JPS61121985A - Apparatus for detecting tape material part - Google Patents

Abstract

PURPOSE:To perfectly prevent erroneous detection and to attain to reduce cost, by providing a means for performing the exposure and light blocking of at least the light receiving part of an optical detection means in connection with the attachment and detachment of a tape material receiving body. CONSTITUTION:In such a state that a cassette 3 is detached, a shutter 26 is pushed up until a thin plate part 26a is engaged with a front edge part 25a by the elastic force of a coil spring 30 and the whole of the front side of at least the light receiving element of a reflective type sensor 22 is perfectly covered with the shutter 26 and the thin plate part 26a thereof. In such a state that the cassette 3 is mounted, the shutter 26 is pushed down into a guide hole 28 by the bottom plate of the housing 4 of the cassette 3 and the front surface side o the reflective type sensor 22 is opened and a light receiving element is brought to a state capable of receiving the reflected light of the light from a light emitting element to perform the detection of the terminal end of a ribbon.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a tape material portion detection device, and more particularly to a tape material portion detection device for detecting a predetermined portion of a tape material housed in a detachable container using an optical detection means. This invention relates to a detection device.

[Prior Art] As an example of this type of tape material portion detection device, a ribbon end detection device for detecting the end of a thermal transfer ink ribbon used in a thermal transfer printer is known. The thermal transfer ink ribbon is housed in an ink ribbon cassette that is detachably attached to the thermal transfer printer, and the unused portion is normally wound into a roll as a supply roll and the used portion as a take-up roll. When in use, the ink ribbon is unwound from the supply roll, unwound, runs in contact with the thermal head of the recording means, and after being used for recording is wound up on the take-up roll. Since the ink ribbon is normally fed out and run in synchronization with printing, if the ink ribbon on the supply roll runs out, it is necessary to stop recording and replace the ink ribbon cassette. For this reason, the aforementioned ribbon end detection device is provided on the supply roll side.

The conventional structure and drawbacks of such a ribbon end detection device will be explained with reference to FIGS. 1 to 4.

Figure 1 is a top view of the carriage section of a thermal transfer printer equipped with the above-mentioned ink ribbon cassette (hereinafter referred to as blade set), Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 1 shows the cassette. Shown with the top cover removed.

In both figures, the symbol l indicates a carriage, which is slidably disposed opposite to a platen (not shown), carries a recording head 2 composed of a heat generating element, and is driven by a drive means (not shown). Then, the recording head 2 is transported along the platen.

Also, what is indicated by the reference numeral 3 as a whole is -1: the above-mentioned kayak 2, and the hollow cylindrical part 5 for positioning formed in the hollow housing 4 is connected to the fitting provided protruding from the carriage 1-1-. It is fitted onto the mating ball 6 and removably mounted on the carriage 1.

An ink ribbon 7 for thermal transfer is accommodated in the housing 4 of the cassette 3. The unused portion of the ink ribbon 7 is wound as a supply roll 9 around a core 87 that is rotatably supported by the cylindrical portion 57, and when used, it is unwound from the supply roll 9 and fed out, and guided. Roller 1 for
0 in contact with the guide plate 11, and the same
It is guided onto the recording head 2 via guiding rollers 12, 13. The recording head 2 is configured to be movable in the directions of arrows a and b in FIG. 1 by a drive means (not shown), and during recording, it moves in the direction "a" to move the ink ribbon 7 onto recording paper (also not shown) on a platen. Press and record.

The ink ribbon 7 used for recording is guided by a roller 14.
A take-up roll 16 is placed on the second rotatable core 15 via the
It is wound up as. The core 15 is engaged with a drive ball 17 with a ratchet provided on the carriage, and the ball 17 is driven by a drive means (not shown) to rotate in the direction of arrow C in synchronization with the recording operation, so that the ball 17 is rotated in the same direction. The used ink ribbon 7 is rotated and wound onto a take-up roll 16.

On the other hand, in both figures, a ribbon end detection device, generally indicated by the reference numeral 18, is provided in the carriage 11-, and is a hollow opening chamber with an open bottom provided in the housing 4 of the cassette 3, facing the guide plate 11. 19. An opening 19 is provided on the side of the opening chamber 19 facing the guide plate 11.
a is formed.

As shown in FIG. 3, the ribbon end detection device 18 is composed of a reflective sensor 22 composed of a light emitting element 20 and a light receiving element 21, and a detection circuit (not shown) provided on a printed circuit board 23-A. Pixel elements 20.21 are connected to said detection circuit.

Further, the light emitting element 20 and the light receiving element 21 are connected to the opening 1 of the opening chamber 19.
The light emitting element 2'0 is housed separately in a housing of the reflective sensor 22 having a partition provided opposite to the light emitting element 2'0.
A polarizing filter 24 is provided in front of the light receiving element 21.
The front is open.

