Note: Descriptions are shown in the official language in which they were submitted.
72~
Title _f_the Invention
Color image display appa.ratus
Background of the Invention
1. Field of the Ihvention:
The present invention relates to a color image display
apparatus comprising a fla~ displaying appara~us with a number
of (for example fifteen) line ca~hodes,
More particularly, the present invention concerns a
color image display apparatus fox displaying a color image by
means of a color phosphor screen and a plural number of parallel
disposed line cathodes.
2. Description of the Prior Art:
Hitherto, for a color image display apparatus for a
color television set, a color cathode-ray tube having three elec-
tron guns or a single electron gun set in a neck part of a bulky
cone shaped vacuum enclosure has been used for a long time. The
shortcoming of the conventional color cathode ray tube is a laxge
depth in comparison with the size of the screen face, preventing
the provision of a fla~ and compact television s~t. Though EL
display apparatus, plasma display apparatus and liquid crystal
display apparatus has been developed, these are not sufficient
for practical use because they have problems in brightness,
contrast or color display.
7~;~
It is an object of the present invention to provide a color image display
apparat~s with a flat shaped display apparatus.
More particularly in accordance with one aspect of the in~ention there is
provided, a color imQge display apparatus comprising:
a color phosphor screen comprising, a first predetermined number of
vertically extending horizontally arranged sections, said horizontally
arranged sect1ons being vertically subdivided into a predetermined nu~ber of
vertically arranged segments, whereby each segment comprise~ a said first
predetermined numbe~ of said subdivided sections arranged horizontslly, each
subdivided section al.so comprising a set of regions each of a prima~ily color
phosphor,
an electron be~m source for each vertically arranged segm~nt or emitting
a hori~ontal row of electron beams7 the row having said first predetermined
number of said electron beams, each beam corresponding to a respective said
subdivided sectlon,
a hori~ontal deflection means or directing each said electron beam onto
the respective primary color phosphors in its respective subdivided section in
turn, thereby simultaneously activating in turn correspondiDg primary color
phosphors in each o said subdivided sections, and producing one horizontal
line on snid screen,
a vertical cle~l~ction means for deflecting each respective horizontal row
of electr3n beams of each vertically arran~ed segment to thereby produce in
turn a plurality of said horizontal lines in each respective vertically
arranged segment,
an electron beam control means for simultaneously controlling the
intensities of the respective electron b~a~s in ~c¢ordance with a resp~ctive
color video signal for each selected primary color to produce a line-at-a-time
display o a color video picture,
a vacuum enclosure containing said electron beam source, said electron
beam control means, said horizontal and sRid vertical deflection means
therein, one end Pace oP said enclosure forming a screen face at whlch said
color phosphor screen is proYided,
and a saMple-hold means for sample-holding in turn said respective color
video signals for each horizontally arranged section, a mamory Por storing
output signals of each said sample-hold means, and elect~onlc s~itch means for
2~
simultaneously feeding signals, for in turn selected primacy colors, out of
sa;cl memory tD respective said electron beam control means to produce said
line-at-a-time display.
In accordance with a second aspect of the invention there is provided, a
color image display apparatus comprising:
a color pho~phor screen comprisin~ a multiplicity of vertically disposed
rows o~ horizontally arran~ed sections r each ssction being subdivided into a
respective region of red phosphor, green phosphor and blue phosphor,
ve2tically disposed groups of said rows of sections for~ing resp0ctive
vertically arranged segments,
electron beam source means comprising a respectivs horizont~l row of
electFon beams for each segment,
vertical deflection electrodes for each said respective row of electron
beams for thereby displayin~ in turn each row of said sections in each
respective said segment,
horizontal deflection electrodes for horizontally deflecting said electron
beam~ for each resp2ctive segment, thereby making the electron beams impinge
individually on the subdivided color pbosphor regions in turn in respective
said sections in each row of sections,
electron beam control means for controlling the intensities of the
respective electron beams in accordance with a respective input color video
signal, thereby to display a color video ima8e on said phosphor screen,
said electron beam control means comprising a sa~ple-hold means for
s~mple-holding in turn respective color video si~nals for each said
horizontally arrangad section, a memory for storing output si~nals of each of
said sample-hold means, and
an electronic switch means for simultaneously feeding sigaals for in turn
selected red, gr~en and blue colors out of said memory to respective said
electron beam control means, to produce a line-at-a-time display.
