JPS5942666Y2 - Photometric device for light emitting elements - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a photometric device for examining the light emitting state of light emitting elements such as light emitting diodes and electroluminescence.
More specifically, the present invention relates to a photometry device equipped with a measurement terminal that can perform photometry efficiently and with high precision.

In the conventional photometric device for light emitting elements, as shown in FIG. 1, an electrode probe 3 is brought into contact with a light emitting element 2 on a lower electrode plate 1,
A current is applied to the light emitting element 2 based on the current, and the light emitted from the light emitting element 2 is detected by a photoelectric converter 6 via a condensing lens 5.

In this device, the focal position of the lens 5 is made to substantially coincide with the surface of the light emitting element 2, so that only the light emitted from the light emitting element 2 is guided to the photoelectric converter 6.

Although photometry is of course possible with a device configured in this way, it is difficult to bring the lens 5 of the light receiving device 8 close to the light emitting element 2 because of the electrode probe 3 and the support section 7 that supports it. It is.

Therefore, it becomes impossible to increase the maximum angle of incidence θ of the light receiving device 8, and an increase in the amount of photometry cannot be expected.

Furthermore, it is necessary to focus the lens 5 on the surface of the light emitting element 20, making efficient measurement impossible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a photometric device for light emitting elements that can perform measurements efficiently and with high precision.

To achieve the above object, the present invention includes a needle-shaped electrode for feeding power to a light-emitting element, an optical fiber for guiding light emitted from the light-emitting element, and an electrical signal for converting the light guided by the optical fiber into an electrical signal. and a photoelectric converter for converting the acicular electrode into a photoelectric converter, the acicular electrode and the optical fiber are integrated so as to be able to move simultaneously, and the optical fiber is arranged such that the light incident end surface of the optical fiber surrounds the acicular electrode in an annular manner. The present invention relates to a photometric device for a light-emitting element, characterized in that the tip of the needle-like electrode is arranged so as to protrude from the light-receiving end surface.

According to the above invention, the following effects can be obtained. Since the (-r) needle electrode and the optical fiber are integrated, photometry of the light emitting element can be carried out easily and efficiently.

(b) Since the light incident end face of the optical fiber is arranged so as to surround the needle-shaped electrode in an annular manner, the ability to collect light emitted from the light emitting element is increased, and measurement accuracy can be improved.

(c) Since the needle-shaped electrode is made to protrude from the end face of the optical fiber, it is possible to easily and reliably bring the electrode into contact with the light emitting element, and the distance from the light emitting element to the end face of the optical fiber is smaller than that of the electrode. It is determined by the amount of protrusion, and measurement conditions can be easily aligned.

Hereinafter, a photometric device according to an embodiment of the present invention will be explained with reference to FIG. It is surrounded and held by optical fibers 14 as shown in FIG.

The measurement terminal 10 is constructed by holding an electrode probe 13 and an optical fiber 14 together with an outer frame 15, and is movable vertically and horizontally by a moving mechanism (not shown).

The electrode probe 13 is connected to a power source 17 via a lead wire 16, and the lower electrode plate 11, which is in contact with the lower electrode of the light emitting diode 12, is connected to the power source 17. By bringing the electrode probe 13 into contact with the top electrode of the light emitting diode 12, the light emitting diode 1
2, a current flows through it and it becomes in a light emitting state.

The light emitted from the light emitting diode 12 enters the optical fiber 14 surrounding the electrode probe 13, is guided by the optical fiber 14, and reaches the photoelectric converter 18, where the amount of light is converted into an amount of electricity.

The dimensions of each part of the device of this embodiment are as follows: The diameter of the electrode probe 13 is 0.2 itt, and the diameter of the circle formed by the optical fiber 14, that is, the inner diameter of the cylindrical outer frame 15 is 1.
The distance from the end surface 13a of the 31111 optical fiber 14 to the tip of the electrode probe 13, that is, the amount of protrusion of the electrode probe 13, is 0.15 m.

In the device configured as described above, of the light incident on the optical fiber 14, light with a large angle of incidence exits and is not effectively transmitted, and only light within 300 degrees of incident light is effectively transmitted. Ru.

