JPH0623010Y2 - Laser light source - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a laser light source, and is preferably applied to a laser light source such as a fine particle meter and a minute displacement measuring device.

[Outline of device]

The present invention, in a laser light source, supports a radiator separately from a laser light source support member, and forms a heat conduction path with a flexible member, thereby preventing deviation of the optical axis of the light beam in advance. The optical axis of the light beam can be adjusted by various adjustment operations.

[Conventional technology]

Conventionally, in clean rooms such as integrated circuit manufacturing plants and hospitals, in order to maintain high cleanliness, fine particles suspended in the air are measured by using a fine particle meter.

That is, as shown in FIG.
For example, the air 2 collected from a clean room forms a laminar flow that flows at a predetermined flow rate.

Further, the laser light source 3 is configured by using a laser diode or the like, and the light beam LA1 emitted from the laser light source 3 is formed.
Is radiated to the laminar flow through the lens 3.

In this way, the light beam LA1 is scattered by the fine particles contained in the air 2, and the light amount of the resulting scattered light changes in proportion to the particle diameter, the number of the fine particles, and the concentration of the fine particles.

Similarly, in the light beam LA1 transmitted through the laminar flow, the light beam LA1 is shielded by the fine particles contained in the air 2, and the amount of transmitted light changes in proportion to the particle diameter, the number of the fine particles, and the concentration of the fine particles.

Therefore, in the fine particle meter utilizing the light scattering phenomenon, the fine particles contained in the air 2 are measured by collecting the scattered light LA2 on the light receiving element 6 through the lens 5 and detecting the amount of the scattered light. It is designed to be able to do.

On the other hand, in the light interception type fine particle meter, the fine particles contained in the air 2 can be measured by detecting the amount of transmitted light of the light beam LA1.

[Problems to be solved by the invention]

By the way, in this type of fine particle meter, when the light quantity and the wavelength of the light beam LA1 emitted from the laser diode are changed, the transmitted light quantity and the scattered light quantity are changed, and the measurement accuracy is deteriorated.

Therefore, as shown in FIG. 3, for example, a method of using a heating / cooling element such as a Peltier element to hold the temperature of the laser diode at a predetermined reference temperature and thereby obtaining a light beam with a stable light quantity and wavelength has been considered. There is.

That is, in the laser light source 10, the laser diode mounting plate 1 made of a ring-shaped metal having a high thermal conductivity is used.
A laser diode 11 is attached to the center of the laser diode 2.

In the laser diode mounting plate 12, by fixing the thermistor 13 in the recess 12A close to the laser diode 11, the temperature of the thermistor 13 is maintained at the same temperature as the temperature of the laser diode 11, and thus the thermistor 13 is used. Then, the temperature of the laser diode 11 is detected.

The laser diode mounting plate 12 is fixed to the end surface of the holder 15 having a cylindrical shape with a screw 16, and after inserting the holder 15 into a cylindrical concave portion of the fine particle meter body (not shown), it is screwed. By mounting, the laser light source 10 is fixed to the main body of the fine particle meter via the holder 15.

On the other hand, a Peltier element 19 and a radiator 20 are provided on the back surface of the laser diode 11, and the laser diode 11 is heated or cooled based on the temperature detection result of the laser diode 11 obtained from the thermistor 13.

That is, in the laser light source 10, with the Peltier element 19 sandwiched between the radiator 20 and the laser diode 11, the radiator 20 is fixed by the screw 21 so as to be pressed against the holder 15, whereby the laser diode 11 and the Peltier device are secured. The element 19 and the radiator 20 are brought into close contact with each other to efficiently heat and cool the laser diode 11.

Furthermore, a heat insulating washer 22 made of, for example, a resin having a low heat conductivity is inserted between the screw 21 and the radiator 20 to thermally insulate the radiator 20 from the screw 21 and heat the radiator 20. Does not conduct to the particle meter main body or the laser diode 11 via the screw 21, and conversely, the heat of the particle meter main body or the laser diode 11 is dissipated by the radiator 20.
Do not conduct to.