Further, the entire ribbon end detection device 18 is connected to a reflective sensor 22.
It is covered with a cover 25 except for the front side.

When the ribbon detection device 18 is activated under the configuration shown below, the light emitting element 20 emits light, and the light irradiates the ink ribbon 7 in contact with the guide plate 11 through the polarizing filter 24 as shown by the dotted line L1. .

Here, the used portion of the ink ribbon 7 is coated with black ink or the like and has a low reflectance, whereas the end portion is configured to have a high reflectance by pasting aluminum foil or the like.

Therefore, while the used portion of the ink ribbon 7 is running on the guide plate 11-1-, the light emitted from the light emitting element 20 is absorbed by the ink ribbon 7 and is not detected by the light receiving element 21. When the end of the ink ribbon 7 reaches the detection position on the guide plate 11, the light from the heating element 20 is reflected toward the light receiving element 21 as shown by the dotted line L2, and is received by the light receiving element 21.

Upon reception of light, the detection circuit receives a signal emitted by the light receiving element 21 and outputs a detection signal, and this detection signal stops the drive of the ratchet drive ball 17, stops the feeding of the ink ribbon 7, and stops the recording head. The second action is also 1 to 1. Further, a display means (not shown) or the like instructs the operator to replace the cassette.

By the way, thermal transfer printers that perform recording via a thermal transfer ink ribbon as described above are often configured so that they can also directly perform recording on thermal paper (thermal recording paper) without using an ink ribbon.

However, when the printer equipped with the ribbon end detection device 18 described in (b) is configured in this way, when recording on thermal paper, the cassette 3 is removed as shown in FIG. Therefore, the reflective sensor 22 may be exposed and the light receiving element 21 may erroneously detect the external light indicated by the dotted arrow L3 as light from the light emitting element 20. In this case, as described above, the recording operation is interrupted.

In order to solve such problems, the following methods are conventionally known.

The first method is to increase the luminous intensity of the light emitting element 20 and lower the sensitivity of the light receiving element 21. However, since the luminous intensity of external light may be significantly greater than the luminous intensity of the light emitting element depending on the environment in which the printer is used, this method cannot completely prevent false detection. Moreover, increasing the luminous intensity of the light emitting element 20 requires a large current, which wastes energy.

A second method is to provide switching means such as a switch that can cut off/connect the detection circuit described above, and when recording on thermal paper, cut off the detection circuit via the switching means.6 However, this method In this case, the switching means is costly and requires a space for its installation. Furthermore, the operator may forget to operate the means.

As a third method, when recording on thermal paper, there is a method of shielding the reflective sensor from light with a cap or the like, but there are also cases where the operator forgets or loses the cap.

As described above, the conventional method has disadvantages such as not being able to completely prevent false detection and being costly. This problem is not limited to the ink ribbon end detection device, but is common to all tape material portion detection devices that use optical detection means to detect a predetermined portion of the tape material contained in the removable container mentioned above.

Purpose] The present invention was made in view of the following circumstances.
- The tape material part detection device of the type mentioned above is simple, inexpensive, and has a configuration that does not require any special operations or work to reliably prevent erroneous detection when the tape material container is not attached. The purpose is to provide equipment.

[Example] Hereinafter, details of an example of the present invention will be described with reference to the drawings from FIG. 5 onwards. Note that the ribbon end detection device of the thermal transfer printer described above is used as an example here, and in each figure, the same or corresponding parts as in FIGS. .

5 and 6 are cross-sectional and cross-sectional views of the carriage section of a thermal transfer printer equipped with the detection device of this embodiment, shown with and without the cassette 3 installed, respectively,
Figure 7 shows the gear ridge part without set 3 installed.
It is an L side view.

As shown in these figures, in this embodiment, a guide hole 2 with a rectangular cross section is provided adjacent to the front surface of the beam end detection device 18.
8 is bored in the carriage 2, and this guide hole 28
A shutter 26 that shields at least the light-receiving element 21 of the reflective sensor 22 from light is fitted therein.

The shutter 26 corresponds to the cross-sectional shape of the guide hole 28.
It is formed into a rectangular parallelepiped, and a round rod 27 is planted on the lower surface of the rectangular parallelepiped. This round rod 27 is slidably inserted into a round hole 29 having a step communicating with the bottom surface of the guide hole 28. Thereby, the shutter 26 is supported so as to be movable up and down in contact with the front surface including the reflective sensor 22 of the ribbon end detection device N18.

Further, coil springs 3 and 0 are elastically mounted between the lower surface of the shutter 26 and the bottom surface 9 of the guide hole 28, and the shutter 26 is always biased in two directions by the elastic force of the coil springs.