Therefore, the maximum angle of incidence θ is 30°, which is larger than the maximum angle of incidence P of the conventional photometric device.

However, since the relationship between the maximum incident angle θ and the solid angle Ω at the light receiving part is expressed as Ω=2π(1-cosθ), the solid angle of the conventional device is Ω1, and the solid angle of the device of this embodiment is If the angle is Ω2, Ω1 = 2 rc (1-cos5°) = 0.0239
Ω2 = 2 π(1-cos30°) = 0.842
Therefore, the solid angle can be increased by 35 times with this invention.0 However, since the optical fiber 14 is used, all of the light incident on the solid angle Ω2 is transmitted to the photoelectric converter. Does not reach 18.

In the cross-sectional area of the light-receiving section, the portion S that effectively functions as an optical fiber is about 60 factors, and the transmittance r at both end surfaces of the optical fiber 14, taking into account loss due to reflection at both end surfaces, is about 80 factors. , optical fiber 1
The transmittance q in an optical fiber having a length of 30 cIrL is about 80%, taking into account the attenuation of light in the optical fiber.

Therefore, by using optical fiber,
The variable decreases at a ratio of 5XrXq=0.384.

When the conventional device and the device of this embodiment are compared in consideration of this decrease in the amount of light, Ω2 nt X5XrXq = l 3°5.

As is clear from this relationship, the amount of photometry by the device of this embodiment is ten times that of the conventional device.

A large photometric amount means that measurement accuracy can be improved.

In addition to the above-mentioned advantages, the apparatus of this embodiment has the advantage that it is easy to operate and can perform measurements efficiently.

That is, the electrode probe 13 and the optical fiber 14 as a light receiving part are integrated, and the optical fiber 14 is also in a predetermined position at the same time as the electrode probe 13 is brought into contact with the light emitting diode 12. There is no need to adjust the focus of the lens for photometry, and efficient photometry becomes possible.

Furthermore, if the optical fiber 14 is used as the light guide as in the embodiment, it is also possible to examine the luminous intensity distribution in the light emitting diode 12.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment and can be further modified.

For example, instead of leading out the lead wire 16 and the optical fiber 14 from the middle of the outer frame 15, the electrode probe 13 is led out from the upper end as shown in FIG. The light may be guided perpendicular to the

Furthermore, optical transmission media other than optical fiber 14 may be used as the light guide.

Further, it is advantageous if the light guide has flexibility, but it can also be used even if it does not have flexibility.

If it does not have flexibility, for example, the lower electrode plate 1
1 is used as a movable structure.

Furthermore, the photometry device of this embodiment is not limited to light-emitting diodes, and can also be used to measure electroluminescence by using the electrode probe 13 for voltage application, and can also be used for photometry of light-emitting diodes in a wafer state. It can also be used for

[Brief explanation of drawings]

Fig. 1 is a front view schematically showing a conventional photometry device, Fig. 2 is a partially vertical front view schematically showing a photometry device according to an embodiment of the present invention, and Fig. 3 is a schematic view of a light receiving section. Bottom view shown in
FIG. 4 is a longitudinal sectional view showing a modification of the photometric device. In the symbols used in the drawings, 10 is a measurement terminal, 11 is a lower electrode, 12 is a light emitting diode, 13 is an electrode probe, 14 is an optical fiber, 15 is an outer frame, 16
17 is a lead wire, 17 is a power supply, and 18 is a photoelectric converter.

Claims (1)

[Scope of utility model registration request] a needle-like electrode for feeding power to a light emitting element; an optical fiber for guiding light emitted from the light emitting element;
a photoelectric converter that converts light guided by the optical fiber into an electrical signal, and the needle electrode and the optical fiber are integrated so that they can move simultaneously, and the light incident end surface of the optical fiber is A photometric device for a light emitting element 0, characterized in that the needle-like electrode is arranged so as to surround the needle-like electrode in an annular manner, and the tip of the needle-like electrode is arranged so as to protrude from the light-receiving end surface.