Specific embodiments of the invention will now be describ~d having
refQrence to the accompanying drawings in which,
Pi~ure 1 is an exploded perspective vie~ of a principal part, with its
vacuum enclosure removed, of a video image display apparatus embodying the
present invention, expanded o~ its size in the hori~ontal direction enlarged
in comparison with the vertical direction ~or easier drawing oP minute
constructioas,
--3--
~6~
1 FIG. ~ is a schematic front view of a phosphor
screen of the apparatus of FIG. 1,
FIG. 3 is a circuit block diagram showing a
fundamental electric construction of the appara-tus of
FIG. 1,
FIG. ~ is a circuit diagram showing an example
of a ver-tical deflect on driver 27,
FIG. 5 is a schematic side view sho-wing a
relation between vertical deflection electrodes and
10 phosphor screen,
~ IG. 6 iS a schematic front view of a displayed
ras-ter on the phosphor screen for illustrating error
and correc-tion of the horizontal lines on the raster,
and
FIG. 7 is a perspective view showing a part
of a modified example of a vertical deflection electrodes
of the apparatus.
~escription of the Preferred Embodiments
One preferred example of the present invention
~0 is shown in FIG. 1, wherein from the back part to front
part -the following components are provided in a flat ~.
box shaped evacuated envelope not shown here, but pre-
ferably made of glass-
a back electrode 1 having horizontal isolation
wal:Ls 101, 101 ... projecting perpendicularly there~rom
.. .. - . ~ . . . . . . , I
~G~
1 forming isolated spaces 102, 102 .... therein,
a row of a predetermined number (e.y. 15 in
this embodiment) of horizontal line cathodes 201, 202, ...
disposed substantially horizontally in the isolated
spaces 102, 102 ....
a vertical beam~focussing electrode 3 having
the predetermined number (e.g. 15 in this embodiment)
of horizontal slits 10,
a first vertieal deflection means 4 comprising
lo the predetermined number of pair of vertical deflection
electrodes 13', 13 ..., held by insulator board 12.
Each pair of vertical defleetion eleetrodes comprises
an upper electrode 13 and a lower electrode 13' both
disposed subs-tantially horizontal and defining a deflec-
tion space inbetween disposed before the corresponding
horizontal slit 10,
a second vertical beam~focussing electrode
3' substantially similar- to the horizontal beam- .
focussing electrode~6,-
a predeterrnined large number (e.g. 320 for
this embodiment) of beam eontrol electrodes 5 consisting
of vertical strip eleetrodes 151, 152 -- 15320 each having
beam-passing slits 14, 14 ~O disposed with uniform
pitch,
a horizonta.l beam-focussing electrode 6
1 having the predetermined number (e.g. 320 for -this
embodiment) of vertical slits at positions in front of
the slits 14,14,... of the beam control elec-trodes 5, 5
....
a horizontal deflection means 7 comprising
the predetermined number (e.g. 320 for this example)
of vertical strip electrodes 18, 18', 18, 18' ... defining
the predetermined number (e.g. 320 for this example) of
vertically oblong deflection gaps inbetween,
lo a beam acceleration means 8 consisting of
a set of horizontally disposed electrodes 19, 19 ....
and finally
a phosphor screen 9, which is ordinarily
provided on the inner wall of a front face of the enclosure.
The line cathodes 201, 202 ... form electron
beam source 2/ wherein horizontal line cathodes are
disposed forming a vertical row, with substantially
uniform gaps with ëach other. In this example, as above-
mentioned 15 line cathodes 201, 202 ... 215 are provided,
20 but only four of them are shown. The line ca-thodes are
made by coating a tungsten wire of, or example, 10 - 20~m
diameter with known -electron emitting cathode oxide. All
the line cathodes are heated by feeding current thereto,
and selective in-turn taking out of horizontal sheet
shaped electron beam from selected one of the line cathode
1 is done by changing a potential of the in-turn selected
line cathode to negative with respect to the poten-tial
of the focussing electrode 3.
