A multiple color recording apparatus records on a sheet of recording paper, the magnitudes of a plurality of varying analog signals as a pattern of dots in different colors, and also records characters, symbols and the like related to the analog recording as a pattern of dots in desired colors.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a multiple-color recording apparatus for 
recording on a sheet of recording paper, the magnitudes of a plurality of 
varying analog signals as a pattern of dots in different colors, and also 
for recording characters, symbols and the like related to the analog 
recording as a pattern of dots in desired colors. 
2. Description of the Prior art 
Recording apparatus of the automatic balancing type for striking dots have 
heretofore been generally used to record the magnitudes of a plurality of 
analog input signals. The prior apparatus have an input switch for 
successively selecting the input signals to effect automatic balancing 
operation and dot striking recording. The known arrangements require a 
substantial amount of time (for example, several seconds) to record one 
dot and hence are not suitable for recording high speed operations. A 
complex mechanism would need to be added to include a function for 
skipping portions to be unrecorded, resulting in a complicated overall 
construction. Printing characters, symbols and the like related to the 
recording would require a mechanism for carrying out such printing. 
The foregoing problems experienced with conventional dot striking recording 
apparatus of the automatic balancing type have allegedly been solved by a 
recording apparatus disclosed in U.S. Pat. No. 4,074,273 issued on Feb. 
14, 1978 to Wayne P. Dupree, et al. The recording apparatus disclosed in 
that patent has a thermal head, movable to sweep in a direction normal to 
the direction of feed of a sheet of thermosensitive recording paper, for 
recording analog data with dots in the order of magnitudes of the data on 
the recording sheet and also for recording characters, symbols and the 
like related to the analog recording as a pattern of thermally printed 
dots. Printed data recording by the thermal dot printer are available only 
in a single color, and hence could not be identified clearly in the event 
the recordings crossed each other or were too crowded. 
Thus, there is still a deficiency in the art in this particular technical 
area. 
SUMMARY OF THE INVENTION 
Accordingly, an object of the invention is to overcome the aforementioned 
and other deficiencies and disadvantages of the prior art. 
Another object is to allow recorded data to be more easily identified by 
printing the data in multiple colors. 
A further object is to provide a multiple color recording apparatus which 
can easily be maintained and which can record data more inexpensively. 
Still another object is to provide a multiple color recording apparatus for 
printing data in multiple colors and at high speeds. 
The foregoing and other objects are attained by the invention which 
encompasses a multiple color recording apparatus comprising an input 
switching mechanism for successively selecting and delivering a plurality 
of analog input signals; a signal converter for converting the analog 
input signals delivered from the input switching mechanism into digital 
signals; a first memory for temporarily storing the digital signals 
supplied from the signal converter; a paper feed mechanism for feeding a 
sheet of recording paper; a recording head for recording dots in multiple 
colors on the sheet of recording paper, a head scanning mechanism for 
scanning the recording head; a second memory for temporarily storing a 
digital signal related to the position of the recording head; and a 
processing unit, operable on a predetermined program, for reading all data 
out of the first memory and data out of the second memory, and for 
detecting selected data out of the data stored in the first memory which 
has a minimum difference with the data stored in the second memory, and 
for moving the recording head along the direction of scanning by a 
selected space interval, in response to the minimum difference, and for 
enabling the recording head to print dots on the sheet of recording paper 
when the minimum difference falls to zero. 
The recording head may comprise an ink ribbon feeding mechanism for feeding 
an ink ribbon having strips of multiple colors along the direction of 
travel of the sheet of recording paper, and a dot striking mechanism 
having an array of dot striking pins arranged along a direction transverse 
(i.e. across) to the direction of travel of the sheet of recording paper 
and corresponding positionally to the plurality of strips of multiple 
colors. The dot striking pins are selectively actuatable for transfering 
desired colors from the ink ribbon to the sheet of recording paper. As an 
alternative, the recording head may comprise an ink jet head for ejecting 
droplets of ink in three primary colors spaced at intervals along the 
direction in which the recording head is movable. 
