BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a color identifying device for multicolor ink ribbon,
employed in a heat transfer color printer or the like and, more particularly, to a
color identifying device employing an optical sensor unit capable of identifying the
colors of a multicolor ink ribbon.
Description of the Prior Art
[0002] Fig. 1 is a front elevation of a conventional multicolor ink ribbon and Fig. 2 is
a perspective view of a conventional color identifying device for multicolor ink ribbon
of Fig. 1.
[0003] In Fig. 1, there are shown a multicolor ink ribbon 10, a yellow ribbon section 1,
a yellow identifying code la, a magenta ribbon section 2, a magenta identifying code
2a, a cyan ribbon section 3, a cyan identifying code 3a and a transparent section
10a. In Fig. 2, indicated at 20 is the main body of the color identifying device.
The main body 20 has the form of a generally U-shaped frame. A light emitting unit
21 is provided on one upright part 20a of the main body 20, while a light receiving
unit 22 is provided on the other upright part 20b of the same. The multicolor ink
ribbon is mounted on a printer so as to run through the gap between the light emitting
unit 21 and the light receiving unit 22.
[0004] The manner of operation of this conventional color identifying device will be described
hereinafter.
[0005] The light emitting unit 21 projects a specific light on the light receiving unit
22. The multicolor ink ribbon 10 runs at a fixed speed through the gap between the
light emitting unit 21 and the light receiving unit 22. The light emitted by the light
emitting unit 21 is intercepted for intervals corresponding to the respective lengths
A, B and C of the color identifying codes la, 2a and 3a; respectively. Thus the light
receiving unit provides output signals corresponding to the lengths A, B and C. The
multicolor ribbon section passing the color sensing position at present among the
color ribbon sections 1, 2 and 3 is identified on the basis of the time equivalent
signal of the output signal. Practically, the next color is decided on the basis of
time equivalent length of the color identifying code among the color identifying codes
la, 2a and 3a after the transparent section 10a.
[0006] The conventional color identifying device thus constituted needs to detect the lengths
of the color identifying codes la, 2a and 3a by converting the lengths into time equivalent
signals. Therefore, when the multicolor ink ribbon runs at a high speed, it is difficult
to surely identify minute intervals corresponding to the color identifying codes la,
2a and 3a and, sometimes, the color identifying device is unable to identify the minute
intervals or provides erroneous identification data.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to provide a useful color identifying
device eliminated of the above-mentioned disadvantages of the conventional color identifying
device.
[0008] It is another object of the present invention to provide a color identifying device
capable of directly and surely identifying the colors of the color sections of a multicolor
ink ribbon by means of color filters and associated optical system.
[0009] The above and other objects; features and advantages of the present invention will
become more apparent from the description of a preferred embodiment thereof taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Figure 1 is a front elevation of a conventional multicolor ink ribbon;
Figure 2 is a perspective view of a conventional color identifying device;
Figure 3 is a color identifying device, in a preferred embodiment, according to the
present invention for identifying the colors on a multicolor ink ribbon; and
Figure 4 is a front elevation of a multicolor ink. ribbon to be used in combination
with the color identifying device of Fig. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] A preferred embodiment of the present invention will be described with reference
to the accompanying drawings.
[0012] Referring to Fig. 3, the main body 30 of a color identifying device has the form
of a U-shaped frame. A yellow identifying light emitting unit 31, a magenta identifying
light emitting unit 32 and a cyan identifying light emitting unit 33 are provided
on one upright part 30a of the main body 30. A yellow identifying light receiving
unit 34, a magenta identifying light receiving unit 35 and a cyan identifying light
receiving unit 36 are provided on the other upright part 30b disposed opposite the
former upright part 30a. Indicated at 37, 38 and 39 are a yellow-transmissive color
filter, a magenta-transmissive color filter and a cyan-transmissive color filter,
respectively, which are disposed between the light emitting unit 31 and the light
receiving unit 34 for identifying yellow, between the light emitting unit 32 and the
light receiving unit 35 for identifying magenta and between the light emitting unit
33 and the light receiving unit 36 for identifying cyan, respectively.