Furthermore, when the temperature of the laser diode rises above the reference temperature, the heat of the laser diode 11 is removed by the Peltier element 19
And the absorbed heat is dissipated from the radiator 20 to the surroundings.

Conversely, when the temperature of the laser diode is below the reference temperature,
The Peltier element 19 heats the laser diode 11, and the heat required for the heating is absorbed from the surroundings via the radiator 20.

As a result, the temperature of the laser diode 11 is maintained at a predetermined reference temperature, and fluctuations in the light quantity and wavelength of the light beam LA1 due to temperature fluctuations in the laser diode 11 are prevented.

However, if the laser diode 11 is fixed to the main body of the particle meter by using such a holding mechanism, there is a problem that the work of adjusting the mounting position of the laser diode 11 and its inclination becomes complicated.

That is, in this type of fine particle meter, the optical axis of the light beam is adjusted so that the light beam emitted from the laser diode 11 is emitted to a predetermined irradiation position. Loosen the screw 16 to adjust the mounting position of the laser diode mounting plate 12 with respect to the holder 15 and its inclination.

However, since the radiator 20 is a large-sized heavy object made of metal having high thermal conductivity so that the laser diode 11 can be efficiently heated and cooled, when actually adjusting the optical axis. Since the radiator 20 must be removed, the work of adjusting the optical axis becomes complicated accordingly.

The load of the heavier radiator 20 can be directly applied to the holder 1
Since it is supported by No. 5, there is a problem that the radiator 20 vibrates and the vibration is propagated to the laser diode 11 such that the optical axis of the light beam is deviated when a shock is applied to the fine particle meter.

The present invention has been made in consideration of the above points, and intends to propose a laser light source capable of adjusting the optical axis of the light beam by a simple adjustment work by preventing the deviation of the optical axis of the light beam. It is a thing.

[Means for solving problems]

In order to solve such a problem, in the present invention, a laser light source support member 31 supported by an electronic device body, a laser diode mounting member 12 supported by the laser light source support member 31, and a laser diode mounting member 12 are mounted. Laser diode 11 and laser diode 1
A heating / cooling element 19 for heating or cooling 1; a radiator 44 supported separately from the laser light source supporting member 31 in the electronic device body; and a heat conduction path between the radiator 44 and the heating / cooling element 19. And a flexible member 36.

[Action]

If the radiator 44 is supported separately from the laser light source support member 31 and the heat conduction path is formed between the radiator 44 and the heating / cooling element 19 by using the flexible member 36, the radiator 44 vibrates. Also, the laser diode 11 can be heated or cooled by preventing vibration of the laser diode 11 in advance.

Further, since the radiator 44 is supported separately from the laser light source support member 31, the optical axis of the light beam can be adjusted by a simple adjustment work.

〔Example〕

 An embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1 in which parts corresponding to those in FIG. 3 are designated by the same reference numerals, numeral 30 indicates a laser light source of a fine particle meter as a whole,
The laser diode mounting plate 12 is a cylindrical holder 3
It is adapted to be fixed to the end face of 1 with a screw 32.

The holder 31 is fixed to the main body of the particle meter through the holder 31 by inserting the holder 31 into the cylindrical concave portion of the main body of the particle meter (not shown) and then screwing the holder.

Further, the holder 31 is made of, for example, a resin having a low thermal conductivity, so that the heat of the laser diode 11 is not conducted to the main body of the fine particle meter through the holder 31, and vice versa. Laser diode 11
It is designed so that it does not conduct to.

The diameter of the screw hole 12B of the laser diode mounting plate 12 is made larger than the diameter of the screw 32 by a predetermined amount, whereby the mounting position and inclination of the laser diode mounting plate 12 with respect to the holder 31 are finely adjusted. Then, the optical axis can be adjusted.

Thus, the holder 31 constitutes a laser light source support member supported by the fine particle meter main body which is the electronic equipment main body.

On the other hand, on the back surface of the laser diode mounting plate 12, a copper plate 33, a holding plate 34, and a silicon sheet 35 are arranged so as to be pressed against the laser diode 11 in place of the conventional radiator 20 (FIG. 3). ing.