The above and other objects, features and advantages of the present 
invention will become more apparent from the following detailed 
description, when taken in conjunction with the accompanying drawings in 
which certain preferred embodiments are shown by way of illustration.

DETAILED DESCRIPTION OF THE PREFERED EMBODIMENTS 
FIG. 1 shows a multiple color recording apparatus comprising input 
terminals 1.sub.1 . . . 1.sub.n to which analog input signals are 
supplied; an input switching mechanism or multiplexer 2 for successively 
selecting and delivering the input analog signals fed from input terminals 
1.sub.1 . . . 1.sub.n ; an amplifier 3 for amplifying the selected input 
analog signals to a certain degree according to a set range of the 
apparatus; a signal converter or A/D converter 4 for converting the 
amplified analog signal into a corresponding digital signal; a first 
memory 5 for temporarily storing the output signal from the signal 
converter 4; a paper feed mechanism 7 having a pulse type motor, for 
example, for feeding a sheet of recording paper 6; a circuit 8 for driving 
the paper feed mechanism 7; and a recording head 9 for printing dots in 
multiple colors on the recording sheet of paper 6 in response to the input 
signals as selected. The recording apparatus also includes a circuit 10 
for driving the recording head 9; a head scanner 11 having a pulse type 
motor, for example, for scanning the recording head 9 in a direction 
normal to the direction of travel of the sheet of recording paper 6; a 
scanning circuit 12 for issuing a signal for driving the head scanner 11 
and issuing a digital signal related to the position of the recording head 
9; a second memory 13 for temporarily storing the digital signal delivered 
from the scanning circuit 12; a processing unit 14 such as a 
microprocessor; a memory 15 for storing characters, symbols and the like 
as dot patterns and also storing data concerning the sequence of 
operations of the recording apparatus; a display unit 16 for displaying 
information related to measurements; a circuit 17 for driving the display 
unit 16; a keyboard 18 for setting modes of operation of the recording 
apparatus, kinds of input signals, recording ranges, alarm settings, 
speeds of travel of the recording paper, and the like; an interface 19 for 
the keyboard 18; an input/output port 20; a battery 21 for backing up the 
memory units 5 and 13; an alarm circuit 22 for detecting any voltage drop 
in the battery 21; a driving string 23; and a panel P. Although not shown, 
an end detecting means may be disposed at least at one end of an area 
which the recording head 9 scans, for generating an end signal in response 
to arrival of recording head 9 at the end detecting means, to reset data 
indicative of the position of the recording head 9. 
The recording apparatus thus described is operable as follows. The analog 
signals fed to input terminals 1.sub.1 . . . 1.sub.n are successively 
selected, for example, at a period of 0.2 second per each dot by input 
switching mechanism 2 controlled by processing unit 14, and are supplied 
to amplifier 3. Amplifier 3, which may be a programmable gain amplifier, 
for example, is controlled by processing unit 14 so as to co-act with 
input switching mechanism 2, such that the magnitudes of the analog input 
signals, as amplified, will fall within a certain range. The amplified 
signals are converted into digital signals by signal converter 4, and then 
temporarily stored in first memory 5. The stored data are linearized, 
dependent on the kind of inputs, and stored as signals for being 
displayed, and also are converted into numerical values ranging, for 
example, from 0 to 2,500 corresponding to the width of 250 mm divided into 
increments of 0.1 mm so as to be recorded, and stored as such numerical 
value. Input switching mechanism 2, amplifier 3, and signal converter 4 
jointly constitute an analog processing section, which is connected to a 
digital processing section through a photocoupler that serves to insulate 
the digital processing section from the analog processing section. 
The sheet of recording paper 6, is caused by paper feed mechanism 7 
controlled by processing unit 14, to travel intermittenly stepwise each 
time recording head 9 is scanned. Recording paper 6 may comprise plain 
paper which is not specially treated. 
Recording head 9 may comprise an ink jet head, wire dot head, or the like. 
Where recording head 9 is an ink jet head, it is constructed in an manner 
that it will eject droplets of ink in three primary colors (e.g. cyan C, 
magenta M, yellow Y) spaced at intervals along the direction of travel of 
recording head 9, as illustrated in FIG. 3. Where recording head 9 is a 
wire dot head, it comprises, as shown in FIG. 4, an ink ribbon 91 which 
can travel along the direction of feed of the sheet of recording paper 6 
and which has a plurality of strips dyed in multiple colors extending 
along the direction of travel of the ink ribbon 91, and a dot striking 
mechanism 92 having a plurality of dot striking pins arranged in an array 
across (i.e. transverse to) the direction of feed of the sheet of 
recording paper 6, and corresponding positionally to the strips of 
different colors of ink ribbon 91. The dot striking pins are selectively 
actuatable to transfer desired colors from the ink ribbon 91 to the sheet 
of recording paper 6. 
FIG. 5 illustrates in detail such a wire dot head, which comprises an array 
of dot striking pins 92a, a plurality of return springs 92b, and a holder 
92c. Ink ribbon 91 is fed by a motor 93 mounted on an attachment base 94 
which is guided by a guide roller 95 along the direction of travel 
thereof. Ink ribbon 91 is composed of an endless ink ribbon guided by a 
guide member 96 and housed in an ink ribbon casing 100. Attachment base 94 
has therein six solenoids 92d for selectively energizing the dot striking 
pins 92a to move into holder 92c. 
The ink ribbon casing 100 comprises, as illustrated in FIG. 6, an opening 
101 for introducing therethrough the ink ribbon 91; feed rolls 102 and 
103; a chamber 104 containing the ink ribbon 91; an opening 105 for 
discharging therethrough ink ribbon 91; a sidewall 106 disposed in 
confronting relation to feed rolls 102 and 103; an outlet passage 107 for 
ink ribbon 91; a cylindrical projection 108 disposed adjacent to sidewall 
106 and having a height substantially equal to the width of ink ribbon 91; 
a sidewall 109 partially defining the outlet passage 107; an end 110 of 
the sidewall 109; a sidewall 111 contiguous to sidewall 106 and 
confronting sidewall 109; and a presser spring 112 fitted in outlet 
passage 107. 
Ink ribbon 91 will move into and out of ink ribbon casing 100 in the 
following manner. The ink ribbon 91, which may be endless, is introduced 
by feed rolls 102,103 through introducing opening 101 into casing 100, 
wherein ink ribbon 91 is gathered into folds, as depicted. Feed rolls 
102,103 may be rotated by motor 93 or may be driven by head scanner 11 in 
synchronization with movement of recording head 9. Ink ribbon 91 is 
discharged in an unfolded condition, through discharging opening 105, out 
of casing 100. More specifically, ink ribbon 91 is caused to be folded 
within casing chamber 104 by action of feed rolls 102, and 103, and is 
pressed against projection 108 which is adjacent to sidewall 106, as 
depicted. Projection 108 serves to tension ink ribbon 91 while the latter 
is unfolded and fed through discharge opening 105 and outlet passage 107, 
without getting jammed. Projection 108 also serves to allow ink ribbon 91, 
as folded, to be housed evenly within chamber 104. Projection 108 should 
preferably be located at a position more remote than end 110 of sidewall 
109 from sidewall 106. If, however, projection 108 were spaced too far 
away from sidewall 106, folded ink ribbon 91 would tend to become 
entangled around projection 108 and casing chamber 104 would become too 
small. To prevent such difficulties, the distance between projection 108 
and sidewall 106 should preferably be smaller than one half the folded 
length of ribbon 91, that is, the distance between sidewall 109 and 
sidewall 111. Projection 108 should be disposed centrally between sidewall 
109 and sidewall 111, since, for example, if projection 108 were displaced 
off to either sidewall 109 or sidewall 111, ink ribbon 91 would be housed 
out of balance in casing chamber 104. With this arrangement, ink ribbon 
91, as it is unfolded, is frictionally held against projection 108 so that 
ink ribbon 91 can be smoothly fed out through discharge opening 105 under 
frictional forces imposed by projection 108. Ink ribbon 91 is also put 
under tension by spring 112 in outlet passage 107 which is pressed against 
ink ribbon 91 as it passes through outlet passage 107 on the way out of 
ink ribbon casing 100. 
