JPH0548164Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a light source device used in optical communications, optical measuring instruments, etc.

[Prior Art] FIG. 4 is a side sectional view showing a conventional light source device.

A light source device 30 that emits light to a fiber or the like has an LD, an LED, etc. as a light emitting element 12.

It is desirable that this light emitting element 12 be driven at a certain fixed temperature.

In particular, among the light-emitting elements 12, LEDs or edge-emitting LEDs cannot be back-monitored, so in order to stabilize the light output, it is necessary to drive them with a constant current and control the temperature of the light-emitting elements 12 themselves to a constant temperature. There is.

Therefore, the light source device 30 includes a Peltier element that cools or warms the holder 31 that holds the light emitting element 12 in response to the heat generated by the light emitting element 12 itself and temperature changes in the external environment, and maintains the light emitting element 12 at a constant temperature. A heat exchange element 21 such as the above is incorporated.

The temperature of the holder 31 is detected by a temperature detection element 23 such as a thermistor. This detection signal is provided outside the light source device 30 and is transmitted to the light emitting element 12.
The light is input to a control unit that controls the light output of the light source. Then, the control section controls the heat exchange element 21 based on this detection signal.
is operated to control the cooling or heating.

[Problems to be Solved by the Invention] However, in the conventional light source device 30, as shown in the figure, the lead wire 12a of the light emitting element 12 must be connected to an external drive source. The structure is such that the heat is conducted directly to the element portion of the light emitting element 12.

As a result, when the external environment temperature is 50 degrees, for example, and the heat exchange element 21 attempts to control the temperature of the holder 31 in which the light emitting element 12 is installed to the target value of 25 degrees, the control unit controls the temperature of the holder 31. In order to detect this, the cooling control is stopped when the temperature of the holder 31 reaches 25 degrees, and only the light emitting element 12 itself has a temperature close to the temperature of the external environment (for example, 28 degrees).

Therefore, as a result, only the light emitting element 12 is driven at a temperature higher than the desired target value of 25 degrees.

The above problem occurs because the light emitting element 12 and the holder 31 are not at the same temperature.

Since the wavelength and output level of the light emitting element 12 fluctuate due to temperature changes, the above structure causes fluctuations in the light output such as wavelength and output level, making it impossible to obtain a light source device with stable light output.

The present invention has been developed in view of the above problems, and allows the temperature of the light emitting element to be the same as that of the holder that holds the light emitting element, thereby improving the stability of light output. The purpose is to provide a light source device.

[Means for Solving the Problems] In order to solve the above problems, the light source device of the present invention includes a temperature-controlled holder 1 and a light emitting element having a lead wire 12a provided inside the holder.
12, and a heat exchange element having one end connected to the holder.
21, and a heat dissipation means 22 connected to the other end of the heat exchange element and opposite to the connection end of the holder, with a part of the lead wire for supplying current to the light emitting element. It is characterized in that it is fixed to at least a part of the holder and led out.

[Function] The light emitting element 12 is connected to a drive source using a lead wire.
12a is led out.

Therefore, even if there is a temperature change outside and the heat is conducted through the lead wire 12a, the lead wire
Since a portion of 12a is fixed to the holder 1 for a predetermined length, heat is absorbed by the holder 1. As a result, heat is not conducted directly from the lead wire 12a to the light emitting element 12, and the light emitting element 12 has the same temperature as the holder 1.

As a result, if the temperature of the holder 1 is measured by the temperature detection element in order to keep the holder 1 at a constant temperature, it will be equivalent to detecting the temperature of the light emitting element 12 itself.
Temperature control can be performed accurately by the heat exchange element 21, and light output characteristics with respect to temperature changes can be highly accurate.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of a light emitting element module which is a main part of the light source device of the present invention.

1 shown in the figure is a light emitting element such as an LED, an optical component,
This is a holder that securely holds an optical fiber or the like. The holder 1 roughly consists of three base parts 3, 4, and 5.

The central base 3 has a cylindrical outer shape, and has a cylinder 3a with both ends opened at the central shaft portion, and has self-cleaning lenses 6 and 7 at each end of the cylinder 3a. It is positioned by a spacer 8.

The front end base 5 is screwed into one end (front end) of the central base 3, and has a bandpass filter 9 at the rear end of the central shaft, a condensing lens at the front, and a front end. An optical fiber 11 is fixed at each position.

The rear end base 4 is screwed to the other end (rear end) of the central base 3, has a light emitting element 12 made of an LED on the central axis, and has a lead wire relay terminal 13 at the rear end. It is. This light emitting element 12 is driven by a control section, which will be described later, to emit light.

The light emitting element 12, self-occurring lenses 6, 7, band pass filter 9, condensing lens 1
0 is arranged on the same axis as the optical fiber 11.

Further, cooling blocks 14, 14 each having an arc-shaped holding portion 14a for fixedly holding the central base 3 are provided at the upper and lower ends of the cylindrical central base 3. The cooling blocks 14 are cooled or heated by a heat exchange element, which will be described later.

Then, the lead wire 12a of the light emitting element 12
is once relayed to the lead wire relay element 13,
It is fixed to one cooling block 14 for a predetermined length and led out.

Each light emitting module configured as above is
As shown in the plan view of FIG. 2(a) and the side sectional view of FIG. 2(b), it is incorporated into a light source device 20 having five systems of light output.