[0013] A multicolor ink ribbon 50 as shown in Fig. 2 has a yellow ribbon section 1, a magenta
ribbon section 2 and a cyan ribbon section 3, which are arranged at fixed intervals.
[0014] The manner of operation of the color identifying device will be described hereinafter.
Light projected on the multicolor ink ribbon 50 by the light emitting units 31, 32
and 33 is transmitted through the color ribbon section, among the color ribbon sections
1, 2 and 3, passing across the light and reaches the three color filters 37, 38 and
39. Only one of the color filters 37, 38 and 39, corresponding to the color of the
color ribbon section transmits the light that has been transmitted through the color
ribbon section. For example, when the color of the transmitted light is magenta, only
the magenta-transmissive color filter 38 transmits the light, whereas the color filters
37 and 39 intercept the light or attenuate the light slightly. The magenta light that
has been transmitted by the magenta-transmissive color filter 38 falls on the light
receiving unit 35 disposed opposite the magenta-transmissive color filter 38. Then,
the light receiving unit 35 provides an electric signal to identify the color of the
color ribbon section passing across the light at this very moment. The yellow light
and the cyan light transmitted through the color ribbon sections 1 and 3, respectively,
can be identified in the same manner.
[0015] These three color filters employed in the present invention intercept or transmit
the light according to the color of the light, that is, according to the color of
the color ribbon section of the multicolor ink ribbon passing across the light at
this very moment, and hence the yellow-transmissive color filter, for instance, intercepts
all the light other than yellow light. Thus, these three color filters transmit only
yellow light, magenta light and cyan light, respectively. Accordingly, each light
receiving unit receives the transmitted light of the corresponding color and provides
an output signal specifying the color of the light to identify the color ribbon section
of the multicolor ink ribbon.
[0016] In this embodiment, the color identifying device is provided with three light emitting
units 31, 32 and 33, however, the same may be provided with a single light emitting
unit and, if necessary, the light may be the natural light. Furthermore, the color
identifying device may be provided, instead of those three light receiving units,
with a single light receiving unit capable of providing an electric signal corresponding
to the energy level of the light transmitted by each one of the color filters 37,
38 and 39 to identify the colors of the color ribbon sections 1, 2 and 3 on the basis
of the level of the electric signal.
[0017] As apparent from the foregoing description, according to the present invention, the
light transmitted through each color ribbon section of a multicolor ink ribbon is
transmitted selectively by only one specific color filter and the light that has passed
the specific color filter is detected to identify the color of the color ribbon section.
Accordingly, the color identifying device of the present invention is capable of identifying
the colors of the color ribbon sections of a multicolor ink ribbon more accurately
as compared with the conventional color identifying device which identifies the colors
of the color ribbon sections of a multicolor ink ribbon on the basis of the lengths
of color identification codes, namely, time equivalent detection signals. The present
invention is particularly effective in identifying the color ribbon sections of a
multicolor ink ribbon, when the ink ribbon runs at high speed. The ink ribbon to be
used on the color identifying device of the present invention need not be provided
with any special color code, and hence the cost thereof is reduced.
[0018] Although the invention has been described in its preferred form with a certain degree
of particularly, obviously many modifications and variation of the present invention
are possible in the light of the above teachings. It is therefore to be understood
that various changes and modifications may be made in the invention without departing
from the spirit and scope thereof.
1. A color identifying device comprising:
a) a main body having side walls disposed so as to form a gap through which a multicolor
ink ribbon runs;
b) light emitting units provided on one of said side walls;
c) three color filters corresponding to the three primary colors, respectively, and
disposed opposite said light emitting units, respectively; and
d) light receiving units provided on the other side wall of said main body so as to
receive the light that has passed the corresponding color filters, respectively.
2. A color identifying device according to Claim 1, wherein each one of said light
receiving units provides an electric signal corresponding to the energy level of the
light passed through the corresponding color filter, and the color of the ribbon section
is identified on the basis of the level of the electric signal.