JPH052830Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a photodetector that measures the amount of light emitted from both directions, for example.

[Conventional technology]

FIGS. 7a and 7b are a side view and a front view of a conventional thin photodetector, in which a light receiving element 1 is attached to one surface of its tip.

This thin photodetector has a thin structure so that its tip can be inserted into a narrow space to measure the amount of light.For example, in an optical disc player, etc., it is used to compare the amount of light 2 emitted from both directions. When measuring, the amount of light on one side was first measured, then the light receiving surface was turned over and the amount of light on the other side was measured. This measured value was then input to and displayed on an optical power meter (not shown) or the like.

[Problem that the invention attempts to solve]

However, with the conventional photodetector as described above, when measuring to compare the amount of light 2 emitted from both directions, a mechanism for rotating the photodetector is required, and the photodetector is rotated. If the reproducibility when rotating is poor, the incident angle of light will change, resulting in poor measurement accuracy. For this reason, it is necessary to use a complicated holding device when rotating the photodetector, and there is a problem that measurements cannot be carried out in a short time.

This invention was made to solve this problem, and without rotating the photodetector,
The object of the present invention is to obtain a photodetector that can efficiently measure the amount of light emitted from both directions.

[Means for solving problems]

The photodetector according to this invention has a light-receiving element provided on one side and a light-receiving element having the same characteristics as the light-receiving element on the back side of the light-receiving element.

[Effect]

In this invention, the amount of light is measured by each of the light receiving elements arranged back to back.

〔Example〕

FIG. 1 is a side view showing the structure of one embodiment of the photodetector of this invention, and FIGS. 2a and b are side and front views showing the structure of another embodiment of the photodetector of this invention. It is.

In these figures, the same reference numerals as in FIGS. 7a and 7b indicate the same parts, and 1a is a light receiving element, which is provided back to back on the back side of the light receiving element 1, and
Its characteristics are the same as those of the light receiving element 1.

Next, measurement using the photodetector shown in FIG. 1 will be explained.

First, as shown in Figure 3, for example, two
Connect to an indicator 3 capable of channel input and 2-channel display. That is, since they are connected in this way, measurement can be performed using either of the light receiving elements 1 and 1a, and the measurement signals generated by optical-to-electrical conversion are sent to the indicator 3. is input and displayed.

Therefore, when measuring the amount of laser light incident from both directions, such as when measuring the amount of light by inserting it near the disk insertion position of an optical disk player, it is necessary to rotate the photodetector as in the conventional method. Since there is no need to hold the device in place, it is possible to perform measurements with good reproducibility without using a complicated holding device.

In addition, especially when the photodetector is inserted into a narrow space where it cannot be rotated without being removed as shown in FIG. 4, reproducibility is improved and measurement time can be shortened.

Also, when measuring each of the incident light and reflected light of the grating 4 as shown in FIG.
By simply moving the photodetector in parallel, for example, the incident light can be measured by the light receiving element 1.
a makes it possible to measure the reflected light, making it possible to perform measurements with very good reproducibility.

In addition, in the above embodiment, the case where the photodetector is straight or bent rod-shaped was explained, but the sixth embodiment
As shown in the illustrated embodiment, a configuration including a flexible portion 5 may also be used to further increase functionality.

[Effect of idea]

As explained above, this idea is based on the fact that a light receiving element with the same characteristics as the light receiving element is placed back to back on the back side of the light receiving element provided on one side, so that the amount of light emitted from both directions can be controlled in a short time with good reproducibility. can be measured,
This has the effect of improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the structure of one embodiment of the photodetector of this invention, FIGS. 2a and 2b are side and front views showing the structure of another embodiment of the photodetector of this invention, and FIG. Figure 3 is a diagram for explaining the measurement in this invention, Figures 4 and 5 are diagrams showing the measurement state in this invention, and Figure 6 shows the configuration of still another embodiment of the photodetector of this invention. The figures shown in FIGS. 7a and 7b are a side view and a front view of a conventional photodetector. In the figure, 1 and 1a are light receiving elements, 2 is a light, 3 is an indicator, 4 is a crating, and 5 is a flexible part.

Claims (1)

[Scope of utility model registration request] In a straight or bent rod-shaped photodetector that has a light-receiving element on one side of its tip and is inserted into a narrow space to measure the amount of light, the back side of the light-receiving element provided on one side has the same characteristics as the light-receiving element. A photodetector characterized by having two light receiving elements arranged back to back.