The back electrode 1 serves to suppress emis-
sions of electrons from other line cathodes than the
selected one and also expel the electrons from the
selected cathode to its front direction. The back
electrode 1 may be formed by attaching conductive sub-
stance such as conductive paint on the inner wall of
lO the back ace of the flat type vacuum enclosure. A flat
plane shaped cathode may be used in place of the row of
the line electrode 201, 202 ... .
The first vertical beam-focussing elec-
trode 3 have the slits 10 at the position to -
face the line cathodes 201, 202 ... and is impressed
with a DC voltage, therefore horizontal sheet shaped
electron beam from a selected line cathode is formed.
The sheet shaped electron beam is then divided into a
large number (e.g. 320 in this example) of narrow
20 electron beams by passing through the second vertical beam~focussing
electrode 3', the control electrode 5 and horizontal focussing
elec-trode 6. In FIG. 1, only one such narrow elec-tron beam is shcwn
for slmplicity. Each slit 10 may have supporting ribs in midway
part of-the length, or further may consists of a large number
(e.g. 320) of openings with very narrow rib par-ts 301
inbe-tweenO
The el.ectrodes 13, 13' of the ver-tical deflec-
tion means 4 are disposed at levels of subs-tantialiy the
centers between vertically neighboring two horizon-tal
slits 10, 10 of the vertical focussing electrode 3~
and a lower e].ectrode 13 and an upper electrode 13~ are
held on both faces (upper and lower faces) o-f an insula-
-tion board 12. A changing voitage (a vertical deflection
signal) is impressed across the pair of upper electrode
lo and lower electrode of each pair thereby forming changing
elec-tric field for vertical deElection. In this example,
as has been elucidated, by impressing the 16-s-tep chang-
ing voltage across the pair electrodes, each electron
beam is deflec-ted in a manner to have 16 levels~ ~nd
the same matter ta~es place in each of 15 ver-tically
divided segments 221, 222, 223 .... 235 on the phosphor
screen. Accordingly, the phosphor screen 9 has 240
horizontal lines in total (16 lines x 15 segments = 240
1 ine s ) O
The beam control electrodes 5 comprising 320
strip electrodes 151, 152... 15320 together with the
horizontal beam-focussing electrode 6 divide the
horizontal sheet shaped electron beam into 320 rod shaped
electron beams/ and each strip electrodes 151, 152... 15320
of the beam control electrodes 5 control in-tensi-ties of
, . . .. .. . , _ . ...
r5~
1 the rod shaped electron beams responding to the informa-tion of the
video signal. Therefore, the 320 strip electrodes control informa-
tion of 320 picture elements on each horizontal line. I`he 320 beam
control electrodes receive 320 control signals respectively and
controls the 320 rod beams in such a manner as, at one time for red
color irradiation, at one time for green color irradiation ~d at
one time for blue color irradiation, in -turn. In order to display
color picture on the color phosphor screen with the control signals
applied to the beam control electrodes, each picture elemient con~
lo prises three elementary color regions, namely red strip region,
green strip region and blue strip region, which are disposed in
horizontal direction.
The feature of the present embodiment is that all the
320 ber~m control electrodes 151, 152 ..~ 15320 receive the beam
control signals for displaying respective three primary colors,
i.e., red and blue or green, at a same time. That is, at one moment,
one horiæontal line on the phosphor screen displays an image of red
color parts and blue color parts of the line by impingements of
red phosphor regions by odd number electron beams and impingements
20 of blue phosphor regions by even number electron beams, at the next
mo~ient an image of green color part of the line, and a-t the next
moment an image of red color parts and blue color part of the line
by impingements of red color phosphors regions by even n~b~r
elec-tron beam~s and :Lmpingements of blue color phosphor regions by
odd number electron beams. In this apparatus, the odd number
1 elec-tronic switches 351~ 353~ 355 ... 3515 switch to feed signal
in the order of R, G and B, and the even number electronic switches
352' 354 3514 swi-tch in the order of Bl G and R.
The horizontal beam-focussing electrode 6 is imrpressed
wi-th a DC voltage and focusses the rod shaped electron heams in
horizontal direction.
