close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3041956

код для вставки
July 3, 1962
L. E. MULOCK ETAL‘
3,041,947
CATHODE RAY TUBE PRINTER
Filed NOV. 16, 1959
3 Sheets-Sheet 2
July 3, '1962
3,041,947
L. E. MULOCK ETAL
CATHODE RAY TUBE PRINTER
Filed Nov. 16, 1959
3 sheets-sheet 3
Wigwam?
C13
F.-
3
Q:£53
5.258
_
55
E2:
_|L|||_P52::35: 10Em
z530E‘
N
miE125%
_I5E 8J
_J_i|a5%3W.1l0.2I
\E::20
2;3%?5
J@2502:°
=
55
a
3
B?il?i?
tes Patent
Patented July 3, 1962
2
analog circuitry and the selection and de?ection circuitry
3,041,947
are exercised to the minimum and maximum limit of their
operation once for each frame of datato be recorded to
CATHODE RAY TUBE PRINTER
Lawrence E. Mulock, Endicott, N.Y., and Milton P.
‘check for proper functioning of the system.
A still further object of the present invention is to
Albert, University City, Mo., assignors to Interna
tional Business Machines Corporation, New York,
provide a cathode ray tube printer system wherein, once
for each frame of data to be recorded, there is unblanked
‘in each of‘two diametrically opposing corners of the
screen two characters having complementary codes which
This invention relates to a cathode ray tube printer 10 are scanned by photo cell means to determine if the
N.Y., a corporation of New York
'
Filed Nov. 16, 1959, Ser. No. 853,187
10 Claims. (CI. 95-45)
system is functioning properly.
and more particularly to an arrangement for providing
an automatic systems check of the printer.
The present invention is directed to a printer system
which functions to transform information from mag
netic tape into a character display on the face of a 15
The foregoing an dother objects, features and advan
tages of the invention will be apparent from the following
cathode ray tube.
ings.
This display is then photographed
more particular description of a preferred embodiment
of the invention, as illustrated in the accompanying draw
In the drawings:
of the displayed information. In a high speed printer
‘FIG. 1a is a block diagram showing the general ar
of this nature, it is extremely desirable to be able to
rangement of the system embodying the invention and
automatically check, at various intervals during the opera 20 including part of the logic circuitry for the limit check.
tion of the system, the operation of component circuits
‘FIG. 1b is a diagram of the remaining logic circuitry
on 35 millimeter micro?lm to make a permanent record
to assure that they are functioning properly. Of par
for the limit check feature as applied to the system shown
ticular interest in this regard are the selection and de
in FIG. 1a.
?ection circuits and the beam unblank control circuit.
FIG. 2 is a diagrammatic view of the tube screen
tIt is also advantageous to be able to check for drift of 25 showing the unblanked limit check squares.
power supplies for the analog circuits and the digital
FIG. 3 is a timing chart.
circuits and for phosphor deterioration on the tube face.
Referring to FIG. 1a, there is shown the general ar
In carrying out the above checking feature, the present
rangement of the printer system for transforming infor
mation from magnetic tape into a character display on
the face of a cathode ray tube. The tape reader 10'
‘which scans the digital data recorded on a magnetic tape
may be any convenient type of reader, such as, for ex
invention makes use of a novel limit check arrangement
which exercises the selection and de?ection circuitry of
the printer at their extreme limits of operation. During
each ?lm advance cycle, the de?ection circuits are ener
gized to cause the beam to de?ect to a position below the
lample, the well-known “IBM” type 729 Tape Reader.
‘right edge of the normal print area on the screen and
‘In the present instance, the information read from the
to a position above the left edge of the normal print area 35 tape is in a binary seven bit code pattern with each alpha
numeric character being expressed in the CBA 8421
code. For example, the character A would be recorded
on the screen so that all de?ection control circuits will
be checked. The selection circuits are also energized for
proper selection of two characters which have comple
mentary codes so that all selection control circuits are
checked. As a result, there is successively unblanked
in both the right bottom corner and the left upper corner
of the screen a blank code square as would occur'with
the beam aligned with an opaque square on the character
matrix so that no light reaches the screen and a retrieval
code square as would occur with the beam aligned with
a transparent square on the character matrix so that
on the tape and read as 1110001. From the tape reader
the input information is passed to any suitable type of
tape control unit or synchronizer 11 which acts as a
buffer storage between the tape unit and the printer. The
control unit shapes and stores the information bits from
the tape and interprets controls between the printer and
‘\tape unit, such as supplying the necessary delays for tapes
" to be reversed, stopped, etc.
