EP0189574A2

EP0189574A2 - Color identifying device for multicolor ink ribbon

Info

Publication number: EP0189574A2
Application number: EP85116029A
Authority: EP
Inventors: Masayuki Mitsubishi Denki Kabushiki Kaisha Tanaka
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1985-01-28
Filing date: 1985-12-16
Publication date: 1986-08-06
Also published as: JPS61172783A; EP0189574A3

Abstract

A color identifying device for the color ribbon sections of a multicolor ink ribbon, capable of accurate color identification. comprising three color filters corresponding to the three primary colors, respectively, disposed opposite light emitting units, respectively, and light receiving units disposed on optical axes passing the light emitting units and the corresponding color filters, respectively.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

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

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.
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.
The manner of operation of this conventional color identifying device will be described hereinafter.
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.
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

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.
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.
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

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

A preferred embodiment of the present invention will be described with reference to the accompanying drawings.
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.
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.
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.
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.
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.
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.
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.

Claims

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.