The horizontal deflection means 7 comprises strip elec-
trodes 18, 18' .~. which are disposed at the positions in front of
center positions between neighboring slits 16, 16 of the horizontal
beamrfocussing electrode 6. Each of the strip electrodes pair 18,
18' is impressed with 3-level changing voltage or a horizontal
deflection signal, and horizon-tally deflects rod shaped electron
beams, thereby making the rod shaped electron beams selectively
impinge red p~losphor regions, green phosphor regions or blue
phosphor regions in turn.
In the example, where a horizontal rcw of 320 rod
shaped electron beams impinge 320 sets of three primary color
regions, one horizontal deflection range corresponds -to one hori-
zontal picture element width.
The horizontally disposed electrodes of the ~eam~
acceleration means 8 are dispose at ~he height l.evel corresponding
to those of the composite body of vertical deflection el.ectrodes
13 and 13' and are impressed with a DC voltage.
The phosphor screen 9 may be provided with known metal
back layer (not shown) formed on the side of cathodes and a positive
1 DC voltage is impressed thereon. In practical example, the phosphor
regions are Eormed vertically oblong strips of red color phosphor,
green color phosphor and blue color phosphor. In FIG. 1, horizontal
broken lines on the phosphor screen 9 show bo~mdary lines between
neighboring vertically divided segments to be impinged by electron
beams of respective line cathodes. Vertical chain lines on the
phosphor screen 9 shown boundary lines between horizontally
neighboring sets of three primary color phosphor strips.
A small segment 20, which is defined by two neighboring
vertical chain lines and two neighboring horizontal bxoken lines,
is shcwn enlarged in schematic view of FIG. 2, whe.rein the small
se~Jr.ent 20 has 16 horizontal lines in vertical row. In an actual
example, one segment has the size of 16mm high in ver-tical direc-
tion and lmm width in horizontal direction, and in
FIG. 1 the sizes are shown enlarged in widthwise direc-
-tion as has been mentioned.
. Apar-t from the above-mentioned example where
320 sets of three primary color phosphor regions are
formed widthwise of the phosphor screen for 320 rod
shaped electron beams produced by 320 slits 1.4 of the
beam-con-trol electrode S and 320 slits 16 of -the horizon-
tal beam-focussing electrode 6, such a modification
may .be made that for the 320 sets of three primary color
phosphor reglons, 160 rod-shaped electron beams are
provided, and in this case the horizontal deflection
i2
1 signal is ~ level changing voltage which deflects the
rod-shaped electron beam to sweep ror the horizontal
range of the color phosphor reglons of RGBRGB, and each
of the beam-control electrodes 5 also receives the
control signal for two pieture elements in sequence.
FIG. 3 shows a eircuit block diagram of a
fundamental electric construetion of the apparatus of
FIG. ].. The explanation starts from the part to drive
the cathode ray tube to form a raster on its phosphor
10 Screen.
A power supply 22 is for impressing neeessary
voltages on various eleetrodes o:E the flat ca-thode ray
tube of FIG. 1. The following DC voltages are supplied
to the electrodes:
-Y1 to back electrode 1,
V3 to vertical beam-focussing electrode 3,
V3' to vertical beam-foeussing eleetrode 3',
V6 -to horizontal beam-focussing electrode 6,
V8 to aeceleration eleetrode 8,
V9 to phosphor screen 9.
An input terminal 23 receives ordinary eomposite video
signal and give it to a synehronizing signal separator
24 and to a chrominanee demodulator 30. ~he synchroniz-
ing signal separator 24 separate and issues vertical
synchronizing signal Vs and horizontal synchronizing
1 signal H . A vextical driving pulse generator 25 comprises
a coun-ter which count the horizontal synchronizing signal
Hs and is reset by the vertical synchronizing signal Vs~
and issues 15 driving pulses pl, p2, p3 ... pl5, each
having duty time of 16H (lH is the time period for one
horizontal scanning). The fiftee~ pulses pl to pl5 are issued
during an effective vertical sweep period, which is the time length of
one vertical sweep p~riod exclusive of vertical fly-back ti~e and is
of 2~0H time length. The driving pulses are-then given
lo to the line cathode controller 26, where they are inversed
of polarity to produce pulses pl', p2', p3' ... pl5' falling down to
oV at respective inversed peak period (of 16H length)
and retaining 20V for other period, and is fed to respec-
tive line cathodes 201, 202, 203 ... 215. The line
ca-tho~es are always heated by a small voltage DC current
so as to be able to emit electrons at any time, and
the electrons are taken out, when the pulse of a
selected line cathode is at its peak (OV), by means of
positive electric field towards the vertical beam-fo-
20cussing electrode 3 and subsequent other electrodes.
