Printer ribbon colour detection

Abstract: A first sensor 102 has a characteristic in that light generated from an associated light-emitting unit penetrates yellow, magenta and clear patches 810, 820, 801-3, 701-3 but does not penetrate cyan and black patches 830, 700a-700c, 600 of an ink ribbon 600, 700, 800. A second sensor 202 installed on a straight line with the first sensor 102 widthwise of the ink ribbon has a characteristic in that light generated from an associated light-emitting unit penetrates the yellow and clear patches of the ink ribbon but does not penetrate magenta, cyan and black patches. A third sensor 204 installed on an opposite side of the first and second sensors 102, 202 widthwise of the ink ribbon, but not on a straight line with the first and second sensors 102, 202, has a characteristic in that light generated from an associated light-emitting unit penetrates the yellow and clear patches but does not penetrate the magenta, cyan and black patches. First and a second reflecting panels 302, 304 reflect the light generated by the light emitting unit of the first, second and third sensors to respective light-receiving units thereof. The apparatus can be used in a method to distinguish between a colour ribbon 800, a black ribbon 700 with clear patches and a black ribbon 600 without clear patches in a sublimating type colour printer.

Description: The present invention relates to printer ribbon colour detection. Figure 1 of the accompanying diagrammatic drawings is a drawing of a conventional colour printer for illustrating how to distinguish a colour ink ribbon 100 having a yellow patch 100a, magenta patch 100b and cyan patch 100c continuously coated with three colours (yellow, magenta and cyan) of sublimating type ink. There are formed transparent and colourless clear patches 30, 31 and 32 between the yellow patch 100a, magenta patch 100b and cyan patch 100c. Black markings (30a) (31a) (32a, 32b) are formed on each clear patch 30, 31 and 32 in order to distinguish the yellow patch 100a, magenta patch 100b and cyan patch 100c of the colour ink ribbon 100. A known apparatus for distinguishing the aforesaid colour ink ribbon 100 comprises: first and a second sensors 10 and 20 each having a light-emitting element and a light-receiving element, and first and second reflecting panels 10a and 20a for reflecting to the light-receiving elements the light generated from the first and second light-emitting elements of the sensors 10 and 20. Accordingly, in Figure 1, if the colour ink ribbon 100 is moved thereby to locate the clear patch 30 between the first and second sensors 10 and 20 and the first and second reflecting panels 10a and 20a, the light generated by the light-emitting element of the first sensor 10 passes through the colour ink ribbon 100 thereby to be reflected at the first reflecting panel 10a. However, the light generated by the light-emitting element of the second sensor 20 cannot penetrate the black marking 30a, so that the same cannot be incident upon the light-receiving element. Accordingly, a signal of high level is output from the first sensor 10 and a signal of low level is output from the second sensor 20. As mentioned in the aforesaid, if the signals of high level and low level are respectively output from the first and second sensors 10 and 20, a microcomputer (not shown) recognizes the yellow patch 100a. Likewise, if the colour ink ribbon 100 is moved thereby to locate the clear patch 31 between the first and second sensors 10 and 20 and the first and second reflecting panels 10a and 20a, the first sensor 10 outputs a signal of low level by way of the black marking 31a, and the second sensor 20 outputs a signal of high level. As seen from the foregoing, if the low level and high level of signals are respectively output from the first and second sensors, the microcomputer recognizes the magenta patch 100b. Furthermore, if the colour ink ribbon 100 is moved thereby to dispose the clear patch 32 between the first and second sensors 10 and 20 and the first and second reflecting panels 10a and 20a, the first and second sensors 10 and 20 respectively output signals of low levels by way of the black markings. If signals of low levels are respectively output from the first and second sensors 10 and 20, the microcomputer recognizes the cyan patch 100c. However, by the method thus described, there has been a problem in that a black marking has been needed on an ink ribbon in the case of colour recognition and at the same time, in the case of a black and white ribbon, as opposed to a colour ribbon, it has been impossible to distinguish the colour ribbon from the black and white ribbon. In other words, in the event that the black and white ink ribbon is mistakenly used in lieu of the colour ribbon, there has been a problem in that no control can be performed in the printer. Furthermore, because the first end of the black and white ink ribbon cannot be detected, there has been a problem in that the ink ribbon has been excessively consumed and there have been errors on the part of consumers. US 5,037,218 and JP-A-60154093 disclose the use of red and green sensors which, in combination, examine an area of the ribbon and determine the colour as cyan, yellow, magenta or black. Reference is also made to EP-A3-0189574 which uses three separate colour filters corresponding to the three primary colours