JPS6126003A - Photodetector provided with optical attenuating function - Google Patents

Abstract

PURPOSE:To join a variable optical attenuator and a photodetector into one body to not only reduce the cost and but also facilitate handling by providing the variable optical attenuator, where the attenuation of the quantity of input light can be controlled manually from the external, in the same housing as the photodetector. CONSTITUTION:A light receiving part 1, an optical attenuating part 2, and a connector part 3 are provided in series in a housing 4. The light receiving part 1 is provided with a photodetector 5 and a lens 6, and the optical attenuating part 2 is provided with a variable attenuating plate 8 fixed to a revolving shaft 7 and an adjusting knob 9 by which the attenuating plate 8 is rotated from the external, and the connector part 3 is provided with a screw 10 on the outside peripheral surface for connection to the other party connector and is provided internally with an optical fiber 11 and a lens 12. The light incident from the optical fiber 11 is inputted to the photodetector 5 through the lens 12, the attenuating plate 8, and the lens 6. At this time, the attenuating plate 8 is rotated by the adjusting knob 9 to control the quantity of light inputted to the photodetector 5. Consequently, the operation in the field work is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light receiver used in optical communications and the like.

Conventionally, in optical communications, when the amount of light entering a light receiver is large, an optical attenuator is inserted in front of the light receiver to adjust it to an appropriate level.

[Problems to be solved by conventional technology and invention]

In the above case, conventionally, the type of optical attenuator to be used (the amount of attenuation) has been selected based on the expected optical reception level based on the distance between the optical receiver and the emitter.

For this reason, when optical fibers are installed on site, it is necessary to prepare a large number of optical attenuators, and the selection thereof requires a lot of effort due to repeated trial and error.

[Means to solve the problem]

The present invention provides a light receiver that solves the above problems, and its means include a variable optical attenuator that can manually adjust the attenuation of the amount of input light from the outside in the same housing as the light receiver. This is achieved using a light receiver equipped with a characteristic light attenuation function.

[For production]

The above photoreceiver is equipped with a variable optical attenuator that can arbitrarily adjust the amount of optical attenuation from the outside, so the amount of light entering the photoreceiver can be adjusted freely, and there is no need to select an optical attenuator like in the past. This makes operation extremely easy.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention as a sectional view.

As shown in FIG. 1, this embodiment includes a light receiving section 1, a light attenuation section 2,
The connector part 3 is provided in the housing 4 in series, the light receiving part 1 is provided with a light receiving element 5 and a lens 6, and the light attenuating part 2 is provided with a variable attenuation plate 8 fixed to the rotating shaft 7. and an adjustment knob 9 that can rotate this variable damping plate from the outside.
A screw 10 for coupling with a mating connector is formed on the outer periphery of the connector portion 3, and an optical fiber 11 and a lens 12 are provided inside.

The variable attenuation plate 8 may be a continuous variable attenuation plate in which a metal such as Ni-Cr is vapor-deposited on a transparent plate and the thickness of the film is continuously changed in the direction of rotation, or a transparent disc 20 as shown in FIG. It may be a step variable attenuation plate in which a plurality of regions 21 to 25 are provided and a metal film is formed so that the amount of light attenuation in each region is different. Further, it is preferable to provide the adjustment knob 9 with a scale that indicates the amount of attenuation.

In this embodiment configured in this way, the light entering from the optical fiber 11 is transmitted through the lens 12 . The light passes through the variable attenuation plate 8° lens 6 and is input to the light receiving element 5 of the light receiving section.

At this time, the amount of light input to the light receiving element 5 can be adjusted by rotating the variable attenuation plate 8 using the adjustment knob 9.

〔Effect of the invention〕

As explained above, according to the present invention, by providing the optical receiver and the variable optical attenuator in the same housing, cost reduction due to integration and ease of handling can be achieved, especially in field work. This has the effect of making the operation easier.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a light receiver having a light attenuation function according to the present invention, and FIG. 2 is a diagram showing an example of a variable attenuation plate thereof. In the figure, l is the light receiving part, 2 is the optical attenuation part, 3 is the connector part, and 4
5 is a housing, 5 is a light receiving element, 6 and 12 are lenses, 8 is a variable attenuation plate, 9 is an adjustment knob, and 11 is an optical fiber.

Claims (1)

[Claims] 1. An optical receiver with an optical attenuation function, characterized in that a variable optical attenuator capable of manually adjusting the attenuation of the amount of input light from the outside is provided in the same housing as the optical receiver.