For period other than the peak (OV) of the pulses
impressed on a line cathode, because of negative electric
fleld formed by impression of ~20V thereon, the line
cathodes do not emit electron beam. That is, one of the 15
line cathodes in turn emit electrons beams. Therefore,
14
1 the line cathodes are activated in turn from the top
one 201 to the bottom one 215 each for 16H time period.
The emitted electrons are ~riven forwar~ to the vertical
beam -focussing electrodes 3, 3' and focussed to form
a horizontal sheet-shaped electron ~eam.
A vertical deflection driver 27 comprises a
counter for counting horizontal synchronizing signal Hs
and ls reset by the O-ltpUt pulses pl, p2 ... pl5 of the
vertical driving pulse generator 25 and an A/D converter
for A/D converting the count output. And the vertical
deflection driver 27 issues a pair of vertical deflec-
tion signals v, v', which are 16-step risiny sawtoo-th
wave and 16-step falling sawtooth wave, respectively,
both havlng center voltage of V4. These vertical deflec-
tion signals v and v' are impressed on the upper vertical
deflection electrodes 13 and the lower vertical deflec
tion electrodes, respectively~ Accordingly, the sheet
shaped electron beams are vertically stepwisely deflected
in 16 steps and repeat the same. And therefore, a
horizontal line displayed on the phosphor screen step-
wisely falls from top position to bottom position in
16 steps in one vertically divided segment 221, 222 ...
or 235 of FIG. 1.
Since the activati.on of the line cathodes is
stepwisely shifted one by one downward every 16H time
1 period, when the horizontal line on the phosphor screen
comes down and arrives at the bottom of the first ver-ti-
cally divided segment 221, the next moving of -the
horizontal l1ne on the phosphor screen starts from the
top position of the second verticall.y di.vided segment
222, and the similar downward shifting of the horizontal
line proceeds until the horizontal line arrives at the
bottom of the 15th (lowest) vertically divided se~ment
235, ~nd the horizontal line goes back to the top of
-the first segment 221. That is, the vertical deflec-tion
of -the horizontal line continuously proceeds from the
top (No. 1 horizon-tal line) to the bottom (No. 240,
i.e,, (15 x 16)th~ of the phosphor screen 9, thereby
forming a raster of 240 horizontal lines.
The sheet-shaped electron beam is then divided
into 320 rod-shaped electron beams havingsubstantially round sections
when passiny through the vertically oblong slits 1~,
14 .... of the beam-control electrode 151, 152 - and
ver-tically oblong slits 16, I6.... of.the horizontal beam-
focussing electrode 6. The rod-shaped electron beams
are controlled of their currents by means of voltage ~-
impressed on respective strip electrodes of -the beam-
control means 5, and further deflected by horizontal
deflection means 7 so as to have one of three positions
corresponding to R, G and B regions of the phosphor
1 screen 9 by means of the horizontal deflection signals
given by the horizontal deflection driver 29.
A horizontal driving pulse generator 28 com-
prises three stages of sequentially connec-ted monostable
multivibrators,the first stages of which is txiggered
by horizontal synchronizing signal Hs. And the horizon-
tal driving pulse generator issues three pulses r, g
and b of the same pulse widths. For one example, an
effective horizontal scanning period of 50~ sec. is
lo divided into 3 periods for the pulses r, g and b,
accordingly, the pulses, r, g and b have 16.7~ sec. pulse
width each. The horizontal driving pulses r, g and b
are yiven to the horizontal deflection driver 29, which
is switched by the horizontal driving pulses r, g and
b and issues a pair of horizontal cleflection signals h
and h'. These horizontal deflection signa~s h and h'
are three step rising signal and three step falling
signal, respectively, and, both have the same center
voltage V7. These horizontal deflection signals h and
20 h' are given to the horizontal deflection electrodes 18,
18, 18 ..~ and 18', 18', 18' ... dispose alternately in
the ho.rizontal ~eflection means 7. As a result,320
rod-shaped elec-tron beams are deflected at the same
-time -to R, G or B regions on a same horizontal line oE
the phosphor screen.
