JP2000076912A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple light source device which resolves the problem caused by deterioration due to aging of a light guide, and equipped with a luminous energy control function. SOLUTION: This device is constituted of a light guide 1, a monitor fiber 2 formed by branching a part of the light guide 1 at an emitting end 1a of the light guide 1, a light receptor 3, an external luminous energy control device 4 for generating a control signal for keeping a luminous energy constant according to a signal from the light receptor 3, and a light source device body 5 equipped with an external luminous energy control function. Here, the light receptor 3 is set at the emitting end 1a of the light guide 1 and housed in the external luminous energy control device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device used for illumination of an image processing / inspection device, illumination for medical treatment or illumination.

[0002]

2. Description of the Related Art Conventionally, in order to keep the amount of illumination light constant,
While monitoring light emitted from a light source such as a light bulb with an optical sensor, based on the output of the optical sensor, a light source device having a function of controlling a power supply voltage so that the light amount of the light source is constant is added. is there. Among them, examples of using a monitor fiber for monitoring a light amount by branching a part of the light projecting fiber at the incident end of the light projecting fiber (light guide) are disclosed in Japanese Patent Application Laid-Open Nos. 5-31273 and 8-3232.
No. 7826 is cited.

However, in such a conventional light source device, only the light incident on the incident end of the light projecting fiber (light guide) is monitored by the monitor fiber, and the light is actually emitted to the object at the emitting end. If the light emitting fiber (light guide) itself deteriorates due to aging, etc., the ratio of the light amount at the incident end and the light emitting end of the light emitting fiber will differ, and the light amount irradiated on the target object will not be monitored. Is disadvantageously changed. This phenomenon becomes more conspicuous as the length of the light projecting fiber (light guide) becomes longer or the diameter thereof becomes smaller.

[0004]

Therefore, in the present invention,
An object of the present invention is to provide a light source device having a light amount control function with a simple configuration, while solving the above-described inconvenience caused by aging of the light guide.

[0005]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, provided a monitor fiber at the output end of the light guide and an external light amount control for controlling the light amount. With the idea of providing the device outside the light source device main body, the present invention has been completed.

That is, the present invention relates to (1) a light source device using a light guide in which a number of optical fibers are bundled for guiding light emitted from a light source to an object, and the light guide includes one light guide at an emission end of the light guide. A light guide having a monitor fiber with a branched portion, a light receiver for receiving light of the monitor fiber, an external light amount control device for generating a control signal for keeping the light amount constant based on a signal of the light receiver,
And a light source device comprising a light source device main body having an external light amount control function capable of externally controlling the light amount, and (2) a light receiver is provided at an emission end of the light guide. The light source device according to the above (1), and
(3) The light source device according to (1), wherein the light receiver is built in the external light amount control device.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a light guide for irradiating a target object with light from a light source, 2 denotes an output end 1a of the light guide, and a monitor fiber for monitoring a light amount obtained by branching a part of the light guide 1; And 4, an external light amount control device for generating a control signal for keeping the light amount constant based on the light amount monitored by the light receiver, and 5, a light source device having an external light amount control function capable of controlling the light amount from outside. The main body. Reference numeral 6 denotes an external light amount control input terminal provided on the light source device main body 5, reference numeral 7 denotes a coating material of the light guide 1, reference numeral 8 denotes a position between the light receiver 3 and the external light amount control device 4, or between the external light amount control device 4 and the external light amount control input terminal. This is a lead wire connecting between the six.

Next, a light guide 1 which is a feature of the present invention.
Will be described in detail with reference to FIG. As shown in FIG. 2, a monitor fiber 2 having a part of the light guide 1 branched for monitoring the light amount is provided at an emission end (tip) 1 a of the light guide 1. By doing so, even when the light guide 1 is deteriorated due to aging or the like, the light amount can be accurately controlled to be constant. In FIG. 2, reference numeral 7 denotes a protective material for protecting the light guide 1.

Next, the operation of the light source device of the present invention will be described. The light incident on the monitor fiber 2 then enters the light receiver 3 and is converted into an electric signal. Next, the light quantity signal converted into the electric signal is input to the external light quantity control device 4 via the lead wire 8. Here, the light amount is compared with a light amount set value (target value), and a light amount control signal is generated.

Finally, the light quantity control signal is input to the external light quantity control input terminal 6 of the light source device body 5, and the light quantity feedback control is performed, so that the light quantity can be kept constant. Here, as the light receiver 3, various optical sensors such as a phototransistor and a photodiode can be used. Here, the light receiver 3 and the external light amount control device 4 are electrically connected by the lead wire 8, but the connection between the light receiver 3 and the external light amount control device 4 is made
Other connection means such as a wireless interface may be used.

Next, the detailed description of the external light quantity control device 4 is omitted, but it is composed of a known light quantity setting circuit, a comparison circuit, a light quantity control circuit and the like. Also, as for the light amount control method, various selections such as a well-known analog method and a digital method are possible. Furthermore, the conditions regarding the interface such as the signal type, the level, and the number of signal lines of the light amount control signal may be adapted according to the specifications of the light source device main body 5.

FIG. 3 shows a second embodiment of the present invention.
Referring to FIG. In the embodiment shown in FIG. 1, the light receiver 3 is provided outside. However, when the light guide 1 has a large diameter and a sufficient space is available, the light receiver 3 is connected to the light emitting end of the ride guide as shown in FIG. 1a. By doing so, the configuration becomes simpler than in the case of the embodiment of FIG.

Finally, FIG. 5 shows a third embodiment of the present invention.
, The light receiver 3 is built in the external light amount control device 4 to simplify the configuration. Also, in the second and third embodiments of the present invention shown in FIGS. 3 and 5, the light receiver 3 described in the first embodiment of FIG. Needless to say, it is good.

As described above, according to the present invention, the amount of light is measured at the emission end 1a of the light guide 1 by the monitor fiber 2 having a part of the light guide 1 branched. Therefore, even if the light quantity deteriorates, the change in the amount of light can be accurately measured. Further, the light amount can be controlled with a simple configuration by incorporating the light receiver 3 in the light guide emission end 1a or in the external light amount control device 4.

[0015]

According to the present invention, since the light quantity is monitored by the monitor fiber at the light emitting end of the light guide, the change in the light quantity due to the aging of the light guide can be accurately measured. Furthermore, accurate light quantity control is possible with a simple configuration in which a monitor fiber and an external light quantity control device are added.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of a light guide used in the first embodiment of the light source device of the present invention.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the light source device of the present invention.

FIG. 4 is a longitudinal sectional view of a light guide used in a second embodiment of the light source device of the present invention.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the light source device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 light guide 1a light guide emission end 2 monitor fiber 3 light receiver 4 external light intensity control device 5 light source device main body 6 external light intensity control input terminal 7 coating material 8 lead wire

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H038 AA54 AA57 BA01 4C061 AA00 BB00 CC00 DD00 FF35 FF40 FF46 GG01

Claims (3)

[Claims] 1. A light source device using a light guide that bundles a number of optical fibers for guiding light emitted from a light source to an object, wherein a monitor fiber in which a part of the light guide is branched at an emission end of the light guide. And a light receiver for receiving light of the monitor fiber,
An external light amount control device for generating a control signal for keeping the light amount constant based on the signal of the light receiver, and a light source device main body having an external light amount control function capable of controlling the light amount from the outside. Light source device. 2. The light source device according to claim 1, wherein the light receiver is provided at an emission end of the light guide. 3. The light source device according to claim 1, wherein the light receiver is built in the external light amount control device.