From the tape control unit the information is gated
maximum light reaches the screen. A photo cell is located
opposite each corner to view the display to determine
if the above operations are satisfactorily completed. In
the event that any of the above operations fail, a limit 50
into a seven bit character register 12 and from the char
acter register, it is gated under control of a suitable dis~
tributor ring 13 and timing control unit 14 into a selection
check interlock trigger will be turned on to indicate that
registers 16. In a normal print operation, a print con- trol character will follow a signal character to set up to
the printer is not functioning properly.
Accordingly, the main object of the present invention
register 15 and the horizontal and vertical positioning
initiate printing.
The next two characters will deter
mine the horizontal position of the ?rst printed character,
5 UT the next two characters will determine the vertical posi
tion, and the ?fth character, through the selection regis
matically checking the operation of the system.
ter, will determine the alphanumeric character to be
A further object of the present invention is to provide
printed. Each subsequent character will print an alpha
a cathode ray tube printer system which functions to
numeric character, the horizontal register advancing one
transform digital input information into a'character dis
play on the face of the tube and then to photograph the 60 character posit-ion per character after the ?rst alpha
numeric character has been positioned. Subsequent
display on ?lm, the system being further provided with
is to provide an improved cathode ray tube printer sys
tem which is provided with an arrangement for auto
characters will be printed one per cycle, each character
being automatically positioned one space to the right
of the previous one, and printing will continue in this
fashion until the end of a line is signalled by a record
mark character. The character following a record mark
for automatically checking the selection and de?ection
is recognized as a control character which selects the
circuits, the digital and analog circuits, and the unblank
next line to be printed.
control circuit once for each frame of data to be re
The digital information in the selection register and in
corded.
the horizontal and vertical positioning registers is directed
A further object of the present invention is to provide 70 to respective digital-to-analog converters 17 and 18 which
‘a cathode ray tube printer system wherein the digital and > convert the parallel digital information to a correspond
means for checking the operation of the system once for
each frame of data to be recorded.
A still further object of the present invention is to
provide a cathode ray tube printer system having means 65
3,041,947
3
4
ing current for use in the selection de?ection yoke 19 and
the positioning de?ection yoke 20 of the cathode ray
tube 21. The system preferably makes use of digital-to
analog circuitry, such as is fully disclosed in US. Patent
may now be scanned by the tape reader 12. The read’
trigger is reset by the end-of-record signal from the
tape control unit indicating that a ?lm advance cycle
is about to take place, during which time there should
No. 2,810,860, to which reference may be had for com
be no scanning of the tape. ’
'
plete details of operation.
There has been brie?y described thus far the general
The cathode ray tube 21 is preferably of the image
operation of the printer system. The description to fol
forming type wherein a tungsten lamp 22 and condenser
low will be concerned with the novel limit checking ar
lens assembly 23 are used to illuminate an external matrix
rangement as applied to a system of the foregoing type.
array of symbols 24. The arrangement of the charac 10
As was previously mentioned, the primary function of
ters in the make-up of the letter chart on the matrix
limit check is to check all selection and positioning cir
follows in this case from the standard teletype code and
cuitry of the printer once each frame. It is accomplished
the use of binary stepped increments of horizontal and
in four steps during each ?lm advance cycle as follows:
vertical de?ection currents. The matrix is reduced by
(a) A blank code square is unblanked approximately
the lens 25 and focussed on the cathode ray tube photo 15 725 lines below the right edge of the normal print area
sensitive cathode 26 where the light images become cur
on the screen.
rent images. The photoelectrons liberated from the
(b) Approximately 453 microseconds later a blank
cathode when the matrix letter chart is projected on it
code square is unblanked approximately 7.25 lines above
are accelerated and focussed upon the plane of a select
the upper left edge of the normal print area on the screen.