1 I-t should be noted that in the construction
, ~ ~ cj/
shown in and-e-~e~ e- referring to FIG. 1, -the number
of strip electrodes 1~, 18' ... of the hori~ontal elec-
trodes are 320 for the 320 rod-shaped electron beams,
and the strip electxodes 18, 18' ... are alternately
connected to the ou-tput terminals h and h' of -the hori-
zontal deflection driver. Accordingly, the electric
fields of horizontal deflec-tion gaps defined by neigh-
boring two strip electrodes 18 and 18' are no-t of the
10 same direction. Namely, the directions of elec-tric
field of the hori~ontal deflec-tion gaps are alterna-tingly
opposite each other for neighborlng horizontal deflec-
tion gaps. The effect of this alternatingly opposite
electr.ic field is compensated as will be elucidated
later.
Thus, the hori~ontal line on the phosphor
screen at one time displays red image at the same time,
at the next time green image at the same time and a-t
the next time blue image at the same time, and at the
- 2~next time the line procee~ to the next lower line whereon
the same is repeated.
The beam intensity-control is made as follows~
The input composite video signal received at
the input terminal 23 is given to the chrominance
demodulator 30 where color d~fferential signals R-Y and
18
~
B-Y are demodulated and G-Y is also produced by known
ma-trix circuit therein, and by processiny these color
di:Eferential signals with a luminance signal ~, primary
color signals R, G and B are produced. The primary color
signals R, G and s are given to 320 sets of sample-hold
means 31l3 312 -- 31320, each comprising l:hree elementary sample-
hold circuits for R, G and B color signals. The output
signals of the 960 elementa_y sarnple-hold circuits are given to
320 sets of memory means 321, 322 32320~ each com-
10 prising -three memories for R, G and B color signalsO
On -the other hand a sampling clock generator
33 comprises PLL (phase locked loop) circuit, and issues
sampling clock pùlses of 6.4 MHz, which is controlled
to have a predetermined phase difference against the
horizontal synchronizing signal Hs. The sampling c:l.ock
pulses are given to the sampling pulse generator 34,
wherein by means of, for example, a shift register of 320
stages, 320 sampling pulses Sl, S2 ... S320, each having
phase difference.by 5011 sec/320 tim.e in~etween, are produced and given
20 to the sample hold circuits 311, 312 -- 31320, respective-
ly. After the last sampling pulse S320, a transferring
pulse St is issued from the sampling pulse generator 34
to the memories 32~, 322 32320. The sampling pulses
Sl, S2 ... S320 correspond to 320 picture elements in
the horizontal direction on the phosphor screen 9, and
19
ç~
1 their ti.mings are controlled so as to have a constant
relation wi-th respect to the horizontal synchronizing
signal Hs- By impressing the 320 sets of sampling pulses
-to respective 320 sets of sample-hold circuits, -the
sample-hold circuits 311, 312 ... 31320 s p
R~ G and B information of video signals therein. After
finishing of the sample-hold for one horizontal line,
upon receipt of -the transfer siynal St by the memories,
the sample-held informations are --trans~erred at one time
1 to -the memories 321, 322 ... 3232~ and retained there
for the nex-t one horizontal scanning period (H = 63.5
sec).
The R, G and B information of the video signal
for the one horizontal line stored in the memories 321,
322 ... 32320 are led to 320 electronic switches 351~
352 ... 35320' which are el.ectronics switches comprising
analog gate circuits for selectively leadlng the stored
signals of a color R, G or B to the respective strip
electrodes 151., 152 - 15320 o~ the beam control means
20 5. The switching ciricuits 351~ 352 ... 35320 are
simultaneously switched,being controlled by swi.-tching
pulses given from a switching pulse generator 36, which
is controlled by the output pulses r, g and b o~ the
horizontal dri.vi.ng pulse generator 28. The elec-tronic
switches 351' 352 35320 switch every 16.7~ sec
1 (= 50~ sec/3) for selectively leading the video siynal
informa-tion of R, G and B color in turn each for 16.7
sec.