That is, the copper plate 33 is configured such that the flat knitted copper wire 36 formed by knitting a thin copper wire is soldered to one end and the Peltier element 19 is soldered to the other end.
9 is disposed so as to be in close contact with the laser diode 11.

By the way, the flat knitted copper wire 36 formed in this manner is excellent in flexibility, has a characteristic of being freely bendable, and is a member having a small elastic force so as not to transmit the external force applied to one end to the other end. .

A screw 38 is planted in the holder 31, and a nut 40 is screwed into the screw 38 to hold the holding plate 3 in place.
The silicon sheet 35 and the copper plate 33 are pressed against the laser diode 11 through the intermediary of 4.

Thus, the laser diode 11 can be efficiently heated and cooled by bringing the Peltier element 19 into close contact with the laser diode 11.

A copper plate 41 is soldered to the other end of the flat braided copper wire 36, and the copper plate 41 is fixed to a radiator 44 with a screw 42.

The radiator 44 is supported separately from the holder 31 in the main body of the fine particle meter, which is the main body of the electronic device.

Therefore, when the laser diode 11 is cooled by the Peltier element 19, the heat absorbed from the laser diode 11 is sequentially conducted from the heat radiation side of the Peltier element 19 through the copper plate 33, the flat knitted copper wire 36, and the copper plate 41. Is dissipated to the surroundings by the radiator 44.

On the contrary, when heating the laser diode 11,
The heat required for heating is absorbed by the radiator 44 from the surroundings, and the heat is sequentially conducted through the copper plate 41, the flat braided copper wire 36, and the copper plate 33 to the cooling side of the Peltier element 19.

Thus, the flat braided copper wire 36 constitutes a flexible member that forms a heat conduction path between the radiator 44 and the Peltier element 19.

Therefore, instead of the conventional radiator 20, the copper plate 33 and the holding plate 34 arranged on the back surface of the laser diode mounting plate 12 are replaced.
In the above, the laser diode 11 can be kept at a predetermined temperature only by conducting the heat required for heating and cooling, and the weight plate 33 and the holding plate 34 are made into a small shape, and the laser diode mounting plate 12 is mounted on the rear surface thereof with the laser diode mounting plate. Board 1
It is possible to obtain a space for adjusting the mounting position and the inclination of No. 2.

Thus, in this embodiment, the copper plate 33 and the holding plate 3 are
4 is made small, and the radiator 44 is fixed to the main body of the fine particle meter by shifting the radiator 44 from the rear position of the laser diode mounting plate 12 so that the copper plate 33, the holding plate 34, and the radiator 44 remain attached. However, the screw 32 can be loosened to finely adjust the mounting position and inclination of the laser diode mounting plate 12.

Thus, since it is not necessary to remove the radiator 44 during the adjustment, the work of adjusting the optical axis can be simplified as compared with the related art.

Further, in this embodiment, the radiator 44 is attached to the holder 31.
A flat braided copper wire 36 that is supported separately from and is made of a flexible member.
By forming the heat conduction path by using, the vibration propagating to the laser diode 11 can be significantly reduced even when a load is applied to the radiator 44 having a large weight, and thus the vibration can be reduced. It is possible to prevent the deviation of the optical axis due to.

Further, in this type of radiator 44, repeated thermal contraction and thermal expansion in accordance with heating and cooling of the laser diode 11 cannot be avoided, and even when impact or the like is not applied to the fine particle meter, the thermal contraction and thermal expansion are performed. This causes the radiator to vibrate.

Therefore, by forming the heat conducting path by using the flat braided copper wire 36 made of a flexible member in this way, even if the radiator 44 vibrates due to thermal contraction and thermal expansion, the deviation of the optical axis is prevented in advance. can do.

By the way, in this embodiment, the copper plate 33 and the pressing plate 3 are used.
By interposing the silicon sheet 35 having a high heat conductivity and made of an elastic member between the four, heat is dissipated and absorbed not only through the radiator 44 but also through the holding plate 34. The vibration of the flat knitted copper wire 36 is absorbed by the silicon sheet 35.

