JPS634449A - Tape end detecting device - Google Patents

Abstract

PURPOSE:To simplify a composition at low cost with less part numbers by equipping an optical reflection member at opposing position of the outer side pinching a tape and the light emitting and receiving elements of which the light emitting part emittable in one direction via a light shielding member and the light receiving part detectable from the direction are set up. CONSTITUTION:The package element 1 consisting of a light receiving element 5 and a light emitting element 4 and becoming in one package so that the light emitted from the light emitting element 4 may not be leaked directly into the light receiving element 5 by a light shielding plate 6 is arranged in two pieces toward the opposing directions. A mirror 2 is set up in two pieces at the linearly symmetric position with the package element 1 as the center a pulse signal is fed by a common pulse signal generator 8 onto each light emitting element 4 and each light receiving element 5 feeds an AC signal to a common DC component removing circuit 9. The passage of these pulse signal and AC signal is made to change according to the running direction, namely according to the positive direction or reverse direction of a tape 7 on two package elements 1. In such a way the power consumption can be reduced.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is applicable to the beginning of a tape, j! The present invention relates to a tape end detection device that detects an end.

[Conventional Technique 4F4] Figure 5 is a schematic illustration of the main parts of a conventional video cassette tape end detection device, in which 3 indicates a cassette half, 1
1 is a light emitting diode (hereinafter referred to as an LED) which is a light emitting element; 12 is a phototransistor which is a light receiving element. Conventionally, this type of device has a double-axis light emitting type LED II inserted into a detection hole provided in the center of the cassette half 3.

Two phototransistors 12 and 13 installed near the tape start/end detection ports provided on the left and right sides of the cassette half 3 detect the optically transparent leader portion of the tape.

[9, 14 or Problems to be Solved] As mentioned above, the conventional detection device requires one light-emitting element and two light-receiving elements on the left and right sides, and uses three independent elements. There was a problem that the cost would be high.

The present invention was made to solve these problems, and an object of the present invention is to provide a tape end detection device that is low cost, has as few as one component, and has a mesh in the cylinder.

[rF! +Means for Solving the Problems] In order to achieve the above object, the tape end detection device of the present invention provides a tape transport mechanism in which the starting end and the ending end are optically transparent. There are 9 light-emitting/light-receiving elements installed on the inside sandwiching the tape, including a light-emitting part that can emit light in one direction through a light shielding member and a light-receiving part that can receive light from one direction. The light emitting/light receiving element is provided with an optical reflecting member installed at a position facing the light emitting/light receiving element.

[Operations] The above-mentioned configuration reduces the number of elements used, resulting in lower costs, and the simple configuration reduces the chance of failure.
Hateful.

['''V Example 1 is a schematic diagram of a cassette mounting device equipped with a tape end detection device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of an embodiment of the tape end detection device of the present invention. A diagram showing the outline of the main parts, Figure 3 is a diagram in which the light emitting element and light receiving element in Figure 2 are combined into one
It is a figure which shows the element which became. Further, FIG. 4 shows a block diagram of a tape end detection device which is an embodiment of the present invention.

:jSl ~ In Fig. 4, 1 is a package element that is a light emitting element and a stitch and a light receiving element, 2 is a reflector (mirror) installed close to the detection ports on both the left and right sides of the device, and 3 is a cassette. This is the first step. As shown in FIG. 3, the element 1 consists of one light-receiving element 5 and one light-emitting element 4, and the light from the light-receiving element 4 leaks directly to the light-receiving element 5 through a light shielding plate 6. This is a packaged element that is packaged in a single puff cage to prevent it from getting too crowded. Two of these are placed facing in opposite directions.

As shown at 11 in FIG. 4, light emitted from the light emitting element 4 in response to the pulse signal generated by the pulse signal generator 8 is caused by the fact that the beginning or end portion 7b of the tape is different from the recording portion 7a and has a magnetic layer formed thereon. Since these end portions 7b of the tape 7 running in the direction of the arrow in FIG. :t21 The light is reflected by each mirror 2 and enters the light receiving element 5, so that the beginning and end of the cassette tape can be detected.

As shown in FIG. 4, since the light emitting element 4 emits light in response to the pulse signal generated by the pulse signal generator 8, the light receiving element 5 receives this light and generates an alternating current signal 't51. After the DC component of the AC signal generated by the light-receiving element 5 is removed by the DC component removal circuit 9, the AC signal is supplied to the tape running stop circuit 10. When the signal is supplied, when the running tape 7 reaches the starting end or the ending end, the running of the tape 7 is stopped by stopping capstan motors (not shown). In addition, since two mirrors 2 are installed at line-symmetrical positions with the package element 2 as the center as shown in FIG. A pulse signal is supplied from a common pulse signal generator 8 to each of the light receiving elements 5, and each light receiving element 5 supplies an AC signal to a common DC component removal circuit 9. Furthermore, by switching the flow paths of these pulse signals and alternating current signals depending on the running direction of the tape 7, that is, whether it is in the forward or reverse direction for the two package elements, it is possible to reduce the power consumption.

In addition, in this embodiment, since the two package elements are placed close to each other as shown in Figure 3, the structure is simple because input/output signal lines are not routed much within the device. Since it is easy to set up, assembly costs can be reduced.

In this embodiment, a mirror is provided as a reflective member, but even if a mirror is not provided on the outside of the cassette holder, a mirror may be provided inside the cassette half, or some parts of the cassette half may reflect light. A similar effect can be obtained by treating the material to function as a reflective member.

[Effects of the Invention] As described above, the present invention makes it possible to obtain a tape end detection device that is low cost, has a small number of parts, and has a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a cassette loading device equipped with a tape end detection device according to an embodiment of the present invention, FIG. 2 is a diagram showing the main parts of the tape end detection device of the present invention, and FIG. The figures show the elements shown in FIG. 2, FIG. 4 is a block diagram of a tape end detection device according to an embodiment of the present invention, and FIG. 5 is a schematic diagram of a conventional tape end detection device. In the figure. l: Package element 2: Mirror 3: Cassette half 4: Light-emitting element 5: Light-receiving element 6: Light-shielding plate agent Bury earth 1) Haru Kitatake 2 Figure 3 Figure 4

Claims (1)

[Claims] In a tape end detection device equipped with a tape conveyance mechanism whose starting end and end end are optically transparent, a light emitting section installed on the inside sandwiching the tape and capable of emitting light in one direction via a light shielding member is integrated. It is characterized by comprising a light-emitting/light-receiving element in which a light-receiving part capable of receiving light from any direction is installed, and an optical reflecting member installed at a position facing the light-emitting/light-receiving element on the outside sandwiching the tape. Tape end detection device.