JPH0752341B2 - Optical sensor unit for automatic playing piano - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sensor of a recording function system used at the time of recording in an automatic playing piano having not only a reproducing function but also a recording function, and further below the keyboard. The present invention relates to an optical sensor unit for detecting a key that is arranged in the key and operated by keystroke.

[Conventional technology and its problems]

The main purpose of using an optical fiber as an optical sensor as a performance information sensor of an automatic playing piano is to prevent noise contamination. For that purpose, it is necessary to attach a light emitting / receiving element and its connector to a part of the circuit. However, for the automatic playing piano, the hammer is provided with 2 points, the key information is provided with 1 point for the key or the wippen, and the total of 3 detection points per key is provided. Therefore, at least 12 elements or 24 elements in most cases and 24 elements on the light receiving side and connectors are required on the light emitting side. Therefore, the space occupied by the elements and connectors in the circuit board mounted in the narrow action part becomes large, which is an obstacle to downsizing.

The length of the optical fiber is naturally lengthened, which causes the adverse effect of reducing the amount of light transmission.

Since it is necessary to attach a cover to prevent damage to the fiber surface and the effect of ambient light, there are many problems in terms of mounting.

[Object of the Invention]

Therefore, an object of the present invention is to reduce the amount of the optical fiber and prevent its damage, prevent the incidence of ambient light, and reduce the size of the circuit board by housing the light guide, the optical fiber, and the photoelectric conversion element or the optical connector in the case. An object of the present invention is to provide an optical sensor unit for an automatic playing piano, which has an improved configuration that can be realized.

[Structure of Invention]

In order to achieve the above-mentioned object, an optical sensor unit for an automatic playing piano of the present invention includes a light guide body having a light incident surface and a light emission surface corresponding to a plurality of hammer shanks, and each of the light guide bodies. A plurality of emission optical fibers, one end of which is connected to the light guide in a state where light is conducted to the incident surface, and one end where light is conducted to each of the emission surfaces of the light guide. A plurality of light receiving optical fibers connected to the light guide, and a plurality of light receiving optical fibers respectively provided at different positions near the light guide, and the other ends of the plurality of emitting optical fibers or the other ends of the light receiving optical fibers are connected. Photoelectric conversion means, an electrical main line that electrically connects the plurality of photoelectric conversion means to the information processing device, the light guide, a plurality of emitting optical fibers, and a plurality of light receiving optical fibers. And it is characterized in that it comprises a casing which houses therein a plurality of photoelectric conversion means.

〔Example〕

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail with reference to the illustrated embodiment. FIGS. 1A and 1B show an optical sensor unit for an automatic playing piano according to the present invention. In the figure, reference numeral 1 denotes a casing, which has an elongated box shape with a rectangular cross section. (FIG. 1B) In the figure, 2 is a light guide, 3 is an optical fiber connected to the light guide 2, 4 is a photoelectric conversion means (optical connector) in which the required number of optical fibers 3, 3 ... ), A plurality of the photoelectric conversion means 4 are provided near the light guide 2 at different positions in the arrangement direction thereof as shown in FIG. 1A. Reference numeral 5 is an electric main line protruding from the photoelectric conversion means 4 into the casing 1, and 6 is an electric connector connected to the electric main line 5,
It is configured to be connectable to the information processing device via the electrical connector.

That is, the light guide 2 made of acrylic resin or the like has a groove 2a on the lower surface side thereof which allows its entry at a position corresponding to each hammer shank 7 of the piano. In addition, also on the casing 1, place the groove 2a at a position corresponding to the hammer shank.
Are formed to have slits 1a ... That enter the hammer shank 7, and each hammer shank 7 is provided with an opaque plate-shaped shutter 8 for opening and closing transmitted light.

In the figure, reference numerals 9 and 10 denote the back surface of the light guide 2, which is a light entrance surface and a light exit surface, which are formed in a circular arc surface as a pair on both sides of the groove 2a.

Of the optical fibers 3, the output optical fiber 3a is connected to the light entrance surface 9 and the light receiving optical fiber 3b is connected to the light exit surface 10 to the light guide 2 in a state of conducting light.

Therefore, the light guided by each of the outgoing optical fibers 3a, ... is there. Then, when the hammer shank 7 interlocking with the key moves into the groove 2a, it blocks the light traveling from the incident surface 9 to the emission surface 10. Therefore, the light receiving element detects this and emits a signal, which is sent to the data recorder for recording as piano performance information.

Further, the optical sensor units having the above configuration are used by being arranged below the keyboard.

〔The invention's effect〕

As described above, according to the present invention, since each element is housed in the casing, the amount of optical fiber used can be reduced first, and the amount of light transmission can be increased. Further, since the electric main line only comes out from the casing and the optical fiber does not come out, it is possible to prevent the damage of the fiber and the bad influence of the ambient light. Furthermore, since the elements and connectors are all housed in the casing,
There is no space limitation on the circuit board, and the circuit board can be downsized.

[Brief description of drawings]

1A and 1B are a front view and a cross-sectional view conceptually showing a simplified configuration of the optical sensor unit according to the present invention, and FIG. 2 is a detailed front view showing a partly enlarged view. The figure is also a perspective view. 1 ... Casing, 2 ... Light guide 3a, 3b ... Optical fiber 4 ... Photoelectric conversion means, 5 ... Electric main line 6 ... Electrical connector, 7 ... Hammer shank 9 ... Incident surface, 10 ... Exit surface

Claims (1)

[Claims] 1. A light guide (2) having a light incident surface (9) and a light exit surface (10) corresponding to a plurality of hammer shanks (7), and each of the light guides (2). A plurality of emission optical fibers (3a), one end of which is connected to the light guide (2) in a state where light is respectively conducted to the incidence surface (9), and each emission surface of the light guide (2). A plurality of light receiving optical fibers (3b) each having one end connected to the light guide body (2) in a state where light is conducted to the light guide body (10), and provided at different positions near the light guide body, A plurality of photoelectric conversion means (4) to which the other ends of the plurality of output optical fibers (3a) or the other ends of the light receiving optical fibers (3b) are connected, and the plurality of photoelectric conversion means (4) and an information processing device An electrical main line (5) for electrically connecting the light guide body (2) and a plurality of emitting electrodes. Pharmaceutical fiber (3a), a plurality of light receiving optical fiber (3b) and a plurality of photoelectric conversion means (4) were housed in the casing (1) and the automatic player piano optical sensor unit, characterized in that it comprises a.