JP3228098B2 - Light source - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source such as a confocal microscope or a spectrometer using a light emitting diode or a semiconductor laser, and more particularly to an improvement for improving efficiency.

[0002]

2. Description of the Related Art Conventionally, there is a light source in which light emitted from a plurality of light emitting diodes (LEDs) that emit light at different wavelengths is combined to obtain white light, and an example of the configuration is shown in FIG. Each wavelength (blue, orange, yellow, green, blue) of LED ₍₁ 1 to 1 ₅₎ Direct the optical fibers 2 ₁ to the light emitting surface of the
Arrange 2 ₅ and combine them with coupler 3 (combination)
By further adjusting the power of each wavelength, white light can be obtained from the coupler 3.

[0003]

However, in the light source having such a configuration, the total efficiency at the time of incidence and synthesis is about 0.006%, which is very inefficient and only a weak power can be obtained. was there.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to realize a light source having a high light use efficiency, in which light emitted from a plurality of light emitting elements such as LEDs is skillfully condensed.

[0005]

In the present invention SUMMARY OF] To achieve the above object, a light source that combines the light emitted plurality of light emitting elements that emit light at different wavelengths, the <br/> each light Optical means having a plurality of lenses for collecting the majority of the divergent light for each element and individually converting the light into parallel light; condensing means for condensing the plurality of parallel lights at one location; An aperture is provided for receiving the emitted light and blocking light outside the collected light.

[0006]

The light emitted from the plurality of light emitting elements is converted into parallel light by individual optical means, and these parallel lights are condensed by the light condensing means and collected at one place. Light condensed at one location is made to enter an optical fiber or a pinhole. As a result, light can be incident on a single optical fiber having a small core diameter, and the light use efficiency can be easily increased without using a conventional optical coupler or a large number of optical fibers. Light can be easily obtained.
Furthermore, the following effects are also exhibited by blocking the light outside the condensed light by limiting the aperture. The present invention
Because the light emitting element in is not a point light source,
True parallel light cannot be obtained. The Fourier transform in the focusing part
It becomes an image. The light condensed by restricting the aperture of the condensing part
Shielding the light outside can remove higher order distortions. I
Therefore, the light emitted from the optical fiber is almost a point light source.
It is a good quality light source that can be handled.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a light source according to the present invention. The same parts as those in FIG. 3 are denoted by the same reference numerals, and the description of those parts will be omitted. In FIG. 1, 5 ₁ to
5 ₅ lens for collimating light divergent light respectively from the LED1 ₁ to 1 _5, 6 is a lens for condensing the collimated light from the lens 5 ₁ to 5 ₅ to 1 point. Reference numeral 7 denotes a fiber, the end face of which is arranged at the light condensing position of the lens 6.

In such a configuration, each of the LEDs 11 ₁ to 11
Divergent light from 1 to ₅ lens 5 becomes parallel light by _{1-5 5,} followed by a lens 6 is focused on one location (1 point),
The light enters the end face of one optical fiber 7 arranged at the light condensing position. The power of each of the LEDs ₁₁ to ₁₅ is adjusted (the adjustment means is a well-known technique, so that illustration and description thereof are omitted) so that the light emitted from the optical fiber 7 becomes white light.

[0009] Incidentally, LED itself because not a point light source, not obtained true parallel light be passed through a lens 5 _{1-5 5.} However, since the Fourier-transformed image is obtained in the light-collecting unit, higher-order distortion can be removed by limiting the aperture. Therefore, the light emitted from the optical fiber 7 becomes a high-quality light source that can be treated almost as a point light source.

It should be noted that the present invention can be subjected to many changes and modifications without departing from the essence thereof. For example, the LED may be replaced by a semiconductor laser (LD). Further, the emitted light is not limited to white. For example, when used as excitation light for a confocal fluorescence microscope, the light emitting element may be a single color such as blue. When the light source is used as a light source of a spectroscope, the S / N ratio is not necessarily required to be white, and a higher S / N ratio can be obtained by increasing the amount of light at a wavelength at which the absorption characteristic of the measurement object is conspicuous.

Further, the condensing portion of the lens is not at the focal position of the lens but at a position slightly out of focus. In this case, although the efficiency is slightly lowered, the light source image of the LED enters the opening in a blurred form, so that a light source with less unevenness in light amount can be obtained. Further, the opening may be formed not as the optical fiber 7 but as a pinhole 9 of the substrate 8 as shown in FIG. In this case, if the lens 10 is inserted after the pinhole 9, parallel light can be obtained. Since no fiber is used, the light efficiency is further improved.
Furthermore, instead of the lens 6, Ho Rogura Moore Rui may use a Fresnel lens.

[0012]

As described above, according to the present invention, L
Since the divergent light of the ED is made into parallel light, each wavelength can be condensed to one point, and it can be incident on one optical fiber with a small core diameter, and the conventional optical coupler and many optical fibers can be used. The light use efficiency can be easily increased without using it. As a result, white light having considerably large power is obtained, and the effect is large for practical use. In addition, since the aperture is limited by the condensing portion, high-quality light can be easily obtained as the outgoing light.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a light source according to the present invention.

FIG. 2 is a partial configuration diagram of another embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating an example of a conventional light source.

[Explanation of symbols]

_{1 1 ~1 5 LED 5 1 ~5} 5, 6 lens 7 optical fiber 8 substrate 9-pin hole 10 lenses

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 19/00-21/00 G02B 21/06-21/32 G02B 6/00

Claims (6)

(57) [Claims] 1. A light source combining light emitted from a plurality of light emitting elements that emit light with different wavelengths , wherein a plurality of lenses that collect the majority of the divergent light for each of the light emitting elements and individually convert the light into parallel light. An optical means provided with the light source; a light condensing means for condensing the plurality of parallel lights at one position; and an aperture for receiving light condensed by the light condensing means and blocking light outside the condensed light. A light source, comprising: a light source; 2. The light source according to claim 1, wherein a light emitting diode or a semiconductor laser is used as said light emitting element. 3. A light source according to claim 1, wherein a lens, a hologram, or a Fresnel lens is used as said light collecting means. 4. The light source according to claim 1, wherein said opening is an optical fiber or a pinhole. 5. The light source according to claim 1, wherein a plurality of light emitting elements of different emission colors are used in combination as said light emitting element. 6. A white outgoing light is obtained by adjusting the amount of emitted light of each light emitting element.
Light source as described.