ing aperture 27. The aperture size is such that one letter 20
(c) Approximately 453 microseconds after (b) a re
only from the array can pass through it at a time. The
trieval code square is unblanked in the same lower right
magnetic de?ection yoke coils 19 de?ect the entire elec
position as in (a).
tron-image stream for letter-by-letter selection. The sin
(d) Approximately 453 microseconds after (c) are
gle-letter portion of the electron stream emerging from
trieval code square is unblanked in the same upper left
the aperture enters the positioning and reproducing end 25 position as in (b).
of the tube. Here it passes axially through a metal cylin
Referring to FIGS. la and lb, ‘during a ?lm advance,
der 28, the potential of which is maintained a few volts
the camera contacts 37 will transfer and ‘a positive pulse
negative with respect to the aperture in order to sup
will be directed from the positive terminal 39 over line
press secondary emission. The cylinder 28 is under con
41 to an inverter 42 (FIG. 1b) and a 10 microsecond
trol of an unblank control circuit 29, to be described, and 30 single shot multivibrator 43 to start the limit check op
an unblank ampli?er 30 to selectively pass the letter beam
eration. The single shot output is transmitted by line
on to the high potential region where the positioning de
44 to the set side of a clock start trigger 45 and the out
?ection yoke coils 20 focus and position the letter on the
put line v46 from the “0” or set side of this trigger is a
aluminized phosphor screen 31. The reproduced letters
reset line which connects to the reset side of the last stage
may be displayed in lines and columns as desired.
35 T9 of a closed clock ring 47 through an AND switch
The data on the tube screen is photographically re
48. The clock ring 47, when in a reset condition, has
corded on 35 millimeter ?lm by a conventional recording
stage Tl turned on with an output being delivered from
camera 32. The system preferably makes use of a re
the output terminal 49 of stage T1. The setting of
cording camera, such as is fully disclosed in Manual No.
clock trigger 45 serves to disable the clock reset circuit
203, dated July 1, 1955, and published by the Instrumen 40 thereby conditioning the ring for operation. The reset
tation Branch, Edwards A.F.B., California, to which
line ‘46 is also connected to the reset side of a binary
reference may be had for complete details of operation.
It will sui?ce to say here that a drive motor M is con
nected through a magnetic clutch-brake to a gear train
trigger 50 and thus the binary trigger is also conditioned
for operation.
A 333 kc. crystal controlled oscillator
51 is stepped down to 167 kc. by the binary trigger 50,
which is the basic drive mechanism of the camera. This
the output of which now drives the 9 stage clock ring 6
gear train, in turn, drives the shutter, in-out feed sprock 45 microseconds per stage to deliver timed outputs T1
ets, the intermittent or frame positioning sprocket, and
through T9 at the output terminals to control the timing
the synchronizing cams. On continuous or cine opera
of the printer. As shown in FIG. 3, each printer clock
tion, ?lm may be fed at the rate of 16 frames per second.
cycle is 54 microseconds with the printer going through 36
The system may be programmed to give a ?lm advance at
clock cycles during the total limit check operation.
the end of a printed line or at the ?rst end-of-record
The limit check start line 44 is also connected to the
mark in that line. For example, referring to FIG. 1a,
set side of an LC'l trigger 52 to set this trigger simul
when an end-of-record mark is encountered on the tape
taneously with the starting of the clock. Triggers 53,
reader, a signal is emitted from the tape control 'unit 11
54 and 55 along with trigger 51 are arranged as an open
to set an end-of-record trigger 33. The positive output
55 ring and serve to provide timing controls for the pre
from the trigger 33 is switched at T5 clock cycle time,
to be later described, by an AND switch 34 to effect
the setting of a ?lm advance trigger 35. The positive out
put from the ?lm advance trigger turns on the camera
motor M to initiate a ?lm advancing cycle. The ‘camera
viously mentioned four steps which make up the limit
check operation. The open ring triggers may be origi
nally placed in a reset condition by closure of an initial
reset switch 56 which connects the reset side of the trig
gers to a positive potential terminal 57. This open
gear train drives a cam 36 which coacts with the center 60
timer ring along with the closed clock ring ‘47 form the
strap of transfer camera contacts 37. The normally
nucleus of the timing control circuitry ‘depicted by box
closed side of the camera contacts is connected to a'nega
14 on FIG. 1a. The setting of LCl trigger 52 raises
tive voltage terminal 38 whereas the normally open side
the potential of output line L1 and through the OR
is connected to a positive voltage terminal 39 and ap
proximately 70 milliseconds after the camera receives the 65 switches 58 and 59, the control lines Ll+L2 and Ll+L3
are also raised in potential. The rise on line L1+L2
impulse to feed ?lm, the contacts will transfer to close
is
passed through an OR switch 60 to an inverter 61 and
the positive side and will remain there during ?lm feed
the resulting inverter negative output is transmitted over
ing. After one frame of ?lm has been fed, the cam 36
line 62 to an AND switch 63 which in turn is connected
will transfer the camera contacts back to close the nega
to the reset side of the clock trigger 45. As a result,
tive side. The ?lm advance trigger 35 is reset upon
the clock trigger 45 is prevented from being reset at T3
closure of the negative'side of the camera contacts at
time 'of each clock cycle until after the limit check opera~
the end of each feed cycle and similarly, a read trig
tion has been completed.
ger 40 is set and the positive output from theread trig
ger is used to signal the tape control unit 11 that the
In ‘the beginning of the limit check operation, the
?lm feed has stopped and that another selection of tape 75 single shot multivibrator 43 was turned on and at that
3,041,947.
5
6
time, the multivibrator output was also passed through
output of which is fed to an AND switch 88. The AND
an OR switch 64 and an inverter-shaper 65 to turn on a
switch 88 is also fed from the limit check delay line 67,
the output line 89 from the set side of the horizontal
advance control trigger 69, and the T7 terminal of clock
400 microsecond single shot multivibrator 66. This mul
tivibrator functions as a limit check delay in that it de
lays the unblanking of the tube 400 microseconds to
allow an interval of time during which the selection and
positioning registers are set. The limit check delay out
put line 67, which has now been raised in potential, is
ring 47.
It Will be remembered that the horizontal ad- _
vance trigger 69 was set at T6 time of the 9th clock cycle
and hence, its output line 89 is up. At T1 time of the
10th clock cycle, the AND switch 89a (FIG. 1b) is ac
connected to an AND switch 68 and at T9 time of the
tivated to turn on the 400 microsecond limit check delay
?rst clock cycle, switch '68 is ‘activated to effect the re 10 single shot 66 and bring up the limit check delay line
setting of a horizontal advance control trigger 69 and
67. At T7 time, then, the AND switch 88 is gated to
an unblank control trigger 70. Referring to FIGS. 1a
sample the error checking circuit and to either set or
and 3, during the ?rst 8- clock cycles,, while the 400
not set a limit check interlock trigger 90, depending on
microsecond limit check delay multivibrator 66 is up and
the photo cell response. For the ?rst cycle of limit check
the LCl trigger 52 is on to maintain line L1 up, the
operation, ‘the timing control line L3 +L4 is down
selection register 15 is reset and the horizontal and po
and the high intensity beam checking circuit is inopera
sitioning registers 16 are set. As shown in FIG. 1a,
tive; however, the timing control line L1+L2 is up and
the timing control line Ll+L2 is connected to the reset
if photo cell 80 senses any amount of light at all, in
side of the selection register 15, thus setting this register
dicating that the beam was erroneously positioned,
at 000000 with the 7th check bit position of the letter 20 switches 83 and 88 will be activated to set the interlock
code not being used in the limit check operation. The
trigger 90. If the interlock trigger is set, its output line
blank code 000000 in the selection register represents
91 will come up to cause the clock trigger 45 (FIG. 1b)
the low limit of selection and will result in the selection
to reset. Trigger 50 will now reset and clock ring 47
coils 19 presenting to the aperture 27 a beam of no
will stop at T1 of the next cycle indicating that the sys
light intensity as would occur if the beam is correctly 25 tem is not operating properly. While the printer is
aligned with the blank opaque square added to the matrix
stopped, the camera will continue its feed cycle until the
24 for limit check operation.