such that one sensor provides an output signal in response to each colour. Further, reference is made to EP-A-0620119 which discloses an arrangement of three sensors with a first sensor positioned over a dye area of the ribbon, and the second and third sensors positioned over coded areas in a margin alongside the colour area of the ribbon to determine the colour and position of the ribbon. Preferred embodiments of the present invention aim to solve the aforementioned problems and to obtain a colour printer for enabling use of both colour ink ribbon and black and white ink ribbon. According to one aspect of the present invention, there is provided a method of detecting colour in a printer ink ribbon, characterised by: a first step of arranging first, second and third sensors to detect light transmitted through the ink ribbon; a second step of transferring the ink ribbon in a forward direction for a predetermined period of time thereby to recognize the same as a black and white ribbon with no clear patches if there is no change in an output of the second sensor; a third step of recognising the ink ribbon as a black and white ink ribbon having clear patches if the third sensor is in an ink ribbon impenetrable state, when there is a change in the output of the second sensor and the first sensor changes from an ink ribbon impenetrable state to an ink ribbon penetrable state; and a fourth step of recognizing the ink ribbon as a colour ink ribbon if, at the third step, the third sensor is in an ink ribbon penetrable state. A method as above may comprise: a step of discriminating a yellow patch in the ink ribbon thereby to print yellow if the ribbon is recognized as the colour ink ribbon; a step of discriminating a magenta patch in the ink ribbon, thereby to print magenta if light generated in association with the second sensor is not detected thereby as penetrating the ink ribbon after yellow has been printed and the colour ink ribbon has been transferred in a forward direction; and a step of discriminating a cyan patch in the ink ribbon thereby to print cyan if light generated in association with the first sensor is not detected thereby as penetrating the ink ribbon after magenta has been printed and the colour ink ribbon has been transferred in the forward direction. If the ink ribbon is recognized as the black and white ink ribbon having no clear patches, printing may be performed after the black and white ink ribbon has been transferred in a reverse direction by the same distance as the transfer in the forward direction. The ribbon may be transferred in a reverse direction for a predetermined period of time thereby to perform printing if the ribbon is recognized as the black and white ink ribbon having no clear patches. Preferably, the predetermined period of time is the time taken to transfer the ink ribbon between clear patches formed on both sides of a colour patch. According to another aspect of the present invention, there is provided a printer ink ribbon distinguishing apparatus comprising: a first sensor having a characteristic in that light generated by an associated light-emitting unit penetrates yellow, magenta and clear patches of the ink ribbon but does not penetrate cyan and black patches; a second sensor for being installed on a straight line with the first sensor widthwise of the ink ribbon and having a characteristic in that light generated by an associated light-emitting unit penetrates yellow and clear patches of the ink ribbon but does not penetrate magenta, cyan and black patches; and a third sensor for being installed on an opposite side of the first and second sensors widthwise of the ink ribbon but not on a straight line with the first and second sensors, and having a characteristic in that light generated by an associated light-emitting unit penetrates yellow and clear patches but does not penetrate magenta, cyan and black patches. An apparatus as above may comprise first and second reflecting elements for reflecting light generated by the respective light emitting units of the first, second and third sensors to respective light-receiving units thereof. The first and second sensors and the third sensor may be installed on a place free from black markings of the ribbon. Preferably, the first, second and third sensors each comprise a light-emitting unit and a light-receiving unit. Preferably, a light-emitting unit associated with the first sensor includes a red light-emitting diode. Preferably, light-emitting units associated with the second and third sensors each include a green light-emitting diode. Preferably, the first and second sensors are installed on a straight line widthwise of the ink ribbon, while the third sensor is installed on an opposite side widthwise of the ink ribbon and installed within a patch length of one colour lengthwise of the ribbon from the first and second sensors. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to Figures 2 and 3 of the accompanying diagrammatic drawings, in which: Figure 2 is a drawing for illustrating one example of a ribbon distinguishing method in accordance with the present invention, wherein Figure 2(a) is a drawing for explaining a method to distinguish a black and white ribbon having no clear patch, Figure 2(b) is a drawing for explaining a method to distinguish a black and white ribbon having a clear patch, and Figure 2(c) is a drawing for explaining a method to distinguish a colour ribbon; and Figure 3 is a flow chart for explaining an example of a printer ribbon distinguishing method in accordance with the present invention. In the figures, like reference numerals denote like or corresponding parts. Figure 2(a) is a drawing for explaining a method as to how to distinguish a black and white ribbon 600 having no clear patch, Figure 2(b) is a drawing for explaining a method as to how to distinguish a black and white ribbon 700 comprising clear patches (701, 702, 703,... ) and black patches (700a, 700b, 700c,...) and Figure 2(c) is a drawing for explaining a method as to how to distinguish a colour ribbon 800 comprising a yellow patch 810, magenta patch 820, cyan patch 830 and clear patches (801, 802, 803,...). The printer ribbon distinguishing apparatus as illustrated in Figure 2, comprises: a first sensor 102 having a characteristic in that light generated by a light-emitting unit thereof penetrates yellow, magenta and clear patches but does not penetrate cyan and black patches; a second sensor 202 installed adjacent to the first sensor 102 on a straight line with the first sensor 102 across the ink ribbon (600, 700 or 800) and having a characteristic in that light generated from a light-emitting unit thereof penetrates yellow and clear patches of the ink ribbon but does not penetrate magenta, cyan and black patches; a third sensor 204 installed on an opposite side of the first and second sensors 102 and 202 across the ink ribbon (600, 700 or 800) but not on a straight line with the first and second sensors (102 and 202), and having a characteristic in that light generated by a light-emitting unit thereof penetrates yellow and clear patches but does not penetrate magenta, cyan and black patches; and first and second reflecting panels 302 and 304 for reflecting the light generated from the light emitting units of the first, second and third sensors (102, 202 and 204) to light-receiving units thereof. The light-emitting unit of the first sensor 102 comprises a red light-emitting diode LED, and that of the second and third sensors 202 and 204 each comprises a green LED. Accordingly, the light generated by the light-emitting unit of the first sensor 102 has a characteristic in that it penetrates yellow, magenta and clear patches but does not penetrate cyan and black patches. The light generated by the light-emitting unit of the second and third sensors 202 and 204 has a characteristic in that it penetrates yellow and clear patches but does not penetrate magenta, cyan and black patches. The first and second sensors 102 and 202, as illustrated in Figure 2(b), are installed on a straight line with the clear patch (701, 702 or 703), and the third sensor 204 can be installed anywhere as long as it is within a length L from the first and second sensors 101 and 202 within any colour patch. Figure 3 is a flow chart for explaining an example of a printer ribbon distinguishing method in accordance with the present invention. If printing is started, the ink ribbon is transferred in a right (or forward) direction at step S102, and a discrimination is made at step S104 as to whether an output of the second sensor 202 has changed within a predetermined period of time t(High→Low,Low→High). Here, the predetermined period of time t is, as illustrated in Figure 2(b), the time taken for an ink ribbon to cover a distance (1) between one of the colour patches (700a, 700b and 700c) and clear patches respectively formed on either side of the colour patch. As a result of the discrimination step S104, if there is no change, the microcomputer recognizes the ink ribbon as a black and white ink ribbon with no clear patches (600, see Figure 2(a) at step S202. In other words, the light coming out of the light-emitting unit of the second sensor 202 penetrates yellow and clear patches, and the ribbon is transferred for the predetermined period of time t. If there is no change in the output of the second sensor 202, the ink ribbon is recognized as a black and white ink ribbon 600 having no clear patch, as illustrated in Figure 2(a). As seen from the foregoing, if the ribbon is recognized as a black and white ink ribbon 600 having no clear patch at step S202, the black and white ink ribbon 600 is transferred backwards for the predetermined period of time t at step S204, thereafter to perform a printing operation at step S206. In other words, the printing operation is performed after the black and white ink ribbon 600 has returned back to its original position. If there has been any change in the output of the second sensor 202 at step S104, the microcomputer discriminates at step S106 whether the output of the first sensor 102 has changed from an impenetrable state (Low) to a penetrable state (High). As a result of the discrimination at step S106, if the output of the first sensor 102 has not changed from the impenetrable state to the penetrable state, the ink ribbon is kept transferring to the right direction at step S108 thereby to repeat the step S106. In other words, because the light output from the light-emitting unit of the first sensor 102 cannot penetrate a cyan patch or a black patch, a continued discrimination is performed as to whether the ribbon has been transferred from a black patch of Figure 2(b) (700a, 700b or 700c) to a clear patch (702 or 703... ), or transferred from a cyan patch 