JPH0428781Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a multicolor ribbon cassette used in a color dot printer.

(Prior Art) Color dot printers are known that perform multicolor printing using an ink ribbon in which a plurality of color bands, for example, yellow, magenta, cyan, and black color bands are repeatedly formed in sequence. The hue of the color band is detected by a detector, and the drive of the print head is controlled based on this detection signal (for example, Japanese Patent Laid-Open No. 127471/1983).

(Problem to be Solved by the Invention) This known color dot printer is provided with a detector to detect the hue in a portion led out from the cassette case. There are times when you want to do so. In such cases, the ribbon may become loose inside the cassette case, and the loosened ribbon may come into contact with the detector.
There was a risk that the detector would malfunction. Furthermore, when the ribbon touches the detector, ink may adhere to the detector, and if this is repeated over a long period of time, there is a risk that the detector may become unable to detect.

In view of the above-mentioned circumstances, the present invention aims to improve the reliability of the detection operation of the detector.

(Means for solving the problem) An opening in which a detector for detecting the hue of a color band of a multicolor ink ribbon is inserted is located in a cassette case at a position corresponding to a part of the path of the ink ribbon. A slack removing means for pinching the ink ribbon and removing slack in the ink ribbon is provided on both sides of the opening.

(Embodiment) In FIG. 1, a carriage 3 is slidably supported by guide shafts 1 and 2. A thermal head 6 facing a platen 5 with a recording paper 4 in between is mounted on the carriage 3 via a head holder (not shown). Further, a ribbon cassette 7 is provided on the carriage 3, and an ink ribbon 10 exposed to the outside through a slit 9 of the cassette case 8 is passed through the front surface of the thermal head 6. As shown in the second diagram, the ink ribbon 10 is of a thermal transfer type in which a plurality of color bands 10y, 10m, 10c, and 10b of a plurality of hues, for example, yellow, magenta, cyan, and black, are repeatedly formed in this order. The ink ribbon 10 is wound around a pair of spool cores 11 and 12, and when one of the spool cores 11 is rotated counterclockwise, the ink ribbon 10 is sent to the left on the front surface of the thermal head 6. An opening 13 is formed in a part of the cassette case 8, and a detector 14 fixed on the carriage 3 is located in the opening 13, and a light receiving element and a light emitting element (not shown) are located inside the opening 13. The ink ribbon 10 is passed between the two buried prongs 14a, 14a. Various types of detectors can be used as the detector 14, such as a type that detects hue based on the amount of light transmitted through the ink ribbon 10, and a type that detects hue based on wavelength. Further, for this hue detection, if necessary, small holes or marks for hue detection may be formed on the upper edge or lower edge of the ink ribbon 10 itself.

At both sides of the opening 13 (in FIG. 1, above and below the opening 13), slack removing means having the following structure are provided. That is, in this embodiment, the pair of slack removing means includes a columnar projection 15 and an elastic body 16 such as felt that elastically pushes the ink ribbon 10 onto the columnar projection 15. Columnar projection 1
5 is formed integrally with the cassette case 8, and an elastic body 16 is attached to the inner wall surface of the cassette case 8.

Note that the present invention can be modified in various ways. For example, as for the slack removing means, the shape of the protrusion 15 is not limited to a columnar shape, and the elastic body 16 can also be made of porous rubber such as a sponge or a metal plate spring in addition to a fibrous material such as felt. Furthermore, the projection 15 may be omitted, and the elastic body 16 may be placed on the side of the projection 15 in FIG. 1, so that the ink ribbon 10 is pushed out onto the inner wall surface of the cassette case. Regarding the type of ribbon cassette, it is applicable to an endless type or a stationary type. However, when applied to a stationary type ribbon cassette, it goes without saying that the detector 14 is attached to a printer frame (not shown) or a holder (not shown) fixed to the printer frame.

(Effects of the invention) According to the structure of the invention, when a plurality of color bands are repeatedly formed in sequence, a multicolor ink ribbon is used, and the hue of each color band is detected via a detector to perform multicolor printing. Furthermore, even if the detector is installed inside the cassette case, the inconvenience of the ink ribbon coming into contact with the detector can be eliminated, thereby ensuring the reliability of the detection operation of the detector over a long period of time. In particular, since the slack removing means is configured to clamp the ink ribbon, it is possible to always prevent the ink ribbon from loosening at the opening even when the ink ribbon is carelessly unwound when the ribbon cassette is stored alone. The inconvenience of the ink ribbon touching the detector can be reliably eliminated. Furthermore, since the ink ribbon does not touch the detector, there is less damage to the ink ribbon. In addition, by locating the detection position within the cassette case, space can be used more effectively and the multicolor printer can be made more compact.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional plan view of one embodiment of the present invention;
The figure is a partially enlarged front view of the ink ribbon, and FIG. 3 is a sectional view of a main part showing a detector located in the opening. 7... Ribbon cassette, 8... Cassette case, 10... Ink ribbon, 10y, 10m, 1
0c, 10b...color band, 13...opening, 14...
...detector, 15, 16... slack removal means.

Claims (1)

[Scope of Claim for Utility Model Registration] A multicolor ink ribbon in which a plurality of color bands are sequentially and repeatedly formed; a cassette case for accommodating the ink ribbon; and a cassette case for accommodating the ink ribbon; An opening is provided in the case into which a detector for detecting the hue of the color band can be inserted; A multicolor ribbon cassette, comprising: slack removing means for removing slack from the ink ribbon.