camera contacts 37 transfer to reset the ?lm advance trig
The timing control line L1+L3, which is also up at this
ger 35 and stop the camera ‘motor M. After the ma
time, is connected to the set side of the vertical and
chine is checked and it is desired to resume operation,
horizontal positioning registers 16 and accordingly, these 30 a manual reset switch 100 (FIG. 1a) may be closed to
registers are turned on to register the full amount of
reset the interlock trigger 90 and a manual start switch
111111. This represents the high limit of positioning and
will result in the positioning coils 20 taking the beam,
(not shown) in the tapecontrol unit 11 is closed to put
the system into operation.
when it is unblanked, to the lower right corner of the
screen. As shown in FIG. 3, the 400 microsecond limit
Assuming that photo cell 80 senses no light at all,
indicating that the beam was correctly positioned, switch
check delay will fall during the early part of the 8th
clock cycle, the single shot '66 ?ipping and raising the
83 will not be activated and the interlock trigger 90
will not be set. Under these conditions, at T8 time of
output line 71. Output line 71 is connected to an AND
switch 72 and at T7 time of the 8th clock cycle, the
the 10th clock cycle, the AND switch 92 (FIG. 1b) will
unblank control trigger 70 will be set on.
be activated to turn on an inverter-shaper 93. The in
With the un 40 verter-shaper provides an advance pulse for the LCl
blank control trigger output line 73 up and the binary
clock trigger output line 74 up, at T4 time of the 9th
clock cycle, the AND switch 75 will be activated to set
an unblank trigger 76. The unblank control trigger,
switch 75 and the unblank trigger, in effect, make up
LC4 ring triggers and will turn the LCl trigger 52 off
and the LC2 trigger 53 on. The LC3 and LC4 trig
gers 54, 55 will not be a?ected at this time because they
had no immediate preceding trigger turned on. Turning
the unbl-ank control box 29 (FIG. 1a), the output of
which is passed through the suitable unblank ampli?er
cycle and the trigger output line L2 is raised which in
turn, through the OR switches 58 and 94, raises the tim
ing control lines L1+L2 and L2+L4. At T9 time of
on of the LC2 trigger 53 initiates the second limit check
30 to cylinder 28 to unblank the aperture 27 and pass
the selected beam through for projection on the screen
the 10th clock cycle, the AND switch 68 becomes acti
31. As shown in ‘FIG. 2, 'for the ?rst cycle of opera 50 vated to e?ect the reset of the horizontal advance
tion, the beam representing the blank code is positioned
trigger 69 and the unblank control trigger ‘70.
at square 77 in the lower righthand corner of screen 31
Referring to FIG. 1a, the timing control line L1+L2
and outside of the normal print area 78. The square
is connected to the reset side of the selection register
77 is shown dotted to indicate that the blank code ex
15 and hence, this register retains the blank code 000000
poses the screen to the minimum or no amount of light. 55 that it had in the ?rst limit check cycle and a beam of
At T6 time of the 9th clock cycle, the AND switch 79
No light intensity will again be selected. The timing con
(FIG. 1b) will set the horizontal advance control trig
trol line L2+L4 is connected to the reset side of the
ger 69 and at T1 time of the 10th clock cycle, the un
vertical and horizontal positioning registers and these reg
blank trigger 76 will be reset.
isters will now switch from 111111 to 000000. The re
Referring to FIG. 1a, a ?rst photo cell 80 is posi 60 mainder of the second limit check cycle will proceed in
tioned opposite the lower right-hand corner of the’ screen
_ the same fashion as described above in connection with
and a second photo cell 81 is positioned opposite the
the ?rst cycle and the blank code is unblanked as square
upper left-hand corner of the screen to sense the un
95 positioned in the upper left-hand corner of the screen,
blanked limit check code squares. The output from the
as shown in FIG. 2. Thus, in the ?rst two limit check
photo cells is fed to a low intensity beam checking cir 65 cycles, the vertical and horizontal positioning circuits
cult ‘and a high intensity beam checking circuit arranged
have been tested for their extreme limits of operation
in parallel. Thelow intensity beam checking circuit
and the selection circuits tested for the low limit of
comprises an ampli?er 82 and one-half of an AND
operation.