830 of Figure 2(c) to the clear patch 801 . As mentioned in the aforegoing, if the output of the first sensor 102 has changed from impenetrability to penetrability during the repeated performance of steps S106 and S108, the computer discriminates at step S110 whether the light generated from the light-emitting unit of the third sensor 204 can penetrate the ink ribbon. As a result of the discrimination at step S110, if the light cannot penetrate, the computer recognizes the ribbon as the black and white ink ribbon (700; see Figure 2(b)) at step S302. In other words, if the first and second sensors 102 and 202 are positioned on the clear patch 701 of Figure 2(b) or the clear patch 801 of Figure 2(c), the third sensor 204 comes to position on the black patch 700a or yellow patch 810, and if the light output from the light-emitting unit of the third sensor 204 does not penetrate the ink ribbon, which implies the black patch 700a, the computer recognizes the black and white ink ribbon 700 of Figure 2(b). As a result of the discrimination at step S302, if the clear patch is recognized as the black and white ink ribbon 700, the printing operation is performed at step S304. Meanwhile, if the result of the discrimination at step S110 is of a penetrable state (which means that the third sensor 204 is positioned on the yellow patch 810 of Figure 2C) the ink ribbon is recognized as the colour ink ribbon, step S400. If the step S400 recognizes the ribbon as the colour ink ribbon 800, the yellow is printed at step S402. Henceforth, the colour ink ribbon 800 is transferred to the right direction at step S404, and it is discriminated at step S406 whether the light output from the light-emitting unit of the second sensor 202 can penetrate the colour ink ribbon 800. As a result of the discrimination at step S406, if the light coming from the light-emitting unit of the second sensor 202 is penetrable through the colour ink ribbon 800, the step S404 is repeatedly performed. During the performance of the step S406, if the light generated by the light-emitting unit of the second sensor 202 is not penetrable, step S408 recognizes a magenta patch 820 and prints the magenta. In other words, if the light output from the light-emitting unit of the second sensor 202 cannot penetrate the colour ink ribbon, it means that the second sensor 202 is positioned on the magenta patch 820 and magenta is then printed. Then, the colour ink ribbon 800 is transferred to the right direction at step S410, and step S412 discriminates whether the light generated from the light-emitting unit of the first sensor can penetrate the colour ink ribbon 800. As a result of the discrimination at step S412, if the light coming from the light-emitting unit of the first sensor 102 can penetrate the colour ink ribbon 800, the step S410 is performed again. During the performance of the step S412, if the light generated by the light-emitting unit of the second sensor 202 cannot penetrate the colour ink ribbon 800, a step S414 recognizes the ribbon as a cyan patch 830 and prints cyan. In other words, the light output from the light-emitting unit of the second sensor 202 penetrates the yellow patch 810, magenta patch 820 and the clear patches (801, 802, 803,...) but cannot penetrate the cyan patch 830, so that cyan is printed. Furthermore, according to preferred embodiments of the present invention, ribbons formed with black markings for classification of the ribbons can be distinguished. In other words, if the first, second and third sensors 102, 202 and 204 are installed where there is no black marking on the ribbon, there will be no change of output in the sensors by way of the black markings, and the distinction of the ink ribbon by the methods thus described can be possible. Conventionally, because the black marking is formed on both ends (both ends widthwise) of the ink ribbon, the first and second sensors 102 and 202, and the third sensor 204 may be installed on an inner side of the ink ribbon, so that the black markings are not detected. Accordingly, the illustrated printer ribbon distinguishing method and apparatus thereof attains an effect of distinguishing a colour ink ribbon from the black and white ink ribbon. Furthermore, in the case of a black and white ink ribbon having no clear patches, the printing can be performed after the ribbon is transferred in the reverse direction as much as the transferred distance thereby to prevent excessive consumption of the ink ribbon. The foregoing description of a preferred embodiment has been presented for the purpose of illustration and description. Still other variations and modifications are possible without departing from the spirit and scope of the present invention. More specifically, though the foregoing description has described only the use of red LED and green LEDs, it should be noted that use of other means for generating the same effect as the use of a red LED or a green LED, belong to the spirit and scope of the present invention. Also, although in the illustrated embodiments of the invention, each sensor 102, 202, 204 has a respective light-emitting and light-receiving element arranged adjacent one another, the light being reflected by the panels 302, 304, direct light transmission from separate light-emitting and light-receiving elements at opposite sides of the ink ribbon may be used, without the need for reflection.