Further, a thin plate portion 26 a is integrally provided on the upper surface of the shutter 26 and protrudes along the front edge facing the reflective sensor 22 . The width and height of the shutter 26 including the thin plate portion 26a are set to a size that can cover at least the entire front side of the light receiving element 21 of the reflective sensor 22 and shield at least the light receiving element 21 of the reflective sensor 22 from light. Also, thin plate part 2.6
The surface of the shutter 26 facing the reflective sensor 22, including the portion a, is colored black to have a low reflectance.

On the other hand, the front edge 25a of the -L plate of the cover 25 of the ribbon end detection device 18 protrudes forward from the front surface of the casing of the reflective sensor 22, and as shown in FIG.
:J? , it is configured to tightly engage with the thin plate portion 26a.

[below] - Ribbon end detection device 18 in parts other than those described.
The configurations of the related parts are the same as those of the prior art example described above.

With the above configuration, when the cassette 3 is removed when recording on thermal paper, the thin plate 26a of the shutter 26 is opened by the elastic force of the coil spring 30, as shown in FIG. The shutter 26 is pushed up until it engages with the edge 25a, and at least the entire front side of the light receiving element 21 of the reflective sensor 22 is completely covered by the shutter 26 and its thin plate portion 26a. As a result, the light-receiving element 21 is completely shielded not only from the light from the light-emitting element 20 but also from external light as indicated by the dotted arrow L3, and erroneous detection of the end of the lipon is not performed. In other words, the printer operates with the ribbon present.

On the other hand, when recording via an ink ribbon and the cassette 3 is installed, the shutter 26 is pushed down into the guide hole 28 by the bottom plate of the housing 4 of the cassette 3, as shown in FIG. The side is opened, and the light receiving element 21 is in a state where it can receive the reflected light from the light emitting element 20 as shown by the dotted arrow L4, and the end of the ribbon is detected in the same manner as in the conventional example described above.

As described above, according to this embodiment, the reflective sensor 22 is automatically and reliably shielded from light when the cassette 3 is not attached, without requiring any special operation or work by the operator due to its simple configuration. Erroneous detection of the end of the ribbon is completely prevented. Further, the shutter 26 operates through the attachment and detachment of the cassette 3 and the spring 30, and does not require paid energy such as electric power for operation. Furthermore, since the shutter 26 is pushed into the guide hole 28 when the cassette 3 is installed, it does not take up much space.

Note that in the configuration of the embodiment described above, the coil spring 3
Instead of zero, another elastic member may be used, or the repulsive force or attractive force of a permanent magnet may be used.

Further, although the ribbon end detection device of the embodiment is composed of a reflection type sensor 22, when the detection device is composed of a transmission type sensor (in that case, the ribbon end portion is configured to be transparent), The configuration in which the shutter 26 described above exposes and blocks light from the light receiving element can be applied as is, and the same effects as described above can be obtained.

Furthermore, the configuration of the present invention as described above can be widely applied to other tape material portion detection devices of the type mentioned at the beginning, such as a tape end detection device for a cassette tape recorder.

[Effects] As is clear from the above description, according to the present invention, in the tape material portion detection/dispensing device for detecting a predetermined portion of the tape material housed in a detachable container using an optical detection means, Since a configuration is adopted in which means is provided for exposing and shielding at least the light-receiving part of the detection means in conjunction with attachment and detachment of the tape material container, the tape material container can be opened without requiring any special operations or work by the operator. It is possible to provide an excellent tape material portion detection device that can reliably prevent false detection when not attached, has a simple configuration, is low cost, and does not take up much space.

[Brief explanation of drawings]

Figures 1 to 4 explain the configuration and drawbacks of the conventional ribbon end detection device. A-
3 is an enlarged sectional view of the ribbon end detection device section taken along line B-B in FIG. 2, FIG. 4 is a sectional view showing the influence of external light when removing the cassette, and FIGS. 5 is a sectional view of the carriage section including the ribbon end detection device without the cassette installed, and FIG. 6 is a sectional view of the same carriage section with the cassette installed. , FIG. 7 is a -L side view of the carriage section with no cassette attached. l... Carriage 2... Recording head 3...
・Ink ribbon cassette 7... Ink ribbon 11... Guide plate 18...
・Ribbon end detection device 20... Light emitting element 21... Light receiving element 22.
...Reflection type sensor 26...Shutter 26a...
Thin plate part 27...Round bar 28...Guide hole
30...Coil spring Part 1 Figure 2 Glue F'''N Figure 5, L3 Figure 6 Dan 4 856 9 71125a25 No. 70

Claims (1)

[Claims] In a tape material portion detection device that detects a predetermined portion of a tape material housed in a removable container using an optical detection means, at least a light receiving part of the detection means is exposed to light and is shielded from light in conjunction with attachment and detachment of the container. A tape material portion detection device characterized by comprising means.