The five holders 1 are each held between separate cooling blocks 14, 14. The lower cooling block 14 is fixed to a heat exchange element 21, such as a Bertier element, which cools and heats the holder 1. A heat radiating means 22 such as a heat radiating fin is fixed to the heat exchange element 21.
The holder 1 is cooled and heated by an external control section (not shown). Note that the heat radiation means 22 may be a heat radiation fan.

On the other hand, a light emitting element 1 is mounted on the upper cooling block 14.
Groove portion 1 having a diameter approximately equal to the diameter of lead wire 12a of No. 2
4b, 14b are formed in two places, and the lead wire 12a of the light emitting element 12 is fixed from the lead terminal 13 to one groove 14b of this cooling block 14, and then folded back again and fixed to the other groove 14b. After that, it is led out to the terminal 25 of the light source device 20.

In addition, the lower cooling block 14 has insertion holes 1
A temperature detection element 23 such as a thermistor is fixed to the part c. The thermistor 23 is connected to the control section and outputs a temperature detection signal for the entire holder 1, which is five modules arranged in parallel.

In the figure, reference numeral 24 denotes an outer frame that accommodates each of the light emitting modules, and is fixed on the heat radiating means 22. Further, each holder 1 has a cooling block 14.
It is fixed to the outer frame body 24 via a fixing plate 24a.

Next, the effect of the above configuration will be explained.

The light emitting element 12 is driven by the control unit to emit light, which is converted into parallel light by the self-occurring lens 6, and then condensed by the condensing lens 7, and is also bonded to the end surface of the optical fiber end 11. Only a predetermined wavelength band is selected by the bandpass filter 9 and is incident on the end face of the optical fiber 11.

Furthermore, when the temperature of the holder 1 changes due to an increase in the temperature of the light emitting element 12 itself or a change in the outside air temperature, the temperature of the holder 1 is detected by the thermistor 23 and a detection signal is input to the control section, thereby controlling the temperature of the holder 1. The part drives the thermophotosensitive element 21 to release the holder 1.
The holder 1 is always kept at a constant temperature by performing cooling or heating corresponding to temperature changes.

Further, the lead wire 12a of the light emitting element 12 is provided between the outside where the control section is provided and the holder 1, and the lead wire 12a is connected to the cooling block 14 at a predetermined length on the outer circumference of the holder 1. Since it is fixed, the temperature of the light emitting element 12 can be made equal to the temperature of the holder 1. For example, even if a change in external temperature is conducted from the lead wire 12a toward the light emitting element 12, the heat is absorbed by the cooling block 14 and the holder 1 in the groove 14b where the lead wire 12a is fixed to the cooling block 14. Therefore, the light is not conducted to the light emitting element 12.

As a result, the heat conducted from the lead wire 12a of the light emitting element 12 is directly conducted to the light emitting element 12,
Only the light emitting element 12 changes in temperature and does not differ from the temperature of the holder 1. Therefore, it is possible to prevent the temperature detection element 23 from performing erroneous temperature detection.

Then, the control unit drives the heat exchange element 21 based on the detection signal from the temperature detection element 23, and maintains the holder 1 at a constant temperature without being affected by the external temperature even if the external temperature changes.

By keeping the holder 1 at a constant temperature, the light emitting element 12 is driven at a constant temperature and can emit light with a stable wavelength and output level.

Regarding the light output stability with respect to temperature,
With conventional light source devices, the optical output fluctuated by 0.3 dB with respect to the reference value in the temperature range of 10 degrees to 40 degrees, but with the light source device of this embodiment, this variation was achieved within the same temperature range.
0.15dB, making the temperature characteristics highly accurate.

FIG. 3 is a perspective view showing a modified example of the cooling block of the light source device of the present invention.
Reference numeral 4 designates the upper and lower parts of all the holders 1 to be held between two cooling blocks 34, 34 at the same time.
Grooves 34b, 34b for 4a and lead wire 12a
are formed respectively. Even in this modification, the same functions and effects as those of the above-described embodiment can be obtained.

In each of the above embodiments, one or both sides of the lead wire of the light emitting element that is folded back to the holder that holds the light emitting element is fixed to the holder, but the number of folding is not limited and may be one or more times. It may also be configured to lead out to the outside after being folded back.

[Effects of the invention] As explained above, the light source device of the invention has a structure that eliminates external heat being directly conducted to the light emitting element, and the light emitting element is connected to the holder that holds the light emitting element. The temperature can be the same.

This makes it possible to control the temperature of the light emitting element as accurately as the temperature of the holder, thereby improving the stability of the light output of the light emitting element.

In addition, conduction of external heat to the light emitting element can be removed with a simple and inexpensive configuration, and the stability of light output can be improved, so a product with high cost performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a light emitting element module which is the main part of the light source device of the present invention, and FIG. 2(a) is
FIG. 2(b) is a plan view showing a light source device incorporating the same module; FIG. 2(b) is a side sectional view of FIG. 2(a); FIG. 1 is a diagram showing a conventional light source device. 1... Holder, 11... Optical fiber, 12...
Light emitting element, 12a...Lead wire, 14...Cooling block, 21...Heat exchange element, 22...Heat radiation means, 23...Temperature detection element.

Claims (1)

[Claims for Utility Model Registration] A holder 1 whose temperature is controlled; a light emitting element 12 having a lead wire 12a provided inside the holder; a heat exchange element 21 whose one end is connected to the holder; a heat dissipating means 22 connected to the other end of the heat exchange element and opposite to the connecting end of the holder, and at least a part of the lead wire for supplying current to the light emitting element is connected to the holder. A light source device that is fixed to a part of the body and led out to the outside.