switch 83, the other half of switch 83 being fed from the
Assuming no error was sensed and the limit check in
timing control line L1+L2. The high intensity beam
terlock trigger 90 was not set, the switch 92 (FIG. 1b)
checking circuit comprises a current limiter 84, an am
will cause the ring to advance to LC3 trigger 54, raising
pli?er-inverter 85 and one-half of an AND switch 86,
output line L3 and, through the ‘OR switches 59 and 96,
the other half of switch 86 being fed from the timing
raising the timing control lines L1+L3 and L3+L4.
control line L3 +L4. ‘ From the switches 83, 86, the two
The timing control line L3+L4 is connected to the ‘set
checking circuits are merged into an OR switch 87, the 75 side of the selection register 15 and hence, this register
3,641,947
tem for transforming digital input information into a
will be switched to the retrieval code of 111111. The
retrieval code 111111 represents the high limit of selec
tion and will result in the selection coils 19 presenting to
character display on the face of the tube comprising, se
lection circuitry, and associated digital-to-analog conver
'sion circuitry controlled by said input information to
select a character for display, positioning circuitry and
the aperture 27 a beam of full light intensity as would
occur if the beam is correctly aligned with a transparent
square added to the matrix 24 for limit check operation.
The timing control line L1+L3 is connected to the set
associated digital-to-analog conversion circuitry controlled
by said input information to position the selected char
side of the vertical and horizontal positioning registers
acter, a control circuit for unblanking the selected char
16 and accordingly, these registers are turned on to
acter on the face of the tube, ‘a cyclically operable camera
register the full amount of 111111. When the full in 10 for photographing the character display onto ?lm, said
tensity beam is unblanked, it will be positioned as square
camera including means for advancing a frame of ?lm
97 (FIG. 2) in the lower right-hand corner of the screen
after a plurality of character displays have been photo
where it will be sensed by the photo cell 80. Assuming
graphed, switching means controlled by said ?lm advanc
that the beam was correctly‘ positioned, the output from
ing means, and circuit means called into operation by
photo cell 80 will be of a value such that the output from 15 said switching means for automatically test operating said
the ampli?er-inverter 85 (FIG. 1a) will cancel the signal
selection, positioning, digital-to-analog, and unblank cir
on line L3 +L4 and the switch 86 will not be activated.
The limiter 84 functions to clip the signal to establish
cuits during each ?lm advancing cycle of said camera to
ascertain if the printer system is functioning properly.
3. A cyclically operable cathode ray tube printer sys
a reference level. If the beam had been incorrectly posi
tioned, the output from photo cell 80 would not be suffi 20 tem as in claim 2 wherein, said test operate circuit means
cient to effect cancellation of the L3+L4 signal and
includes means for exercising the digital-in-analog, se
switch 86 would be activated to cause setting of the
lection, and positioning circuits to the minimum and
interlock trigger 90.
maximum limits of their operation, and a checking circuit
For the fourth and last cycle of the limit check oper
operable to check said digital-to-analog, selection, and
ation, the ring is advanced to LC4, raising the output 2-5 positioning circuits to determine if they function properly
line L4 which in turn, through the OR switches 94, 96,
at the vafore-mentioned limits of operation.
raises the timing control lines L2+L4 and L3+L4. Ac
4. A cyclically operable cathode ray tube printer sys
cordingly, the selection register will again register 111111,
tem for transforming digital input information into a
the vertical and horizontal registers will be reset to
character display on the screen of the tube comprising, se
000000, and the full beam will be unblankcd as square 30 lection circuitry and associated digital-to-analog conver
98 in the upper left-hand corner of the screen and oppo
sion circuitry controlled by said input information to se
site the photo cell 81. In the third and fourth limit
lect a character for display, positioning circuitry and as
check cycles, then, the vertical and horizontal position
ing circuits are again tested for their extreme limits of
operation and the selection circuits tested for the high
limit of operation. The unblank circuits are also checked,
since if the beam fails to unblank, the output of photo
cell 81 will be insu?'icient to cancel line L3 +L4 and the
sociated digital-to-analog conversion circuitry controlled
by said input information to position the selected char
' acter, a control circuit for unblanking the selected char
acter on the screen of the tube, ya cyclically operable cam
era for photographing the character display onto ?lm,
said camera including means for advancing a frame of
interlock trigger 90 would be turned- on.
?lm ‘after a plurality of character displays have been
‘If no error occurred during the fourth limit check cycle, 40 photographed, switching means controlled by said ?lm
the next advance pulse from the switch 92 (FIG. 1b)
will turn off the LC4 trigger and the fall of output line
L4 is transmitted by wire 99 to effect the reset of the clock
trigger 45. The clock trigger, in turn, through output
line 46, will now cause the trigger 50 to reset and the
clock ring 47 to stop at T1 of the next cycle. Also, the
camera contact 37 now transfers to the negative side to
disable the limit check circuitry and to cause the read
trigger 40 to set and the ?lm advance trigger 35 to reset.
Accordingly, the camera motor M stops so that no more 50
?lm is advanced and the read trigger 40 signals the tape
control unit 11 to start the next tape advance and read
cycle.
While the invention has been particularly shown and
described with reference to la preferred embodiment
advancing means, circuit means called into operation by
said switching means for automatically operating said
selection, positioning digital-to-analog, and unblank cir
cuits during each ?lm advancing cycle of said camera to
unblank in each of two diametrically opposing corners
of the screen two characters having complementary codes,
and photocell means for sensing said unblanked com
plementary codes to indicate if the printer system is func
tioning properly.
5. A cyclically operable cathods ray tube printer sys
tem for transforming digital input information into a char
acter display on the screen of the tube comprising, a se
lection register and associated digital-to-analog conver
sion circuitry controlled by said input information to
select a character for display, horizontal and vertical
thereof, it will be understood by those skilled in the art
positioning registers and associated digital-to-analog con
that various changes in form and details may be made
version circuitry controlled by said input information to
therein without departing from the spirit and scope of the
position the selected character, a control circuit for un
invention.
blanking the selected character on the screen of the tube,
60 a cyclically operable camera for photographing the char
What is claimed is:
1. In a cyclically operable printer system of the class
acter ‘display onto ?lm, said camera including means for
described, a cathode ray tube, cyclically operable means
advancing a frame of ?lm after a plurality of character
for supplying input data to said tube, selection circuitry
displays have been photographed, switching means con
and positioning circuitry associated with said tube and
trolled by said ?lm advancing means, circuit means called
controlled by said input data to cause said tube to cycli 65
into operation by said switching means for automatically
cally display data information, a cyclically operable re
setting and resetting all positions of said selection register
cording camera for recording the displayed information
and horizontal and vertical positioning registers twice
onto ?lm, said camera including means for advancing
during each ?lm advancing cycle of said camera to select
a frame of ?lm after a plurality of displays have been
recorded, switching means controlled by said ?lm advanc 70 and position two characters having complementary codes,
circuit means effective during each ?lm advancing cycle
ing means, and circuit means controlled by said switching
of said camera for operating said unblank control circuit
means for automatically test operating said selection and
positioning circuitry during each ?lm advancing cycle of
whereby there is unblanked in each of two diametrically
said camera.
opposing corners of the screen said two complementary
2. A cyclically operable cathode ray tube printer sys 75 coded characters, and photocell means for sensing said
3,041,947
9
unblanked complementary codes to determine if the
6. In a cyclicaily operable printer system having a
‘advancing cycle and feed a frame of ?lm after a plurality
of character displays have been photographed, a cam op
erated by said ?lm advancing means, switch means in
cathode ray tube, (a light beam source, a character matrix,
said camera and operable by said cam during a ?lm ad
printer system is functioning properly.