While in the embodiment shown in FIG. 6, spring 112 is separate and is 
disposed in outlet passage 107, spring 112 may be dispensed with and the 
sidewall 109 may be arranged to provide resilient action to ink ribbon 91 
while it goes through outlet passage 107. Projection 108 may be a separate 
member of a desired shape, which is attached to casing 100, or it may be 
formed integrally with casing 100. Alternatively, projection 108 may be 
integral with sidewall 106. Projection 108 may also be rendered rotatable. 
For example, another cylindrical member may be rotatably fitted over 
projection 108, or a member with a rotatable roller mounted thereon may be 
attached in place of projection 108. Such a rotatable projection 108 would 
tend to collect less dust while in operation. 
Recording head 9 thus constructed is controlled by head scanner 11 (see 
FIG. 1) under control of processing unit 14 to effect raster scanning, for 
example, in increments of 0.1 mm stepwise in a direction normal to the 
direction of travel of the sheet of recording paper 6. The positions which 
recording head 9 takes are converted into digital signals, which are 
temporarily stored in second memory 13. Although in the illustrated 
arrangement (see FIG. 1) the first memory 5 and second memory 13 are shown 
sharing a common memory unit, they may be formed of separate memory units. 
Processing unit 14 reads all data corresponding to the input signals 
temporarily stored in first memory 5 and data corresponding to the 
position of recording head 9 and temporarily stored in second memory 13, 
and detects selected data out of the data stored in first memory 5 which 
has a minimum difference with the data stored in second memory 13. 
Processing unit 14 causes recording head 9 to move along the scanning 
direction for a selected space interval, in response to such a minimum 
difference. When the minimum difference falls to zero, processing unit 14 
issues a control signal to enable recording head 9 to print a dot in a 
color which corresponds to the selected input signals. The recording 
positions for these colors are compensated for during delivery of the 
control signals. Such compensations are effected by adding to or 
subtracting from the input signals temporarily stored in first memory 5, 
signals indicative of phase differences between a reference element and 
elements of recording head 9 which are assigned to the input terminals, 
respectively, to print data in different colors. Two or more colors may be 
mixed as desired in the printing operation. The foregoing operation is 
repeatedly carried out while recording head 9 is scanned once, to thereby 
print the magnitudes of the input signals with dots in given colors. 
Processing unit 14 also serves to control the printing of characters, 
symbols and the like stored in memory 15 onto the sheet of recording paper 
6, the displaying operation of display unit 16, the changing of setting of 
parameters through keyboard 18, and other operations. The above operations 
are effected in accordance with a predetermined program in processing unit 
14. 
Panel P, shown in an enlarged scale in FIG. 7, includes display unit 16, 
keyboard 18, and the like. Panel P has a display section 16.sub.1 
including seven segment display elements for displaying date, hour, range, 
and alarm settings and index table 16.sub.2 for indicating the displayed 
data on display section 16.sub.1 ; a display section 16.sub.3 including 
seven segment elements for displaying the speed of travel of the sheet of 
recording paper; a lamp 16.sub.4 for indicating the end of the sheet of 
recording paper; a lamp 16.sub.5 for indicating a voltage drop of battery 
21; a switch 18.sub.1 for changing display modes for the display section 
16.sub.1 ; a switch 18.sub.2 for setting various parameters; a switch 
18.sub.3 for setting recording modes; a switch 18.sub.4 for setting the 
speed of feed of the sheet of recording paper and changing modes of 
operation for feeding the sheet of recording paper; and a switch 18.sub.5 
for temporarily fixing switches 18.sub.1 . . . 18.sub.4. Switches 18.sub.1 
. . . 18.sub.4 include built-in lamps, respectively, which are energizable 
when the associated switches are actuated. 
Display section 16.sub.1 displays "MONTH-DAY-HOUR-MIN" on the item "CLOCK" 
in index table 16.sub.2, when "CLOCK" in switch 18.sub.1 is actuated. It 
displays "CH NO.(channel number)-H/L (alarm condition)-DATA (magnitude of 
a measured signal)" on the item "DATA" in index table 16.sub.2 while the 
channels (30 channels at maximum according to the illustrative embodiment) 
are, for example automatically renewed every three seconds irrespective of 
the recording operation, when "DATA(AUTO)" in switch 18.sub.1 is actuated. 
It displays the contents on the item "DATA" in index table 16.sub.2 while 
data in a particular channel is renewed in response to actuation of "CH 
NO." of switch 18.sub.1, when "DATA(MAN)" in switch 18.sub.1 is actuated. 
Display section 16.sub.1 also displays parameter settings. 
Display section 16.sub.1 further displays the contents on the item "CLOCK" 
in index table 16.sub.2 when "CLOCK" in switch 18.sub.2 is selected. It 
displays the contents on the "Range" in index table 16.sub.2 when "RANGE" 
in switch 18.sub.2 is selected. It displays the contents on item "ALARM" 
in index table 16.sub.2 when "ALARM" in switch 18.sub.2 is selected. 
Switch 18.sub.2 contains four "SET" switches a,b,c,d for changing contents 
displayed in established modes. Switch a serves to shift designated 
figures to be changed on display section 16.sub.1 one figure at a time to 
the left. Switch b serves to shift such figures one figure at a time in 
the opposite direction. Switches c and d serve to reduce and increase, 
respectively, a numerical value in a designated figure one step at a time. 
"ENTRY" in switch 18.sub.2 causes the contents displayed in display 
section 16.sub.1 which are set by switches a,b,c,d to be temporarily 
stored in a memory. When the established content is permissible in each 
mode, the prior content is renewed. When the established content is not 
permissible, display section 16.sub.1 flickers as a whole to let the 
operator know that the setting is erroneous. In the setting modes, the 
designated figures are caused to be lighted at an intensity which is 
different from that of the other figures. 
In the "RANGE" mode, display section 16.sub.1 displays "CH NO. (channel 
number)-SKIP (indicative of whether there is skipping or not)-RANGE (kind 
of range)"- / (indicative of a lefthand end or righthand end)-VALUE OF / 
(set value at the lefthand end or righthand end)". Complete skipping is 
indicated by "-", analog recording only is indicated by "A", and both 
analog and digital recording is indicated by "P". The kinds of ranges are 
indicated in 16 displays which range from "O" to "F". The setting at the 
lefthand end or righthand end may be of any desired value provided it 
falls within a zone determined by the range selected. In this "RANGE" 
mode, the channel numbers may be individually designated and set, or five 
groups from "AO" to "EO" each containing six channels may be designated 
and set for simultaneous setting of the channels in one group, or all the 
channels indicated as "OO" may be set as a whole. In the "ALARM" mode, 
display section 16.sub.1 displays "RELAY NO. (relay number)-CH NO. 
(channel number)-H/L (alarm setting condition)-SETTING VALUE (alarm 
setting)". 
According to this embodiment, sixty relays may be combined as desired for 
the maximum thirty channels. In this mode, a desired alarm setting can be 
given to each relay for a desired channel. Where all of the channels are 
set for a common range, relays #1 . . . #30 may be controlled by "LO" to 
correspond to channels #1 . . . #30, and the relays #31 . . . #60 may be 
controlled by "HO" to correspond to channels #31 . . . #61, so that "LO" 
and "HO" can be set for an alarm setting common to all of the channels. 
"H" indicates an upper limit setting for the alarm. "L" indicates a lower 
limit setting for the alarm. "-" indicates no setting for the alarm. 
Individual display lamps and output terminals are provided, respectively, 
for the relays to indicate and deliver the outputs from the relays. Two 
additional display lamps are also provided which are energizable in 
response to operation of one relay in each group, and two additional 
output terminals are provided to deliver common output signals. These 
display lamps and output terminals may be constructed as a unit to be 
attached to the apparatus. Since alarm detecting operation is digitally 
effected after the outputsignal from amplifier 3 has been converted into a 
digital signal by signal converter 4 as shown in FIG. 1, the operation is 
stable with respect to a signal falling out of the recorded range on the 
sheet of recording paper 6 provided the alarm detection is within the 
operating range of amplifier 3. 
Switch 18.sub.3 serves to set the recording modes. In the "SCAN (AUTO)" 
mode, the scanning interval of recording head 9 is automatically varied in 
response to the speed of the feeding of the sheet of recording paper 6, so 
that the density of recorded dots on recording paper 6 will become 
constant irrespective of changes in the speed of travel of the sheet of 
recording paper 6. In the "SCAN(FIX)" mode, the scanning interval of 
recording head 9 is kept constant, (for example 8 seconds) at all times 
for dot printing. In the "LIST" mode, "CLOCK" information and contents set 
in "ALARM" and "RANGE" are printed with dots according to predetermined 
formats. In this mode, the speed of feed of recording paper 6 and the 
scannin interval of recording head 9 are automatically set for suitable 
values. Digital recording on blanks at the ends of the sheet of recording 
paper 6 is carried out according to a predetermined program in the "SCAN" 
modes, except the "LIST" mode. "CLOCK" information and designated "DATA" 
information are recorded at certain intervals of time or at certain 
intervals through which the sheet of recording paper 6 is fed. When an 
alarm signal is generated, such fact is recorded on recording paper 6 at 
the time of occurence of the alarm signal. 
The speed of travel of the sheet of recording paper 6 and the modes of 
operation are set by switch 18.sub.4. Switch 18.sub.4 includes three 
switches a,b,c which serve to change the setting for the figures in 
display section 16.sub.3 and can set each figure in the range of from "0" 
to "9". In the "STOP" mode, the feeding operation of the recording paper 6 
is stopped. The "START" mode starts feeding recording paper 6. When the 
"FEED" mode is selected, recording paper 6 is fed rapidly irrespective of 
a set speed. 
Switch 18.sub.5 serves, as described above, to fix temporarily, operation 
of switches 18.sub.1 . . . 18.sub.4 mounted on panel P. When switch 
18.sub.5 is locked, all of the other switches are fixed as selected so 
that they are protected against inadvertent or accidental actuation. 
With the arrangement of the present invention, the magnitudes of input 
signals supplied to the input terminals can be printed with dots in 
corresponding colors, and related characters, symbols and the like can 
also be recorded with dots in desired colors at high speeds while 
recording head 9 moves from one end to the other and back in the scanning 
zone. 
The recording head is of a relatively simple structure. Where the recording 
head is capable of printing data with dots in different colors spaced at 
intervals along the direction of travel of the head, it can produce 
superimposed multiple colors at folds of recording paper 6. 
No sliding mechanism is needed for feeding back signals of positions of the 
recording head, which will thus have a longer service life. Where the 
recording head comprises an ink jet head, no wear on the recording head is 
experienced, resulting in a prolonged operating life of the recording 
head. As ordinary plain paper can be used for recording paper 6, the cost 
of recording can be reduced. 
Control of the operations of the apparatus can be programmed or set with 
digital signals by operating keyboard 18 to set alarm values, change 
measurement ranges and speeds of feed of recording paper, record 
characters and symbols, skip unwanted measuring points, and perform other 
functions, without adding special mechanisms. The apparatus is therefore 
of a greatly simplified construction. 
While in the foregoing embodiment a pulse type motor is employed for the 
head scanner, the head scanner may comprise a combination of a synchronous 
motor or d.c. motor and an encoder. The recording head may be composed of 
a plurality of individual recording head units for printing dots 
respectively in multiple colors. 
The multiple color recording apparatus according to the present invention 
is of highly practical advantage in that it is of a relatively simple 
structure, has a variety of functions, can print data with multiple dots 
in multiple colors stably at high speeds, can produce recorded data easily 
identifiable or legible, can be maintained with ease, and can record data 
less expensively. 
Although certain preferred embodiments have been shown and described in 
detail, it should be understood that various changes and modifications may 
be made therein without departing from the spirit and scope of the 
appended claims.