generate displays compatible with 873 line closed-circuit
television monitors, for example.
It will be understood that the video information applied to the
tracks TR1 through TRN could be applied on a carrier such as an FM
carrier and then recorded on disk 72. Such a suitable selector 60
and FM recording is illustrated in co-pending application Ser. No.
682,432 filed Nov. 13, 1967 in the name of J. L. Adkisson and A. B.
Manildi. On readout, an FM demodulator is used to drive the video
signal.
The heads 71 through 71N are always connected to a distribution
network. In so doing, the video information is applied through the
network 80 to a monitor such as 90, even during writing or
recording so as to provide a non-interrupted display drive. A
display selection can be accomplished by way of the keyboard
terminal 100 which is connected to the subsystem control 20 to
thereby command the readout of one of the storage locations 11
through 13 to the graphic generator 30, or to select an alternative
input such as 150, 160 or 170.
Since the magnetic disk storage 70 regenerates to produce a
continuous display on the monitors such as 90, other auxiliary
displays can more easily be provided in the system such as
photographic file 151 which can be picked up by a scanner or TV
camera 150. Furthermore, a TV camera 170 can provide live
information for displays. Both 150 and 170 can be connected to a
video file or tape recorder 160 or alternately to one of the scan
converters 40 or 50 in asynchronous mode; in a synchronous mode,
they may be connected directly to channel selector 60, thence to
disk storage 70, and directly to distribution 80 for displaying
continuously scanned information. When transducers 150, 160 and 170
are connected to the scan converters 40 or 50 in asynchronous mode
the horizontal and vertical sync pulses from generator 74 are
employed to provide synchronous readout therefrom.
Thus, it is seen that in a conventional type display, the binary
coded information in the computer is normally directly converted
into either stroke or video raster information and applied to a
monitor. As such, the only video displays possible from any storage
or regenerating means must come from the computer. In the present
invention, however, it is seen that the binary coded information is
converted first into a stroke image and then by using the scan
converter, it is converted into raster information. As stated
above, these scan converters are read out in synchronism with the
sync pulses on the cyclic storage means such as disk 72. Thus, it
is seen that by utilizing this double transformation of the image,
it is possible and easily adaptable to include in the system
virtually any asynchronous display source by applying it to the
input of the scan converter. Furthermore, synchronous raster
information can be applied directly to the channel selectors and
this image information can come also from virtually any source of
raster information. It will be understood, of course, that this
noncoded raster information can be analog in form similar to a
conventional television signal and also can be digital display
information where only on and off information on the electron beam
provides the display. Furthermore, it will be understood that this
noncoded information could be applied to a carrier such as by
frequency modulating the carrier in a conventional manner. In such
a case, demodulators would be present in the distribution system
80.
It will be noted that a single record and read head is employed for
each track so that during recording the information will continue
to be supplied to the monitor connected to that particular
channel.
As stated above, vertical and horizontal sync pulses are applied
either to a single track or two tracks on the disk 72. Normally,
coded signals for a single binary coded display message or pattern
are applied to the graphic generator and the resulting XYZ signals
are applied to a scan converter, so that a single frame will be
read out from the scan converter through the channel selector 60
onto the disk 72 when actuated by the vertical and horizontal sync
pulses from track TRC. Asynchronous sources are normally applied to
a scan converter for conversion to a synchronous output and to
accommodate differing resolutions, field sizes and types of scan.
They may then be applied through track selector 60 for direct
recording on the disk. In this case, either the vertical sync
pulses or a single home pulse on disk 72 can be applied to gate
these inputs so that signals corresponding to only a single frame
will be recorded on the tracks 71 through 71N.
An additional feature is that by regenerating the raster
information on disk 72 in the form described above, relatively
inexpensive television monitors can be employed, resulting in a
relatively large cost saving when a number of output channels or
stations are in the system.
The XY locator 110 provides two digital output signals which
represent the XY position of a pointer 113 on a tablet 114. Various
conventional means can be employed to produce the desired XY
signals. Such an example is illustrated in U.S. Pat. No. 3,399,401
in which a tablet is employed which does not overlay the display
but rather is below or to one side of the display. In such a case,
coordinates on the tablet 114 correspond to coordinates on the
display. The details of such a system will not be shown, but for
purposes of illustration, a converter 111 is shown to develop
digital Y.sub.O coordinate signals from the pointer 113 and
converter 112 is shown to illustrate developing digital X.sub.O
coordinate signals from the signals from the pointer 113 and the
tablet 114. Any suitable system which would so produce binary or
digital X or Y coordinate signals in response to positioning of
pointer 113 can be employed.
In the system shown in U.S. Pat. No. 3,399,401, the tablet is not
transparent and thence cannot overlay the display. If it is desired
to have a system wherein the identifying area overlays the display,
such systems as illustrated in U.S. Pat. No. 2,338,949; 3,527,835
and 2,241,544 can be employed. These systems in general utilize two
pairs of plates in the X and Y direction across which an AC signal
is employed. A pointer is employed on the display, and the
resulting AC output signals from the system which varies as the
pointer is moved, can be rectified and converted to an analog
signal which subsequently can be converted to digital signals to
provide XY digital coordinate signals. This XY digital information
from locator 110 is selectively applied to a coordinate compare
140. The other input to the compare 140 selectively is the XY
generator 30. Thus, the operator can regenerate the information in
the graphic generator 30, and compare it with the point selected by
pointer 113 in the coordinate compare 140. When coincidences of the
X and Y signals occur simultaneously, an output is provided which,
by way of proper timing or clocking, identifies this point within
the subsystem control 20.
More specifically, when the difference or distance, between the XY
position signals from graphic generator 30 and the corresponding X
.sub.O Y.sub.O signals from pointer 113 are within a selected
range, coincidence is recognized. A means is provided either in the
unit 10 or unit 20 to indicate the range of coincidence. This
comparison can either be done in an analog form or digital form. As
a particular example, if the comparison, in fact, is done digitally
in the compare unit 140, the X.sub.O Y.sub.0 signals from pointer
113 (if not in digital form originally) would be passed through
analog to digital converters, the output being the contents of one
register containing the X.sub.O position and one register
containing the Y.sub.O position. Likewise, the X and Y information
from generator 30 would be passed through analog to digital
converters to provide at the output thereof an X position and a Y
position. THe contents of these converters, of course, would be
dynamic and change as the output of generator 30 changes. When the
magnitude of the difference between X and X.sub.O and between Y and
Y.sub.O is less than a value established by coded limits from the
digital storage and processor 10, a coincidence true condition is
established. When coincidence is detected, either the position
registers from graphic generator 30 could be stopped or the binary
coded display information to the graphic generator could be
interpreted so as to locate the position of the particular code or
step within the stream of data and orders which initiated the X, Y
position placement. Additionally, the X, Y coordinate position at
coincidence could be obtained from XY registers of 30.
The multiplex means 130 is employed to selectively apply the
signals from pencils such as 110 at a plurality of display
stations, to the coordinate compare circuit 140.
FIGS. 3 and 4 illustrate a method of comparing the coordinates
identified by the pointer 113 and the output of the graphic
generator 30. In FIGS. 3 and 4, the computer is adjusted so as to
determine if a stroke from a graphic generator goes through the
window W shown in dotted lines in FIG. 3. To this end the signals
from the pointer 113 and tablet 114 are passed through converters
111 and 112 to provide binary signals representing X.sub.O and
Y.sub.O, the position of pointer 113. Alternatively, pens,
pointers, or teaching devices with direct digital output may be
used. The digital processor provides a selected window by providing
arithmetic unit 141 with, as shown, -.DELTA.X+.DELTA.X, -.DELTA.Y
and +.DELTA.Y. The -.DELTA.X is added to the X.sub.O to provide an
X.sub.L coordinate output as shown in FIG. 3. The +.DELTA.X is
added to the X.sub.O to provide a binary X.sub.R output. The
-.DELTA.Y is added to the Y.sub.O to provide a Y.sub.L binary
coordinate output. The +.DELTA.Y is added to the Y.sub.O to provide
a Y.sub.U output. These coordinates are representative of the
boundaries of the window W as shown in FIG. 3, as illustrated
therein in dotted lines. The X deflection applied to deflection
coils 42, during compare, is applied to an A to D converter 144
which provides a binary indication of the horizontal coordinate of
the electron beam in converter 40. X.sub.L, X.sub.R and the output
of A to D converter 144 are applied to an arithmetic unit 142. This
unit has a one output when X is larger than X.sub.L and smaller
than X.sub.R. The output of this unit is then applied to AND gate
146.
Point D is connected to A to D converter 145 so that Y deflection
current applied to coils 43 of converter 40 provides a binary
indication of the vertical deflection of the electron beam in
converter 40. The Y.sub.L, Y.sub.U outputs of unit 141 are applied
to an arithmetic unit 143. Likewise, the output of A to D converter
145 shown as Y is applied to unit 143. When Y is larger than
Y.sub.L but smaller than Y.sub.U, there will be one output from
143.
A variation of the preferred method is to convert X.sub.L, X.sub.R,
Y.sub.L, and Y.sub.U to analog voltages by using digital to analog
converters after the arithmetic function 141, while eliminating
analog to digital converters 144 and 145. In this case, the compare
functions 142 and 143 are accomplished with analog threshold
circuits. As used in a binary mode so that the beam is either off
or on, the output of Z amplifier 36 is also applied to AND gate
146. Thus, if units 142 and 143 have a one output, the deflection
currents have directed the beam within the window W. When the beam
is on so that the Z input to 146 is also a one, the intensified
beam is passing through the window W. It will be understood that
this window W can be altered in many ways to provide various
functions. If shown as a square, it allows a predetermined
tolerance to identify a position of the beam. It could, for
example, however, by a horizontal line, by making .DELTA.+Y and
+.DELTA.Y both zero. Thus, the pointer 113 and the beam could be
moved up and down to effect a bountary indicator or a height
comparator.
When used as a window to provide tolerance in selecting a beam
trace, the output of the AND gate 146, as stated above, will be a
one when the beam passes through the window W. This output could,
for example, stop the reading out of the display information from
one of the locations 11 through 13 to thereby identify within the
computer exactly the program step which corresponds to where the
pointer 113 is pointed. Thusly, this identifies in the storage
location within the computer, the area of interest without
requiring any work done by or programming of the computer.
Alternatively, a counter in the subsystem control could be employed
to count the output words by bytes of the selected display location
11 through 13. When an output occurs from AnD gate 46, this output
would stop this counter which would identify the byte or bit within
the storage locations 11 through 13 that the pointer 113 has
identified. It will be understood that the multiplex means 130 has
not been shown in FIG. 4 for purposes of clarity. This, however,
would be located between the locator 110 or other digital
coordinate indication signal lines and the arithmetic unit 141
solely for switching purposes.
In addition to the other features, two channels can be connected
from the output of the distributon network 80 to compare these
channels in a raster compare unit 120. The compare unit 120 will
compare the signals of the two channels in analog or digital form
and by conventional logic will provide an output signal defining
the presence and/or magnitude of any difference between the
signals.
The subsystem control 20 can be actuated by the station keyboard
100 or processor so as to actuate and control various positions of
the system illustrated in FIG. 1. For example, this control system
is connected to graphic generator 30 so as to command the generator
to produce alphanumeric symbols as well as to produce displays from
data in locations 11, 12 or 13 by reading out from processor 10
into generator 30 and then to a scan converter 40 or 50.
Furthermore, the control 20 is connected to scanner 150 and
photographic file 151 to select a predetermined image on the film
151. Likewise, the subsystem control is connected to tape recorder
160, and television camera 170 to thereby select images from either
of these sources. The image selected from 150, 160, 170 can be, as
stated above, synchronous or asynchronous. Other portions of the
system controlled by the subsystem control 20 via commands of the
keyboard 100 are the switches S1 and S2 to select scan converter 40
and 50, the channel selector 60 to determine the channel selection,
the coordinate compare 140 to effect coordinate compare, and raster
compare 120. In providing coordinate compare, it will be understood
that normally the pointer 113 will be manually positioned at the
desired point and then the selected coded display from locations
11, 12, and 13 will be fed into the graphic generator 30.
OPERATION OF THE INVENTION
When the operator at the remote station S desires a particular
display, he actuates ths subsystem control 20 by way of a keyboard
100 which thereby selects an output from one of the storage
locations 11, 12 or 13 to be applied to the graphic generator 30.
These storage locations contain binary coded information
representing a display. This graphic generator generates XY stroke
type electron beam deflection signals and Z intensity or beam
gating signals from the binary coded information signals which are
then applied to the scan converter 40 or 50. While this stroke
information is applied to the scan converter, e.g., 40, as shown in
FIG. 2, switches 46a and 46b are up (and closed) applying
deflection signals from the graphic generator 30 to the pairs of
deflection coils 42 and 43. The amplifier 36 is connected to the
control grid 41 of the scan converter, which in the preferred
embodiment is a conventional vidicon tube 40 operating in darkness.
The Z information from 36 being applied to grid 41, gates on and
off the electron beam from cathode 47. It will be understood that
the Z information could be applied so as to gate the cathode 47
directly without being applied to the control grid 41. During
readout, the electron beam emanating from the cathode 47 of the
scan converter vidicon tube, sweeps the target 44 in the
conventional raster mode (as done with a conventional television
pickup). This provides a conventional television raster signal at
the output terminal 45. During readout, switches 46a and 46b are
down (and closed) so that the horizontal and vertical deflection
circuits 46 apply conventional raster deflection signals to the
pairs of deflection coils 42 (horizontal deflection) and coils 43
(vertical deflection).
It will be noted that, by utilizing the scan converters in this
system, various display sources 150, 160 and 170 can be fed into
the scan converter although they are asynchronous and may have
scans differing from the system output standard. The readout of the
converter then delays, synchronizes, and insures the correct
scanning sequence of the video signals, since the circuit 46 is
driven or synchronized by vertical or horizontal sync signals from
generator 74. Alternately, where feasible, the units 150, 160 and
170 can have their readout synchronously driven directly by the
sync signals from 74. In such a case, the outputs thereof are
applied directly to the distribution means or through track
selector 60 to the disk storage 70.
Commands from keyboard 100 to control 20 may directly or indirectly
via control programming select the scan converter (40 or 50) to be
utilized. In addition, commands from keyboard 100 to control 20
condition selector 60 to selectively apply the output of scan
converter 40 (or 50) to one of the tracks TR1 to TRN on disk 72
providing a display for monitor 90. Thus, it is seen that the
graphic generator 30 and the scan converter 40 and 50 are a means
to convert binary coded information from the processor 10 into
video raster information. This conversion could be achieved by
other translation techniques. Such a recording and switching (of
unit 60) is set forth in detail in the above co-pending application
Ser. No. 682,432.
After so recording, this frame of display information continues to
be regenerated on disk 72 and displayed on the CRT of monitor 90.
When the operator desired to process corresponding binary coded
information in CPU 10, he does so by way of keyboard 100 through
control 20 or by pen feedback using coordinate compare. This
information can thereby be modified processed within processor 10,
etc., without disturbing the displayed image as originally provided
by this coded information from 11, 12 or 13. This is in contrast to
other systems that recirculate the binary coded information in unit
10 or in an associated buffer memory to produce the display.
If the operator desires to locate a point on the display, he
employs the pointer 113 that develops X.sub.O Y.sub.O coordinate
signals of a point on the display. This signal is compared with
signals being generated from the graphic generator 30 in the
coordinate comparator 140. This enables identification of
intermediate points within displayed symbols or line segments not
represented by binary coded information in the processor, without
complicated processing within unit 10. As set forth above, it is
generally desirable to identify an area through which a portion of
a displayed construction passes, such as shown in FIG. 3, and
identified as W. The processor 10 provides digital signals
representing the dimensions of this area in -.DELTA.X, +.DELTA.X,
-.DELTA.Y and +.DELTA.Y. The pointer 113 provides digital X.sub.O
and Y.sub.0 information which specifies the position of area W and
which are added to the .DELTA.X and .DELTA.Y information to define
the sides of the window W identified in FIG. 3 as X.sub.L, X.sub.R,
Y.sub.U and Y.sub.L. When a trace of the beam on target 44 passes
through such a window, there is an output from AND gate 146 which
then can effect an indication of the position of the pen relative
to the displayable information, without the use of translation in
the processor 10. THis is made possible by comparing the
information from pointer 113 with the stroke information in the
generator 30. As stated above, the window W could be made various
sizes of a rectangle or even a line. Further, when identifying a
line element of the display, this window provides a programmable
tolerance limit.
While in accordance with the Patent Statutes, we have described
what at present is considered to be the preferred embodiment of our
invention, it will be obvious to those skilled in the art that
various changes or modifications may be made therein without
departing from the present invention.
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