Claims: A method of detecting colour in a printer ink ribbon, characterised by: a first step of arranging first, second and third sensors (102, 202, 204) to detect light transmitted through the ink ribbon; a second step of transferring the ink ribbon in a forward direction for a predetermined period of time thereby to recognize the same as a black and white ribbon (600) with no clear patches if there is no change in an output of the second sensor (202); a third step of recognising the ink ribbon as a black and white ink ribbon (700) having clear patches (701-703) if the third sensor (204) is an ink ribbon impenetrable state, when there is a change in the output of the second sensor (202) and the first sensor (102) changes from an ink ribbon impenetrable state to an ink ribbon penetrable state; and a fourth step of recognizing the ink ribbon as a colour ink ribbon (800) if, at the third step, the third sensor (204) is in an ink ribbon penetrable state. A method as defined in claim 1, comprising: a step of discriminating a yellow patch (810) in the ink ribbon (800) thereby to print yellow if the ribbon is recognized as the colour ink ribbon (800); a step of discriminating a magenta patch (820) in the ink ribbon (800), thereby to print magenta if light generated in association with the second sensor (202) is not detected thereby as penetrating the ink ribbon (800) after yellow has been printed and the colour ink ribbon (800) has been transferred in a forward direction; and a step of discriminating a cyan patch (830) in the ink ribbon (800) thereby to print cyan if light generated in association with the first sensor (102) is not detected thereby as penetrating the ink ribbon (800) after magenta has been printed and the colour ink ribbon (800) has been transferred in the forward direction. A method as defined in claim 1 or 2, wherein, if the ink ribbon is recognized as the black and white ink ribbon (600) having no clear patches, printing is performed after the black and white ink ribbon (600) has been transferred in a reverse direction by the same distance as the transfer in the forward direction. A method as defined in claim 1 or 2, wherein the ribbon is transferred in a reverse direction for a predetermined period of time thereby to perform printing if the ribbon is recognized as the black and white ink ribbon (600) having no clear patches. A method as defined in claim 4, wherein the predetermined period of time is the time taken to transfer the ink ribbon between clear patches formed on both sides of a colour patch. A printer ink ribbon distinguishing apparatus comprising: a first sensor (102) having a characteristic in that light generated by an associated light-emitting unit penetrates yellow, magenta and clear patches of the ink ribbon but does not penetrate cyan and black patches; a second sensor (202) for being installed on a straight line with the first sensor (102) widthwise of the ink ribbon and having a characteristic in that light generated by an associated light-emitting unit penetrates yellow and clear patches of the ink ribbon but does not penetrate magenta, cyan and black patches; and characterised by: a third sensor (204) for being installed on an opposite side of the first and second sensors widthwise of the ink ribbon but not on a straight line with the first and second sensors, and having a characteristic in that light generated by an associated light-emitting unit penetrates yellow and clear patches but does not penetrate magenta, cyan and black patches. A method or apparatus as defined in any of the preceding claims, wherein the first and second sensors 102, 202) and the third sensor (204) are installed on a place free from black edge markings of the ribbon. A method or apparatus as defined in any of the preceding claims, wherein the first, second and third sensors (102, 202, 204) each comprise a light-emitting unit and a light-receiving unit. A method or apparatus as claimed in claim 8, further comprising first and second reflecting elements for reflecting light generated by said respective light emitting units of the first, second and third sensors to said respective light-receiving units thereof. A method or apparatus as defined in any of the preceding claims, wherein a light-emitting unit associated with the first sensor (102) includes a red light-emitting diode. A method or apparatus as defined in any of the preceding claims, wherein light-emitting units associated with the second and third sensors (202, 204) each include a green light-emitting diode. A method or apparatus as defined in any of the preceding claims, wherein the first and second sensors (102, 202) are installed on a straight line widthwise of the ink ribbon, while the third sensor (204) is installed on an opposite side widthwise of the ink ribbon and installed within a patch length of one colour lengthwise of the ribbon from the first and second sensors. A printer ribbon distinguishing apparatus as claimed in any of claims 6 to 12, wherein the apparatus is formed within a printer.

Inventors: PARK MUN-BAE, PARK, MUN-BAE
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO., LTD.
Application year: 1993
Main classification: B41J35
IPC codes: B41J35