In the switchiny, the switching circuits of
the odd number orders are switched in the order of
R ~-G -~ B while the switching circuits of the even number
orders are switched in the order of ~ ~ G ~ R, so that
the effect of the alternatingly opposite directed
electric fields produced by the horizontal deflection
lo means 7 is compensated,
Hereupon it should be noted that timing (phases)
of the switchings of the electronic switches 351' 352 ...
35320 and the horizontal deflection driver 29 should
be completel~ synchronized with each other, in order to
avoide poor color impurity caused by undesirable mixing
oE a color siynal with other color signals.
~ s a result of the operation as has been
elucidated, -the phosphor screen displays red color imaye
o:E one horizontal line at one time, followed by yreen
20 color image of the horizontal line at one time and
further followed by blue color image of the horizontal
line at one t;me, and then the same displayiny is made
pxoceeding to the next (lower) line, and thus displayiny
of one field having 240 horizontal lines is comple-ted.
And the displayings of the fields are repeatecl and
1 television picture is obtainable on the phosphor screen
9.
In case the number of picture elements on one
hori.zontal line is selected twice or three times of the
number of rod shape electron-beams each individually
controlled by independent beam control electrodes 151~
152 ~ the number of the above-mentioned sample-hold
circuits must be increased twice or three times, to the
number of the picture elements on the line, and rele~ant-
lo ly, the numbers of the memories should also be increased
to the same number. ~nd each electronic switch should
selectively connect the outputs of the increased number
of memories time sharingly to the corresponding beam-
control electrodes.
The primary colors of the phosphor regions
ar.e not necessarily limited to the combination of the
R, G and B, but any other combmation as the primary color
of phosphors may be usable.
. . In the above-mentioned description, the words
2~ "horizontal" and "vertical".are used to imply that
"horizontal" is the direction that the lines are dis-
pla.yed on the phosphor screen, and "vertical" is the
direction that the displayed line is shifted to the
ne~t line to form a raster, and accordingly these woxds
are not bound to the absolute spatial relation of the
,, - ~
screen.
The above-mentioned apparatus can provide a color
television apparatus of very flat and compact type, and a
sufficiently bright and clean display image is ensured since
known combination of the color phosphors and cathode ray beams
is used.
The embodiment apparatus may comprise a measure to
eliminate undesirable effects caused from inaccurate construction
of the deflec~ion electrode or the like, which is likely -to re-
sult in non uniform spacing of, or departure from parallelismof, the horizontal lines, leading to an unpleasant distorted
video picture display.
Figure 4 shows a representative example of the vertical
deflection driver 27. ~ ring-counter 37 is reset by rising edges
of the vertical driving pulses pl, p2 ... pl5 from the vertical
driving pulse generator 25, coun~s the horizon~al synchronizing
signals H and issues output signals ~, ~ , y ..~ o ~nd from
its 16 output terminalsO On the other hand, a potentiometer 38
has 16 intermediate output terminals, ~hrough which 16 output
voltages oE different levels are talcen out and given to the
analog switches 39~, 39~ ... 39~, respectively. These analog
switches axe controlled by the above-mentioned sîgnals q, ~,
y ... ~, in a manner to be made canductive each for lH time
period in different timing sequence.
- 22 -
l ThereEore, at the common connected output-terminal of
the analog switches 39~, 39~ ... 39~, a stepwise rising
outpu-t having 16 step voltage levels is ob-tainable. The
stepwise output is taken out through an emitter follower
40, adjusted of amplitude by the variable resis-tor 41,
amplified by a B-class amplifier 45 constitu-ted by
transistors 42, 43 and 44, and issued~as the vertical
deflection signal v through an output terminal 46. On
the other handJthe vertical deflection signal v' is
l0 issued through the output terminal 46' in the similar .
manner, by switching the voltages of the poten-tiometer
38' by the analog switches 39'~, 39'~ ... 391~. As
shown in FIG. 5, the vertical deflection signals v and
v' are impressed to the upper vertical deflection
electrodes 13', 13' ... and the lower vertical deflec-tion
electrodes 13, 13 ... , and thereby the~electron beams
from a line cathode is ver~ically deflected to have 16
vertîcal positions, thereby fbrming 16 horizontal lines
on the phosphor screen 9.
~ereupon, when mounting of the electrodes 13,
13' of the vertical deflecting means 4 is no-t accurateJ
I,f,~
making them non-parallel'each other, or tilted with
respect to plan view, then the horizontal lines of -the
raster does not become parallel and uniform, accordingly
for example making -the lines partly non-uniform or partly
. ~
24
1 tilted. FIG. 6 exemplarily shows such sta-tes of the
raster, wherein solid lines show ideal posi-tions o~ the
horizontal lines and chain lines show states o~ slipping
of the horizontal lines. The paxts "a" and "d" show the
state -that lines are uniform and parallel. In the part
l'bl', the line gaps shrink in the left part. In the
part llc" the line gaps expands in the left part. FIG. 7
shows a circuit for enabling corrections of such one
sid* shrin~age and expansion of the line gap. In this
example, the strip electrodes 13 and 13l of the vertical
deflection means are formed by sheet resistors, and
connecting electrodes 120 and 120' are formed on both end
par-ts thereof. The vertical deflecting signals v and
v' are impressed on the connecting electrodes on the
ends of one sides, and connec-ting electrodes on -the ends
of the other side are grounded through series connections
of variable resistor and analog switch 471 + 481~ 472 ~ 482
^`- 4715 + 4815 and 47'1 + 48'1' 47'2 + 48'2 '' 4715 + 48'15'
and the control elec-trodes of the analog switches 481,
2~ 2 15 8 1' 48 2 ~ 48l15 are Connected to
the output terminals of the vertical driving pulse gene-
rator 25. In the above-mentioned cons-truction, by
adjusting the variable resistors 471~ 472 ' ~715 and
47ll~ 47'2 ~ 47'15~the amplitude of the ver-tical
deflec-tion signal at a desired end part can be adjusted,
L thereby forming tapered voltage distributions on the
sheet resistor and hence tapered electric fields in the
gap space between a pair of vertical deflection elec-
trodes 13, 13'~ In order to make desired correction.
of shrinking or expansion of either side of the raster,
the connec-tions of the left ends and the right ends may
be exchanged. It is of course necessary that the adjust-
ment should be made without losing balance between the
adjus-trnent of -the deflection signal for the upper deflec-
o tion elec-trodes 13' and that for the lower deflection
elec-trodes 13.
~ r ~ ~ 7 ~2 ~ " 7
As a result of the above-mentioned'~
even when distortions of parallelism between horizontal
lines in the raster due to the causes of dimensional
errors in assembling or mounting of the vertical deflec-
tion electrode ~ happens to take place, it is possibl.e to
correct horizontal lines in the raster to the right positions
as they are designed, by means of the adjustments
of the voltage distributions in the sheet resistors of
20 the ver-tical deflection electrodes. Thus, a distortion
free video image is obtainable.
Furthermore, the means for independen-t adjust-
ments of the voltage dis-tribution of the ver-tical deflection
means is no-t necessarily limlted to the consti-tu-tion as
elucidated referring to FIG. 7, but any other circuit
of the same or similar function may be applicable. Instead
of the sheet resistors 13 and 13l, wires of a suitable high
resistance material may be of course used. Besides, the
positions where the ad~ustment means are to be coupled to may
be arbitrarily selected within a range to obtain the function.
Since the adjusting means described with reference
to FIG. 7 can correct the distor~ion or irregularity of the
horizontal line in any region of the raster, the conventional
problem of the flat type multi line-cathode color television
tube such as liability to non-uniformity or irregular dis-
tortion of the horizontal lines in the raster can be relatively
easily overcome~ thus making the flat color tube useful in
practice and enabling the display of a high quality color
picture.
- 26 -