and associated control circuitry for transforming digital
Vancing cycle, limit check circuit means ‘called into op
eration by said switch means for automatically develop
ing during said ?lm advance cycle a series of signals
of the tube, the combination of, a cyclically operable
which successively set and reset said selection and posi
camera for photographing the character display onto ?lm,
tioning registers and operate said unblank control cir
said camera including means for advancing a frame of
?lm after 1a plurality of character displays have been 10 cuit to un-blank in each of two diametrically opposing
corners of the screen two characters having complemen
photographed, cam operated switch means controlled by
tary codes, photocell means for sensing said two un
said ?lm advancing means, circuit means called into op
blanked characters in each of said opposing corners, said
eration by said switch means for automatically operating
photocell means developing an output only when the un
the control circuitry of said tube during each ?lm ad
vancing cycle of said camera to unblank in each of two 15 blanked characters sensed in said opposing corners do not
represent complementary codes, and interlock circuit
diametrically opposing corners of the screen two charac
means respon ive to an output from said photocell means
ters having complementary codes, one of said charac
for stopping operation of said printer system.
ters representing a beam of maximum light intensity and
9. A cyclically operable printer system as in claim 8
the other of said characters representing a beam ‘of mini
including means eilective upon the absence of an out
mum light intensity, photocell means for sensing said two
put from said photocell means for disabling only said
unblanked characters in each of said opposing corners,
limit check circuit means.
and interlock circuit means responsive to said photocell
10. vIn a cyclically operable printer system having a
means for indicating the absence of either of said com
cathode ray tube, a light beam source, a character matrix,
plementary coded characters.
input information into a character display on the screen
7. in a cyclically operable printer system having a 25 and associated control circuitry for transforming digital in
cathode ray tube, a light beam source, a character matrix,
put information into a character display on the screen
‘and associated control circuitry for transforming digital
of the tube, the combination of, a tape reader and tape
control unit operable to read digital data and end-of
input information into a character display on the screen
7 of the tube, the combination of, a tape reader and tape
record marks on a tape and to initiate a read cycle dur
control unit for supplying said digital input informa 30 ing which digital input information is supplied to said
control circuitry, a cyclically operable camera for photo
tion, a cyclically operable {camera for photographing the
graphing the character display onto ?lm, said camera
character display onto ?lm, said camera including means
including means for advancing a frame of ?lm, a read
for advancing a frame of ?lm, means controlled by said
control device responsive to a tape end-of-record mark to
tape control unit for operating said ?lm advancing means
to make a ?lm advancing cycle and feed a frame of ?lm 35 terminate said read cycle, an end-of-record indicator de
vice operable in response to an end-of-record mark, a
after a plurality of character displays have been photo
?lm advance control device responsive to said end~of~
graphed, cam operated switch means in said camera and
record indicator device ‘for operating sm'd ?lm advancing
operable by said ?lm advancing means during a ?lm lad
vancing cycle, circuit means called into operation ‘by said
means to make a ?lm advancing cycle and feed a frame
switch means to test operate said printer control circuitry 40 of ?lm, I3. cam operated by said ?lm advancing means,
switch means in said camera and operable by said cam
during said ?lm advancing cycle, and means controlled
during a ?lm advancing cycle, and circuit means called
by said switch means at the end of la ?lm advance cycle
into operation by said switch means to test operate said
for signaling said tape control unit to supply digital input
printer control circuitry during said ?lm advancing cycle,
information to said tube control circuitry.
said ?lm advance control device and read control device
8. In a cyclically operable printer system having a
being controlled by said switch means ‘at the end of a
cathode ray tube, a light beam source, a character matrix,
?lm advance cycle to disable said ?lm advancing means
associated selection and positioning registers and an un—
and to initiate a read cycle.
blank control circuit for transforming digital input infor
mation into a character display on the screen on the tube,
References Cited in the ?le of this patent
the combination of, ‘a tape reader and tape control unit 50
for supplying said digital input information, a cyclically
operable camera for photographing the character display
onto ?lm, said camera including means for advancing a
frame of ?lm, means controlled by said tape control unit
for operating said ?lm advancing means to make 1a ?lm 55
UNITED STATES PATENTS
2,624,798
2,659,828
2,808,768
2,818,466
Dinga _______________ __ Jan. 6,
Elliott ______________ __ Nov. 17,
Squassoni _____________ __ Oct. 8,
Larson _____________ __ Dec. 31,
1953
1953
1957
1957
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 047 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа