Color ink ribbon and printer using this ribbon

A color ink ribbon comprising a ribbon body on which a plurality of colors are sequentially aligned in a ribbon feeding direction, color recognition marks which sequentially represent next colors on the ribbon body by bar code information, and ribbon speed detection marks formed on the ribbon body at equal intervals in the ribbon feeding direction. The bar code marks and the speed detections marks are used together with a compensation coefficient to determine the identity of the subsequent color portion on the ink ribbon body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an improvement of a color ink ribbon and a 
printer using this ribbon. 
2. Description of the Related Art 
In a color ink ribbon used for, e.g., a color bar code printer, three 
primary colors, i.e., yellow (Y), magenta (M), and cyan (C) are 
sequentially aligned in the ribbon feeding direction. In addition, color 
recognition marks (bar codes) representing the types of primary color are 
formed immediately before portions of the three primary colors. A detector 
is arranged in a printer using this color ink ribbon to detect a color 
recognition mark of each of the three primary colors. The next color of 
the ink ribbon fed by a ribbon drive motor is detected in accordance with 
a detection output (i.e., a color recognition mark read output) from this 
detector. More specifically, black level detection outputs from the color 
recognition mark detector are counted to recognize a bar code width of 
each color recognition mark in accordance with the count. If the 
recognized bar code width is only width a, the color is discriminated as 
yellow (Y). If the width is a combination of width a and width 2a, the 
color is discriminated as magenta (M). If the width is only width 2a, the 
color is discriminated as cyan (C). Cuing of the ink ribbon corresponding 
to printing data is performed, and then a color image is printed on paper 
by a thermal head or the like. 
Most of the color ink ribbon is wound around a ribbon supply core in an 
initial condition, and the color ink ribbon is sequentially supplied upon 
constant-speed rotation of the ribbon drive motor and is taken up by a 
ribbon take-up core. In an end condition, the most of the ribbon has 
already been taken up by the ribbon take-up core. Therefore, the ink 
ribbon feeding speed in the initial condition is different from that in 
the end condition. In particular, when the overall length of the ribbon is 
large or a core diameter is small, a speed difference is large. 
Since a color to be fed next is determined by recognizing the width of a 
bar code formed on the ink ribbon, as described above, a large speed 
difference tends to cause color discrimination errors because the width of 
each bar code is erroneously detected. For this reason, an ink ribbon 
having a small overall length or a large core is conventionally used to 
overcome the above problem. 
As described above, in the conventional color ink ribbon, since each bar 
code represents only the next color, color discrimination is erroneously 
performed by a change in ribbon feeding speed. For this reason, only a 
wasteful color ink ribbon having a small overall length or a large core is 
used in a color printer to always perform accurate color discrimination. 
SUMMARY OF THE INVENTION 
The present invention has been made in consideration of the above 
situation, and has as its object to provide a color ink ribbon capable of 
giving color information and ribbon feeding speed information. A bar code 
detection error caused by a change in ribbon feeding speed can be 
corrected on the basis of the ribbon feeding speed information, and the 
color to be fed next can always be discriminated. 
It is another object of the present invention to provide a printer capable 
of accurately discriminating the color to be fed next by using the above 
color ink ribbon, of eliminating an influence of a color discrimination 
result caused by a change in ink ribbon feeding speed, and of using an 
economical color ink ribbon having a small ink ribbon take-up core 
diameter and a large overall length. 
A color ink ribbon of the present invention has color recognition marks 
representing types of color and formed on a ribbon body on which a 
plurality of colors are sequentially aligned in a ribbon feeding 
direction, and ribbon speed detection marks are formed at equal intervals 
along the ribbon feeding direction. 
A printer according to the present invention comprises a first mark 
detector for detecting a color recognition mark formed on a color ink 
ribbon, a second mark detector for detecting a ribbon speed detection mark 
formed on the same color ink ribbon, speed recognizing means for detecting 
a feeding speed of the same color ink ribbon on the basis of a detection 
output from said second mark detector, and color discriminating means for 
discriminating the next color on the basis of the ribbon feeding speed 
recognized by the speed recognizing means and a detection output from the 
first mark detector. 
In the color ink ribbon of the present invention, since the ribbon speed 
detection marks are formed at predetermined intervals (e.g., equal 
intervals) in the ribbon feeding direction, the interval between the 
ribbon speed detection marks is detected during ribbon feeding, and 
therefore a ribbon feeding speed can be recognized. A read color 
recognition mark is corrected by the ribbon feeding speed, and the next 
color is discriminated, thereby performing accurate color discrimination. 
In the printer of the present invention, when the color ink ribbon is fed 
through a drive mechanism, the color recognition mark formed on the ink 
ribbon is detected by the first mark detector. The ribbon speed detection 
marks formed on this ink ribbon at the predetermined intervals are 
detected by the second mark detector. The ribbon feeding speed is 
recognized by the intervals between the ribbon speed detection marks in 
accordance with the detection outputs from the second mark detector. The 
color recognition mark (bar code) represented by the detection output from 
the first mark detector is corrected on the basis of the recognized ribbon 
feeding speed, thereby discriminating the next color. In the printer 
having the above arrangement, cuing of this ink ribbon is performed on the 
basis of printing data, and desired color data is printed on paper through 
the printing head. 
Additional objects and advantages of the invention will be set forth in the 
description which follows, and in part will be obvious from the 
description, or may be learned by practice of the invention. The objects 
and advantages of the invention may be realized and obtained by means of 
the instrumentalities and combinations particularly pointed out in the 
appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of the invention will be described with reference to 
the accompanying drawings. In the description the same or similar elements 
are denoted by the same or similar reference numerals, in order to 
simplify the description. 
FIG. 1 is a view showing color ink ribbon 10 according to an embodiment of 
the present invention, three primary colors, i.e., yellow (Y), magenta 
(M), and cyan (C) are sequentially aligned on ribbon body 11 in a ribbon 
feeding direction (i.e., a direction of thick arrow L in FIG. 1), and 
color recognition marks 12 representing the types of primary color in the 
form of bar code information are formed immediately before the respective 
primary colors. In this embodiment, yellow (Y) is represented by color 
recognition mark 12Y consisting of bar code information of width a. 
Magenta (M) is represented by color recognition mark 12M consisting of bar 
code information of width a and width 2a. Cyan (C) is represented by color 
recognition mark 12c consisting of bar code information of width 2a. 
Ribbon speed detection marks 13 consisting of black bars at equal 
intervals b are formed in ribbon feeding direction L of ribbon body 11. 
FIGS. 2 and 3 are sectional views illustrating an arrangement of a color 
bar code printer 20 using the above color ink ribbon 10. FIG. 2 shows a 
printing state, and FIG. 3 shows a paper feedback state and a cuing state 
of color ink ribbon 10. In the figure, a paper roll is denoted by numeral 
21. Paper 22 wound around a paper holder is conveyed by pinch roller 27 
and platen 28 rotated counterclockwise through belts 25 and 26 looped 
around pulley 24 upon forward rotation of feeding motor 23. Paper 22 is 
then exhausted outside printer 20 through paper exhaust port 29. 
In a feedback mode (FIG. 3), paper 22 is conveyed by pinch roller 27 and 
platen 28 rotated clockwise upon reverse rotation of feeding motor 23 and 
is then drawn inside printer 20 from paper exhaust port 29. 
In a printing mode (FIG. 2), color ink ribbon 10 wound around supply core 
30 is fed by platen 28 rotated counterclockwise upon forward rotation of 
feeding motor 23. Color ink ribbon 10 is taken up by take-up core 31 
rotated clockwise through belt 35 arranged on pulley 34 upon forward 
rotation of ribbon motor 33. In this case, thermal head 32 serving as a 
printing head abuts against platen 28 through color ink ribbon 10 and 
paper 22. Desired bar code data is printed in color on paper 22. 
In a cuing mode (FIG. 3) of color ink ribbon 10, thermal head 32 is 
separated from platen 28, and ribbon 10 is taken up by ribbon take-up core 
31 rotated clockwise upon forward rotation of ribbon motor 33. 
Reference numerals 36 and 37 respectively denote first and second mark 
detectors each consisting of a pair of light-emitting and light-receiving 
sensors arranged to oppose each other through color ink ribbon 10. First 
mark detector 36 detects color recognition mark 12 on color ink ribbon 10, 
and second mark detector 37 detects ribbon speed detection mark 13 on 
color ink ribbon 10. 
FIG. 4 is a block diagram showing a control circuit of color bar code 
printer 20. Reference numeral 40 denotes a CPU (or microcomputer) serving 
as a controller. CPU 40 is connected to ROM (Read-Only Memory) 41 for 
storing permanent data such as programs and a character generator, RAM 
(Random Access Memory) 42 for storing variable data required for 
controlling the respective components in FIG. 4, interface 43 for external 
devices for receiving printing data from external devices (not shown), and 
keyboard controller 45 for keyboard 44 on which various keys such as a 
start key and a stop key are arranged. The circuit of FIG. 4 also includes 
head driver 46 for thermal head 32, and I/O (Input/Output) port 47 for 
outputting a drive signal from CPU 40 to ribbon motor 33 and feeding motor 
23 and supplying detection signals from first and second mark detectors 36 
and 37 to CPU 40. 
The processing shown in a flow chart of FIG. 5 is executed by CPU 40. More 
specifically, when CPU 40 detects that a black bar detection output from 
second mark detector 37 during the operation (YES in ST10), relative 
interval b between adjacent two ribbon speed detection marks 13 is 
obtained from time difference t between the previous detection output and 
the present detection output (ST12). Feeding speed v of color ink ribbon 
10 is calculated by the following equation on the basis of relative 
interval b: 
EQU v=b/t (1) 
When a detection output from first mark detector 36 is present (YES in 
ST14), color recognition data identified by widths a and 2a of color 
recognition mark (bar code) 12 is fetched (ST16). This color recognition 
data is corrected by the following equation on the basis of the calculated 
ribbon feeding speed v (ST18). 
Period ta for detecting detection mark width a is given as: 
EQU ta=a/v (2) 
Correction coefficient C for detecting width a is given as: 
EQU C=ta/t=(a/b; constant) (3) 
Period t2a for detecting detection mark width 2a is given as follows: 
EQU t2a= 2a/v= 2ta (4) 
Correction coefficient D for detecting width 2a given as follows: 
EQU D=t2a/t= 2ta/t= 2C (constant) (5) 
The types of primary color arranged on the ink ribbon body are 
discriminated on the basis of corrected color recognition data (a or 2a) 
multiplied with coefficient C or D (ST20). That is, if the bar code width 
of the color recognition data is only width a, then color recognition data 
is discriminated to represent yellow (Y); if a and 2a, then magenta (M); 
if only 2a, then cyan (C). Ribbon cuing is controlled in accordance with 
desired printing data on the basis of this color discrimination result. 
In this embodiment having the above arrangement, in the printing mode, 
paper 22 and color ink ribbon 10 are fed upon rotation of platen 28, and 
the feeding speed of paper 22 is equal to that of color ink ribbon 10. In 
the paper feedback mode or the cuing mode, paper 22 is fed at a constant 
speed upon rotation of platen 28. However, since color ink ribbon 10 is 
taken up by ribbon take-up core 31 upon its rotation, the feeding speed of 
color ink ribbon 10 varies depending on the diameter of the ribbon take-up 
portion. 
In this embodiment, color ink ribbon 10 is almost wound around ribbon 
supply core 30 in the initial condition of color ink ribbon 10, as shown 
in FIG. 6. The diameter of ribbon take-up core 31 including a ribbon 
portion is M as the diameter of the ribbon take-up core 31. In the initial 
condition, since the ribbon feeding speed is low, a detection signal for 
color recognition mark 12M of magenta (M) from first mark detector 36 is 
generated such that bar code information of width a is read during a time 
interval between time t1 and time t3, and bar code information of width 2a 
is read during a time interval between time t5 and time t9. 
To the contrary, in the end condition of color ink ribbon 10, as shown in 
FIG. 8, most of color ink ribbon 10 is taken up by ribbon take-up core 31, 
and the diameter of ribbon take-up core 31 including a ribbon portion 
becomes, e.g., 2M. In the end condition, the ribbon feeding speed becomes 
twice that in the initial condition. A detection signal for color 
recognition mark 12M of, e.g., magenta (M) from first mark detector 36 is 
generated such that bar code information of width is read during a time 
interval between time t1 and time t2, and bar code information of width 2a 
is read during a time interval between time t3 and time t5. 
In this embodiment, ribbon speed detection marks 13 formed on color ink 
ribbon at equal intervals in the ribbon feeding direction are detected by 
second mark detector 37, and the feeding speed (v) of ink ribbon 10 is 
calculated in accordance with a relative change in mark intervals. The 
detection signal (a or 2a) from first mark detector 36 is corrected (xC or 
xD), and color recognition mark 12 on ink ribbon 10 is decoded by the 
corrected data. The next color is then determined to control cuing. 
In this case, the ribbon feeding speed in the initial condition of color 
ink ribbon 10 is given as reference speed (v0), and a detection output 
from first mark detector 36 may be corrected in proportion (v0+ 
.DELTA.v)/v0) to a change in speed with respect to the reference speed 
(v0). For example, since the ribbon feeding speed in the end condition is 
twice the reference speed, output data (FIG. 9) from first mark detector 
36 is doubled. The corrected output coincides with the detection output 
shown in FIG. 7, and the next primary color can be discriminated as 
magenta (M). 
In this embodiment, since ribbon speed detection marks 13 are formed on 
color ink ribbon 10 in the ribbon feeding direction, a change in speed or 
a speed change correction coefficient (C or D) of color ink ribbon 10 can 
be calculated by a detection interval of marks 13. The detection output of 
color recognition mark 12 is corrected on the basis of the change in speed 
of the ribbon or its correction coefficient, and the next primary color 
can be discriminated, thereby always performing accurate color 
discrimination. 
As a result, speed control can cope with a great change in speed between 
the initial condition and the end condition. Therefore, color ink ribbon 
10 having a small core diameter and a large overall length can be used in 
printer 20, thereby reducing expenses. 
In addition, since accurate color discrimination can be performed even if a 
ribbon having a small core diameter which causes a change in ribbon 
feeding speed is used, a large-capacity color bar code printer ribbon can 
be formed in practice. 
In the above embodiment, the feeding speed in the ribbon initial condition 
is given as the reference speed (v0), but is not limited to this. Since it 
is necessary to detect only a relative change in speed, correction can be 
performed using the feeding speed of the end condition as the reference 
speed. 
In addition, black bars are exemplified as ribbon speed detection marks 13 
in the embodiment of FIG. 1. However, holes 13H may be formed along one 
side of ribbon 10, as shown in FIG. 10, or projections 13X may be formed 
along one side of ribbon 10, as shown in FIG. 11. 
As shown in FIG. 12, four types of width marks 13-1 to 13-4 arranged at 
equal intervals (b) repeated by predetermined period T may be used for 
speed detection. 
Alternatively, as shown in FIG. 13, four types of intervals (b1 to b4) 
repeated at predetermined period T may be used for speed detection. 
Furthermore, as shown in FIG. 14, parts (13Y, 13M, and 13C) of speed 
detection marks 13 may be formed by Y, M, and C inks. 
The embodiment shown in FIG. 1 exemplifies color ink ribbon 10 having three 
primary colors. However, the present invention is applicable to a color 
ink ribbon having at least two arbitrary colors (e.g., red and black). 
Various changes and modifications may be made without departing the spirit 
and scope of the invention. 
FIG. 15 is a flow chart explaining how the color of an ink ribbon is 
determined. 
When the feeding of ink ribbon 10 starts, the feeding speed is calculated 
from each interval b of the speed detection marks (ST21). This calculation 
corresponds to step ST12 in FIG. 5. The width a or 2a of color 
discrimination mark 12 is compensated for in accordance with the 
calculated feeding speed. This compensation corresponds to step ST18 in 
FIG. 5. 
If neither color discrimination mark 12 of width a (thin bar code) nor that 
of width 2a (thick bar code) is detected (ST22 NO; ST23 YES), the process 
returns to step ST21. 
When color discrimination mark 12 of width a is detected (ST22 YES), after 
elapsing a time period required to detect the discrimination mark of with 
a, it is checked whether or not color discrimination mark 12 of width 2a 
is detected (ST24). If, at this time, mark 12 of width 2a is not detected, 
(ST24 NO), the feeding operation of ink ribbon 10 is stopped (ST25), and 
the positioning of the tip of the cyan part is completed (ST26) 
When color discrimination mark 12 of width 2a is detected after elapsing 
the time period required to detect the discrimination mark of with a (ST24 
YES), the feeding operation of ink ribbon 10 is stopped (ST27), and the 
positioning of the tip of the yellow part is completed (ST28). 
When color discrimination mark 12 of width a is not detected (ST22 NO) but 
color discrimination mark 12 of width 2a is detected (ST23 YES), the 
feeding operation of ink ribbon 10 is stopped (ST29), and the positioning 
of the tip of the magenta part is completed (ST30). 
The above process for positioning the tip of each of cyan, yellow, and 
magenta corresponds to step ST20 in FIG. 5. 
As has been described above, the present invention has the following 
features. 
(i) There is provided a color ink ribbon wherein the next color can be 
represented by bar code information, and at the same time the ribbon 
feeding speed information can also be provided. A bar code width detection 
error caused by a change in speed can be compensated on the basis of the 
speed information, and the color to be fed next can be accurately 
discriminated. 
(ii) There is also provided a printer wherein the next color can be 
accurately discriminated by using the color ink ribbon described above, 
and the influence of the color discrimination result by a change in 
feeding speed of the ink ribbon can be eliminated, and an economical color 
ink ribbon having a small core diameter and a large overall length can be 
used. 
While the invention has been described in connection with what is presently 
considered to be the most practical and preferred embodiment, it is to be 
understood that the invention is not limited to the disclosed embodiment 
but, on the contrary, is intended to cover various modifications and 
equivalent arrangements included within the scope of the appended claims, 
which scope is to be accorded the broadest interpretation so as to 
encompass all such modifications and equivalent arrangements.