In the above structure, the laser diode 11 mounted on the laser diode mounting plate 12 is heated or cooled by the Peltier element 19 while being thermally insulated from the fine particle meter main body by the holder 31.

At this time, the heat required for heating is absorbed from the surroundings by the radiator 44 supported separately from the holder 31 in the main body of the fine particle meter,
The heat is applied to the Peltier element 19 via the copper plate 41, the flat braided copper wire 36, and the copper plate 33.

On the contrary, the heat required for cooling is dissipated to the surroundings from the radiator 44 through the copper plate 33, the flat braided copper wire 36, and the copper plate 41.

According to the above configuration, the radiator 44 is supported separately from the holder 31 in the main body of the fine particle meter, and the heat conduction path is formed by the flexible member between the radiator 44 and the Peltier element 19, so that the laser diode 11 is provided. It is possible to reduce the propagating vibration of the radiator 44, thus preventing the deviation of the optical axis due to the vibration of the radiator 44, and simplifying the optical axis adjusting work.

Although the radiator 44 is mounted in parallel to the laser diode mounting plate 12 in the above-mentioned embodiment, the mounting position of the radiator 44 is not limited to this, and the radiator 44 and the Peltier element 19 are not limited thereto. Since the heat conduction path is formed by a flexible member made of a flat braided copper wire having excellent flexibility, the arrangement position can be freely selected as necessary, for example, when the heat conduction path is arranged vertically to the side of the copper plate 33. be able to.

Furthermore, in the above-described embodiment, the case where the heat conduction path is formed between the radiator 44 and the Peltier element 19 using the flat knitted copper wire 36 formed by knitting a copper wire as the flexible member has been described. The flexible member forming the conduction path is not limited to this, and may be a member having a small elasticity and a high thermal conductivity, such as a metal processed into a spring shape and having a high thermal conductivity.

Further, in the above-described embodiment, the case where the annular laser diode mounting plate 12 and the cylindrical holder 31 are used has been described, but the laser diode mounting plate 12 is used.
The shape of the holder 31 is not limited to this, and various shapes can be widely applied as needed.

Furthermore, in the above-mentioned embodiment, the case where the laser light source 30 is fixed to the fine particle meter main body through the holder 31 by screwing and attaching the holder 31 to the fine particle meter main body has been described. Not limited to this, various supporting methods can be widely applied, for example, when the holder is pressed into the main body of the fine particle meter.

Further, in the above-mentioned embodiments, the case where the present invention is applied to the laser light source of the fine particle meter has been described, but the present invention is not limited to the laser light source of the fine particle meter, and a laser light source such as a minute displacement measuring device, and various It can be widely applied to laser light sources of electronic devices.

[Effect of device]

As described above, according to the present invention, by supporting the heat sink separately from the laser light source supporting member and forming the heat conduction path of the flexible member with respect to the heat radiator, the heat radiation propagated to the laser diode is dissipated. It is possible to reduce the vibration of the vessel and simplify the optical axis adjustment work.

Thus, it is possible to prevent the deviation of the optical axis due to the vibration of the radiator and to obtain the laser light source in which the optical axis adjustment work is simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall structure of a laser light source according to an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining the operation of a fine particle meter, and FIG. 3 is a sectional view for explaining problems. is there. 1 ... Particle analyzer 3, 10, 30 ... Laser light source, 11
... laser diode, 12 ... laser diode mounting plate, 15, 31 ... holder, 19 ... Peltier element,
20, 44 ... Radiator, 36 ... Flat braided copper wire.

Claims (1)

[Scope of utility model registration request] 1. A laser light source support member supported by an electronic device main body, a laser diode mounting member supported by the laser light source support member, a laser diode mounted on the laser diode mounting member, and the laser diode. A heating / cooling element for heating or cooling, a radiator supported separately from the laser light source support member in the electronic device body, and a flexible member forming a heat conduction path between the radiator and the heating / cooling element. A laser light source characterized by comprising: